LOSING PATIENCE With This Project 😮‍💨 (Building Our Own Aluminum Catamaran Pt. 20)

[@barrywaters6336]

Hey Brian ex marine engineer from the British Navy here. Most, if not all, our tank hatches did not have tapped holes but studs welded to the tank and nuts to hold the hatches down. May be worth considering if or when you begin to get leakage

[@bearitraeb]

This is the Smartest solution I’ve seen so far

[@frederickpetereek998]

I was just wondering the same thing. Im a mechanical engineer and mabye there is a reason why, that I did not think of(please let me know). But why don't you get aluminium bolts and weld them to the bottom or as barrywaters said studs?

[@court2379]

​@@frederickpetereek998I agree, get aluminum studs. Or switch to the flanged design where the screws don't penetrate and solve the space issue by recessing a box into the lid for the other parts. Also the edge of the plate needs a stiffener to compress the gasket. That or closer fasteners spacing.

[@andyrusten5748]

@@court2379studs are not a bad idea. it’s his threads biting him i think

[@NomadSurvivor]

@@frederickpetereek998If you wanted to get right safe and fancy just use Fuel Bladders inside the current tanks. You'd only lose 5-10% capacity , but diesel isnt very corrosive and the bladders would last 10+ years easily.

[@timoldguysgaming8432]

Hi Brian, I've been working in the heavy truck industry for almost 3 decades. We use loctite 5699 to seal rear carriers to the axle housing, the holes are tapped into the axle housing, and the carrier is bolted to the housing, very similar to how you have your tanks set up. The good thing about using this sealant, it can be also added to your threads to help seal around the bolts. We pressure test out axles at 8psi, and this stuff holds every time. It is oil, water, and glycol resistant, and is NSF. We buy the large caulk tubes, and use a caulking gun to apply it, makes things easier. Good luck with whatever you decide. The new boat is looking great!

[@glenndennis6801]

As a former mechanic, Yup, I second this method, you have to use a sealant (food safe for water tank) that will flow around the bolts and set up. Sealed all sorts of things over the years, I was very skeptical when I first saw those covers way too much flex.

[@hankfava]

I think Tim has a solution maybe even silicone for water tank just need to figure out foot pounds of torque

[@JamesRook]

I have to agree that using a type of liquid sealant would be the smart way to go. There's a reason so many manufacturers now use sealants instead of gaskets. Ease of use, fills small gaps in uneven surfaces, will seal threads on nuts and bolts, does not require much, if any, torque to hold your parts together, and can be food safe and or fuel safe.

[@areliablesource4558]

I also second this ☝️

[@johnwaters4566]

This guy seems to like wasting time and money. How ridiculous, all of these issues have been sorted out decades or centuries ago. Why the heck is this Gumby trying to figure it out again.? It's so silly.

[@JohnMitchellRocna]

Hi Folks, John Mitchell from CMP Global here…. Producer of Martyr Anodes. You have selected the proper Al Alloy for your project. It is produced to US Military Specifications. As to passivation.. the Al alloy actually has less of a passivation activity than Zinc… so you will not have to worry about leaving the anode without cleaning for a couple of months… but yes keeping an eye on the “hydrogen oxide” build up is a very good practice.

[@tfmendes131]

Up

[@MUDNROCKS]

I've been through this exact problem with a hydraulic oil tank and trust me you ain't done, yes you might have a seal now with what you've done but it's not reliable and it will leak again. I finally sealed mine by welding 12mm thickening flanges around all the openings, that means welding the inside and outside edges to the tank so there is no path to the bolt holes in the thickening flanges which you should drill and tap before welding them on. Weld up and clean back the existing holes in the tanks first before welding the thickening flanges on so the finished fastening holes are essentially blind tapped holes. Red loctite studs into the flanges don't use bolts. Yes you now have 10mm plate lids, I would have used 12mm. Torque the fastening nuts so clamping pressure is even. Consider making a test rig to check deformation on the 10mm plate lid, just jazz it up with some off cuts and include the rubber gasket material, make it about 4 bolts long at the bolt centers you have chosen for the tanks, torque it up in stages, evenly and measure the deformation with a vernier so you know what the torque limit is without deformation. It is possible you might need to double up on the studs for the fuel tank and of course the flanges would need to have the extra holes drilled and tapped before welding down. A bit of a dribble on a water tank is annoying but a leak on a diesel tank is a pain in the arse, remember diesel is quite capable of finding a hole in a glass bottle with a screw on lid and a drip go's a mile, hydraulic oil is worse it go's about 2 mile.

[@4144sbrs]

Hey Brian marine engineer from here. Most, if not all, our tank hatches did not have tapped holes but studs welded to the tank and nuts to hold the hatches down. We algo Fust use Garlock 3000 gasket material and a cotton but hole washer for studs and a regular washer under the nut, For all access hatches of the fuel tanks and piping connections

[@steves1266]

Have some poly tanks custom made and be done with it Brian. Love you guys

[@glensebzda]

Hello Delos, I'm Glen from Edmonton Alberta, Canada. I've been watching you guys since the start, as well as many, many reruns. I really appreciate and enjoy all the adventures and misadventures you have shared with us over the years and show the struggles as well as the high points. You have given us all an amazing look into your lives and what the cruising life can be like. I love that, though life's progression has changed the dynamics of your adventures. You have grown yet remain the same people as you were in the beginning. So many people start acting like sports broadcasters or change their personalities as success brings them wealth. I really appreciate how you are still the same people as you were in the beginning. I have been watching your amazing new boat build, and I'm excited for you and eager to see the completion of your incredible new yaught and the start of your new adventures. I have worked with aluminum cable trays and electrical components, and I've seen how drastically, temperature can cause expansion and contraction. I've seen large-scale aluminum cable support systems buckle and come crashing to the ground because the sun shone on them, and they expanded enough to rip off their support structures. How does expansion and contraction affect an aluminum boat? Are there engineered expansion areas in the structure? Does the hull shape change as the sun heats it? Part of the hull is in the water and remains cool while part of the structure is heated by the sun. How is warping, expansion, and contraction managed? Thanks for the many years of entertainment and education.

[@TiagoVascoAbreu]

I wonder about that too, good points.

[@kenpeckham3536]

Working on aluminum aircraft for 22 years that have integral fuel tanks in the wings we had all kinds of fun keeping the fuel inside the tanks. Imagine the flexing of the wings on every flight! We used a Mil-S-8802 rubber fuel sealant. It is flexible and seals all kinds of stuff. We actually installed panels with a wet layup of this stuff all over the plane. Excellent sealant. Google 8802 Fuel Cell Sealant. It is a two part rubberized (epoxy type) mix that will come in handy. We painted it over screws, seams everywhere. It can also be scraped off with phenolic scrapers to replace the seal.

[@raftguy]

I was wondering about the impact of flexing on the tank covers and if this might create leaks down the line. It makes sense that the aircraft guys would know exactly what methods and products to use for this situation. Just remember, even a small amount of fumes leaking on a continuous basis below your bedroom is going to cause you some serious long-term health effects and you may not realised it until a lot of damage is done.

[@Mike-uc1eu]

+1 on what Ken said. I worked for a defense subcontractor for many years, used looooots of 8802. Made by the Flame Master corp. if I recall correctly. Excellent fuel sealant.

[@tkalbo76]

On aircraft, there are dome nuts installed around the opening that are sealed with 8802 or a similar type of PRC Sealant. These dome nuts are installed inside the tank so the screws holding the access panels must be an exact length so they go thru the nut, but not break the dome portion of it. The tank plates are then installed with a gasket and the screws are torquered to a specifed torque.

[@Kathikas1]

We installed a small window in the hull just for viewing the prop/rudder area. When kept clear it proved very useful for viewing what had got wrapped around what. If Delos 2 is cruising cold murky kelp and fishing line infested waters with two sets of sterngear to consider you might consider welding in stackpipes that extend higher than the waterline to allow an action cam on a pole to be lowered for examining sterngear and keel without having to first go overboard

[@Youtuber-k2p]

I like this idea. Access to the props etc from the boat and they can’t leak. Imagine if you could lower a blade down the pipe to cut off entanglement.

[@OcRefrig]

soon we may have underwater drones that have hands to cut off / Remove entanglements.

[@timdunn2257]

We wrapped a line around our prop shaft while sailing from Honolulu to Seattle in the fall long ago. It was just too cold to cut the line off. 😐

[@ssn608]

Why can't action cam on a pole just be stuck into water over side of the boat? What benefit of dedicated huge diameter standpipe?

[@Kathikas1]

@@ssn608 Holding something like an action camera stable to give a clear picture when mounted on longish pole, especially when the boat is moving around is not easy (I have experience). Lowering it through a tube would make it a one handed and much easier task - maybe a boathook could even be adapted to serve as the pole …

[@dumbwabbit]

First Like! Love the Delos crew. I had a similar upbringing as Sierra's, my dad converted an old bus into a mobile home and we spent the first 15 years of my life, I traveled throughout Europe, Africa and the US. Almost completely home schooled. On land vs the sea, but similar traveling experiences. I am so happy to see how Sierra is growing up, she is experiencing wonderful things and will keep these memories with her forever. I love the way Delos 2.0 is coming along, Brian's capacity for engineering and finding creative solutions is so entertaining! I also like how Kazza contributes to the buildout in the living spaces of the ship. I've binge-watched every video Delos has released, simply fascinating in all regards. Go Delos!

[@glennburch1081]

Gaining experience is always a long, laborous and expensive adventure. As an aviation mechanic (Electrical-electronic) it would always take me 2 years of a 3-year tour learning the aircraft (ie getting experienced) b4 I could routinely troubleshoot the systems and get it right the first time. It is a glorious feeling to be in that space. Brian, the lessons you are putting on video are invaluable! Thank you and Kazz, you guys are awesome!

[@gregorydaley9496]

Hello Brian, I was involved in the industrial repair industry and worked on a very large raw water pump from a nuclear plant that had - literally - 1000 lbs ( initially ) of zinc anodes bolted to it. After 6 years of service, this pump had almost no rust on the steel components. Still amazed at how well sacrificial anodes work. Dry cell batteries work on the same concept. A friend worked for a natural gas pipeline, they would use 50 lbs of zinc ingots in a can -- connect the buried can to a copper cable and the other end of the cable to the pipeline for protection. Good luck

[@stretch34318]

consider counter sinking the fuel pump mounting surface down lower in the lid to allow for the extra room needed while using the raised flange style on top of the tank.

[@Youtuber-k2p]

These vids are a week or more old, your comment is redundant. Do you really think they’ll rip all that out to start again?

[@bobrodgersonsmostlymotorcy9265]

A reinforcing ring around the tank opening and thicker material for the ccover will help greatly with getting a good seal. The thin material of the cover may give problems if you have to open the tanks while at se and the boat flexes. On most large ships man hole covers and inspection hatches have thickened flanges around the opening to which studs are screwed into and the cover is secured and sealed by tightening the nuts against the flange.

[@williamgrimberg2510]

Agree , it seems the bobbles are more prevalent between the bolts indicating the sheeting is flexing when tightening the bolts. Maybe a thicker metal or a flange welded onto the sheet metal and more bolts will even out the clamping pressure on the seal preventing the leaks.

[@cochinaable]

Good idea and he should torque those bolts in a similar pattern on how you'd bolt down a cylinder head and use a torque wrench to apply the same pressure on each bolt.

[@ed1658]

Triple the amount of bolts

[@Drenec1324]

Hi Brian, First the plate thickness of the lid. You should use a maximum pitch of the bolt 8 times the plate thickness. Now you have 8mm plate, the pitch should not exceed 64mm. Since you already have the bolts pitched use the 1 to 8 ratio to make the choice for the lid thickness. Do not underestimate the pressure since you will be pitching and rolling and the slushing fuel will hit the lid violently. Thin lid will make your boat have a diesel fuel smell soon. The bolts: Since thread is not tight by design one should either use blind tapping (like you did with the small lid) or use cap nuts with a stiff ring like you are using underneath the square plates you did. That is why they make cap nuts: to stop the leaking. Greetings from Holland. Frank Mulder

[@bailahie4235]

Always to nice to read comments from a fellow Dutchman... A sailing (and sailboat building) nation... ;-)

[@gradycooper475]

Another benefit of the recessed anodes is that you are much less likely to get hung up on something, or struck by water born debris, damaging the hull. Brian your patience is outstanding. I think I would have been tempted to switch to plastic tanks placed inside those cavities, (loss of capacity being the downside) but with your patience and hard work you got it right. Thank you for bringing us along, I look forward to your videos and it is always a welcomed break to sit down and check in on your progress.

[@MrDonasol]

The problem is the lidd and the tanktopp, they are only made of thin aluminium plates. They are not stiff enough, they flex when you are tigthening the bolts. And the more you tights, the more they flex. You must make the tanktopp and the hatches stiffer by welding on an additional strip of aluminium. SkipPer

[@jabberwockytdi8901]

The original design had a much stiffer hatch opening , that got canned to reduce the height. I commented last weeks video they should keep the stiff hatch opening but the flange inside the tank instead of on top, to get the height they want, and that lid needs thicker rim as well.

[@Youtuber-k2p]

You didn’t watch the video! This is the exact topic that was discussed and the solution found.

[@1982mako224]

Just wait until the hull starts flexing in the water and expanding and contracting with temperature changes. I can smell the diesel in the cabin already.

[@joec1978]

Consider using two-part aviation fuel tank sealer. I used to repair 3 marine diesel tanks 14 years ago. I used rivits while the sealant was setting. Use for the large panel..

[@smoepick5855]

Flex, flex, flex! Use screws from the top into closed rivnuts installed in the tank flange. You need twice as many screws as you have now. Use MIL-PRF-81733D (B1/2) to seal the tank and flex and leaks will no longer be an issue.

[@rayb3117]

Brian, you are the boss. You literally can learn to do anything and become an expert at it. Building this cat is your best project yet. Great job

[@AllenChildress]

Farewell Kurt! Thanks for all your well-rounded talents! ;) Safe travels and come visit again!

[@DavidLynch-j4g]

hey Brian love the boat! I was a machinist for a while and an easy way to seal the tanks is either tap the the threads in the tank and use thread sealant this is relying on the product you are using or weld a flang around the inside of the tanks with only blind holes

[@Doug306]

Hey guys .... those anode recessed boxes are a granite idea for hydrodynamic but in my experience if the stray currents have to take any sort of corner they hit the sharp corners next to the anode... I would suggest rounding the corners where the box meets the hull on the outside and also put a big fillet well on the inside to give it more thickness just in case...because it will become a concentrated area of electrons .... grate build I'm love you channel ...

[@dacamstafool]

Hi Brian. I used to build water tanks with inspection hatches on and we used to have almost the exact same fixing setup. We used a product called Boss White Jointing Compound on bolts that had been wrapped in hemp or cotton string. Basically you wrap the bolt a bunch of times with the string/hemp into a cone like shape, slather it with Boss White then tighten the life out of the nuts with an impact wrench. The boss white goes off pretty soon after and some of these bolts have held for 25/30 years easily. What you are trying to achieve with the seal around the bolts is the exact problem the above fixes almost in exactly the same application (although you are on a boat and I was a landlubber!) Shout if you want some more help/in depth details. Hope this helps.

[@BrianMac1525]

Landlubber here, however, having seen some folks trying to seal tanks and a relative few having even short-term success, a poly tank eliminates a best-effort, no-sea-tested system with virtually unlimited failure points. The poly is a sure long-term solution regardless of any hull deformation from anything at sea or shore. Best wishes and Great Sailing.

[@luigicrispo6853]

that is exactly what I thought

[@jonathanjohnson294]

I worked offshore for 6 1/2 years on underwater robotics. we dealt with a lot of dissimilar metals and corrosion we had anodes spread all throughout the robot. The biggest piece of advice that I could give when dealing with those anodes is to coat the bolts with a marine coating/lubricant. We used Evinrude Johnson Triple guard grease. This helped to keep the salt water and bit of the anode from getting into the bolt threads. It made removing the anodes much smoother than not using it. When someone would forget to grease the bolt it would often shear off the head of the bolts and we would have to retap the holes. I really hope this tip helps prevent any future issues with removing anodes after you launch. Always love to see the content. Thanks so much for the videos as always.

[@abilitymagnorbs5023]

Hi Brian I worked as an engineer repairing and installing petrol and diesel pumps for many years. We used sheets of Cork to make gaskets. Lay the Cork over the top of your tank and cut your gasket using a small ballpoint hammer, tapping gently around the edges cuts the gasket to perfect size. Good luck.

[@JimmyJamesJ]

He's right. Cork is one of the best gasket materials there is. Only way to beat cork is with O-rings set in grooves machined with a ball mill. EPDM is pretty great too though.

[@kjellberntsson4840]

Cork was used many year ago ,there must be a better material .Rubber is often to "hard" any type of flexibel material,dieselresistent ,must be usefull.

[@MonkPetite]

It will not work as the flange is way to big. The bold-hole start leaking and wil do as the boat is flexing and or temperatures will work the panel. Cork or even paper will work with thick flanges like on pumps . But these panels are suck. Way to large

[@SPDLTD]

Exactly, Machinist Engineer here that deals with custom gaskets and seals all the time. You have to understand the fundamentals of what a gasket does, and how it works. It's main job is to take up the inconsistencies and variances in gap in two mating surfaces. You may think you have two flat plates you are working with. They are not flat. In order for the gasket to work you have to achieve 2 things, 1 adequate clamping force, and 2 rigidity of the mating surfaces when those clamping forces are applied. Your problems right now are that 1 you do not have adequate clamping force for the material type and width you are using, in PSI, and 2, you are getting localized deformation at each fastener location as they are spread too far apart. Cork solves this as it is a much more compressible material than nitrile sheet. Secondly, a wider gasket is not necessarily better, Wider gaskets have more surface area, more surface area means greater forces need to be applied overall to achieve adequate deformation psi. This is why o-rings work so well, the clamping force is concentrated in a very small cross section of the gasket material meaning it can easily deform to the contours it needs to seal against.

[@jonathanwetherell3609]

@@JimmyJamesJ Agreed and EPDM is just about the standard for food contact. You still need enough rigidity in the flange to minimise distortion.

[@davidmcgee1413]

In aviation we use a product that is generally called Pro Seal. It comes in many different varieties, a good one is PPG Aerospace® PR-1440 B-1 Gray AMS-S-8802 Type 2 Class B-1 Spec Fuel Tank Sealant - Pint Kit. It’s going to take some scraping of you need to get back into it but it will def seal the lid. Sorry to be another know it all. Btw you’re doing a great job!!

[@johncampbell9216]

As Brian and I discussed last week, the issue is not the gaskets but the nylon studs and nuts he's using. They simply do not generate the compressive pressure to properly seal the gaskets. It's an entirely understandable error given that he was wisely trying to avoid galvanic corrosion between steel bolts and the aluminum hull. However, two things should be considered: not only is nylon not strong enough as a fastener, it deforms with heat and also absorbs water over time. It swells and weakens as it does so. So anyone thinking of using Nylon in a damp/wet area should be careful, especially if consider using it as a bearing material (e.g. plastic bushes). If it were me, I'd have welded aluminum bolts into the hull holes. Welding them seals the bolts in the holes and holds them while you come to tighten the nuts above. Just be sure to check the torque settings before wrenching them up too tightly and stripping them!! Using a combination of aluminum washers and nuts is also wise A retaining compound like loctite is also recommended on the threads to prevent the nuts from slackening over time due to vibration and/or heat/cold cycling. Yes, engineering can get this detail oriented!

[@ToddAlanSloane]

Welded bolts are a very good solution in part, however, you’ve already discovered the sheet metal is not thick enough with the type of gasket being used because tightening the bolts creates leaks in the gasket so bolts will solve problem one problem, but exacerbate problem two. I personally think the concept of The aluminum tank with multiple bolted lids is the issue. All the solutions tried so far have assumed that that’s a requirement, rather than challenging that assumption. And these are simple dry tests nothing like what will happen at sea. Consider the forces on those hulls and the fact that well under a millimeter gap in that gasket will generate leaks . For me personally, I would not risk this type of failure at sea. There will be an incredible amount of torque and torsion on those lids. What can be worse than having a slow possibly unnoticed fuel leak beneath your living quarters? Why not a completely enclosed tank with only seals at the port, perhaps with baffling if you’re worried about slashing, or something modular as others have mentioned. First time writing and doing so 100% out of care and concern for your safety and that you may solve this in the short term but wind up with a major issue and repair after going to sea. Tons of respect and admiration for what you all are doing here.

[@johncampbell9216]

@@ToddAlanSloane The metal is perfectly thick enough since the bolts are close enough together and the seal thick enough to spread the load sufficiently.

[@ToddAlanSloane]

@@johncampbell9216 it looks like he solved the problem based on the end of the video. However, the metal being thin was part of the issue. The reason I suspected this is because when he did change the bolt so that he could really torque them down he started getting leaks between the boltsat the gasket

[@Kathikas1]

@@ToddAlanSloaneAt some stage access to the tanks will be needed to clear out dead bacteria that forms at the condensation/diesel interface and then drops down to the tank bottom as a grey sludge to eventually block filters - and in colder waters that condensation is accentuated due to the thermal gradient across the aluminium of the hull. This sludge will have to be scooped out manually If that does prove to be an an ongoing issue the large tank access covers will make installation of flexible bladder bags relatively easy

[@johncampbell9216]

@@ToddAlanSloane It is possible to overtorque.

[@crisdafar]

Posted on FB but thought I’d chuck it up here too cause it might gain a bit of traction…. a few thoughts, in west Aus we build a lot of aluminium boats. We use cork gaskets. Have no issues whatsoever. A point to note, try not to scribe the Ali lids when marking out the bolt pattern. Leaks can run along the scribe line. Also there’s no need to sand the surface of fresh aluminium plate like you did with the underside of the lids. Why put scratches in a perfectly good smooth surface 🤷🏼‍♂️ Also we use stainless nuts and washers with a bit of 567 or similar. Corrosion isn’t an issue. It will outlast your lifetime. If you get a bit of surface corrosion on those T6 ali bolts good luck getting them undone. And they’re still dissimilar anyways. The irony is if your Annodes are doing their job it won’t be a problem. There’s going to be hundreds of other dissimilar metal contacts all through the hull. Filler and pickup could probly have been welded into the tank. Wouldn’t have been a height issue with floor then. And just one other thing. Why are they using a tig on external underwater seams. Tig welding isn’t a penetrating arc. Recipe for disaster there. Followed you guys and this build closely and started scratching me head when they filled the boat up checking for leaks….

[@crisdafar]

The reason cork gaskets are used is because rubber in contact with aluminium is a big no no. The rubber has compounds in it which will corrode the aluminium faster than any galvanic corrosion that might happen between the aluminium and stainless.

[@Mark-r5k6z]

On our Vans Aircraft aluminum fuel tanks we use proseal a two part mix. Cures in a few days, never hardens - fills in the uneven surface. Might look into it.

[@alonzothompson4221]

pro seal is being replaced by this sealant: part # MC-236-B2

[@WesleyGullidge-p4v]

Brian, Wes again. Trust me when I say our wing tanks were just like yours. Only we we flying four engine turbo prop. Much bigger wet tanks that took up both wings. The rubber seal by itself will leak. With the fuel resistant putty no problem. Call an aircraft maintenance that works on larger wet tank wings.

[@robertmccabe7523]

Take a look SeaBilt inspection ports.

[@TimTimTomTom]

I'm honestly surprised Brian hasn't (seemingly, anyhow) consulted more experts in these individual fields as he works on the core systems of their boat/home. I'm still wondering what he plans to do about that bus bar... that itself has some huge potential failure modes that aren't exactly unlikely to happen. But he's a smart guy, maybe he has worked these things out and just not put it to video.

[@1982mako224]

@@robertmccabe7523 The sportfisher I used to run carried 800 gallons and in had 8" round inspection ports in the tanks. There is no reason for the whole top of the tank to be removable the way he is doing. He should just weld up the top of the tanks and make reinforced flanges to accept inspection ports.

[@DaveArnold-c8v]

Hi, I have a suggestion for your fuel tanks --> Check out how Single Engine or Multiengine trainer aircrafts store fuel in their wings. If I'm not wrong they store fuel in "bladders". Moreover, I notice that when you are trying to seal your fuel tanks you are doing it from the outside. Note that when fumes accumulate in your tanks they will have a propensity to exert outward pressure from within. So note that even in balloon or tubeless car tyres they use a sealant powder to guard against leaking punctures and they use soap and a perfect fit iron gasket seal within the tyre extremities to fit perfectly in the rim. Now you can't use a sealant as it will contaminate the fuel itself. If I were you I would still go in for the "bladder" fuel tank approach. This would drastically reduce the possible number of structural manufacturing defects to 2 - one, the bladder and nozzle seal and two, the nozzle itself. The only other possible operational defect would be one or more punctures. In your current approach, each of the nuts and bolts is a possible defect in addition to the gasket. A gasket is used in the engine manifolds but not the fuel tanks as there you have metal meeting metal which requires a seal which cannot be avoided. But in your fuel tank you can avoid this in the design itself. Even the Refueling heavy aircraft use bladders to store fuel in bulk for their client F-16 or B-2 or Falcon clients. My friend, forgive my bluntness but I think your approach is seriously flawed due to the number of possible defects in your design. Please reduce the number of possible defects in your design.

[@raisingcane225]

Bladders are absolutely the way to go here I think.

[@haraldhannelius]

Can't use bladders along stringers and frames. You need to redesign the structure to take bladders.

[@DaveArnold-c8v]

@@haraldhannelius Ohhhhh . . . dang ! Can you install a plate above the stringers & frames? This will reduce the capacity of each bladder but you could think of more compartments for the fuel but still not compromise on the bladder approach. This way you could also utilize fuel transfer valves like we have in Boeings and Airbuses for the sake of brevity and redundancy. Each compartment could be isolated from its neighbor using check valves.

[@Youtuber-k2p]

@@DaveArnold-c8vTwo problems here and you could have answered one of them by simply paying attention to the video. A plate above the stringers leaves very little room, it was discussed how the fuel unit barely had any room under the sole. Secondly these videos are weeks old and they are just not going to rip everything out and install bladders. It was also discussed very early on about the appropriate method for storing fuel, a naval architect designed this boat, do you not think they were qualified to come up with the best solution?

[@DaveArnold-c8v]

@@KZbinr-k2p Are you a member of this channel owners / design & build team ?

[@mathysviljoen6870]

Hi mate, we in Brisbane and you can get this local, Think of using fiber washers. we use Loctite 567 we use in on bolts in tanks for hydraulic oil, Yes, Loctite 567 can be used on diesel tanks because it's resistant to oil and can tolerate minor surface contaminations from various oils. Loctite 567 is a thread sealant that's used to lock and seal tapered metal pipe threads and fittings

[@davidmaynard-m2h]

You may think about looking into methods and materials for sealing aircraft wet wing tanks.

[@itsverygreen532]

We use bladders for that.

[@sawmill123456]

@@itsverygreen532yes that’s what i was going to say!

[@CurriedBat]

I've always wanted to build my own aluminum boat. You guys are inspiring for so many. It would be so cool to see a collab with you guys and Parlay, R. I bet those guys would know a thing or two about catamarans (if not perhaps, aluminum ones). It would be so cool to see a side by side pic of your two cats one day. Best of luck, you got this.

[@amunderdog]

The challenge of reinventing the wheel. Carry on.

[@Ranchpig67]

Thank you

[@kemmhs]

Hey guys, I cleaned my water tank on an Allures 51 last season, (all aluminum hull and tanks). Redid the gasketing of the water tanks very much as you did Brian, using 90 mil soft EPDM gasketing rubber (roofing material grade). I would not use this rubber for the diesel tanks, since as you mentioned, EPDM is incompatible with petroleum products. I did not do any air test once done. (To be honest I did not even think of it). After sailing all summer, I have not had any leak at all. My sense is that once the tanks are vented, you do not have the kind of pressure you are putting the tank through with an air test such as the one you performed. There is pressure created by the water splashing against the gasketed covers when the boat is in motion, but not enough it seems to cause a leak on the covers. I assume this is the reason why my gaskets and tanks have not been leaking. I have holes through the cover and the tank housing similar to your set up as I recall and used nylon washers as you did on your first try. (My boat is spending the winter onshore in a yard, but I'll double check the set up next time I am on it, as you have made me curious after watching your video. I am going to have to do a cleaning of my diesel tanks as well one of these days, it is a 2009 boat which I have owned for 3 years, I love it). I have a question for you guys as I have scheduled redoing the entire electronics on the boat this Spring. Have you done the research or already know how to best protect yourself and the boat systems from lightning strikes? I am currently going through the materials offered by the ABYC and NFPA but have not come upon any particular directives yet for boats made of aluminum (or other metals for that matter). I have just begun my enquiry. All the best to you guys, beautiful project :)

[@marktinkler6897]

And this is the main reason many boats (mine included) that have plastic tanks for both diesel and water. Only have to seal the main line and one small air vent both of which are international pipe thread.

[@luigicrispo6853]

my thoughts

[@johnbucknell901]

As someone who has worked on seals for engines for ever - use RTV sealant for hatches you aren't going to open very often. It is resistant to oil and fuel, and never leaks and works even if your surfaces aren't flat. The bolts will leak unless you put studs in (or use more RTV).

[@bobfitz6358]

What’s wrong with flexible fuel tanks, like in Aircraft?

[@uncleansanchez]

Exactly what I was thinking. As a mech on H3 and H60 helos, which are essentially the same construction as that aluminum boat, the fuel bladders could be deflated, stuffed into any irregular shaped vessel hold, and filled up with no leaks.

[@philipmackin1025]

@@uncleansanchez How well would the bladders shape around the the ribs of the hull that are present in this Cat?

[@johnallen8094]

@@philipmackin1025works in Aircraft!

[@donrhead-nb5bj]

I was recalling my experience with aircraft like the H60 series self sealing fuel tank bladders.

[@bryancohn9406]

@@philipmackin1025 the bladder would be molded to the interior shape of the hull, rubs and all. It would take a bit more work when deflating and stuffing it inside the cavity but once "popped" back into shape would fit fine.

[@JimKJeffries]

Consider taking a 2" strip of metal and weld it to the back of the fuel tank lid @ 90 degrees (short it so the lide gasket is not even close). Think baffles, but on the lid. Stiffens the lid by a ton, quiets the tank, adds only a little weight. Keep up all the awesome teamwork, you guys are doing great. Know your/you're love

[@echapp1]

Bladder tanks,as in aircraft wings?

[@Youtuber-k2p]

Over stingers? Dumb idea.

[@ctown6971]

17:52 Use the same idea here for the tank covers. Cut some slugs out of bar stock drill and tap them, then drill holes in the tank and weld tapped slugs in the tank top and grind flush, and than bolts will be sealed.

[@johnwheatley231]

The problem is that the bolts themselves are not sealed. Either weld the ends inside the tank or use rubber washers for the bolts inside the tank.

[@Youtuber-k2p]

The problem is that you didn’t watch the video. The lids were too thin and buckled allowing air to escape. The solution was heavier plate and fibre washers. Why do you need someone to summarise the video for you?

[@GeorgeLittle-ft2yx]

@@KZbinr-k2p he doesn’t need someone to summarise, he does however need protection from keyboard warriors hiding behind stupid KZbin generated names making stupid comments.

[@johnwheatley231]

@@KZbinr-k2p I watched the video but thank you for your in depth summary. The problem may have been a combination of both, I suspect however that the rubber or fibre washers would have solved it alone.

[@mvintrigue-trawlerdiy1101]

PR1428 sealant will seal that tank perfectly. And 1428 is low adhesion so you can eventually remove it. I've used it in that exact scenario. You can also install dome nuts on the inside to seal the bolts perfectly.

[@JohannSwart_JWS]

You're designing a flaw right into your new boat. Custom made poly capsules for sure. Worth every cent.

[@jimconnelly816]

ya that is my idea also, it would work perfect.

[@rickadvocaat]

I was wondering if there is a reason why not to use a custom poly fuel cell.

[@DataRew]

Agreed, they will likely list this as one of thier biggest regrets of things they did during thier build in a few years.

[@pauls477]

@@DataRew judging from all the comments on this video and past ones - im thinking this boat is going to be a mess?

[@1982mako224]

@@DataRew That and that insane buss bar concept.

[@JohnBrookhouse-j8q]

Brian..my experience with fuel tank manhole lids (always circular) and fitted on a flange about 2” raised up from tank top, and holes at a minimum distance from each other…this way bolts never enter the tank space, use a thicker material for gasket…works every time but this with a steel fabrication, but I would think there would be no difference with a aluminium fabrication

[@jackdbur]

A thickened flange around the top of the lid is often necessary with aluminium .

[@JohnBrookhouse-j8q]

It’s leaking exactly between the bolts…another set of additional bolts is gonna solve your problem!!

[@petermagnuson2116]

Have you thought about welding in aluminum female threaded inserts? So that the bolts themselves do not have to be sealed, it would just be the cover and tank then. Just like the original flanged plan.

[@bouldertim8372]

seems like you're trying to use a mechanical solution to fastening the bolt to the tank. why not weld on the bolts to a flange plate outside of the sealed area.

[@bouldertim8372]

ha! should have waited for the end. Congrats on the solution!

[@jackdbur]

They should have used nutserts/rivnuts with the bolts on the outside 😊.

[@Helicamman]

Machine groove in top, buy roll of nitrile o ring material glue o ring in reciever groove use silkaflex to seal but ends of o ring.bolt down and be done, keep roll of oring material on boat for repairs. Put o ring inside of studs not outside.

[@richardrudkin2298]

You are on the right track milling a grove, but an extruded seal is a much better option than sikaflex...

[@Charlie-Oooooo]

Glad you got the tanks figured out. Custom work sure is a challenge but you guys can do it! 👍❤

[@jabberwockytdi8901]

Not the end of this story yet not by a long chalk......

[@Takohunter53]

Hey Captain...25 plus years in the metal trades...you need to stiffen your cover plat for your fuel tanks...or any tanks...aluminum is not stiff, hard, or how ever you wish to describe it a piece of angle around the out side edge...flange up...drill and tap should work fine...ask you ship builder how he sealed his tanks...unless they weren't built in....

[@patraymond3791]

I have found in my industrial career that a wider gasket is not as good as a narrow gasket, think of the PSI (pounds per sq inch), more square inches is less PSI while less square inches of gasket equals a higher psi. The Teadit or Gore Tex as we called it should have been perfect fort this application Pat

[@pieterbezuidenhout2741]

Got a valid point there. I would also suggest BOLTS CLOSER to each other to have a more evenly spread pressure on that Aluminum.

[@MonkPetite]

I said the same in episode before this

[@DanielSimon1995]

other thing is, those fuel tanks wont hold compress gas at high psi, it has to have a venting hole; maybe they were discusing what psi they were testing it...

[@TimTimTomTom]

Problem was how he handled the corners... instead of key cutting them together he overlapped it.

[@richardrudkin2298]

Yes... correct, but that is only part of the problem. Rubber should never be compressed in a sealing application. It will develop a set and leak over time. It must be designed to deflect. There are many design solutions for seals, but this is a fundamental principle.

[@dr32803]

A tiny coat of grease between the surfaces of the gasket, cover could eliminate leaks. Also when you tighten the bolts, do so in an alternating (left right front to back) method to ensure a gradual and equal pressure all around the cover.

[@rkiheavy3002]

Delos 2.0 is going to be AWESOME!!!! Can’t wait for the episode series where your daughter sails YOU around the world on its 20th trip around:)

[@richard0202]

I would get the tank lids milled with a groove inside the of the bolts and make up an o-ring, that way you can also get perfect compression on the seal. Works well on many industrial applications. You could even have dual concentric grooves an o-rings if you really want a belt and braces solution.

[@TimTimTomTom]

That's a really good idea, placed inside the bolt hole line... would be ideal. But he'd still have to mount the tanks on flexible mounts, so the tanks don't flex with the hulls... so many considerations on this kind of build.

[@TheOnlyJuann]

Thank you so much Kurt for helping build Delos 2.0 -- you will always be a part of this Tribe!

[@JayDGee]

The flange is the most proven way to secure a pressure vessel hatch this size and allow ease of service for the bolts that’s secure it. To preserve the floor heights have you consider inverting the flange inside the tank instead of the flange protruding above it?

[@CD3MC]

11:33 - why dont you just stud weld short threaded rods onto the top of the tank and ditch through-holes altogether? That way you dont nee a flange or to compromise the tank seal.

[@FallenHoot]

For some odd reason if the needed to access the tank, they can't

[@Ketniyi91]

Good man Kurt. The trees be calling me back too at times. Boats looking good!

[@rburn99]

Since Dan and Kurt have finished their work this build is making me anxious.

[@gradycooper475]

I have confidence that Brian will get it right. He is smart enough to figure most anything out but also seems to know when to ask for help. He has a pretty big "brain trust" of experienced sailers and Marine Techs as viewers so I would think that that should be helpful.

[@michelvanwoudenberg]

Hi Brian, I dealt with exactly same tank lid issue and word of caution on using alu bolts: if the mix of alu in your bolts is different from the alu of your sheeting you CAN still experience (light) corrosion. The effect of that could be seezing of the bolts in the thread so be sure to use some threadlock or other ‘stuff’ to prevent that since they can easily sheer off when stuck since as you pointed out they’re weaker than SS bolts. My 2 cents

[@Webcrawler45]

Warning!!! Aluminum doe NOT have a fatigue limit like stainless. The Aluminum bolts will stretch and loosen over time!!! I HIGHLY recommend replacing them with stainless bolts...The only issue with your fuel lid was that it needed a stiffener about 1/2" (11mm) x 1(25mm)" wide welded to the top edge where the boats go through... Would have solved all of the issues and I would have use a liquid sealant material. It will also minimize any galvanic corrosion. (just the opinion of an old grouchy engineer)

[@kevinhildum9186]

They needed an angle aluminum bar on the tank lid to keep it from warping while tightening it down.

[@TimTimTomTom]

I was thinking if they had just designed a hinged hatch lid access, somewhat like an ammo can they would have had no issues to begin with. But yes, I had the same thought about adding a reinforcement at the perimeter, to stiffen that edge. Wasn't aware of the aluminum bolt issue though, I actually recommended using aluminum bolts last episode...

[@wilmeaux12]

@@TimTimTomTom Yes, the aluminum bolts can stretch over time. if they are over torqued. Depending on the particular bolts you are using, this figure could be rather low. Thus, I suggest care in running them down. Another thought is, are you compromising your anodes effectiveness by recessing them, especially over time?

[@jacobdixon5335]

those aluminum bolts are gunna be a huge problem later on down the road.

[@mkllove]

Hey Brian, Another improvement would be to add some centering/alignment crossbeams on interior face... a rectangle of right angle profile aluminum tacked in numerous places rather than fully welded to avoid warping... It would help align lid with access port and stiffen structure nearest bolts to avoid localized deflections that caused leaks. Remember this is all going to twist and move from changing temps, sailing forces and dissimilar expansion & contractions of rubber vs aluminum... Doug on SV Seeker also used cap nuts to prevent leakage via threads if I'm remembering right, I think ? They can be obtained with o ring seals or polymer faces as I recall. ( if you remember how VW's had copper washers and cap nuts as seals on types 1,2.3 and maybe 4? for oil changes )

[@Rockatansky-ei4je]

You just know Riley is glued to this video somewhere in Japan.

[@cwgarr]

If Riley had chosen this design and this build method, it is likely that when the collision occurred the other boat would’ve been damaged and this boat would’ve been intact.

[@TonyRaincoat]

@@cwgarrif Riley had half a brain unblemished by massive ego, he wouldn’t have bought that dumbass boat.

[@anabrochado7272]

You're probably right 😂

[@davidbarker6899]

I think Riley has his eye on another boat, lol.

[@thomasquigley7040]

My view of Delos & Vagabonde is like a Bronco & a Mustang. Each is good for their intended purpose, but you wouldn't want to track a Bronco or offroad a Mustang.

[@11thhourcustom]

Just to add. I haven't read many comments but making bars to go across the top and the bolts go through the bars instead of washers helps torque the lid down evenly. That's how it is done on heavy equipment radiator tanks and cork is always king.

[@kaapporaivio]

Brian, I would really consider having a separate fuel tank. You sont want to have to deal with flexing structures and sealing those. Sure, you'll lose some fuel capacity but is that really a big deal in the big picture?

[@jackdbur]

It is faster & cheaper when production building! It is very expensive when custom building. 😊

[@kaapporaivio]

@@jackdbur as if saving money was the primary objective of this build

[@JanLouisFourie]

I would suggest a O-Ring on the inside of the bolts with a recess milled from the tank to house the O-ring, we have had this work for many years on transformer tanks, the O-Ring is cheap and easy to repair.

[@mikepetersen5024]

Did you try torque wrench to even out the pressure on your gasket?

[@hansjmo]

The issue with sealing is that the surface they are trying to seal is not flat. needs to be machined surfaces.

[@richardrudkin2298]

Never compress a rubber seal.... it must deflect, not compress.

[@soggybottom3463]

Great fix Brian on the tanks...methodical good sense wins the day, and keeps the workload and budget under control. So long Kurt, what a geezer. Be careful in the forest big fella, tough tough work x🤗🤗

[@jimconner1028]

Gaskets fail. I like the thought of some sort of bladder tank or lining. It would give some sort of double wall effect. Extra strength, insulation, flexibility and a sort of automatic leak protection. Ready Containment in Palmetto, FL makes custom diesel bladders. Might give them a call.

[@6226superhurricane]

bladders fail just the same.

[@dannyarcher6370]

@@6226superhurricane Mine did at 2am this morning, at any rate.

[@jimconner1028]

@@6226superhurricane yes but theoretically would offer another layer of leak protection fitted into the aluminum tanks

[@jackdbur]

They rub through, are crasy expensive & if any moisture gets between the bladder & aluminium it will cause corrosion very fast. Also trying to clean bladders out is horrific.

[@psutex6070]

Hello Brian. I've designed a few sealed door in my work. A couple tips. The seal material should deflect 20% to cerate the best seal. Find out what your force is needed to get this 20% deflection. I think that you will find that you need a tremendous amount of force with your bolts and gasket to get 20% deflection. The wider you cut your gasket adds into this force needed. Narrow your contact area. In fact do something like weld a bead of aluminum along your flange and this will reduce your area and give you a localized force to compress the gasket. A bolted gasket seal in general needs a lot more fasteners spaced closer or a very thick or stiff flange. Make gasket or seal as large as possible. 20% of .10 thick gasket is .02. 20% of .50 gasket is .10. your correct compression range is larger and easier to maintain as the seal size increases. Also dont use any non metal. hardware. Over time all hardware will creep and relax then you loose compression/sealing. Just my 2 cents. Good luck.

[@timn6864]

Here to read all the experts in the comments saying how they would've done it ...

[@nhm2896]

About sacrificial anodes during long stationary stay... Six standard zinc anodes hanging overboard in wires attached with clamps to the hull will keep you safe while away.

[@outsidethelinessailing]

Brione, just a thought; even if you sealed the tanks, the flex of the boat underway will create deformations. What about molded/removable tanks?

[@Bullshit1011]

Wasting your time , he never listens

[@bendunne101]

​@@Bullshit1011ok bot.

[@Youtuber-k2p]

wasting your time too, the tanks were finished some time ago. What is the point of listening to every armchair expert when the job was finished weeks ago?

[@colinmansell3524]

Great to see you have found the solution to the tank Brian. Now to go forward. Keep our dream alive.

[@DarrenBainbridge]

I have been wondering - Why do you keep trying to reinvent the wheel with this stuff (buzz bars, tank sealing etc...). When you have a naval architect who has designed and overseen the construction of many commercial vessels in aluminium. Surely, there is a set of industry best practices for this stuff.

[@Youtuber-k2p]

What the hell are “buzz bars”, they are bus bars. Hardly reinventing the wheel when they’re universally used in most electrical applications.

[@sbdreamin]

@@KZbinr-k2pnot the way he did it.

[@mirror1675]

@@sbdreamin Agreed. There is good reason why nobody else has installed DC busbars the way that Brian did.

[@sbdreamin]

@ I’m hoping he’s redone them since. As a pilot (planes and helicopters) I’ve had my fair share of vibrational chaffing. Those fiberglass tunnels he shoved the bus bars thru are gong to chaff thru on one of those bulkheads he cutout, and theres gonna be a BIG fire. They will be lucky to get off the boat before its a toxic conflagration.

[@leonardbertaux6897]

“Buss” bars folks

[@davidmbryant]

the tank lid/cover should be strong backed. It will flex under air pressure breaking the seal. A sealing compound from Locktite or 3M will be better than a gasket. Also, running studs, spot welded from the inside of the tank to hold them in place is usually a better practice. I worked as a mechanic/fabricator at Stephens Marine in Stockton Ca 40 years ago.

[@winelion1318]

I'll never go through the excitement of building a boat from scratch myself, but I really enjoy learning about the processes, problems, and accomplishments of this built. I have nothing to do with building this boat, but have the same thrill as watching my favorite sports team win by exclaiming "We did it!", as I cheer you on past each milestone. I look forward to each chapter every week like it's next week's game of my favorite winning team!

[@larrylegg8245]

You should install removal fuel tanks. If you puncture the hull by accident, your removal fuel tank will most likely not suffer the puncture because it's like having double wall tanks. If you need to clean them or repair them, you have the option to remove clean or repair and reinstal. It's a plus for your ship.

[@addogmoney2340]

Hey Brian, I've Built Ethanol pipework to storage tanks in the past, and we found the combination of thick teflon thread tape, combined with loctite 577, never let us down. You may also consider thicker storage lids? I'd be using 10mm or 12mm thick aluminium personally, as there would be less deflection between studs. I'd also recomend that you don't go beyond 3mm thick for your gaskets. Hope that helps!

[@jackdbur]

You only need a flange plate around the lid

[@douglasperkins7592]

Weld down the big hatch, the small hatch is big enough to clean the tank if necessary.

[@philipmackin1025]

The small hatch for delivery, monitors and suction to engine is only 1/3 the size of a tank lid. There are three large lids over the long tank (10 ft?). Hull ribs are also present. As such, you would be unable to inspect or clean this tank.

[@BBBrasil]

What a journey! So glad you are sharing all this with us 🙂

[@williamknight9033]

Weld studs on the tankis sealed perfectly

[@apollo5751]

Too much risk to thread damage, can't easily replace at sea. Two issues were obvious can't use bolts with 100% thread, can't use plastic washers and for gosh's sake don't make ALL the hatches at once until you prove at 1 WORKS.

[@howiefeltersnatcher]

That’s why you install nutserts on tank side run bolts into tank if one fails you have new ones to install small kit keep on board

[@NomadSurvivor]

HI BRIAN FOR YOUR TANKS. use the Nitrile Gum Adhesive on your gaskets first. THEN , after you tighten your bolts over each tank access hatch use a thicker Nitrile Gum and completely cover to about 2" outside the total perimeter. I know saying it doesn't make sense, but if you call me I will explain. We use the method for large Iso-Butane tanks ( 55 gallon ) it will hold to 15-20psi depending on the hardener used.

[@pauls477]

Why dont you just get a professional boat builder to solve this issue? This boat can't be the first to face this issue ?

[@jafranswa]

man this might be old news but I feel like access to a laser cutter would go a long way to cut out gaskets assuming yall have some sort of cad file with the bolt patterns you need. I cant express how inspirational yall are, I love your channel =D

[@dycecooper]

Do you have baffles and a swirl pot to prevent fuel starvation?

[@berndheiden7630]

Probably not. I wonder if that whole tank solution is compatible with any specs that will surely exist, if not for anything other than being able to insure the vessel? Like how much pressure is diesel developing at a 100-some º F summer day? Will it solidify being in close contact with winter water temeratures? Is a single hull allowed for fuel tanks? Is the tank really gas tight (which could be a fire hazard)? Does it even conform with fire hazard regulations? Too many questions for my liking! The problem is that everything is long done and finished by the time we are seeing it!

[@Cptnbond]

Although swirl pots are used on racing cars, they are not found on slow fuel consumption sailboat engines. In addition to the tank, you have the fuel filter that acts like a temporary reservoir. Baffles are a good idea for large tanks, though. Cheers.

[@skyhawk7935]

You're basically building a monocoque airframe that floats. Use the same sealant that the aerospace industry uses to seal aircraft fuel tanks. Also use dome nuts for the plate fasteners. They self seal when installed.

[@VR6NAVYVW]

why are you not using internal bladders? like a racing fuel tank. Also, when hole punching, you should put a piece of wood behind it so you don't damage the cutting edge on your metal work top. For the bolt holes you can't used silicone caulk or RTV.

[@jff0111]

Absolutely, turtlepac are down in Currumbin, make great tanks

[@hansjmo]

Hi, on the topic of anode and passivation of the Al-Zn-In anode, I think it would take a year or longer for it to become fully passivated. It ofc depends on temperature, salinity, etc.

[@2nd_of_3]

You aren’t an engineer, you’re guessing, somewhat educated but guessing all the same. Two most important concerns would be Fresh Water and Fuel Storage. Get some tanks made to order. Then the covers can be attached however works best.

[@hodadyou]

The Al washers are genius! This might be relevant to SS to Al mast applications as well. We always learn so much from your vids.

[@roaddog1973]

This tank design is worthless and will only fail out on the open ocean over time even if you are lucky enough to get it to seal long enough for your test. You would be better off using high-density polyethylene (HDPE) fuel tanks no different than most cars, trucks or recreational boats. Everything else is a waste of time.

[@davemc1297]

Ex MAR E 1 here. Unfortunately, Brian doesn’t read or listen to comments you put here, no matter how well informed (same as his busbar installation). I watch on now just out of interest, but he’ll just have to find out about marine engineering design, certification and insurance for himself

[@jackdbur]

Having custom hdpe tanks made is horrifically expensive. 😊

[@niko918]

I love you guys, I really do. I thought when you decided to build your own boat you were taking on a burden that manufacturers have been struggling with for years, and that buyers have been dealing with endless problems with the manufacturer backing for years and that taking on this was a not just massive task of epic proportion but too much was at risk, your sanity and your families health. I wish you the best and I believe it can be done but the cost will be extraordinarily high in time, $, and sanity. 🍀

[@garganega]

The only gaskets a fuel tank should have are for the sender/pick up/evap and the fill neck. Small openings.

[@1tnslim]

Another method of sealing is to machine the tank lids to fit an O rings made from solid copper wire. It works on race engines for cylinder pressure. Just a thought and would be fairly easy to do. As for the bolts I'd recommend welding the bolts to make studs. Thanks for all the videos, have been a subscriber for years.

[@billbaxter2914]

I don't understand how the designer of the boat didn't have a solution for the tanks. Also the guys building the boat. Haven't these guys put in fuel tanks before?

[@domalash]

the owners changed the design.. they didn't use the designer's solution.. they changed it to make the fuel pump connection fit without raising the floor.. but the new design made all the bolts leak points... in the original design the bolts didn't go through the tank.. they were bolted to a flange around the tank so air couldn't pass around threads in the original design like in the new design

[@NeilSearle]

They covered it in the video. They have changed the design from the original spec to allow more space below the floor for their chosen fuel pickup. The original design has a raised flange so the bolt holes were not directly into the tank.

[@Nate-bc1el]

on the zincs... yea ok if u wanna go offshore/ or clean the hull more then regular... assuming the hull is painted... but rule of thumb i was taught was to always go ATLEAST 1 step below in the table... and zinc is a slight step down.... magnesium is even below that if i remb right.... but will be replaced quite often in saltwater, although provide the most 'protection' i am no metalurgest though

[@robstubbs2772]

Soo good to see such professional work guys Brian your clearly a Profectionist and caz your a bloody hard worker 🎉