I Soooo Underestimated This Project 🙈 (Custom Aluminum Catamaran Build Pt. 19)

[@svdelos]

Ahoy Delos Tribe! We're BACK after a short break for the holidays with another doozie of an episode! If you can't wait to see part 2 of this beast of a project, join our inner tribe at patreon.com/svdelos. All our patrons get to watch every episode a week early with NO ADS, plus direct messaging with us, exclusive bonus content & behind the scenes of the build, invites to meetups, and more!

[@jackechan1311]

We soooo hope you had a great restful happy break!

[@jackechan1311]

...and the next youtube advertiser that interrups Ramukanji is gonna get a strongly-worded email....!

[@Coleen_West]

Nice video! -- QUESTION -- Brian, if I can make a suggestion, PLEASE try not to do all that "smiling guy" look. Not sure why, but recently you are doing the effem guy smile all the time. You never did this before and you don't need to do it now. Just be yourself. Guys that are constantly fake smiling are a bit off-putting to us women. Women smile. Real men rarely do and they don't need to. Check out your older videos and see the difference. It makes you look unconfident and just weird tbh. Loving you so we had to point it out as lots are talking about it.

[@svdelos]

@@jackechan1311 Wait did you get an ad during Ramukanji??? We've been really frustrated lately because KZbin gives us the option to choose how many ads go in the video and choose the placement...but sometimes when we watch the videos there are wayyyy more than what we set up and not in the correct places at all. We've been trying to contact them about it but as you can imagine it hasn't been the easiest process. Nice to have confirmation from someone else that it is really a problem. Thanks for watching and we will do our best so that it doesn't keep happening 🫡

[@jackechan1311]

Not today but last episode. Maybe the one before that too. We were both singing along `de vive voix` (heartily) as one does, and whammo. LOL Y`know, some things are sacred. Thanks for caring and for your reply, tribe!

[@dreney85]

Hey Brian, I am a retired aircraft structural mechanic. On fighter jets with integral tanks we used an epoxy sealant with domed blind nuts that are crimped into the tank structure after coating the hole with wet sealant for all bolts. Then a bead of sealant under the outside edge of the cover. The sealant was a Mil Spec 899-B1/2. If the panel was needed to be removed often, such as inspection plates, wipe a very thin layer of petrolatum on the surface of the inspection plate and lay the bead of sealant on the structure and only torque the bolts to half torque the first day and final torque after 18 to 24 hours. The petrolatum acts as a release agent that prevents adherence to the cover but allows the sealant to conform to a perfect gasket. The sealant is also a barrier to galvanic corrosion and fuel safe. JP8 Jet fuel is very similar to diesel but thinner and aircraft fuel tanks use constant dynamic air pressure to transfer fuel. These seals are reliable for decades of high G maneuvers and thermal extremes.

[@stankythecat6735]

This comment is why I love this community ! So much brain power

[@hanssolo4ever]

Hopefully they won't do any G manovers.

[@KevinRicard-l6j]

I was wondering why they did not use riv-nuts for the clamping force

[@heaven-is-real]

fantastic Dreney (Just ask a Jet mechanic engineer) :)

[@ShannonVincent]

i was going to say the same thing. Encapsulated dome nutplates on a fuel tank ring and 1422 B 1/2 sealant

[@guillaumeroche1879]

Hi Brian, I'm a marine engineer and I've been a boatbuilder for 30 years and I am watching your videos with keen interest. Fantastic project! Needless to say, I have been dealing with a lot of tank hatches and outfittings in all materials, including aluminium. Actually, I started my boat building career building 72-100 foot aluminium sailing yachts. I'm afraid that without some stiffening of the tank tops (normally achieved with the baffles) and a reasonably thick and/or stiffened tank hatch flange, you will never achieve proper gas-tightness. You have to take into account that however stiff it seems, your boat will be flexing at sea, which will in turn flex the tank tops as they are welded to the structure. If this is not stiff and we'll fastened, there is a strong risk of play and weakening the seals. I therefore recommend that you weld 25mm thick flanges to the tank tops. These can be welded internally to avoid adding height to the tank top. Beforehand, you can drill & tap the flanges and then plug weld the holes on the inside for gas-tightness. Use 10mm dia. x 25mm long hex head bolts to secure the hatch down with a nitrile or silicone ring seal. There is no problem using stainless bolts with Loctite, Teff-Gel, grease or even Sikaflex, as the risk of electrolysis is quasi inexistent as long as there is no oxygen reaching the connecting surfaces. If you want to stiffen the flange areas more, you can always weld L-Profile stiffeners on the inside, connecting them to the beam sections. For future reference, I would recommend doing all the tank top outfittings, with their flanges, hatches, pick-ups, etc. before you weld them into the hull. It is so much easier. Good luck and keep up the good work! All the best

[@lutomson3496]

ive never had luck with diesel on bare aluminum especially in a vessel the water contamination is high and creates a corrosive environment odd never seeing any film coating the aluminum

[@guillaumeroche1879]

​@@lutomson3496I I know what you mean. It would indeed be better to coat the diesel tanks, especially the underside of the tank tops (condensation) and from the bottom up to 20 cm (water & sludge). I was continually criticised for doing that even on steel diesel tanks. But the question is: build to cost or build to last? That's a choice for the owner. 🤷🏻‍♂️

[@69lure]

I would have made removable Aluminum tanks with inspection plate then any problems you can just remove tank and what you have to watch with Aluminum tanks is they sweat Moisture but so do other Material tanks ..Qualified Master 5 driven many different boats all round the world for past 40yrs ..Commercial Hull yep but a Live aboard nope removable tanks ... Have dealt with leakage and fumes ,Hull welds Cracking, Sloshing of diesel in the hull ..

[@Morrisfactor]

Gosh, I hate to say this, but 12 years of fishing in Alaska and three decades of boat building makes me believe that integral tanks are a bad idea on most any boat - and especially the light aluminum plating used on multihulls which can flex and crack welds. I'd cut out the entire lids on your current tanks to enlarge the openings, get some manufactured polypropylene diesel fuel tanks that come close to fitting the space, and install them - no seams to leak nor aluminum to corrode! Yes, you will lose some fuel capacity, but it is worth it to not have weeping diesel sloshing about. I have a bad feeling that otherwise you will be fighting leaks for years....

[@waltervanderboor]

Years of boating in cold Northern Europe.. that’s roughly what I would. Separate, removable stainless steel tanks for diesel and “plastic” food grade water tanks.

[@douglassmith2055]

As a machinist and experienced fabricator, I completely agree with this post. Trying to use the hull skin as a fuel tank opens the door to a spaghetti of problems. A poly tank could have been shaped to the space and use bolt in strut supports in place of the welded bracing.

[@JohannSwart_JWS]

I was typing exactly this problem, when I saw this comment. 100% agree. This is going to bite you in the ass big time later. Not to wish anything bad on you. But its a huge mistake. Also, I see no baffles to prevent shloshing.

[@jsjs6751]

I agree. At some point you guys could end up with salt water in the fuel tanks, and you wouldn't even know...

[@weinerdog137]

Seen it many times, surprised it's not common knowledge. Maybe your builder hasn't seen it yet. Might take years to show up, but it will.

[@BillSmith-q5z]

Hi Brian! We met at the Annapolis boat show. One word of advice…invest in a torque wrench and use it on EVERYTHING. Although not visible to the eye, NOT using one creates irregular stresses on the aluminum (especially flange plates and such…i.e. your fuel tanks!) Using a torque wrench will also help to keep fasteners from loosening and/or failing prematurely.

[@flyingcheff]

Both of you look like your skin is loving a bit less sun. You look rosy and radiant. But more importantly, you seem happy and relaxed into this time of the build. Awesome!

[@carjacklane3930]

As a aussie, the cost of living is mad, i cant imagine building a boat here, but thankyou for using our beautiful country & skilled companies to build your forever dream boat. Loving the content.

[@daltonm6764]

After 10+ years of following you. I feel so fortunate to have watched from almost the beginning. Episodes 40-200 will always set the vibe for me when I need something comforting playing in the background. I'll forever watch those episodes on repeat. ❤

[@dionysiaex5538]

As a multi-year subscriber who always loved the tech videos the most, I am obviously loving all these boat-building vids. You guys are so inspiring to even attempt what you are doing. Of course there will be problems and mistakes along the way. But your determination and commitment will get you over the line.

[@Jacob-W-5570]

I work on cargo ships, and where we have flush manholes/hatches they don't use bolts. In the deck /tank top there are holes drilled, and then on the under side there are acorn nuts welded all around. making a closed steel (or any metal) surface. Then studs are screwed in from the top. The lid is dropped over and tightenned by nuts. The gasket only has to seal between lid and tanktop, no need to worry about the studs.

[@rodhogg8858]

I just finished building two 750 litre aluminum fuel tanks for a local fisherman in the Newfoundland fishing village where I live. These were not built-in tanks like yours but separate removable tanks. These tanks were a copy of the steel tanks that had corroded and were leaking. They had the same flange type access hatch that you described. When leak testing the tanks I was not able to get a seal where the flange welded to the tank so I abandoned the flange idea and went with a cover that actually went on the inside of the tank. I welded aluminum bolts to the cover, installed a nitrile rubber gasket onto the bolts (3/8” bolts on 2” spacing) and inserted the bolts through the pre-drilled holes in the tank from the inside of the tank. The aluminum bolts avoided any galvanic corrosion and are strong enough to get good clamping on the 1/8” thick nitrile gasket. This provided a good seal. My access panel was in the side of the tank so it was submerged in diesel fuel all the time. It had to be absolutely leak tight. The gasket has to surround the bolts. The gasket was cut from one sheet of nitrile and was about 2” wide all around the opening with the line of bolts in the middle of the 2” width. No need to seal the threads on the bolts with this arrangement.

[@heinrichwesson]

Congratulations, the progress you made in 1 year is insane!!! Thanks for the great content, been following for years.

[@robertlee8042]

I’ve been riding bikes for 60 years. Adventure, bikes, or dirt bikes. I cannot believe that you managed or even attempted to ride dirt bikes in those conditions. More power to you. I don’t know too many people who could do that who don’t ride.

[@jeffdibb9052]

Don’t give up Brian you’re too good for that.

[@GamePlay-zb2qy]

I really enjoy your KZbin channel. An idea… You can inset the larger hatch similar to the small hatch, with no through holes. You would need to weld in a frame inside the tank creating a shelf for the large hatch to set in place. Make the frame thickness greater than the threaded bolts. No through holes needed that would cause any leaks. I would always prioritize safety when dealing with fuel tanks. The last issue you want is fuel leaking over time when seals begin to age. Diesel fuel and fumes will persist if it leaks over time.

[@WrittenbytheOne]

🎉 you guys are radiating joy, the type of joy that comes through a lot of hard work and devotion and big rewards. So excited for you both, and of course little nugget. I have to say you’re both looking really well, both beautiful inside and out. Always here for your videos, and journey - it’s always filled with love. Love from the UK ❤

[@svdelos]

Aww thanks so much for the kind words, we really appreciate it 🥰 Sending lots of love right back at ya!

[@williamhamill813]

We use stainless fasteners with shouldered nylon washers and oversized drill holes. Acorn nuts are a nice touch when sealing tanks.

[@jeffmorton9220]

The military has used fuel bladders for decades with success. Civil aircraft use bladders between wing ribs. Bladders don’t last forever, but can be replaced easily enough. Maybe you could give bladders some thought.

[@Aerostar509]

I would think that the ribs in the tank rules out using a bladder. If it were flat then that would work.

[@robertduncan4612]

I posted a comment recently and was talking with my brother who has some sailing experience and is a retired senior corporate pilot. We both keep up with your channel and receive a lot of vicarious enjoyment following your adventures. We spoke about the issues you are encountering with your fuel storage. My brother expressed his concern that the sloshing fuel in unbaffled fuel tanks can generate a lot of noise but each wave encountered can also significantly affect the lateral fuel weight distribution. We ask that you speak with a naval engineer and get their professional opinion.

[@chuckarrand4281]

Can’t wait til it’s in the water!!! Looking amazing.

[@joshua7564-s4m]

Happy 2025 all, it's amazing seeing little Sierra growing up rapidly too. Been watching you guys since well before she became part of the family :D

[@SteveP-vm1uc]

Lots of great comments here. I love that so many here have worked in so many areas of what Delos is doing and can bring many issues and corrections and suggestions to light.... The Delos family absolutely KICKS AZZZZZZ... Oh, and,,, BO BILLS!!!

[@Tutterzoid]

Sometime being Blissfully unaware of what lies ahead in a project is a good thing, as sometimes knowing all the problems ahead can make us give up before even starting :)

[@codystout5353]

Really can't wait to see you guys back on the water

[@aktxyz]

I have similar size aluminum tanks lids on my 1988 Dutch build Jongert motor vessel (8 tanks, 4500gal). They are attached using the angle stock method similar to what you showed in the original designs, this allows 48 m8 bolts/nuts to attach each lid. Just guessing, but it looks like you have about half the bolt "density" and that may make it more difficult to get a good seal. Also, each of our tanks has a single lid. Getting 3 big lids all sealed, and the little sub-lid you have is going to take a lot of patience ! Not to mention that as this stage part of the initial pressure test process is also to test the welds. We have 4mm nitrile gaskets and just had some new ones made up new last year. We took the tank lids to a shop and they scanned the lids and laser cut the rubber, just amazing. I had bought some hole punch thing but that was a mess. I am curious what is holding the bolts/studs underneath inside the tanks? to keep them from falling out and spinning. Also I would love to know what that fitting is that has all the connections for fill, depth, etc. I would like to add a smaller access on top of my big lids, 48 bolts with the underside being blind takes a while to get off and even longer to get on. I bought an electric battery ratchet just for this. One final thing, I have found that integral aluminum tanks sweat A LOT. We have a special condensation manifold that sucks fuel from a point lower than the main fuel manifold. I did not get the point at first but I sure do now. About every 2 weeks in the summer I can suck out over a liter of water using this manifold. The main Racors would catch it, but the bowls are not the easiest to reach, so the condensation manifold is a big help. Even better would be a filterless water separator in the fuel transfer plumbing, a project I hope to do one day. Bottom line, you will probably get quite a bit more condensation with your integral tanks than you are used to.

[@MizzAugust7]

Sierra looks much different & older, like almost 6! I have Missed seeing her. ~ In the early 1970s we used Liquid Neoprene to coat the roof of Domes we built, it did great for many years, But - it never rained Gasoline! Thanks, may your build continue safely w/ fewer faux pas Thank you !

[@rigobertorivera7949]

Nitrile is the right choice. Check for hardness, "duro 80" is recomended. For corner joints use a dovetail cut.

[@miguelfrancism]

Thanks!

[@ncedwards82]

Thanks for bringing us along on the adventure!

[@roberthandlon1877]

Not an expert but after reading the comments I conquer with the bladder within the hull theory. Seems like less headache down the road. Glad your holiday was good, really enjoying the build series. Thanks

[@figitt88]

Im an aircraft mech as well and agree with some of the comments below with B1/2 sealant. I would also consider sealing the inside of the compartment with a fuel safe sealant. The expansion and contraction of the aluminum will eventually cause a crack or weld crack and leak. Such you could wait till that happens i guess.... but something to think about.

[@gradycooper475]

As a 30+ year Marine Mechanic I can feel your pain with having to rethink/redo the tank lids, but at least you do not have an angry customer breathing down your neck. Keep on plugging along - you will succeed.

[@svdelos]

This is very true, glad its only us we have to answer to when we mess up 😂 Thanks for watching and coming along with us in 2025 🥳

[@gradycooper475]

@@svdelos I love you guys and have been watching since very near the beginning. My favorite KZbinrs!!

[@berndheiden7630]

Watching this episode I asked myself if you are building the first aluminum cat in the world? All the problems with electric, fuel tanks and corrosion should have been solved long ago. And if they have not been solved you are taking a big risk with this build.

[@happyhorizons9247]

@@berndheiden7630 Paying attention will possibly help ya... i'm doubting that thought process of mine though:/

[@chrisparola3949]

So I’ve been building industrial beverage plant Reverse osmosis systems for close to 20 years. We quit using gaskets on tank lids we use Gortex rope seal it never leaks. Another thing we have learned is to weld a brace across the lids stops flex which is causing the leaks

[@rolandhiltz5197]

Persistence pays off in the long run ,Don’t give up.

[@chopper3lw]

There's absolutely no way that the Loctite will prevent galvanic action between the stainless screws and the aluminum. Want proof? Just use a multimeter on the resistance setting and test between the top of a screw and the hull.

[@jimcalver-oj4xf]

Likely needs to do a microvolt assesment with presence of seawater. No doubt there will be galvanic action.

[@flamethrower5794]

Loctite 567 is good stuff, never heard of it being used to stop corrosion. It's a pipe sealer, not an insulator. Looks like a good time to try some aerospace aluminium bolts and nuts. Used them, they are surprisingly strong.

[@russbetts1467]

Hi Brian, Kazza and Sierra. Thanks for this update. Happy New Year to you and the gang at Stradbroke Yachts. Here's looking forward to more craziness in 2025. Cheers, Russ. UK

[@robhowen]

You will have an amazing vessel because you never compromise on quality.

[@davidgallefoss1254]

Sir, I went through this pain on my Ovni. The whole dance. I found this 5 things to work; 1. 6mm Rubber sheet 2. Countersunk Steel bolts. 3 Tef-gel. 4. Pilot hole Countersink drill. 5. Thread drill Process: A 6mm rubber sheet to cut out a gasket. You could make each manhole cover -1 cm smaller to fully utilize the rubber sheet. Wants to be as slim as possible to compress. less than 0,6- 1 cm wide. Then drill threads into the alu on the hull side. Do one bolt at the time. Drill Holes into the rubber gasket as you go. Use tef-gel on bolts. The compression will make the bolts leak proof. And PS: The actual pressure in the tank is not that high from diesel alone, so it may be sufficient for its purpose. It is important to have enough walls in the tank to stop the diesel from sloshing.

[@davidgallefoss1254]

Forgot to mention, that you would probably be eternally grateful if you make steel tanks, or custom plastic tanks. Aluminum tanks are a terrible idea for longivety and cleaning.

[@grahambeyer6254]

900K SUBS well done!!! 1 million here we come!!!

[@MonkPetite]

A tip for the next time Tank seals in aircraft are very small.. wings are most flexible and subjective to temperature changes of 90 C from freezing to desert heat. The seal is O type or H type of a mix of it. But the seal must be compressible. The tank panel rest on the tank material / flange squeezing the seal in between or maybe 2 seals in between. The old school way of preventing corrosion was / is hobilon and beeswax. The edges are sealed with a sikaflex type or Tycol 1400 type If the nut side is in the tank install dome nuts to be glued to the hole Torque all bolds with same and not too tightly. There is no need to compress and deform the metal. Be advised a tank panel must be able to move / grow and flex.

[@weiniesail]

Agreed. This boat is going to have so many problems, it will never leave the dock.

[@garganega]

You hit the nail on the head. Flexibility and temperature swings. Why automotive fuel tanks are injection molded with one hole for pump/sender/evap and one for filling.

[@drewb7211]

@@weiniesail I sure hope not, but them removing the flange connection on their FUEL tank UNDER THEIR BED and relying on thread sealant had me really worried really fast. It's an even worse decision than the flat-stock conductor choice! The obvious solution was change the tank top shape to lower it, maybe lose a few gallons of capacity, and keep the much safer flange. Sometimes using the tried and true methods is the correct choice when your family's lives are at risk. I'd have either fabbed or installed separate tanks down in that space anyway.

[@saggioricercatore5279]

Love following the build - thanks for sharing challenge as well as wins. We did miss our weekly “woohoo” at the end of the episode.

[@Daniel1962007]

Such a beautiful and definitely memorable journey so far…We so appreciate you all…Blessings from this 🙏🏼🇨🇦’ian…

[@johncampbell9216]

5 minutes in and I see the problem immediately: You're using nylon washers but no steel washer to take the pressure of the nut. The nylon is distorting and you're losing the pressure from the nut as a result. Use a nylon washer on the bottom and a steel washer on the top, problem solved. A better solution is aluminum bolts, carefuly tightened, or plated stainless bolts. Also, use Nyloc or anti-vibration nuts. Because when you vibrate your nuts, things get loose (that's what she said)!! ;D

[@sbdreamin]

I don’t think he reads comments, otherwise a lot of stuff would be resolved. Plus we are like 2 months behind his build.

[@mikehoy4238]

@@sbdreaminYou are right. We’re only here to cheer them on and provide funding.

[@jonathanalea]

@@mikehoy42381% cheer, 99% funding

[@TheCrazySquirell]

Nordlock washers are the one to use, nothing else is close.

[@svdelos]

We need to post hangups like these in real time for advice, our audience is so full of knowledge and expertise this would have saved us a lottttt of struggles although we do eventually get it all sorted with a set up pretty dang close to what you suggested 😂 But we're definitely learning a lot through all the mistakes! and 💯 on the vibrating nuts 😂😂😂

[@Aspie44]

I was surprized at the introduction with the relief I felt when I heard the old Delos theme song! Now, as to those lids, I'm thinking that this is one of those times where the bolt-tightening order is critical. I'd've welded a perpendicular "flange" stiffener just inside the floor edge to the lid, and possibly the bottom of the floor, which would also resist flexing as people walked around.

[@Sirilfors]

Hi guys! I would go with Zink. Remember what happened with Maggie with its hull. Better to go with bigger difference in potential between the two metals to ensure the function. 😊

[@tjmac8235]

Hello Delos crew! My wife Ellen and I just returned from a week in the Gold Coast (Brisbane) and the weather was perfect! I thought about a visit to see you guys but we were too busy with other activities walking in the rainforests of Tamborine and Springbrook. BTW we spent NYE in Sydney and it was spectacular! We are back in Charleston SC now and looking forward to watching your progress.

[@troybabs]

Kirt: "Better hope your boat doesn't take on this much water"... Best quote of this episode. Nice chuckle.

[@martinbinney]

Love that you guys show the rough and the smooth.

[@kenburkimsher1356]

Although my wife and I have decided to sell our sailboat and start a new chapter, Delos remains a source of inspiration and entertainment.

[@nearlynativenursery8638]

Yes indeed trial and error is the best tried and true way to know for sure what will work. It is always important to due research as you did to get more details on what ever a salesperson says. When doing that it often exposes false info about said products. Superb follow through and Great work Brian. The boat is coming along super fine. Jim Rodgers

[@trondwell13]

Set the lid as before and add voids in the lid to accept the pump etc

[@nobigting]

This comment needs more likes. Use the flange/riser as originally designed and dish the lid in places where fittings need to go. Also add more anti-slosh dividers inside those tanks, the noise will make you crazy! umm…crazier! Best of luck Delos crew, amazing project!

[@faircompetition1203]

Have you taken into consideration the hydraulic pressures of the fuel sloshing in the tank ? I suspect it could be surprisingly high with that large a tank . I know in plumbing water hammer can blow fittings right off

[@ronnyhaldorsen2740]

As long as the aluminium is this thin it will be a pain to get this leak free. The plates will buckle between the bolts so you will not get even compression on the gasket. Beef it up and you will get even load distribution in the flange thus a better sealing from the gasket.

[@dmarykavanagh]

Thank you for the update. Great place to be for the Holidays. Great show!!!

[@davidjessee7701]

As I sit in my den in Kentucky watching the snow fall, I can only imagine a bike ride In the summertime but I’m not into the mud like I use to be when I was a kid

[@thorconley894]

Have you considered ordering custom fuel bladders from fuel safe or maybe atl? I think it would be an excellent solution to your problem

[@mikezurlo8514]

Nitrile Rubber (Buna-N) Properties: Nitrile rubber, also known as Buna-N, is the most commonly recommended material for gasoline applications due to its excellent resistance to fuels, oils, and solvents. It maintains its sealing capabilities even in harsh environments and does not swell when exposed to hydrocarbons15. Temperature Range: Typically effective in temperatures from -30°F to 200°F (-34°C to 93°C)5. Applications: Widely used in automotive and aerospace industries, making it a reliable choice for gasoline tank seals3

[@MrDannyr2000]

wow come so far in only one year , can't wait to see how she looks this time next year

[@leepeacock3099]

Why not weld studs on top of tank then gasjet/seal the nuts on top? Tapping those holes is gonna create a VERY Specific bolt length which might be a pita to find whn you're out and about. Tack weld bolts on top of tank, put cover down and bolt it down.

[@chadd9637]

But the tank is aluminum.......Do they make aluminum studs? I guess I have never looked.

[@leepeacock3099]

They do. Aluminum all thread cut to size. Usually use stainless (316 or higher) on the nuts.

[@quillibrium-dk6jz]

I think I would be looking at a liquid gasket solution. Will require a trip to the store in the event of having to do a tank inspection, but how often do you need to do that? Weld the large lid, liquid gasket the smaller hatch. Also 3 psi, seems massive, that's 1,700lbs on the large hatch. You'll be hunting down leaks that won't be there in practice because of the deformation. The lid in the original design would perform much better under pressure.

[@Div3r]

Coupled with nylon bolts he is lucky the lid didn’t blow off and launch him into the stratosphere.

[@adrenalineissues]

Big tip - pickup suction off the lowest point with a T. Suck everything out and deal with it in the polishers / filters. Raised pickups promote diesel bug growth and corrosion. Second tip - very few hoses are rated for diesel immersion. Read up really well if using flex hose in a tank. Third tip. Get ultra low permeable hose, or it will always stink of diesel. Standards vary by country. Put the Suction and Return at different locations to promote circulation for polishing.

[@cbeh4670]

Lots of small planes have rubber bladders that you might be able to buy and cut up or order in a way. Planes also have special sealant for wet wings that don’t have rubber bladders. Anything aviation is expensive but it definitely works.

[@faircompetition1203]

Any thoughts on what you will do on the water tanks to make sure the aggressive RO water does not absorb aluminum ? Drinking aluminum could be unhealthy according to a few studies . Are you going to paint the inside of the tank with some kind of cistern epoxy ?

[@chrishusak7100]

We need more boat build! 😛 Can’t get enough. Also it’s going to be so cool to see the maiden voyage!!

[@patwhite640]

What about baffles? They should be there for the restriction of movement but more importantly for noise reduction. Same with the water tanks. A half full tank can be extremely loud in a pitch and roll sea. I'll never have another boat with out the correct baffling in its tanks. Just a thought.

[@arczealdesigns9512]

Hey Brian, Products like Permatex Aviation Form-A-Gasket No. 3, Seal All, or specific thread sealants for fuel applications are recommended for ensuring a good seal. However, if your bolts are spaced too far apart, it could cause a micro-gap and lead to leaks. Make sure the rubber gasket goes around the bolts unbroken; use a hole punch, the same as those for leather which works great. Also for extra leak protection there are self sealing nuts and bolts that have a o-ring built into them. I posted a link but I think it got deleted.

[@grizzle251]

Excellent Episode, I have been following you since almost the beginning and you never cease to amaze me with your courage, skill and determination with everything you do in life, the only limits you impoze on yourselves are ones that would put you (your family) in danger. Carry on and thank you for sharing your advntures.

[@rickstevens1479]

Will you be using baffling in the tanks .. by stopping fuel from sloshing around it should help to cut down on leaking ...

[@glennhertel1165]

I can't wait to see the boat finished.

[@DrBrian0450]

I have built several aluminum boats with integral tanks and they are a PITA! Even when you get them to pass the air test, when you fill them with diesel you find more leaks. Luckily, there is a USCG approved fix for leaks in the weld seams that is as simple as using a center punch and wacking the weld near the leak until it stops. Good luck!

[@peterbryttne4755]

Just some thoughts on the tanks. On my Derector 50 (alu ketch) the tanks were all welded with small inspection holes that were quite easy to seal and on top of that we had a daytank which was a great way to avoid mishaps with the diesel. We never had any problems with leakage. If I did it again I would probably go for plastic tanks - either standards sizes or bespoke ones that could be lifted out if we ever needed to inspect/repair the outer hull. Good luck from me in a very cold Sweden, and all the best for 2025.

[@LabRatJason]

Bryan, the best way to seal up those access hatches would be to weld the bolts to the flange. Then no air can get through the threads. If that is a no-go, then consider buying bolts with larger heads and cutting gaskets that fit around the bolts. Run them up from inside the tank so the gasket is sealing between the flange and the bolt head from the inside. Then drop your cover plate down over the bolts and bolt it down.

[@joemehere1151]

Good to see you guys in this new year. Lessons cost. Either in effort, money or however, lessons cost. Happy, Prosperous and Healthy New Year 🥳🥰

[@pauleohl]

I can envision the nitrile rubber getting vulcanized to the hull and/or the tank lid over time and the lid getting bent if it has to come off. Same problem with the access hatch in the lid.

[@CurriedBat]

Glad you guys are doing well! Happy sailing!

[@jasonyoung1596]

Let go! I hope you get it done this year!

[@mariusgrobler4235]

You guys rock, and congrats on your determination! It will all pay off! Happy 2025! 🎉

[@anabrochado7272]

Thanks for your mistakes, and for sharing them with us as you learn along. So much valuable knowledge 😊

[@virtualmojo]

Happy New Year. Can’t wait to see this beast on the water.

[@tomtribby2309]

Thank you for letting us build a boat with you.

[@aktxyz]

HELICOIL ! I suggest looking into helicoil inserts for those threaded aluminum plates. US Coast Guard procurement for aluminum hulls requires any tapped aluminum to have helicoil (or similar) inserts. There is tons of info out there on these inserts and aluminum. Use a little tefgel when installing the inserts, and you will have a secure, corrosion protected, thread you can use over and over. Aluminum is too soft for many bolt/unbolt cycles.

[@Upi_inu]

Bryan on a two stroke over the handlebars has to be a Delos highlight. Good on you Bryan.

[@westie4ageturbo.749]

Riding at the beer is bloody Awsome!

[@imabeliever244]

I've also been following Matt and Jessica's glass cat build and think you guys made a great choice in going aluminum. All the priming, faring and sanding they are having to do would kill my enthusiasm for the build, but you guys (so far) are all about cutting, welding and grinding...which fits my more barbaric build style. lol So, did the nitrile seal leak???

[@jasonweb9720]

Look to the aviation side. Fuel tanks in jets are built like that and we use a black sealer to seal the panels and I almost never had a leak. Easy to clean sealer with a scotch bright pad on a grinder.

[@Paul-kz3by]

I miss you guys happy new year to all of you can't wait to see your boat on the water

[@brucerhodes8197]

During the holiday break instead of missing out on my Friday addiction for some SV Delos, I just binged on the episodes during the Two Titty Yacht Club era.... Just like TV shows, that take breaks mid season, they show reruns, so I applied the same system and never missed out on feeding that Delos addiction.. Super excited to see what the 2025 journey is like!

[@crisdafar]

Brian, as others have mentioned the common way to do this is to use the outward turned upstand so that the bolts don't penetrate the tank. The blind holes are also a good idea when space is limited. But why could the filler tube and breather not be made of ali tube as well and been welded into any other part of the tank? The filler and breather don't have to be in the middle at the top... And as for the gasket, never use rubber of any sort for gasketing on aluminum. It has compounds in it that will corrode the ali very quickly. You should be using fuel safe cork gasket. Standard on all vessels we build here in West Aus

[@ai4313]

Dome Head Aluminum Bolts with sealant through the tank, groove for O-Ring milled into the cover inside the bolt area, Nitrile Rubber Cord as your gasket which you can cut to length and superglue together. Done!

[@imdawolfman2698]

Ya, superglue the SH!T out of it! Superglue? You're kidding, right ? You know superglue is so brittle it tea's tears holes in denbim? Just because your cousin supergliued one of his false teeth back in doesn't mean it would work in peak performance longevity prioritized aluminum sealing catamaran. . Mayebe he needs a bigger hammer, a left handed screw driver and a lot more glue.

[@ejs6010]

Can't wait to see how the hatches turn out. Happy New Year!

[@JayDAnderson]

Consider ceramic bolts and nuts. They are fairly galvanicallt neutral and very high tensil strenth. Shear strength not so good though perfect for panels.

[@derekgodfrey5]

I would look at using viton or nitrile O ring for the seal , you can buy it on a roll (different diameters)and cut to size , then superglue the ends to make it one piece and a few spots of superglue to hold it in place on the tank before you put the top down . A spare roll wouldn't take up much space in your "spares" compartment . Clark Rubber should've suggested it .

[@michaelwhitewolf10]

Nothing ever goes as planned you just keep going untill you figure it out!😊

[@svdelos]

Exactly! Our motto with this whole build 💪

[@louwriebadenhorst5676]

If that rubber doesn't work, perhaps you guys should consider going to a small airport and having a look at how they do tank panels on aircraft wings. Perhaps you should see if you can get your hands on aircraft tank sealant, or if you know someone with a CNC machine, perhaps you can CNC out a grove on those lids for an O-ring and buy some o-ring material and make your own o-ring that you put in the grove. Also, instead of making a square panel, rather make it a round panel, this will improve sealing as corners are part of your problem (after looking at the video again I see it is rounded off)....

[@bmitch3020]

Adding to the list of arm chair suggestions, I wonder if the original flange could have been used with a nested/inverted flange in the lid to mount components below the top of the lid. It would be a pain to service those components, removing the entire lid since the nested flange would be inside the tank. But you would always be confident in only needing to seal a single gap and none of the bolt holes.

[@skyfarley88]

Neaprim bladerss with volcanization seals. Used for waste ponds.

[@tadvaughn833]

Assuming the lids are around 18”x30” and 3 psi results in over 1600 lbs of force trying to distort and blow the lid off. That’s likely a lot more force than the fuel could ever exert on the lid. I suggest a lower test pressure.

[@stargazer7644]

The first rule for making airtight tanks is not to drill holes in them. No matter what kind of gasket you put on the top, they're going to leak through the threads of the 30 holes you put in the tank. Your only hope is to put a rubber washer under the head of each bolt inside the tank. That will stop air getting to the threads and going out. A better solution is to do what you did for the smaller panel. Plug all the holes, put a thicker bar around the edge of the tank and tap blind holes for the lid to attach to with a gasket. Or weld studs on the top of the structure with no penetrations into the tank.

[@captainjimolchs]

But if the holes are surrounded by a gasket?

[@stargazer7644]

​@@captainjimolchs If you only put a gasket on the outside (as he is doing) then there is a path for air to flow from inside the tank, around the head of the bolt, up though the threads and out around the nut which is exactly what he's seeing. The outside gasket doesn't do anything stop this as there is nothing forcing the gasket to seal around the bolt. You also need a gasket under the head of the bolt inside the tank to stop that.

[@happyhorizons9247]

@@stargazer7644 FACTS!!

[@Scott64T]

It seems like you are trying to re-invent the wheel with the tank covers. The smaller, removable openings for the fill/vent makes a lot of sense, but why not just go with what already works? Use Black/automotive RTV for the perimeter of the large covers on the fuel tanks and around the bolts and clear/food-safe silicone for the water tanks. Also, why use stainless bolts and worry about the corrosion when you could use aluminum bolts that give more strength than than the plastic bolts and are definitely strong enough for that application?

[@MrBertHeylen]

Hi there, I'm just watching the latest episode and I'm probably late with my comments. But if you can, put bladders in the tanks. In the long run it will save a lot of trouble. In the UK there are companies like ATL and Premier who can provide a perfect custom solution.