Kit E23: Fuel Polishing System Design for our Catamaran Build

[@dc1544]

I would suggest a 5 gallon running tank where polished fuel is stored. Its not much added cost. That is how they complete the system you have. Plus it keeps diesel pressure up and eliminates air in lines I would also have a tube connecting your 2 main tanks so if one gets over full it auto fills the other one. I have seen a switch bumped and fuel lost because of not having this. This also allows you to run your engines from day tank while polishing both tanks after a fill up. Hope this helps.

[@SailingSVLynx]

That sounds like an excellent idea, we will consider adding that to our system.

[@tomgibson9291]

I was going to say the exact same thing

[@rustie4242]

G’day from Australia, I think you guys may well be the most organised private/owner building team around … It is definitely a smart move buying every thing you can, as prices escalate over time. I am amazed how much denatured alcohol (methylated spirits, used for cleaning uncured epoxy off tools), paper towel, and sand paper I have used on our boat, and rolls of clear plastic, round brush vacuum heads,(at least 20), cheap paint brushes, (hundreds) as you only use them once and then chuck em. It all adds up, but in the end you will have a true blue water cat that will take you anywhere, and it will be worth it. Cheers Rustie.

[@SailingSVLynx]

You are, no doubt, correct, Rustie. Lots of consumables will be used while building this boat!

[@carlf8291]

Can't wait to see the build start looking forward to it.

[@SailingSVLynx]

Not long to wait now! Our Cargo ship with the kit is just passing Hawaii. It will be here in about 7 days. :)

[@jackdbur]

This is why commercial marine engines have header/day tanks between the engines and bunker tanks.

[@SailingSVLynx]

We are looking into the possibility of a header/day tank. It could also work as a fuel test tank when we are getting new fuel, especially from a questionable source.

[@SailingSVLynx]

UPDATE: We did further reseach into the magnetic diesel bug killers and independant testing showed no signs that it works. So, we are eliminating that from our fuel polishing system.

[@morgananderson9647]

I just wanted to send positive vibes and encouragement to you. I think your doing an amazing job developing everything. I continue to look forward to your videos as they come out weekly! Best regards, Mo-

[@SailingSVLynx]

Morgan. We really appreciate the support! This is a huge and, somewhat, scary size project we're taking on, and all the positive vibes we can gather help! The kit is due to arrive in port in just seven days now... yikes!

[@leonply]

An excellent design and I'm certain that you'll be altering and upgrading as the build progresses. A friend built a large cat a few years ago and decided upon an almost Rube Goldberg approach to the fuel filtration system, as he plans to cruise the IndoPacific almost exclusively (the diesel in the Philippines and the Indonesia Archipelago is notorious for dirty fuel). ALL new fuel is pumped into spotlessly clean 100 liter cans. From here, the diesel is passed through four (fairly) inexpensive pre-filters, before the De-Bug Filter. Then comes the magic/tragic, depending on the level of absurd humor employed. Three large mouth funnels (his wife is still upset about losing her canning funnels!), fitted with paper coffee filters, then an ultraviolet sterilizer (my salt water aquarium system was getting an upgrade, so there that went!). Then another three canning funnels/paper filters, into a separator to eliminate water, then a second De-Bug Filter. From there, the fuel passes through a 10-micron filter and a 5-micron filter. Then to the tanks. In the tanks, which he built (just as you are doing), he placed two small impellers in the bottom of each tank, which cycle on and off, keeping any water in the tank from allowing much bacteria growth. This belt-and-suspender method takes about 7 hours to refuel, but he has never had any problems with blockage and clogged lines. All of this was fairly inexpensive, relatively speaking, and the tanks are drained, cleaned and re-filled every 12 months, just to be on the safe side. I am hoping that you'll be coming up with something just as efficient but far less involved, as you've proven so many times that your engineering skills are incredible. Thank you for sharing!

[@SailingSVLynx]

That does sound like a Rube Goldberg system!

[@laurapitre5797]

SV Catalpa has a video that shows how they made a Baja style filter out of 6" pvc pipe that uses aquarium filter bags that are available in different micron ratings. We built one and it is incredibly faster and better filtering than our old Baja filter. This filter will filter fuel as fast as a fuel station pump can supply it. We used a 10 micron filter bag and it has filtered several hundred gallons of Indonesian fuel and is still flowing plenty fast. We made ours 12 inches tall and used the 6"×18" filter bag and just pushed the filter down till it all fits and it works perfectly.

[@SailingSVLynx]

I'll have to watch that video!

[@johngroom7665]

Day tanks are the way to go , Also fuel polishing is done with a centrifuge then 10 micron Racor then 2 micron Racor and final engine mounted filter.

[@SailingSVLynx]

Hey John, thanks for posting! We understand that you think that is how fuel polishing is done, and that's great, but there are many ways to build these systems, just search on DIY fuel polishing for marine use. Everyone seems to think they know how to build a better mouse trap. As for our planned system, our fuel polishing system will send the fuel back to the tanks after it has been polished, not straight to the engine. We plan to use a different path (and some different filters) when we send fuel to our engine and the built in 2 micron filter that is attached. We did not go over that filter because it is part of the engine, not the system we are building. The system we showed in our video is only a preliminary concept, which has already been improved. We will show the final system when we construct it in another video. We hope that some of the comments we are getting in here help us improve that system, including yours. And though we appreciate your input we will weigh all the many ways that people have built their polishing systems as we design our own.

[@johngroom7665]

Yep It’s a great plan , and plans are just that , I always start with a denoting letter of the alphabet but consequently use numbers as well . however you will notice when you start your build the tanks are not that deep once you put the lids on and they are fairly long so you will not get that fuel at the other end of the tank to pass through your “Polisher” as you’d planed because of internal bulkheads and a flat ish bottom . We just pull the lids of the tanks every couple of years to clean the tanks properly . Make sure when you build the tanks in , you have access to get in and clean them out scrubbing brush and vacuum will do it , we run the fuel down low in the tanks , pump what’s left across to the other side through the Racors to clean the fuel , take the lids off and get in and clean , it’s not a pretty job . I understand the design I have an older Schionning , but we didn’t build it . You will understand later when you go sailing out through a bar crossing and you will get some green water up over the bows , the dorade boxes will get some serious water on occasions , don’t put them in until you try it . We have had some heavy water all the way up onto the forward screens punching out through the bar crossing some days .

[@SailingSVLynx]

Hey John, thanks for the post and suggestions! We were already planning on putting in enough inspection ports to reach all parts of the fuel tanks, so we will be good to go when it comes time to do any tank cleaning. But on to the fuel tank shape. Ours will be differently placed and shaped than yours, even though you have a Schionning. For one thing, we already know ours are square. And one great thing about building the boat is that we get to make things the way we want. I've always wondered why builders make fuel tanks flat on the bottom. I did up a design awhile back for ours that slopes the bottom to a central point where I added a sump. There is a fuel pickup rod that goes down into the bottom of the sump, plus a second fuel pickup that is just higher than the top of that sump. The higher one is used the majority of the time, so that it doesn't pick up the water and debris that collect in the sump. However, by switching a valve, we can pull fuel from the lowest point in the sump when we want to polish the fuel so that we clean out all that muck. OK, so that's my plan, anyone want to tell me why it is a bad idea? :) Now, onto the Dorade boxes. We will most certainly test the boat before adding them. However, I'm not sure why anyone is concerned about them if I do decide to add these to the boat. I can make them incredibly strong (carbon fiber or stainless steel, or even titanium; I can 3D print in any of those). I can design the low profile opening at the front so that it may be sealed off completely if we are in bad weather or going across a bar, and they can sealed be sealed on the inside as well so no water may enter. They stick up less than a cleat or stanchions, yet no one seems concerned that those will be torn off the boat in a green water wave situation. So, to summarize, they can be sealed so that they don't let water in and can't be torn off, they are very strong and very low profile, so I'm not sure why anyone thinks these are a bad idea. Again, comments are welcome.

[@montanadan2524]

My humble opinion is if you are purchasing fuel from a respectable source, there is no need for such equipment. For new construction, a simple access plug to the deepest part of the tank should be sufficiant. I use a water reacting paste on a long rod to test for tank build up, we do keep our tanks full during off season storage. I do use additive in new fuel because it's so easy. Storage of the product and the other handful of toxic substances required for a cruising sailboat, is manageable. We also run short of most expectations in that we only run one Racor and a small final engine mounted filter. I have never seen water in the bowl and the small amount of solids I removed (first cleaning in 30 years?) appear to be non organic so Im calling it refinery dust. Not saying this is the answer for everybody but it sure works for us.

[@SailingSVLynx]

Sadly, we have no way of knowing if we will be purchasing fuel from a respectable source as we travel around the planet on a circumnavigation, often traveling through third world countries.

[@andrewbelanger8241]

Good afternoon. I did not see a pickup pump at the tanks to ensure that at max pitch and roll you are accounting for the pickup limits in the transfer and attached fuel pumps. There are good worksheets available online to help with that calculation and I am sure your engine manufacturer and transfer pump specs give you clear specifications on pickup capacities. Looks like some pressure gauges, overpressure reliefs, and overflow lines with vacuum breakers for fuel temperature changes would be useful as well.

[@SailingSVLynx]

Hey Andrew. We weren't really going over the system at the tanks, other than that we are adding a couple of electric valves . There is a whole design for the building of the fuel tanks, but this video was more about the fuel polishing end, and even that was only a preliminary design. We'll show more when we get to building both the tanks and the fuel polishing system later. :)

[@normanboyes4983]

If it is not too late to make comments on the fuel system and the polishing system. Based on my own seagoing experience. 1. Good fuel husbandry avoids many of the horror stories that abound. Fuel husbandry is tedious and has to be routinised. 2. There are all sorts of contaminants that effect diesel fuel MBC which you majored on here, basic dirt (from the supplier) water and one surprise - fuel derived dirt. Modern diesel is cracked further up the distillation column and essentially it is now an unstable product and during long term storage it will start attempting to revert to crude (black particles). Avoid refuelling from facilities who do not sell in volume. 3. I think you need to review you fuel system in a fairly significant way. If your design is hell bent on the forward fuel tanks which involves running fuel lines through the boat to the engine compartment, then it would be very worthwhile considering a ‘day tank’ much closer to the engine for supply/return to the engine. 4. On the polishing side of the equation, first ditch the MBC filter (snake oil product) and rename the system ‘polishing and transfer’. 5. On the husbandry side - tank design is fundamental to this to. If at all possible ensure you have the largest possible access ports in each baffles area of the tank. Fuel draw needs to be right in the bottom of the storage tanks (because you want the polishing system to draw out any water). For the day tank the supply to the engine should be above the bottom of tank. 6. Fuel Management - prior to refuelling (you should aim to be only refuelling one tank) transfer the fuel out of the tank that will be refuelled to the other storage tank. Then once refuelling is complete the tank should be embargoed until it has been polished for 24 hours. 7. Size the day tank using your usual estimating methods to provide for 24 hours running at say 70% power.😉 8. You are unlikely to suffer MBC if you keep on top of the fuel husbandry BUT if you ever do - the polishing system will not clean it up - only tank cleaning will do that( comment at 5 applies).

[@SailingSVLynx]

Hey, thanks for the detailed suggestion list, we appreciate you taking the time. Now, onto some of your points. :) 1) Yes. 2) We agree completely. 3) We were already considering a day tank, but still haven't decided on it yet, but are leaning that way. As for hell bent... we have no choice, to balance the boat, both diesel tanks must go forward. 4) We already ditched the MBC filter after doing more research, snake oil indeed. 5) We designed our own diesel tanks. You may see that in Episode 25, about midway in. They only require one access port to reach into all baffled compartments, plus other 'innovations'. 6) Good suggestion. 7) Agreed. 8) That's why we made it easy to clean out the tank, either from the sump, or just cleaned from the access port in extreme cases.

[@normanboyes4983]

@@SailingSVLynx Yes I indeed, I only found your channel a week ago and I am doing a near binge catch up. I have now seen the proposed design of your tank, if I may - if you have four baffles or four compartments in the tank - put four access ports in the top. Cleaning out a contaminated tank is a horrible task (I have done it a few times), the sheer fun is magnified if you do not have a universal joint on your elbow. Enjoying the series and your approach.👍

[@terryroth9707]

I'm curious, would you be able to use a uv light system to kill off the bugs? Like is done with a well water system. Admittedly diesel isn't as clear as water, but maybe close enough?

[@SailingSVLynx]

Unfortunately though UV light would help, it also degrades diesel fuel, or so we have read.

[@terryroth9707]

@@SailingSVLynx Interesting. Did not know that. Off to Google! 😀

[@rickcreel3657]

I'm so cheap that I wrap my Epoxie paint brushes with Cerran wrap then I leave them in the freezer overnight. The next day they are good to go. I don't recommend this but I have many gallons of used engine and transmission oil that I have saved up so I mix used oils with diesel 1to1 and put it in my fuel tank. I no longer have a problem with algae but I don't know why.

[@SailingSVLynx]

Interesting on the diesel.

[@bunyipdan]

I understand you showed a basic scematic of your fuel system not nessesarilly the design plan (so you probably already have this covered), however I would encourage you to centralise the location of your valve assemblies as much possible so that servicing, maintenance and potential trouble shooting is made more efficient. Also important to consider vertical location of your elements to avoid introducing air locks in the system. You will also find it helpful to fit fuel line pressure gauges to show when filters need changing. Either installing pressure gauges, mounted on the return side of the pump on the input side of a filter head to monitor the pressure of the fuel flow. When pressure on the input side of the filter head increases, it indicates increased back pressure (resistance to flow through the filter) = filter needs to be changed. Or vacuum gauges can be mounted on the output side of the filter and before the pump, this will show an increase in vacuum when the filter is restricting the flow of the fuel = filter needs to be changed.

[@SailingSVLynx]

Thanks, we will absolutely add those pressure gauges. The valve assembly and filters are all located where we showed them, in an easy to access location inside that large compartment that we can enter to do maintenance. I'm not sure what else you mean by centrally located. We don't want them in any of the living areas of the boat. As for vertical location, they are mounted to a wall, vertically. Was there something else in the arrangement that you are talking about to avoid air locks in the system?

[@bunyipdan]

@@SailingSVLynx just suggesting that valves be fitted next to filters or on a central manifold rather than at T junctions, remote tank returns and tank selection valves in one spot either at one of the tanks (this improves ease of maintenance) or in a separate central area (like you have indicated). Try and keep filter assemblies at same level to minimise the potential of creating air locks in your fuel system

[@SailingSVLynx]

@@bunyipdan Good advice. The Electronic T-Valves for switching fuel tanks and the fuel return are in a compartment near (between) the fuel tanks. Everything else is located in one accessible location in that compartment near the engine. We will make sure to keep the filters at the same level, as you suggested. :)

[@SpeedySailor]

@@bunyipdan Would heavy swells be enough to introduce fuel system air locks?

[@jimlofts5433]

your a very inventive and innovative couple so depending on price I could see you building a cheaper acme version UV filters are very common in water purification have you seen the GRIFFIN MicroPure System, an innovative system that improves fuel quality and kills diesel bugs. The system has 3 stages of bacterial elimination using exclusive technology namely: 1) Filtration of solid particulate and removal of moisture in suspension 2) Disruption of microbial cell-walls by opposing magnetic force-fields 3) Sterilization by an intense Ultra Violet light source This system not only destroys microbial contaminants, it alters the environment in which it grows, resulting in the cleanest possible fuel to your engine. This system is indeed a breakthrough in fuel purification. Nine out of ten boats with diesel engines will have some form of microbiological contamination or “diesel bug” growing in their tanks. There are an estimated 100 different types of diesel bugs internationally. With the reduction of sulfur levels in diesel and the introduction of biofuels, the number of vessels with fuel quality issues has increased markedly.

[@SailingSVLynx]

We would have to know the price before we considered any system. Most we have looked at cost too much, as in something like $7,000, which is way out of our price range. Our system, as described in the video would run about $1,100 for the fuel polishing portion.

[@bryanmyers9977]

Here's a crazy idea for an electric outboard. Since you have a brand new bottom end for an outboard that will work well worldwide and you can build a new cover, how about just buying a naked electric motor and mating that with the lower end? Are any of the motors that you could use for an inboard small enough and have appropriate RPM and torque for a outboard? Also, you are a couple of years away from being done and this is a rapidly evolving industry. Not a single one of those options you researched existed when I first looked 3 years ago. You might just want to wait and see if something new comes up in the electric outboard world.

[@SailingSVLynx]

We do plan to wait and see what happens in the boat industry.

[@bradfordsimms715]

Hi Guys, We all need a good filter rig and I have a nice one but don,t have a fuel deputy. Can you add a link please.

[@SailingSVLynx]

Hey Bradford, thanks for the question. Please read my reply to Sailing Someday it answers your question.

[@bradfordsimms715]

@@SailingSVLynx Thanks Phil

[@SailingSVLynx]

@@bradfordsimms715 Hey Bradford, I got more information and replied to Sailing Someday, so see go to that new comment.

[@bill2292]

Baja filters are a great start, but they are really slow, and only filter 100 microns. I'd say that a good polisher is the better plan.

[@SailingSVLynx]

Well, as we showed, we are using both in S/V Lynx. Slow or not, we want to filter the fuel prior to introducing new fuel to the tanks so that we can make sure we are not getting bad fuel to start with. After that, we will use our polisher to clean up anything that is not visually obvious. So, though we agree the fuel polisher is the better plan, we have both plans :)

[@sailingsomeday5975]

could you put a link to the fuel deputy? uncle Google doesent find it?

[@SailingSVLynx]

Sorry, we just called it the Fuel Deputy for the video. We didn't give out the real name or company in the video because we are currently in talks with them and are not yet willing to advertise their product until we know more. We don't like to plug products unless we feel they are worth using. We are still on the fence about this brand and this model. Their website is a mess of links that don't work, so not much info to be had. I have been in communication with the company, originally because I was interested in a different product that is now discontinued. They replied and told me about this filter and sent me some literature, which looks good. However, I am currently waiting on more information. If it turns out we feel this is worth telling others about, we will post the company and product name, with links, in another video.

[@SailingSVLynx]

We got a response from the makers of the filter you inquired about, and it turns out to be small manufacturer who won't sell to anyone outside the UK. If you are in the UK, the company is Fuel-Guard, but I warn you, their website is a mess.

[@sailingsomeday5975]

@@SailingSVLynx Thanks looks intresting -If this is something you really want you can join a company called ShopandShip - they offer 34 addresses from around the world - It would ship to your name at their UK adress and S&S would send to you....I grew up on the east coast - but now I work and live in Nigeria( in the Oil And Gas Business) - we have used it to get packages sent here and to Dubai when we lived in the UAE....Keep up the good work - Cant wait to see your offgrid workshop -

[@SailingSVLynx]

@@sailingsomeday5975 Thanks for that info, we will look into that company.

[@sailingsomeday5975]

@@SailingSVLynx might come in useful as your sailing too

[@sergueiothonucci1638]

😃

[@SailingSVLynx]

👍

[@christopherledesma8435]

What about eliminating diesel completely and instead, having both electric motors and one gasoline generator as your hybrid option? You will not have this fuel issues with gasoline and maintenance on gas engines is easier and cheaper! Also will save money on all of those diesel polishing and filtering systems!

[@SailingSVLynx]

Watch Episode 18. But I will give you the short version. Hybrid electric is under powered, heavier, less range, and far more costly. But it is the under powered part that is that primary reason we can't go with a hybrid electric system.

[@christopherledesma8435]

@@SailingSVLynx thanks for the reply, already watch episode 28… thanks!

[@DRB68]

Pretty bad design not being able to put a port light on the inside of the hull.. i agree with the comment that its a great way of getting ventilation as it filters through the hulls

[@SailingSVLynx]

We don't consider this a bad design, just a compromise. All choices in designing a boat likely involve a compromise. In the case of a Solitaire 1520, this is a performance catamaran. That means she has very sharp bows and narrow hulls to reduce wetted surface. To widen the living spaces chamfer panels were incorporated. Without them, the bunk forward would be much narrower. Or, we could have moved the forward cabins more toward the bows, to where the hulls are more vertical and a portlight might work. However, that also narrows the forward cabin to nearly a single bunk width. We choose to have a performance cat with chamfer panels for wider forward births that are also set back more towards mid-ship to increase living space rathat than compromise those cabins just to get portlights on the inside of the hulls. Others might make a different choice, but neither is bad design, just a choice.

[@gavingrantham136]

fuel centrifuge alfa laval

[@SailingSVLynx]

What is the smallest and least expensive version? All I could find was one that costs 13k.

[@briantasse5257]

So, basically, that's how we pass gas on our catamaran. 🤔

[@SailingSVLynx]

Always the funny guy!