Diesel Fibreglass Resin New Tanks?

[Paolo]

My 38' Swanson is undergoing an engine refit (to Volvo D2-55).

It has been discovered that the 360lt stainlees steel tank had corrosion and small leaks. It partly sat under the engine.

The suggestion is now to build a 250lt fibreglass resin diesel resistant, smaller so that would allow better access to bilges under engine.

Any advice on new resins long-term resistance to diesel?

Thank you

Paolo

[speedoo]

Isn't the key to fiberglass diesel tanks the epoxy paint on the inside as a barrier to the diesel? If that's true, I don't think the type of resin matters a lot.

[DWT]

Paolo,

I would not tempt fate...... Build the tank, all of it, with epoxy!

[thinwater]

* Are all of the layers rated for diesel, fatty acids, esters, and bio-diesel, and alcohol? Who knows what the future holds - all of these exist or have been suggested. I speced alcohol rated resins in a gas tank 15 years ago, and boy was that a good call!
* No coatings. At the very least, any lining or veil coat should incorporate a very light cloth or non-woven fiber as a support. Never what is called an "unsupported lining".

That said, FRP would be my first choice, after many good refinery and boat experiences. But review the resin specs. Post them here!

[Cheechako]

is it a shape that can be built out of the boat? You might consider the plastic tanks. I had one custom built for black water out of 3/8 thick welded plastic, super tough and strong. It was no more money than a stock size! They put the fittings where I wanted them. I have used similar large tanks in industrial app's like nitric acid (!)... so the welds better be trustworthy (and seem to be)! I've never asked about diesel though.... One consideration now days is the poor shelf life of diesel. You probably dont want more tank size than you really need so it doesnt go stale. Two tanks would be better than one... leave one empty except if going on a long trip....

[speedoo]

Originally Posted by Cheechako

is it a shape that can be built out of the boat? You might consider the plastic tanks. I had one custom built for black water out of 3/8 thick welded plastic, super tough and strong. It was no more money than a stock size! They put the fittings where I wanted them.

Who built that tank for you?

[Paolo]

Thanks all for the prompt replies.

The intended material is Vynilester Resin.

This can be supplied for diesel OR for biodiesel.

There is not one for both, which is very limiting.

Any further views?

Thanks

Paolo

[Paolo]

I add that the new engine is a Volvo D2-55 and I am now checking whether it can indeed run on biodiesel.

I feel inclined to go again for Stainless Steel at this stage.

P

[Stevens 47]

Built mine in place out of Epoxy and then coated the interior with Ceram-kote. Ceram-kote has been been making epoxy paints for underwater oil production for a long time. Industrial Coatings by Ceram-Kote

[Cheechako]

Who built that tank for you? I believe it was Plastic-Mart.com It's priced by a basic price and then so much for each fitting installation. 3/8 wall thickness.

[Cheechako]

The problem with stainless is if it sits on a wet stringer or floor member, that is usually where it will corrode fast...

[s/v Jedi]

Pls. explain the tanks "built out of epoxy". Normally, stuff like fiberglass or plywood are used with epoxy but this all sounds like it's just the epoxy??!!

To me, the photo's look like a fiberglass/epoxy lay-up, using the actual bilge as the mold but I have this feeling I completely miss the point....???

cheers,
Nick.

[Stevens 47]

The tank was built using a series of steps using biax eglass and epoxy. I prebuilt the tank ends, baffles,sides and top on a release mold. These then where fitted and tabbed into the sanded bilge. Then all of the tank pieces and the bilge where glassed together with biax to form a monococ structure. I use peel ply on the final laminations. Followed by a couple of coats of the ceram-kote. It was Bill Stevens the gentlemen that my boat is named after who suggested I use this method. When I first started this project I gave him a call, the first thing he suggested I do was to remove all of the SS tanks especially the main fuel tank in the bilge as they are suspect in this vintage from Taiwan. Hope this clearly explains the process.

[cat man do]

Originally Posted by Stevens 47

Built mine in place out of Epoxy and then coated the interior with Ceram-kote. Ceram-kote has been been making epoxy paints for underwater oil production for a long time. Industrial Coatings by Ceram-Kote

Whats the difference between using epoxy paint and just having a good coating of epoxy resin apart from it looking purdy?

Mine were done underfloor and as the boat is low profile, I only had 250mm of depth to play with.
The hull is the side, the floor (sole) is the tank top, plenty of internal baffles for strength.

I have been worried about if from day one, but I see no compelling reason why I would have issues.

[Paolo]

Well...after a couple of days of intense research and useful advice, I have opted for Vinylester resin impregnated fibreglass, rated for diesel (not biodiesel. A decision that has to be made at the time of ordering).

This resin is 'produced by the esterification of an epoxy resin with an unsaturated monocarboxylic acid' (Vinyl ester - Wikipedia, the free encyclopedia)
Originally created for its antiblistering and fatigue resistance, it has for several years now proven useful for fuel tank production.

It has advantages towards Stainless Steel -and disadvantages. My reasoning has been that advantages (resistance to corrosion and movement stress) outweigh the disadvantages (limited either to standard diesel or biodiesel).

This is as far as I could go. Price was much of a muchness S/S vs resin.

Time will tell if my reasoning and the advice I received from our local experts was correct.

Many thanks to all.

Paolo