Suggestions for a diesel day tank.

[Mikado]

I've used the tank sealer that you pour in and rotate the tank around on a '55 T-Bird gas tank with great success. I would just verify that the chemical is compatible with diesel. Use it and fiberglass the exterior and you should be good to go for another 20+ years.

[Terra Nova]

Stainless isn't recommended for diesel tanks--use aluminum.

[Wotname]

Originally Posted by GILow

Sort of flimsy looking in the photos, and the threaded sockets for the various fittings look to be made of a separate material, making me worry that they will start to leak themselves. Might be paranoid, but that's the difficultly shopping on the web, hard to get a sense of the quality sometimes. At least with the $400 SS tank I could pick one up and have a good inspection, got to say I was not impressed though.

M

That would do it!
Are there any plastic fabricators in Adelaide?
Around here there are several -mainly for the salmon fishing industry - and their stuff is very robust.

Originally Posted by Terra Nova

Stainless isn't recommended for diesel tanks--use aluminum.

What is the issue with SS for diesel?

[GILow]

Originally Posted by Wotname

That would do it!
Are there any plastic fabricators in Adelaide?
Around here there are several -mainly for the salmon fishing industry - and their stuff is very robust.

I will ask around, might be an option. It would be nice to have something a better shape and size to maximise the day tank capacity. Maybe I could add a new tank to my shopping list for when we finally do Tassie. Won't be this summer though, just not going to be ready in time, us or the boat.

Matt

[GILow]

Originally Posted by Mikado

I've used the tank sealer that you pour in and rotate the tank around on a '55 T-Bird gas tank with great success. I would just verify that the chemical is compatible with diesel. Use it and fiberglass the exterior and you should be good to go for another 20+ years.

A belts and braces kind of guy. I like that sort of thinking.

[Terra Nova]

ABYC says stainless diesel tanks must be cylindrical, be smaller than 20 gallons and have domed ends.

Because of the flexing that occurs in rectangular tanks (stainless work hardens) and because of stress corrosion that occurs at stainless welds.

[DumnMad]

Originally Posted by GILow

Yep, checking out Boden36's suggestion now. Looks to be some decent sealants I can pour into the tank. They are cheap so I reckon they are worth trying first. Luckily the tank is very easy to remove and refit.

I think the construction of the tank is such that any attempt to reweld or braize the leaking area would just cause the next section to start leaking, so a liquid sealant will be more likely to work.

M

I would ask the fishermen down there (or phone Port Lincoln fishing companies.) "who's the go to for stainless diesel tank repairs?"

No braizing, no sealant - just good welding.

[hpeer]

I have installed a Moeller poly day tank in each boat. Not great but OK.

They come with standard size fill, pick up, gauge, and vent. If you want to return diesel you have to spen an extra $60 to get a special gauge with a return line. Yet another special gauge will act as either a return line or secondary pick up.

If you want to have more than that you need to get creative. I have a diesel heater and have ended up putting a T in the return line, which is also a pick up, to feed the heater.

In the US there seem to be few other choices than Moeller, seems they bought out the competition.

As to fuel tank sealer you can get aviation grade sealer from Boat Life, but I found it cheaper at aviation specialty stores. It works on diesel and the paste grade stuff will seal a 1/4" vertical crack.

I've used that to seal seems in my keel tanks. Others claim to have used it for years with good success.

You would however need to be able to get a spatula or something in to push it into the crack, it does NOT slosh around.

[UNCIVILIZED]

Fiberglassing is an option. Particularly as with proper preparation, & use of epoxy, the glass bonds structurally to the metal. Plus, it'd make it easy for you to add some external stiffeners to the tank, via the fiberglass on the outside.
If you need instructions, go to the WEST System website, & download them, and or the whole book.

Though it'd be nice to keep an all stainless tank IMO. Can you get a good welder to weld angle stainless overtop of the joints on all 6 sides of the tank you have now? Particularly if he doesn't mind if you cut & prefit the pieces to be welded on. That way you'd save a bit of coin, by doing the prep work yourself.

If you want to go the belt & braces approach on welding on angle stainless pieces, have him both; plug weld them in place, as well as seam welding all of the new, metal edge, reinforcements.

[GILow]

Originally Posted by Terra Nova

ABYC says stainless diesel tanks must be cylindrical, be smaller than 20 gallons and have domed ends.

Because of the flexing that occurs in rectangular tanks (stainless work hardens) and because of stress corrosion that occurs at stainless welds.

Now that is VERY interesting, as I would say it is consistent (the rectangular ends bit) with the failure of my tank... hmm... seems some of those regulations make good sense.

[GILow]

Originally Posted by UNCIVILIZED

Fiberglassing is an option. Particularly as with proper preparation, & use of epoxy, the glass bonds structurally to the metal. Plus, it'd make it easy for you to add some external stiffeners to the tank, via the fiberglass on the outside.
If you need instructions, go to the WEST System website, & download them, and or the whole book.

Though it'd be nice to keep an all stainless tank IMO. Can you get a good welder to weld angle stainless overtop of the joints on all 6 sides of the tank you have now? Particularly if he doesn't mind if you cut & prefit the pieces to be welded on. That way you'd save a bit of coin, by doing the prep work yourself.

If you want to go the belt & braces approach on welding on angle stainless pieces, have him both; plug weld them in place, as well as seam welding all of the new, metal edge, reinforcements.

I think these two approaches sum up my present dilemma. If money was no object, I'd go to the best boilermaker/polytank-maker in town and have a very well made tank, optimised to give me the best capacity for the space I have and with plenty of inlets/outlets for the engine needs.

However, I have just finished a pretty significant round of spending on the electrics, and I am feeling just a little price sensitive at the moment.

I am increasingly thinking I will go the fibreglass around the tank option, should be about AU$120 for materials, treat this as an exercise in improving my fibreglass skills and see how it lasts. If it gives me a few years then I will feel ok about buying a good custom tank later on. If it fails in a couple of months, well I will have learned something about my fibreglass skills before I do something that might sink the boat.

Some phone calls to make on Monday, just to check the custom tank prices, but I suspect it will be fibreglass for me. At least I could put an extra return fitting on the tank before I glass it up.

Matt

[Terra Nova]

If you don't have the time and money to do it right, how will you be able to do the job twice?

[lonesoldier0408]

I understand the need to rebuild the, "Boat Improvement Account." G-Flex 655 seems to be a solid choice from West Marine, for that patch job, while planning for that new custom tank. Preparation of the patch areas will be the make or break on this job. Acetone is the order of the day. :thumbup:

[GILow]

Originally Posted by lonesoldier0408

I understand the need to rebuild the, "Boat Improvement Account." G-Flex 655 seems to be a solid choice from West Marine, for that patch job, while planning for that new custom tank. Preparation of the patch areas will be the make or break on this job. Acetone is the order of the day. :thumbup:

Thanks for the heads up on that one, seems to be particularly suited to the job.

[UNCIVILIZED]

I'm not entirely certain that I properly communicated my meaning regarding the use of epoxy & fiberglass to fix the tank. What you're essentially going to be doing/HAVE TO DO, is to, for all intents & purposes, create a fiberglass tank which has stainless steel stiffeners/liners.
Once you decide to reach for the composites, they're not just something you'll be using to reinforce or patch the weaknesses in the tank. Knock on wood, such isn't a proper solution.

My apologies if I sound harsh, I just want to make sure that what I'm saying is clearly understood. Particularly when working on something as potentially volatile as a fuel tank.
Speaking of which, it does have a ground strap right?