cool, now my diesel tank is leaking

[rebel heart]

Not 100% sure it's the tank, but pretty sure. Have the heat exchanger and a few other items off so I guess that might have put some diesel in the bilge but I flashlighted under the tank and I'm seeing a tiny drip every few seconds.

Black iron tanks, sort of coated/epoxied on the inside, super hard to get at minus the inspect ports. No way to pull it out without ripping the floor open.

And I have two weeks to leave the country. So I'm thinking:

1) Verify tomorrow morning that indeed it's leaking diesel.
2) Drain the tank into cans.
3) Rinse / soap the tank.
4) Chop the top off with an angle grinder.
5) Remove the baffles.
6) Strap a flexible tank inside as much of the space as I can.

Ideas?

[xymotic]

When it rains it pours I guess.

[hellosailor]

Pinhole leaks in welds, maybe.

You could try scrubbing the exterior of the tanks with detergent, get them clean and dry.

Then fill the tank all the way and add a shot of UV dye while doing so. You can get UV dye in mineral oil, it is used to leak check air conditioning systems.

Let it sit for a while, run the engine to circulate the fuel and make sure the dye is all mixed around. Use a black light to examine the exterior of the tank. Again, available from any AC repair shop, probably $50 will buy you a high power black light (not just a bulb from the hardware store), some yellow goggles to enhance the contrast, and the dye. The goggles really help, any type of yellow "shooters" lenses will help.

You should be able to spot a line of glowing fuel trace from the leak, probably from a pinhole in a weld. And at that point? clean again, dry, apply a generous epoxy patch with an epoxy putty. If there's a pinhole in a larger flat area, you can also put in a self-tapping screw with a small rubber gasket, then epoxy over that.

But if leak chasing isn't feasible or doesn't show up a leak, the other option is to clean down the tank then apply a couple of layers of epoxy and fiberglass. Odds are pretty high that will cover and seal the leak and buy you months and months of time to plan a liesurely replacement. Or, years of more use.

Would ABYC or anyone get upset at a frp wrapped tank? Damfino. Yankee ingenuity has other solutions to paperpushers.<G>

[resilientg]

If your going to go as far as cutting the tank open, why dont you clean it up and just put a liquid membrane in there?

ifs its an epoxy type one then you can even put some glass in it to give it some extra strength, couple of coats and your done.

If the steel keeps rusting then whoo hoo so what.

Matthew

[msponer]

Originally Posted by resilientg

If your going to go as far as cutting the tank open, why dont you clean it up and just put a liquid membrane in there?

That's my thought, but even more ghetto -- don't cut the top open at all, just clean thoroughly through the inspection ports, maybe even try to stick a pressure washer in there, then pour enough epoxy in to cover the bottom in an inch or two of resin.

I have no idea if this would work, but I'm guessing that the rust and holes are on the bottom of the tank, where the water has sat and rusted it.

[rebel heart]

Okay, that sounds like the smart approach.

Drain tank, scout out the holes, try to epoxy them. There are parts of my tank that are super hard to get to. My worry is the leaks are in that area, in which case I'm fubar'd. I suppose after the epoxy I can fill it with water (cheaper and easier to dispose of than diesel) and check to see if it's still leaking.

If it is, then it's just drain the water and bust out the angle grinder.

[DeepFrz]

This may work for you.

Gas Tank Sealer - Gas Tank Liner - Diesel Tank Sealer - Fiberglass Tank Sealer

[bobconnie]

Ya might try a low pressure air connection to get the leak to be more visable ! even a bike pump will do it ! then ya can make a good choice for repairs ! I have used the screw and rubber gasket and glass over a couple of times ! it works till ya can do a complete repair! (one I fixed that way in a anchorage in Belize, 3 yrs ago is still working !) Hope ya get it fixed so your Trip won't be put off anymore then needed !! Good luck ! still hope to meet you and your family down the trail !!

[s/v 'Faith']

Wow that is lousy... sorry to hear that you have another item on the must do list.

Sounds like really tough access to the tank, the idea in your OP sounds good to me... patching an old black iron tank sounds like a good way to have to fix the problem over and over again...

What ever you do, good luck.

[rebel heart]

I just checked again: same drip rate as a few hours ago so yeah, it's leaking. Maybe a gallon a day.

So let's say I try to put epoxy / glass on the inside of the tank. Is it just drain/clean the thing, then acetone it and get a clean work area, then apply a few layers of epoxy? I have some glass I can put in there as well for structural support.

[rebel heart]

Guy with a similar make/year of my boat, had a similar problem. Looks like he glassed the whole thing.

Run For The Border: Search results for tank

[minaret]

Originally Posted by rebel heart

I just checked again: same drip rate as a few hours ago so yeah, it's leaking. Maybe a gallon a day.

So let's say I try to put epoxy / glass on the inside of the tank. Is it just drain/clean the thing, then acetone it and get a clean work area, then apply a few layers of epoxy? I have some glass I can put in there as well for structural support.

I am planning on doing this with some of my tanks. I have put a lot of thought in to my plan, and have made a few posts about it here and there in the last few months.
It seems to me one of the problems is the lid. You can't glass a lid to the original tank lid from the inside, for numerous reasons. Even if you had inspection ports massive enough to allow you to work in the tank, the glass wouldn't stick unless you only did a couple of plies at a time. It would be a nightmare. My plan is to cut off the top of the tank in question, leaving a 2 1/2" horizontal flange in the steel/iron around the top edge. Then glass the interior of the tank including glassing up onto the flange, green trimming at each lam. Build and install baffles from fiberglass flat stock or Coosa. Pre grind the entire interior for later barrier coat. Then cut off both the metal flange and a strip of the metal sidewall also about 2 1/2" wide, leaving a solid glass flange and 2 1/2" of exposed vertical fiberglass tank sidewall. Do this carefully with a cut off wheel so you only cut through the metal tank and not into the glass tank. Then cut a lid out of Coosa board, G10, or equivalent. Pre cut inspection ports and pre glass both sides of it if it's Coosa. Bond the lid to the fiberglass flange, radius the top edges, and glass the whole lid with a few plies which come down the exposed fiberglass sides to tie the lid and sidewall together. Green trim the inspection ports. Then use the inspection ports to epoxy barrier coat the interior of the tank, 7-8 coats. Perhaps sand, etch and epoxy coat the metal exterior of the tank as well, to prevent messy rust staining. Build and install inspection port lids, plumb, and voila!, a new glass tank using an old metal tank for a mold. There are some complicated refinements I'm not mentioning, such as adding a sump for the bottom drain, etc. etc.
Laminate schedule and resin is also an important situation. I would do this with Proset laminating resin from WEST. Not sure if you can even get it. The laminate schedule needs to be really heavy. Not for strength purposes, a fairly light schedule would provide enough strength. What you are looking for is panel stiffness, so the tank is not flexible. If it continually flexes under load it will eventually fail due to load cycling. So it needs to be thick enough to provide enough panel stiffness to keep flexing at a minimum. I would consider 3/8" to be a minimum unless the tank is really small. This means at least 12 plies of alternating DB1708 and 24 oz WR. A tough lam in that tight a space, I would suggest 2-3 laminate sessions instead of trying to do it in one. One advantage to this method is that if you have tanks which are too large to be removed from the boat, like I do, the whole job can be done in place. Since my tanks are much too big to fit through any opening on my boat, my only other options would be to cut up the old tanks and replace them with multiple new tanks that actually fit through the pilothouse door, or to cut off the pilothouse roof and then reinstall it after getting the tanks in, something I have done for clients before. Neither appeals.

I know this is probably too much for you to consider as an approach right now, but thought explaining the gist of my plan might cause you to think about some of the details involved. No way it could be done in two weeks. I sure am glad I decided to replace mine on general principle this winter before shoving off next summer, I'm sure if I didn't mine would also begin leaking two weeks before the departure date. They are original from '83, though SS.

[Dockhead]

I am really sorry, Eric. What a bummer

I guess it would border on unhelpful, given time and financial constraints, for me to mention that the only really proper repair for a leaking fuel tank is to rip it out and replace it. Once they start leaking in one spot, they will soon be leaking in other spots. Cutting the top open and fiberglassing the entire tank might do it, but it might very well also be an immense expenditure of time and labor without the desired result. And you would hate to find out that it didn't work only after you have departed civilization.

I'm sorry, but it's a really carpy problem, especially on the eve of departure on a big trip.

[Pete7]

Have to agree with Dockhead, once it starts to leak repairs are going to be tricky and the task of cleaning it up to a standard that epoxy will stick to it will be very time consuming and dirty.

Price up the cost of GRP and epoxy or a flexible tank, then price up a standard polythene tank of about the same size. If its close then a new tank would give you peace of mind. The last thing you need is another leak in 6 months time, especially in a foreign port. Also the smell of diesel throughout a boat is terrible never mind the mess. I viewed a Sigma 33 which had a fuel tank leak over a winter. 20 gallons had sloshed throughout the bilges for months and soaked into the ply bulkheads. I didn't think it could be cleaned up without a huge amount of work.

How about something like this, okay it's a UK company but they are available everywhere.

http://www.tek-tanks.com/website/wp-...el_1_Tanks.pdf

Pete

[Jryder]

I know I am a yachting n00b but can you use outboard style removable tanks for diesel and just get rid of the old ones? I know they come in heaps fo different sizes and shapes.

Sure you still have to remove the old gear but any maintenance down the track is simplified plus you can daisy chain a couple if you need extra for times when you are motoring.

They are not even expensive in Aus under $200 for stainless tanks so in the USA they will probably be 1/4 the price like everything else.