Fuel TankCoating

[blockislandguy]

I think I read on another forum recently (ClassicMako.com?) that in replacing fuel tanks you should coat the alum tank with "cold tar epoxy". While I don't know what that is (and wouldn't know where to buy it), we just installed new fuel tanks (yes, tanks) in one of our F150 Supercabs. It was a major pain in the butt (we had a bad fuel pump and to get at the pump which Bill Ford--way to go, Bill, real American engineering at work-- located within the tank, both tanks had to come out and so while we had them out we put new ones ine, etc. etc.) that took our not so skilled guys about a week to do ( I figure that the whole job that began with the need to replace a fuel pump cost about $1500). I didn't want to do it again so we coated the hell out of each new fuel tanks' exterior with cans of spray on undercoating.

This seemed to work well, although it would rub off on our mechanics hands as they wrestled the tanks back up into the frame rails. We used up all the cans a local NAPA had and then bought 3M undercoating spray cans from another vendor. Much, much better quality. So, if I were going to replace a marine fuel tank and couldn't find the "coal tar" stuff, I'd use 3M spray on undercoating.

YMMV

[CJR]

I purchased my coal tar epoxy from Benjamin Moore. Shermin
Williams industrial division also carries it.Moore was about $75/gal where as Williams was about(as I remember)$90/5gal.

[warthog5]

BlockIslandGuy What you did to the Ford truck tank's was not nessissary. Stil not a problem.
Sounds like you got some BS undercoating and then you got the 3M Rubberized undercoating which is a much better product.

Don't even think about using it on a marine tank. [img]/images/graemlins/frown.gif[/img]

Coal tar epoxy was first used in the offshore oil industry.
The reason for using it in boat's is to keep any water from coroding the outside of the tank. This is especially true if the tank is foamed in.
The biggest factor is a leaking tank hatch. keep the water out and there is not a problem.
Another factor that coroides tank's is place rubber aginst the tank. Rubber has carbon in it and react's to alum.

[abl1111]

There's a lot written on this site about the proper protection of a fuel tank. What I did; sanded tank, cleaned with acetone, then I sprayed (2) part epoxy paint - that should have done it, but I had some Awlgrip around so I shot it with that too.

The tank will not corrode anytime soon.

However, it is very important that if water does get in contact with an aluminum tank, that the water has a way to dry or that the surface is prepped i.e. epoxy to avoid galvanic corrosion.

There is info on this site as to how to properly place strip mounts on the bottom of the tank to allow water a way to flow freely and away - and to prevent water from finding it's way to a oxegyn-free area - when water, aluminum and no oxygen are present - this is the place where severe corrosion will happen to bare aluminum.

Keeping water out in the first place is a great idea, but I like to be doubly careful either way.

[cc]

As previously stated, I coated my new fuel tank several years ago with line X truck bed liner. Have been very pleased. They charged me $100 for my 120 gallon tank. I had previously painted tanks with just about everything, all had failed in a saltwater environment. Just my two cents worth.

[EBEACH]

Try this link: Yacht Survey.com

off subject, David Pascoe made this comment while surveying a blackfin:

"And it is this, along with the other features I've described, that makes projects like this so economically practical. It's got that certain same "something" as old Bertrams and SeaCrafts do, and which is why we find so many of them being restored."

[Briguy]

My new 95gal tank was coated with a 2 part gray epoxy before going in. I might add my origonal tank(probablly at least 12 years old) had zero issues, never any more than a drop of water and no grit/sand in the filters. This is an uncoated tank so aluminum if properly maintained will last quite a long time. Wall thickness is important too and my old tank seemed thick.

Able111, you should have sprayed some gelcoat over the awlgrip and 2 part just to be sure..... [img]/images/graemlins/wink.gif[/img]

[abl1111]

You know if I had any laying around, I would have ! Just did my gas tank the way I did the rest of the boat - over built it ... [img]/images/graemlins/smile.gif[/img]