Fuel Tank repair

[Yellow Machine]

New to this great site. Has anyone repaired a fuel tank for a 440ICD crawler safely don't want any big booms. Any suggestions would be very helpful.

[Tigerhaze]

Here are some helpful posts:

http://www.jdcrawlers.com/messageboard/ ... =fuel+tank

http://www.jdcrawlers.com/messageboard/ ... =fuel+tank

[Yellow Machine]

Thanks for the info. But I was actualy kooking for some info on welding it. mostly from a safety perspective.

[jdcollector]

I'm nt sure what you are trying to weld on the tank but I have had good luck with fiberglass patch kits for larger holes and tank sealer for the smaller holes. If you still want to weld on the tank give us a little more detail and we will see what we can do to help.
Pat

[Yellow Machine]

The tank seems to have been loose for some time and the washers from the bolts they had used to hold it in place wore a hole in the tank at the seam. It also looks like someone tried to weld it before but it was a bad attempt. The tractor is new to me and as I am going over it it looks to me that every attempt at repairs were very much just patchs.

[Paul Buhler]

Hi: Based on what you've described so far, I'm in the fiberglass or epoxy fix corner. Safe, fast and inexpensive. The epoxy gas tank sealers work nicely on seams since they flow well when they heat up and don't open up the seam further like soldering or brazing might. Epoxies sand and mold well too. Good luck.

[Tigerhaze]

Thanks for the info. But I was actualy kooking for some info on welding it. mostly from a safety perspective.

I think I would be concerned about purging ignitable vapors after fuel removal before welding. Purging can be done with a number of gasses such as CO2, argon, nitrogen, etc. Filling with water is another good way to address this issue.

Here is a NIOSH fatality report with preventative measures discussed:

http://www.cdc.gov/niosh/face/stateface/ca/07ca006.html

DO NOT purge with exhaust gasses from a running vehicle- there is often enough unburned fuel in exhaust to increase the danger of explosion.

[Yellow Machine]

Thanks for all the info. Looks like epoxy it is.

[OneWelder]

If I were going to weld fuel tank theses are the methods I would use :
Steam clean out the inside throughly with detergent , make sure tank gets hot to touch for at least thirty min..
option A is then pipe car/truck exhaust into tank for at least thirty min.- tank must be hot to the touch - continue running exhaust until your finished
welding.
B- fill and continue to Run inert gas into tank while welding .
C- Put dry ice into tank - when it melts it creates carbon- dioxide gas All these methods remove the oxygen from the tank The heat will vaporize any gas that has impregnated the steel
Do not try filling with water* as water does contain some oxygen , which may produce some dangerous and startling results

[Tigerhaze]

Sorry, I wasn't sufficiently clear in my post. When I mentioned use of water, I meant filling the tank to rinse residual fuel in conjunction with an inert gas purge. I agree that solely using water in tank can cause problems, especially if a gas pocket exists.

Not that everyone has one laying around, but I use a combustible gas indicator at my work to determine whether the LEL is exceeded. That is really the only "sure-fire" way to know whether you have an explosive atmosphere in the tank. They can be rented but may not be worth the expense relative to buying a new tank or other repair methods.

YM, here are a few discussions on other boards regarding purging during welding that may be useful to you or others:

http://www.millerwelds.com/resources/co ... 12217.html

http://www.hotrodders.com/forum/welding ... 19062.html

http://www.busconversions.com/bbs/index ... 49.10;wap2

http://www.millerwelds.com/resources/co ... a-gas-tank

[pop pop]

i have done that very same tank, i just drained all fuel, left it open until dry,, a day or 2 in the summer sun here is all i needed,, i did rinse it with water and stuck my nose in it for the final test,,, (before i stuck the torch tip in it )
so then i proceeded to braze it up,,, hardest part was chasing the seams,,, the original solder would flow out so i had to sneak up with the heat when brazing,, i patched several places along the seam and maybe a dozen other places, it was old cracked patchwork,, lota crap from several previous patches,,,so i ground it all clean and now it is good.. i did submerged pressure tests to check for leaks and after all that ,,, she's good.

[CELSESSER]

Looking at his post it indicates that it is from a 440ICD. Therefore he is dealing with diesel and not gasoline. Not the same boom issue in my opinion but then again I cut apart propane cylinders. Ya gotta be aware of what you are dealing with and respect it. I am not promoting doing anything life threatening but if you try to make sure even the smallest little bit of excitement doesn't happen you will never get anything done (and it isn't as much fun).
I think the biggest problem would be overheating the seams and having leaks there.

[Lavoy]

I have welded several other fuel tanks with C25 as a purge gas. The crawler tanks weld easily, but for what it costs, take it to a radiator shop, have it cleaned, then silver soldered.
Lavoy

[markvdh]

We clean and repair tanks like this regularly in our radiator shop. Rinse it with MEK (readily available at a hardware store). That will cut and remove all the fuel residue. Then rinse it with water and Simple Green. Run an inert gas in it if you have it, or the exhaust from any late model vehicle (anything later than about 1994 won't allow any unburned hydrocarbon through, unless it's really running bad!). As someone said, keep the exhaust running through it until your done welding. Do all your welding repair. Then if you have any internal rust that needs removed, you can do that too, before you line it, with muratic acid, then water, then a final bath of MEK. Then the liner for two coats.

This probably sounds complex, but it's really not, and it's a permanent repair for a tank.

If you need more detail and want to go this route, let me know. I'll spell it all out, and the sources for the liner material.

Mark V

[Yellow Machine]

Thanks to all for the great help. It is in being repaired as we speak.

Everyone out there have a very Merry Christmas.