Machine Builders Network+
Posted By: sonny Diesel tank repair ideas??? - 09/29/2022 06:23 PM
Need ideas on fixin a couple of pin holes in my diesel tank on the F-350. Got the tank pumped out and off.
Would love to braze it BUT that probably would turn ugly! lol! -- Soldering, same deal, --- heat might set it off with fumes in it.
I know diesel takes a lot more heat to burn but even soldering needs a lot of heat.
Neighbor says to slap JB on it and go! --- dont think JB is going to hold diesel fuel in!
Cant find a used tank in decent shape,---they are all MUCH worse than mine! lol!
Posted By: bunkclimber Re: Diesel tank repair ideas??? - 09/30/2022 01:10 PM
Sonny you're NOT gonna 'set off' the fuel tank..you really only have that problem with gasoline tanks. The JB repair won't last,you'll be pullin it out again..I'd wash it out with water(and you really dont even have to do that) and then run shield gas from a MIG welder into it for 10mins or so, even that is really unneccessary...Clean off any exterior coating or paint then MIG it or braze the holes up, then rinse out with 1202 (Diesel)-use that same rinse diesel to check the pinholes for leaking..you'll do fine. Ive welded and cut on diesel fuel tanks for 20 yrs without ever one 'going off'..Ive even seen welding done on gas tanks in cars with gas still in them..no big blast,no fire either.

Welding up gas tanks
Posted By: sonny Re: Diesel tank repair ideas??? - 09/30/2022 04:02 PM
I never had much luck with jb! -- I sure as hell dont want to have to drag this tank out again! Its a bitch to get out being under the middle of the truck inside the frame! THATS why I want to braze or solder it to start with!
I have a 50 gallon tank off of a semi, BUT its the round one and would be hard to mount plus my suction unit wont fit in it, so its fix this one.
Its the long 19 gallon one. I would love a square 25 or 30 gallon one mounted outside the frame instead but,---- dream on I guess!
I have the corners cleaned and polished with wire wheel and washed clean. I dont think it would take much brazing to fill the pitted areas on it.
Inside the tank is shinny and clean. Looked at a couple in a junkyard and they were NASTY as hell, but they still wanted $500. for one!!!!!!!!!!!!!!!!!!!!!!! GOTTA be jokin!--RIGHT??????
When I got the truck it also had a plastic rear tank which got taken off cause the mounting straps and plate rusted off. The guy that worked on the truck at the time was going to make me a plate to hold the tank in but never did make it. --- not sure how to re-mount the rear tank back on but it did help when it was on there. -- I think it only held maybe 15 or 16 gallons but it did help.
Cant mount a 50 gallon tank in the bed cause it has to be able to dump.
Posted By: bunkclimber Re: Diesel tank repair ideas??? - 10/01/2022 12:20 PM
heat it and braze it up Sonny..I'll expect it to be repaired and back in the truck and running by 3pm today..finish that coffee and get that torch warmed up
Posted By: bunkclimber Re: Diesel tank repair ideas??? - 10/02/2022 11:41 AM
what year truck is the F350
Posted By: sonny Re: Diesel tank repair ideas??? - 10/02/2022 04:33 PM
Its a 1997 F-350 7.3 diesel automatic (that is junk) and a 10' flatbed.
Got the tank brazed yesterday, ---- I'm still alive,--no fires in the process. I stuck the air hose in there and turned it on half way to blow the smoke/fumes out. worked great. still had about a gallon of fuel in it that didnt come out but it didnt burn.
Hope today to put the tank back under the truck.
pix. of the mess! lol!

Attached picture DSCN1066.jpg
Attached picture DSCN1170.jpg
Attached picture DSCN1171.jpg
Attached picture DSCN1172.jpg
Attached picture DSCN1173.jpg
Attached picture DSCN1174.jpg
Attached picture DSCN1175.jpg
Attached picture DSCN1176.jpg
Attached picture DSCN1045.jpg
Posted By: bunkclimber Re: Diesel tank repair ideas??? - 10/02/2022 05:54 PM
Hollywood has so many people scared of gas tank explosions..too many movies..
at least she's workin for ya Sonny..I always put a strip of roofing felt inbetween the tank and the mount strap,it cuts out the friction wear of the strap and gives it some cushion.It looks like thats what got you so may holes in yer tank...Anyway if you get tired of workin on that 7.3L Ive got a brand new,in the crate 6V53T Detroit for sale if you wanna swop in some fun to that truck
Posted By: GatorS Re: Diesel tank repair ideas??? - 10/08/2022 03:43 AM
I've got a gas tank in a mini truck that I need to fix...I would probably use the inert gas method before trying to weld it.
Posted By: bunkclimber Re: Diesel tank repair ideas??? - 10/08/2022 10:12 PM
diesel tanks Ive welded on many without issues, I just did a run of 4 aluminum diesel generator tanks, modifying used tanks with diesel residue in them,no worries...but for a gas tank I try to avoid them but if absolutely necessary I would definitely purge with inert gas. I've heard of using a simple gas lawnmower engine and directing the exhaust into the tank to displace any oxygen to prevent a fire & minimise risk...for my money, a blast of argon,nitrogen or CO2 is cheap and right on my shop floor. For that matter, let the purge gas flow during welding if it's compatible with the metal of the tank/weld process..can't hurt
Posted By: sonny Re: Diesel tank repair ideas??? - 10/12/2022 12:02 AM
So far the tank is holding. Still gotta figure out how to re-mount the rear tank back under the truck. Really wanted to mount the 50 gallon semi tank on the outside of the frame but dont think
it would clear the ground enough.
I put a chunk of old fire hose between the strap and tank.
I dont have the fancy stuff to use, so I gotta use the lesser stuff/ideas! lol! The main thing is to either kill the fumes or keep them from the weld areas. Some guys put water in the tanks but I dont want it in mine! too hard to get out after your done and does little to keep fire out.
Posted By: bunkclimber Re: Diesel tank repair ideas??? - 10/12/2022 11:13 AM
at least you have something inbetween the strap and tank..you'd be surprised just how much the frame/chassis flexes and moves during operation,creating movement and friction on the tank strapped into the frame. Welding on the diesel tanks isnt that hazardous,drain the fuel and even use compressed air to vent the fumes out. I think its a lot less risky than you think.Best of luck to you
Posted By: sonny Re: Diesel tank repair ideas??? - 10/12/2022 05:53 PM
Ya! I used just air hose turned on about half way----- worked great! Not sure I would do a gas tank,--- Probably do a LOT more cleaning and air out first! LOL
© Machine Builders Network