I'm in New Jersey. Years ago it was no problem, but today I couldn't find a radiator shop that would clean a gasoline tank. As a teen I used to braze leaks on steel tanks. I don't think I'd be doing that now.
First they will blow up bigger than life if not done right. Seen it! Now I have also done a few, always used dry ice.Here's how and why; In order to weld a gasoline fuel tank safely, first remove all traces of fuel. Before welding, wash out your fuel tank with warm soapy water, then rinse with clear water. This should remove fuel residue. Next, you'll need to remove all traces of flammable gasoline fumes. To remove the fumes from the gas tank, insert small pieces or pellets of dry ice into the filler neck of the tank, I ususally put about 5 lbs or more in. As the dry ice comes in contact with air, it will sublimate directly into carbon dioxide gas, which is the fog effect dry ice is known to produce. Dry ice produces no liquid but rather sublimates from solid to gas. Because CO2 gas is heavier than oxygen, it displaces, or pushes out oxygen from the fuel tank. The fumes will be pushed out of the tank and without oxygen present, the risk for fire or explosion when welding can be eliminated if done properly using this dry ice technique.
You might even do it 100 more times and be fine, but it is the one time that doesn't go the way you wanted that everyone will remember you for
My 73 Nova had pinholes where the tanks straps were. My Step-Dad & I remove the tank, sanded it down, spread a thin coat of JB weld around the holes, covered it with window screen, then JB again. It lasted until I let it go. A truly sad day, in hindsight.
I dont know how or why it works but i've seen an old timer weld up a gas tank on two diffrent occasions by filling it with diesel fuel first. I didn't bother to ask why because i'm never going to try it myself, and would never recommend it to anyone else. About 20 years ago we had a guy working at our shop that started welding on a gas tank after it was cleaned out by the radiator shop and it blew out on him. I say it blew out because it was like the tank blew up on the inside when the heat ignited the fumes, and it oil canned the tank blowing out the seams where it was put together. Luckily nobody got hurt on that one. The radiator shop that cleaned it said there was leftover fumes/residue in the seams of the tank that you could never get out no matter how much you clean it and thats what caused it. If i had a leaking gas tank id buy a new one or clean it up and jb weld it until i could afford to buy a new one.
What I have done several times. I drain the tank and rinse it out. I put dry ice in the tank and a little watter. The co displaces the oxygen. However I always keep a fire x near by just in case!
i've got a good welder friend that will weld any gas tank you take him. if you wash it he makes you stand beside him when he tips his torch towards the fill spout, if he washes it you don't even have to watch. that said i soldered a tank years ago (with the watchful guidance of an experienced "old timer"). the tank had to be full of gas and i mean plumb full, we wire brushed the tank where the leak was, pre-heated some solder in pop bottle cap, then heated the tank around the leak (and yes the leaking gas burned) once hot enough you hit the oxy button and blow the flame out then press the bottle cap full of heated solder against the hole. done. holy crap, that sounds even worse than i felt that day. I DO NOT CONDONE OR RECOMMEND ANY PROCEEDURES DESCRIBED ABOVE OR RELATED TO OPEN FLAMES AND GAS TANKS.
Yes same as all above, I've seen it done on gas tanks. I've done a diesle tank myself. 50 gal. Filled with water, cut end off with 4" grinder, wash out with rust killer and metal prep, weld end back on. The process is not something I would recomend, major pain in the butt. Buy a new tank or build one!!!
I used to do them like he said except, I would put some newspaper inside and make a trail out of it and light it and hid behind something. If it didn't go boom, I welded it. Now adays it just seems easier to make a new one or buy one if possible.
The only way to 100 percent safely weld a fuel used tank is to remove the oxygen. Iv personally done it dozens of times by piping exhaust or argon onto the filler tube. Also open up anything else you can , like remove the sender .. Washing it out = waist of time Filling with water = steam will F up the weld Theres a reason the military puts inert gas into the aircrafts fuel tanks as the fuel is consumed. No air / oxygen = you can shoot at it all you want and no boom! This is like I said foul proof and 100 percent safe - easy - cheap and NOT MESSY. Im fairly sure it still works, The last one I did was 4 days ago.
Speaking as a FBI certified explosive device technician (bomb tech) your advice is not correct. First it is not the liquid fuel that is the subject of combustion it is the vapors of the fuel still left in the tank. And be assured that they DO IN FACT burn at a rate that is sufficient to cause a mechanical explosive failure of said tank if the mixture is correct. Even if there are vent holes of insufficient diameter as found in fuel tanks in automotive use there can and sometimes will be a catastrophic vapor explosion which in turn will explosively rupture said tank. While it can be and has been done many times it's not worth the cost of injuries or lives either let a professional with the proper equipment effect the needed repairs or invest in another used or new one. "Let's be careful out there people"
Thank you for all the good advice. I’m planning to stick around a long time yet so I just ordered this stuff
A guy I once worked with told me that he welded on full diesel fuel tanks all the time while he was stationed in Korea. He always made sure that the fuel level was above the area to be welded so the fumes wouldnt ignite. He found it funny that a lot of the guys would take off qiuckly when they found out what he was about to do...Id have been right there with them!
I dropped and cleaned my tank last weekend. I put a few handfuls of bolts in there to shake around--- but before I did so I let the tank dry out on its own and then put some soapy water in there. Before I added the bolts I passed a lit propane torch over the openings to see if anything ignited.
A few years ago maybe 4-5 the filling station east x the street of the rock springs wyo flying J had a pump blow up. the motorist filled a gas can in the back of his truck and boom the gas can and the fuel pump exploded blowing the windows out and torched half the store outside
replacement tanks are available for alot of old cars now.they are to inexpensive to take a chance on welding on an old tank.
Although I have never used this exact product, I have heard good reports from this type of sealer system: http://www.kbs-coatings.com/Gold-Standard-Tank-Sealer-Information-Instructions_ep_39-1.html
dude i feel your pain!! i had that problem with my lincoln, what i ended up doing is having the tank media blasted and i epoxy the outside of it and i ended up with 70 holes that needed to be tig welded, shitty but it was 6 hundred dollars to replace my stock tank!! luckily my boss was a bad ass tig welder and could keep the blowing up of holes under control!! so my advice is if you can find another repop new one or if the holes are minor?? us standard fuel tank sealer by por 15!!
I tried to repair a rusty 36 Ford tank with brazing rod once. I filled it with water and went at it. The more I brazed, the more pinholes appeared. Turned out the entire inside bottom surface of the tank was badly pitted. Tanks often rot from the inside and most of the corrosion cannot be seen. I purchased a new poly tank and never worried about it. I wouldn't ever consider repairing a rusty tank again. That was a 100.00 education.
This is the add for POR 15 in a tube. It is great stuff!!! For years our customers have asked us for a thicker version of our world-famous POR-15® for filling seams or holes. Here it is! POR PATCH™ is, quite literally, POR-15® in a tube, and like POR-15® it dries as hard as a rock, remains flexible, and once dry is totally impervious to fuels and solvents. It's so tough it actually adds strength to weakened metal. And it won't absorb moisture and swell like conventional body fillers. Try it yourself, it's incredible
Displace the O2 with a inert gas (ie argon) and you won't have a problem. If you don't have oxygen in the mix there won't be a big boom. I have done it on gasoline, diesel and propane tanks and i still have ten fingers ten toes and two eyes. -Mike
If it's a small drip type leak clean the metal and cover the crack or hole with fiber glass cloth and resin. It will stick. I covered my entire tank with fiberglass many years ago and it has never leaked since.
not to hyjack your thread, i have fixed a few gas tanks, the largest was a 5000 gallon tank i cut the end out of the make a cement sylo, that one we ran diesel exhaust into for a few hours and then used a sniffer to check for fumes, and still i had to overcome some shaky nerves just before the torch made the first cut, but all went well, the gas tank on my 55 fairlane was like swiss cheese on the bottom, i removed the tank and carefully cut the bottom out with tin snips, i have yet to weld a patch back on, two days ago a guy brought a couple diesel boat tanks to my shop for repair, looks like i have to cut the top right off and replace them, so i ask, what would some of you guys do before cutting the tops off with a plasma, anything?, will diesel explode when not under compression
Good question and thread! To be honest I washed my 56 chev tank with dawn soap for a week off and on every day out of the car of course, then welded a sump pick up on bottom of tank.
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