Welding thin gas tank

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Hi everyone. I just starting welding for the first time today, I practiced on some old sheet metal for a while just making lines. I have a small motorcycle gas tank that has been sitting for 30 years and the rust inside it was unbelievable. I cut the gas tank in half in such a way that it makes a corner joint, figuring this would be easiest for welding when the time came. So i cleaned out the gas tank really well (no more rust or flammable liquids) and started trying to weld it today. The metal is really really thin. I have a 70 amp campbell hausfield stick arc welder and I used 1/16" 6013 welding rod and set the welder to its 1/6" setting (that is the only setting you can set) and plugged it into a 15 amp outlet. Where the gas tank's corner joints matched up almost perfectly i was able to welding decently. Where there was a gap, I melted huge holes in the gas tank where I was trying to weld. First, how do I weld these gaps before doing more damage? Second, how can I fix these holes I made?
Reply:I'm sorry that image is way too big. Here it is again.
Reply:if thats a rare,obsolite tank,you could repair it with lead,get a mini torch. but you have to prep it with tin-it compound for the lead to grip i used to work for an old timer inthe 1980s at a radiator shop.he used to fix motocycle tanks.never try to weld a tank with a stick welder.i would also go from inside with some sheet patch of steel.if you cant get your finger to hold it, rig a magnet, stickextension. or something, hope i helped.,
Reply:oops, the tin-it compound is for soldering on brass and non tin,sorry.
Reply:its a gas tank don't weld on it not unless you don;'t value your life i don't care if a customer offerd me a million dollars i'll never weld on a gas tank jm2cLincoln Pro Core 125Lincolin sp 100Miller Big 40Lincoln Idealarc SP250miller matic 212http://www.facebook.com/hdwelding?sk=wallwww.hdweldingbeds.com
Reply:Originally Posted by heimbuckweldingits a gas tank don't weld on it not unless you don;'t value your life i don't care if a customer offerd me a million dollars i'll never weld on a gas tank jm2c
Reply:There's no longer any flammable material in there. I torched it after I cut it in half, then grinded out the entire inside until it was shiny new metal.
Reply:Don't think you'll ever get that done with a stick welder.  Even using a MIG with no experience would probably be difficult since it's so thin.  Tig would be the way to go.  I wish you luck.
Reply:Tig welding will be best, I took a stainless sink and cut 3" off the bottom and replaced the bottom of a tank. I put a argon purge and tig welded it with 3/32 309 stainless wire1960 Redface SA-200 F 1621973 Black face SA-200 F 163 with 5" chop2013 Miller Trailblazer 2752013 GMC 3500 welding car
Reply:What about using a larger welding rod? Will that help lower the heat so I don't make holes?
Reply:Leaving aside the question of safety,Because of a property called  cohesiveness whereby the molecules of a material are attracted to each other, the molten metal will form small spheres if allowed to by melting too much at a time. The "too much" depends on the material and on its thickness; for thin metal, it's much smaller than with a thick piece. Even in the hands of an expert, stick welding very thin material is difficult and with rusting-caused variations in thickness, residual rust in place, holes in places and perhaps pockets with air or gas or water, it becomes darn near impossible.It might be easier to repair the tank by cleaning very well, then applying a metal-filled epoxy to the outside (maybe doing in steps, being careful not to push globs through the holes) and when that stage is finished, using "sloshing compound" to seal and protect the inside. Very good removal of all inside rust and then coating the steel surface with a phosphate conversion layer should be done before the "sloshing" is.
Reply:Very low chance of success here. I have done a fair bit of work with 1/16" 6013 on thin rusted out junk, and it is not easy. I think I posted one here about a gravely deck I fixed a couple years ago. If you are set on doing this, I would practice on some similar material first,  to be sure you can do it, before you ruin the tank. I might try downhill DCEN. The hole sucks, A patch may work better than trying to fill it in with weld. Again, this is unlikely to work out for you with a stick welder unless you are very skilled... Just not the best process. I'll take your word that the tank is safe to weld on. Not a big fan of gas tank welding myself. Good luck.
Reply:peter,Number 1.  You need to thank your lucky stars that you're still here to describe your problem.  Proper procedure would have been to clean the tank and fill it with argon, nitrogen, or CO2 BEFORE attempting to weld.  You got lucky.Number 2.  You have now created a problem that's going to cost you three times what it would have, had you taken it to a pro and had him weld it properly.Number 3.  If all you have at your disposal is a stick welder, then you DON'T have the right equipment to do the repair.  This is not a job for a stick welder, even in the hands of an experienced welder.Post up your location and there may be an experienced tigger nearby that could correct your FUBAR attempt.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Your chance of a sound repair is zero. Let alone-that you're blowing holes in thru the tank---you have no clueas to how/what making a seal tight weld involves.Sloshing the tank with sealer to close up big holes is zero. [This poster---as opposed to most of the rest--has actually repaired/rebuiltaround 180 m/c tanks, 900 vehicle tanks, 150 boat tanks and over 280 misc. tanks in the last 23 years.....in SS, AL, steel, aluminized steel....coast guard,DOT, FAA....and Hell's Angels-(who expect quality or 'else')]If this tank's important, then take it to a shop that does this work,on a regular, competent basis.First thing---since there's heavy corrosion in the lipped flange is a thoroughinspection/brushing/ p-test of the tank, possibly with acid etching/neutralize to remove all internal rust. Water corrosion in flanges is wholly common.Heavy corrosion, can create cracking outside the weld/patch repair area.That's where experience in this repair helps, to gauge the real condition of the tank,if it's judged to even be repairable.Next is patching, then p-test, then internal coating to prevent further corrosionand drying that coating.Blackbird
Reply:First off, if you have no experience with tanks...walk away and hand it back to your friend.Rusty tanks with bubbling or even ONE hole...is bad news!!!(you're fighting an uphill battle...more holes will develop)However, if money is tight, and the tank must ride again...Smaller holes and pin holes can be repaired without welding.JB weld the outside, then use a Quality tank liner for the inside.If prep is done correctly, and products ate applied correctly, it WILL last a very long time.The trick is also to use a Quality tank liner, POR-15, Caswell,etc.(avoid Kreem) If the tank is rusted badly, just swish Acetone in there, and use Caswell Liner , it binds better to rust than metal.(note that caswell is basically a clear epoxy, so the tank will look rusty underneath still, but it won't actually leak)Lincoln 125HD, yep I'm a big spender.
Reply:To all of you who think I'm going to explode, as I said before there is no way in hell there is any flammable material in the tank. I cut it in half, torched it, and grinded the crap out of every inch inside. I don't care whether you think I made a stupid attempt either. Anyways, I've got my caswell epoxy liner right here waiting to be used, I just want to close up the gaps and I'm not paying a pro welder to weld the tank of a motorcycle I bought for a dollar. To those of you who gave me good recommendations, I really appreciate it. Thank you
Reply:I'm thinking a strip of jb weld or quiksteel around the tank and the epoxy tank liner inside. Anybody tried this?
Reply:Originally Posted by peterfI'm thinking a strip of jb weld or quiksteel around the tank and the epoxy tank liner inside. Anybody tried this?
Reply:take it down to a local tech school and have them weld it back up, they usually dont charge much if anything and they will have equipment made for doing this. They go ahead and seal it up
Reply:Quick question   why did u cut it in half, how did u get it back together?  Did i miss something?   Anyway   i used jb weld on a few dirt bike tanks, and it worked well.  Area has to be CLEAN  to the metal and DRY.  I used laquer thinner..Dries quick, no residue
Reply:Originally Posted by dave powelsonI've had a good 100 tanks in for repair where JB Weld/epoxy, etc. jive 'fixes' didn't work;and there's a bunch of reasons as to why it won't.
Reply:Looks like you've f***** it up beyond repair & sounds like you won't listen to good advice like having a pro tig it to begin with, lots of luck with your project. Try the epoxy route as some advise & if it vibrates like my rigid you'll have gas running down your legs before you've gone a mile.
Reply:Originally Posted by peterfTo all of you who think I'm going to explode, as I said before there is no way in hell there is any flammable material in the tank. I cut it in half, torched it, and grinded the crap out of every inch inside. I don't care whether you think I made a stupid attempt either. Anyways, I've got my caswell epoxy liner right here waiting to be used, I just want to close up the gaps and I'm not paying a pro welder to weld the tank of a motorcycle I bought for a dollar. To those of you who gave me good recommendations, I really appreciate it. Thank you
Reply:Ooops"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Well you have made a bit of a mess but if you can get it all sanded down smooth again, maybe both inside and out, it is probably possible to solder it. Was the way a lot of gas tanks were fixed way back when. The whole safety thing is another issue, I'm assuming here it has been rendered safe to use an open flame on it.You need something like this tinning butter. The metal is made bright and shinny, the butter put on and heated, then quickly wiped with a dry cloth. This provides a tinned surface on the steel that is possible to solder.http://www.eastwood.com/ew-tinning-butter-1-lb-jar.htmlMaybe you can use a covering strip inside or out or both. Everything that comes in contact with each other must be tinned. Then I would try using solder, maybe a big thick roll with flux in the core. Extra paste or liquid flux doesn't hurt.I've done a bunch of it over the years. Is a standard thing done in the auto body trade, usually there lead is used as the fill material. You can join dissimilar materials using the trick, if they can be tinned, they should be able to be soldered. Lots of weekend type repairs can be done using these methods. Always have the tinning done well. Lots of times it is possible to do it with just a propane torch.But beware once this is done, it is very difficult to get everything clean enough again to attempt to weld. It helps to play around with some scrap sheet steel until you get the hang of it. This same method is used to attach temporary pulling lugs in the auto body trade to various parts of a car when doing very complex fixing of a bad wreck or were you are undoing something that got crumbled and you need a lot of force. Reheating it makes it possible to remove again.Originally Posted by heimbuckweldingits a gas tank don't weld on it not unless you don;'t value your life i don't care if a customer offerd me a million dollars i'll never weld on a gas tank jm2c
Reply:Originally Posted by peterfWhat about using a larger welding rod? Will that help lower the heat so I don't make holes?
Reply:if your near me , i will weld up the hole and we'll pressure check all the welds and seems .  Epoxy wont last long. Harley doesnt even use the epoxy liner anymor        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Been there done that... TWICE. Wont ever try anything like that for a LONG time.  By the way. If anyone has a Wassell banana tank they wanna sell. Send me a PM.
Reply:Peter... A bike tank is not a good choice to experiment on. Stop messing with it. I'm sure it can be repaired but, it's gonna cost you. Maybe burning through that tank will be the best lesson you'll ever learn. See if you can get a replacement or a re-pop and get you bike going. I know EXACTLY how you feel and I'm sure there are more guys on here that have done this.
Reply:Originally Posted by pipehackBeen there done that... TWICE. Wont ever try anything like that for a LONG time.  By the way. If anyone has a Wassell banana tank they wanna sell. Send me a PM.
Reply:Well I have done a gas tank about 15 years ago. I haven't driven it in a few years so I cant say it still holds. I will not explain how to make it safe its been covered in this forum ( search for it). I soldered it with plumbing solder and a propane torch (after good cleaning and fluxing). This wasn't just "any" old tank because I spent about 20 hours on it...so be aware it's a lot of fussy work. Mine was empty for about 20 years so fumes was not an option. Most tanks are now available as a reproduction which is absolutley the way to go, (because after what ever time and effort you put into this) it's still an old rusty tank. Good luckLast edited by dumb as a stump; 03-24-2012 at 08:46 AM.Miller thunderbolt 250Decastar 135ERecovering tool-o-holic ESAB OAI have been interested or involved in Electrical, Fire Alarm, Auto, Marine, Welding, Electronics ETC to name a just a few. So YES you can own too many tools.
Reply:If you can get a chunk of copper or brass on the inside as a backing plate, your weld will not penetrate the copper or brass, but will puddle back on itself, thus fusing with the tank material and filling those holes. Turn your heat down.Aws:  SMAW d1.1 , d1.5, b31.3 , 1104