Soldering gas tank

Hi Have an old engine gas tank that the filler neck has broken loose on.I need to know what type of solder works best.I`ve tried to solder it with "general pourpse" solder but it won`t stick.I`ve sand blasted the tank and fluxed but this doesn`t help. Thanks! Chuck

Chuck

Sand Blasting leaves a residue when you are done. You must wire brush that residue off before you can solder it. The same applies to the neck.

IT MUST BE CLEAN, CLEAN, CLEAN BEFORE THE SOLDER WILL STICK !!!!!! A paste type flux is the best to use. Stay away from the liquid types.

As to the type of solder, any will work just fine. Even Silver Solder, but that takes a lot more heat and may warp the tank.

The newer types of solder have no or very little lead in it. Harder to use but it is safer for the drinking water system. I don't know if you can still buy the resin core or the acid core solders. I only use the newer type for plumbing.

Hope this helps,

Jim

Hi Chuck. I've got Polaris standard soldering, Mil standard 2000 soldering and it still beats me sometimes why solder wont take to certain joints. I can try all day to repair something with no success and pass it on to one of my workmates and it works first time, Conversely wee Stevie who works next to me goes daft when a job thats driving him crazy goes first time for me. All joking aside it depends on the base metal your trying to solder. 99.9999% of all my soldering jobs are electrical and as such pose little problems. Cleanliness, and heat are the main constituents to a good solder joint. Your soldering iron or bolt must be up to the job of heating the two metals to be joined. I've seen so many people touch the joint with the iron and then offer up the solder to the iron and wonder why it doesn't take to the joint. I've also seen the joints heated so much with a flame that the solder just runs straight off. To make a good solder joint :-

1 cleanliness is next to godliness. Wire wool, emery cloth, grinder or whatever get it clean and degrease. Also flux is not an absolute necesary you can get just as good a joint without flux if the area is prepared properly.

2 make sure your heat source is powerfull enough to heat the area to be joined without overheating.

3 apply the solder to the metals to be joined not the iron. remove your solder stick before you remove the heat source.

4 If all else fails Braize or weld.

hope this helps somehow. Simon

Is there a consensus as to whether the best heat source is a flame (torch) or a soldering iron (elec.,or heat sink)? I wonder if the flame would contaminate the clean metal with carbon.

A friend of mine solders with propane and oxygen and says it wont contaminate the flux it burns so clean.John.

I haven't given it much thought Garrison. I work for the military and tend to shy away from flame for obvious reasons (explosives dont like flames). Regards Simon.

use muratic acid to clean the parts to be soldered

Don't depend on wire wheels or ANYTHING like that! A previous post was correct: grind, sand, scrape or whatever! If you don't have PERFECTLY CLEAN surfaces nothing will stick....period. If you don't see perfectly clean, shiny metal you're screwed before you start. And that includes galvanized too. Just for the record I use liquid flux almost exclusively: Johnson's Lloyds No. 6 soldering fluid---alcohol based and it's great stuff!!!

Skip the solder and use fibre glass resin to put it back together. Mix the resin and hardner and coat both sufaces and hold in place. Sets fast and won't leak. I've used it for putting filler caps on gas tanks I've made.

I wonder if JB Weld could be used to replace a connection on a gas tank??

Warren

JB Weld and aluminum foil can and will PATCH a gas tank, so it should work

I use solid core solder and paste flux-same stuff I use for pipes (flux that is). For solder I use good old 60/40 tin/lead. Contrary to popular belief you can still buy it and you can use it without dying I get mine from my wife's stock that she keeps for her stained glass work. And I've found that buying it at the stained glass supply house is cheaper than any other source - go figure!

Norm

If the tank is galvanized, you need to use acid core solder otherwise the solder will bead up and not "wet" the surface. I prefer sandblasting the area and using silver solder, but at $9.00 a troy ounce, it can get costly. Good Luck!!!!! Ron

If I were you I would make a sample and put in a bucket of the modern gas to see if it will dissolve.

I think I tried JB Weld on my cork float and after a night in the can of gas, it had all dissolved.

Maybe that was plain old epoxy, heck I can't remember for sure, but I would try it on a sample before I put it on a fuel tank.

I like to use a big copper soldering iron. (1-1/4" diameter and 3" long) Don't let it get too hot or it will ruin the "tinning" on the tip. I file the tip and us "ruby flux" with a cotton swab and apply solder until the tip is nice and shiny.

I use the no lead solder. It is supposed to be stronger than 60/40 and melts at a lower temperature. It also will not oxidize nearly as quick. I also wash every thing very well with water after soldering to remove any flux left.

I get the "ruby flux" at the HWI Hardware store.

HEY! It works for me and I'm sure other proceedures will work as well.

"DELCO DON" Southern Illinois

"DELCO DON" Southern Illinois

Plain old "BONDO" body filler or putty works also. I have used it on quite a few tanks and haven't had it leak yet. Clean metal, sand with coarser paper to rough it up. apply bondo, sand smooth and paint or what ever you preffer to finish. Cheers Paul Hokanson

I think if I was going to just patch i.e a temp repair then fiberglass or J.B.Weld would be ok.But for a genuine permenant repair the only way is cut out the rot,replace and solder,or just simply solder the small stuff,I used to use liquid tinners flux but its messy.Now I use a No-Ko-Rode tinners paste with solder in it.When the paste turns grey it means the solder in the flux is melting and its time to apply the actual solder rod to it.I havent has a problem even with galvanized.Mind you im only using a Blazer Big Shot1000 butane torch to do this to,not propane,mapp,etc.Its all in the prep work!John.

I have used fiber glass fabric and fiber glass resin to repair a broken threaded boss on a die cast Stromberg carburator used on a 1933 Packard engine. Treated the inside and outside with the fabric and it has been running for 5 years.

Please be careful if you use an open flame tourch on a gas tank.

I have seen a dry fuel tank that has had nothing in it for years go off like a bomb when trying to do just what you are asking about. Is not a pretty site.

At work, if we weld a fuel tank, we have analysers to check for explosive gases, or we fill it with water. Now I know that will screw up a soldering job, but please be careful.

DB

Daryl, I work with explosives so you can imagine the precautions i have to take for any type of hot work. Any time i solder or weld a tank its filled with water as a matter of course. Remember an empty tank is infinitely more lethal than a full tank. Thanks for highlighting it for other users of the board. Regards Simon.