Gas tank

[newtothis]

I am torn between two ideas,  so this is basiaclly what would you do thread?

My gas tank currently has three pin holes and a leak at the seam. I was lead to beleave that the right cleaning followed by bondo with the tiny glass fibers would fix it. Followed by POR 15, for further rust protection.  

 I have tried the JB weld:; both kinds. As well as automobile  gas tank repair, however the gas keeps eating thru the patches.

Have any of you heard of this?  

I do not want to buy another old/rusted tank...How ever if going to buy a new tank is the only answear, do you men, know of something newer that is interchangeable?

I am going to replace the tank when I start chaning the looks. I am leaning towards a sportster tank.  

Any ideas?


Update,  I said heck with the dumb stuff. I bought new clamps. exhaust crush gaskets, and  those five millimeter brass adapters for the home made manometer. New spark wires.  Will get new coils when I get the voltage/hms reader. After all this is complete, I will put up a new video. Thank you every one for all your help. And a speacial thank you to who started this site, Awealth of knowelage can be found here. that can not be found in the books.

[easyrider12]

A good bet would be to SOLDER it, especially the leak at the seam.  May have to remove your other quick fix first.  A radiator repair shop might help for a few dollars.  Good luck ;)

[Piute]

       If were mine I'd fiberglass it ,
       while I looked N bought a good tank.

[Hoosier Daddy]

Bondo will not hold long, I'm with easyrider on this one. Either solder or braze the tank. You will have to grind of all remains of your previous attempts.
 Then if you have an air compressor and a regulator hooked up you can connect an air hose to the petcock, PSI turned WAY down, petcock "on" and lid closed put it under running water and watch for bubbles to check for leaks. (Spit even works)

[newtothis]

like plumbing solder?   sounds scary, but hey i'm game!!!

[Hoosier Daddy]

Yep, I'd use solid core with paste flux just like sweating pipe together.
There are always cautions to take to work on a tank with a torch. Be sure you know it is dry, and put an air hose in it blowing constant air for a while to remove all the fumes ( hour or more).  I've even seen old timers leave the air hose on while doing the work... or fill the tank with another non-flamible liquid to displace the fumes.

[shultz_1978]

newtothis These guys seam to know what they are telling you. The biggest thing is get all gas and fumes out of the tank.  

If you have soldered copper pipe together it is kind of the same thing. I have a tank I am thinking of doing the same thing to. If I get to it befor you I will let you know how I did it.

[Piute]

    I use soap N water and blow dry,I've also never used a rusty tank.

[newtothis]

Thank you shultz.  

[shultz_1978]

Well I tried the soldering the other day and I think I like welding it up better. I don't like the solder kind of pudle up.

I melted it back out and will use the mig on it. Just turn the welder down so I do blow any holes.

I was told that brazing will likely do the same thing pudle just not as bad.

[Hoosier Daddy]

Yes, didn't know that was an option.
 When soldering or brazing you need to get the surrounding area hot enough that it flows. Not just heat it so it melts. Solder does it at lower temps than brazing... that has to be orange before it flows right.

[shinyribs]

If at all possible,and it's really hard to pull off with a gas tank,it really helps to 'back up' your work when trying to weld thin sheet metal. Hold a piece of wood behind what you are welding and it will help with burn through. It absorbs some of the excess heat and also prevents the wire from wanting to ''push thru'' the work when it's molten. Wetting the wood helps to keep it from smoking and contaminating the weld,but too wet and you have problems too. And only wet with water. Anything else can flame up or smoke. Aluminum works well,too.But it's kind of tricky since it will react to the arc and can do really funky stuff sometimes. You really just have to try it and get the feel for it,but once you figure it out,and it not hard,you'll be able to do it easily.

[Lucky 1]

Do not weld on a used gas tank!

No matter how much you clean it it still can make an explosion.
What happens is as the tank starts to heat up vapors start forming
in the tank from fuel that is in the metal.

It will make a bang and you can get your hair or eyes singed.
It is also very scary.

Two months ago a young man was killed trying to cut a 50 gallon drum open
at his high school shop class. They washed it out.
The drum had formally contained coconut oil,a petroleum based product.

Needless to say that high school shop teacher lost his job.

If you go to Welding web.com you can read about all the
accidents when people weld on old gas tanks.


Clean the tank and use Caswells' two part tank liner
with some white colorant that you can get at TAP plastics.
Get the premixed 2oz. jar of colorant. about $6.00
Caswell approved the colorant.

IF it is a CB750 tank use the whole kit. Not half.
http://www.youtube.com/watch?v=9DP5l9yYt-g

[shinyribs]

Coconut oil is a petroleum based product?

[motogrady]

yikes..........weld/braze/solder any used tank or can is very dangerous.  I've heard of
venting (one guy ran steam while he was brazing) while at work, but I'd be leery
of any open flame around a gas tank.

When soldering, the work must be shiny clean, the right flux must be used, and you can't
get the work too hot.  There are things called soldering irons out there.  I've used them on
roofing jobs.  You stick them in a fire, the copper ends get and hold the heat, you hold these to the work and add solder.  Kinda like an electric soldering gun.

Brazing, especially on sheetmetal as light as that, I dunno.  Only difference between soldering/brazing is the heat, much more heat.  It's real easy to get too hot and burn or oxidize the metal, warp the surrounding metal or plain blow a bigger hole in the tank.

Welding, a mig would prob do it.  A tig welder would do a neater job, but remember, there will be sparks
jumping all thru that tank when you do.  Any fuel vapors left over will ignite and blow the tank.

I dunno, for the peace of mind, I'd go to a new or different tank.
The horror stories on tank sealer kinda scare me away from that route.   good luck guy.

[Lucky 1]

Bondo will not fix a gas tank.
It is not gas proof.