Fuel tank pinholes

[YammieBruh]

Hey everyone. So I've been trying to get this bike put back together to hopefully be able to ride this summer. After I added gas to the tank I started to notice some of the paint on the sides of the tank where the emblems used to be start to bubble. I was hoping this was a coincidence but decided to investigate. This is what I found. Looks like the usual handyman special with booger welds, but I've found a pin hole. My question is, since I don't have access to a welder is this worth trying to repair, I also think ther is a leak on a seam near the tank mount bolt that I was hoping to solder. Not sure if I should continue on or buy a new tank. Not really looking to get a used one since I might be in the same boat as this one especially for the prices some people want around my area.

 

[TwoManyXS1Bs]

Do a forum search on "Caswell"...

 

[RustiePyles]

If it were my tank I would drain it, vinegar soak, rinse, flash it off, and purge it with an inert gas like C25. Then braze up the holes. But I'm guessing since you don't have access to a welder you don't have access to an oxy/acetylene rig either. I'd be hesitant to try a tank coating with holes that big. Might try putting up a wanted ad here on the forum for another tank.

 

[gggGary]

Using flame heat on a used gas tank is not for the faint of heart.
Cannot caution enough proper methods to eliminate remnants of gasoline in the pores of the tank need to be scrupulously followed.
The rear seam may be the bigger of the two problem areas. A leak there is usually limited to factory 1973 tanks that had a factory flaw and were mostly replaced during a Yamaha recall.

 

[jetmechmarty]

I’d be willing to try a Caswell liner on that tank if it were mine.

 

[rsor]

I would try soldering it up after a good clean out.

View attachment 188387
No leaks, 3 years later

 

[gene xs]

There is a gas tank patch epoxy available at auto stores. It's a two part putty that is very stiff. I've used it on similar holes in two tanks with success.

 

[Mailman]

There is a gas tank patch epoxy available at auto stores. It's a two part putty that is very stiff. I've used it on similar holes in two tanks with success.

Yeah I was just researching and there are two companies that make a two part epoxy specifically for gas tank repairs , JB Weld and Permatex,
The JB Weld product gets good reviews and claims to be chemical and ethanol resistant. I was reading some reviews and for the most part it got very good reviews, the only failures noted was when the repair was in a high stress area such as a crack at the edge of a bracket.
Looking at where your pinhole is, it appears to be located inside a small scrape/ dent , this area could be filled with a good amount of JB Weld and sanded down , and finished off with a final cosmetic cover with some body filler.
Whether or not you choose to then line the tank, I think this would be a decent , no welding required fix.
If you go with a liner, Caswell is probably your best choice, it dries hard as glass and won’t melt from today’s oxygenated gasoline like some others do, ask me how I know......

 

[lakeview]

What year and model do you have? Bike pictures always welcomed here.

 

[Jim]

Keep in mind that if you go the epoxy route.... petroleum (gas) residue gives poor adhesion. Scrub that area real good with a solvent such as acetone.

 

[Paul Sutton]

I would try soldering it up after a good clean out.

I recently patched several dozen pin holes in a steel generator tank. I used normal electronic solder and Fluxite for the flux. It was difficult because the flux I used was not quite suitable for steel. Judging by the work of rsor above he had a very good flux. Perhaps rsor could share with us the flux he used because that is really the secret to good soldering on steel.

Thank you.

 

[miketweedie]

RedKote is a great option here. I used it in my Cafe tank that was littered with pinholes and it is holding up great. Prep is the key to this, though. Thoroughly clean as per the manufacturers instructions.

 

[Jim]

I recently patched several dozen pin holes in a steel generator tank. I used normal electronic solder and Fluxite for the flux.

Same here... on a lawn mower tank. Don't recall the flux, but I soldered it using a heat gun and basically flowed/coated the entire bottom of the tank. Was still leak free 4-5yrs later when I got rid of it.

 

[rsor]

Sorry guys, all I can tell you is that flux paste came with a soldering gun kit that I brought some time back. There are actually no markings on the small container, I would have to figure it's for electrical soldering. It is fairly dark in color. The solder was regular 50/50, lead, tin.

 

[jetmechmarty]

RedKote is a great option here. I used it in my Cafe tank that was littered with pinholes and it is holding up great. Prep is the key to this, though. Thoroughly clean as per the manufacturers instructions.

RedKote is solvent based. @Mailman posted a list of what was in his (Arizona) gasoline. After seeing that, I won't trust anything solvent based. YMMV

 

[Rasputin]

If you are soldering on steel or other metals with tinmans solder you will need Bakers fluid.
Also you will need a decent sized soldering iron. Don’t know why the call them irons because the bit is copper.

 

[YammieBruh]

the bike is a 78 but the tank is not, its only got one petcock. the hole is where the PO shaved off the emblems. I might just give the caswell a try if i can find it around here, but will first use the tank epoxy.