gas tank leaking - repair? replace?

[Guest]

I had the tank off of my '79 GS750e today and was poking at some rust that I hadn't really looked too closely at before, and the poking opened a pinhole in the tank. It's at the rear bottom corner of the tank, about up against where the seat would hit. I can weld, but it's a gas tank, so that seems like a pretty risky idea to me. What's the best way to repair the tank? since it isn't rusty on the inside and there aren't any available elsewhere in better condition, I'd really like to fix this one. Anyone know of people who do tank restoration? fwiw I did try to search, but it keeps coming up with some error about memory allocation.

[rustybronco]

fwiw I did try to search, but it keeps coming up with some error about memory allocation.

Use less search terms or limit you search to titles only.

[AJ]

I have had excellent results with the KBS coatings kits.

http://www.kbs-coatings.com/cycle-tank-sealer-kit.html

It takes about a week start to finish including cure time, but I've never seen one fail (compared to other products).

If it's really rusty inside, you can fill it with a cup of sheet metal screws and shake the heck out of it to break off the bulk of the rust before you start the whole sealing process.

[Steve]

If it's really rusty inside, ...

Just one small problem there.

... since it isn't rusty on the inside ...

.

[rustybronco]

I had the tank off of my '79 GS750e today and was poking at some rust that I hadn't really looked too closely at before, and the poking opened a pinhole in the tank.

Me thinks it very well may be...

[eil]

The tank can be patched by welding, as long as you have the foresight to completely drain, rinse, and dry the tank before putting fire in it. Problem is, you found one hole. How many others might be well-hidden elsewhere?

I'd go with a tank lining kit. I've never done it before, so I can't recommend a particular brand or method. But it's a semi-regular topic, so you should be able to find a thread or twelve about it once the search feature is fixed.

[lemonshindig]

Replace the tank, man. It's not worth it.

I just did the POR-15 fuel tank sealer, but my tank didn't have any holes or thin metal in it. It had a lot of surface rust inside that was clogging filters and carbs, but the metal was still plenty solid everywhere so it made sense to fix it.

You, on the other hand, have holes. Buy a good used tank, and recoat THAT if necessary. Throw this one out.

[Badooka]

POR 15 is good stuff!!!!!!!!!!!

[chuck hahn]

Actually doing the liner IS worth it. As per the instructions for the Caswell 2 part epoxy kit, you simply put duct tape over pin holes, do the deristing and apply the liner as you normally would and let it cure.

Then you peel off the tape, do any bondo filler, and repaint as normal.

Here is how the instructions told me to perp the tank on the TX project for protecting the paint. I dont know if this tank had any pinholes or not, but it was rusty as all heck, so the liner was in order regardless.

Duct tape off everything, get some set screws for the petcock bolt threads and oil them so the epoxy doesnt bond to them, cut a slot for putting in the liner and retape the slit shut. Apply the liner per the instructions. Remove the set screws once it has BEGAN to cure..in about 1 hr.

[chuck hahn]

Here is a link with the instructions..pay special attention to the duct taping parts...

http://www.caswellplating.com/restoration-aids/epoxy-gas-tank-sealer.html

[gearheadE30]

Thanks for all the suggestions. I have heard so many things about those tank liners flaking off after a while that they make me a bit nervous, but that does seem like the best option right now.

As to the rustiness of the tank, the reason there is a rust hole is that the seat was rubbing on the tank, which eventually rubbed through the paint and caused it to rust. Visually looking in the tank, it looks good, and there no grit or flakes or anything came out when I drained the fuel out of it. So far as I know, there isn't really another great way to check without cutting the tank open, which I'd like to avoid.

I'm going to to a little more research on that liner to see what other people have to say about how well it holds up over time, but it looks like I'll probably go with that.

[AJ]

Thanks for all the suggestions. I have heard so many things about those tank liners flaking off after a while that they make me a bit nervous, but that does seem like the best option right now.

As to the rustiness of the tank, the reason there is a rust hole is that the seat was rubbing on the tank, which eventually rubbed through the paint and caused it to rust. Visually looking in the tank, it looks good, and there no grit or flakes or anything came out when I drained the fuel out of it. So far as I know, there isn't really another great way to check without cutting the tank open, which I'd like to avoid.

I'm going to to a little more research on that liner to see what other people have to say about how well it holds up over time, but it looks like I'll probably go with that.

I have done 3 tanks that sound exactly like yours with the KBS kit. Actually, one of those was probably quite a bit worse, requiring reinforcement mesh. The wash removes all gasoline residue, the etchant eats the rust and leaves a protective chemical coating to prevent further rusting, and the sealant is a metal-filled polyurethane, which is the same stuff used to seal aircraft tanks.

The bad results others have had with products like comes from poor prep work and poor adhesion. In fact, KBS sells a product to remove the remains of failed coatings like Kreem.

[mike_of_bbg]

Some coatings (like Kreem) are rubbery and will flake. Never tried POR15 so I don't know. Caswell is an epoxy and cures HARD - think like structural liner, here. It's rather thick and doesn't "slosh" during application so adding a little MEK to thin it might help for a more complete coating. I've never heard of a failure with Caswell. A few things of note:

Caswell's kit is enough for two tanks. Don't mix it all together at once!

They say you don't have to de-rust inside before application, and I didn't fully de-rust. In fact they say the epoxy can "bite" better to a rusty surface. The rust will not grow due to oxygen deprivation. What they don't tell you is that the stuff cures perfectly transparent and you'll be able to see your rust forever...

Chuck gives good advice about application. If I had a leaking tank, Caswell would be my only choice.

Thanks for all the suggestions. I have heard so many things about those tank liners flaking off after a while that they make me a bit nervous, but that does seem like the best option right now.

As to the rustiness of the tank, the reason there is a rust hole is that the seat was rubbing on the tank, which eventually rubbed through the paint and caused it to rust. Visually looking in the tank, it looks good, and there no grit or flakes or anything came out when I drained the fuel out of it. So far as I know, there isn't really another great way to check without cutting the tank open, which I'd like to avoid.

I'm going to to a little more research on that liner to see what other people have to say about how well it holds up over time, but it looks like I'll probably go with that.

[gearheadE30]

Cool, that's what I'll do then. Thanks guys.

[oldgrumpy]

I have done 3 tanks that sound exactly like yours with the KBS kit. Actually, one of those was probably quite a bit worse, requiring reinforcement mesh. The wash removes all gasoline residue, the etchant eats the rust and leaves a protective chemical coating to prevent further rusting, and the sealant is a metal-filled polyurethane, which is the same stuff used to seal aircraft tanks.

The bad results others have had with products like comes from poor prep work and poor adhesion. In fact, KBS sells a product to remove the remains of failed coatings like Kreem.

.....................hi guys look i,ve stuffed around buying tanks off ebay and i got caught .. i purchased a gs1000 tank supposed to be a 1980 from usa ... i got it well packed pulled it out and here was a black shiney high gloss tank with gold/silver flec thru it as well i put it on the gs1000e and the petcock position was over the top of the carbys,,, ,,,it just wasn,t worth wasting my time with ,,,,,, its still sitting under my bench i tried to use it but wasted my time ....buy a vg tank ,not a cheap bargain regards oldgrumpy