Topic: Gas tank rust - how many pin holes is too many? Tank shop grenaded my tank

[eigenvector]

"Hey man I don't know what happened.  We filled the tank with nitroglycerin to get the rest of the rust out - and when we set it down on the work bench it just exploded.  I just don't understand what happened man."

[Smudgemo]

One day just for the hell of it I'm going to get my hands on a rusty tank and try brazing up the holes with the bronze I use for making bicycle frames.  After soaking it, of course.  I keep thinking I could fix rust holes, but maybe I'm full of crap.

[calj737]

One day just for the hell of it I'm going to get my hands on a rusty tank and try brazing up the holes with the bronze I use for making bicycle frames.  After soaking it, of course.  I keep thinking I could fix rust holes, but maybe I'm full of crap.

Nope, you're not. It works perfectly well. I use 0.045 SilBrz wire with a TIG to repair tanks. Works a treat. Just gotta be rust-free inside and out.

[slikwilli420]

So this happened this morning...



I am at a total loss for words. Its totally destroyed and while not beyond repair, it would cost far more than the effort is worth. I do have a backup tank (in background) that I will have to try and figure out myself.

They claim some gas vapors were hidden in the rust and it exploded. He also mentioned he had not checked to see if the vent was working properly. This tank has been stripped and soaked more than once with non-flammable products and I just don't see any way on God's green earth what he is telling me is the truth.

Im going to give the other tank a soak in Evaporust and then go from there.

[calj737]

If they sealed the tank with acid inside, the gases of the acid eating the rust expanded the tank. Was that a K or F tank, Willi?

[slikwilli420]

He claimed when he put flame to the area he was working on that's when it ballooned up. Thing is, about 90% of the work was already done. He was just finishing up, which mean he has a torch on just about every other square inch of the bottom of that tank with no issues.

It was a nice SS tank (minus the rust holes), but now its a modern art masterpiece. I can't even chalk up to the Gods of Speed since it never even had a chance to be used on a running bike.

[PetesPonies]

Its really not that difficult. I wish someone here would do as I suggest, come back and tell everyone how well it worked. Then there wouldn't be such worry and such destruction. A rusted tank, start by pouring in phosphoric acid. Leave it in a couple days. You can get it at the big box stores. It is not expensive. After that, pour it out and  blow air inside the tank until it is dry. Let it sit for a couple days, airing it every so often. Then pour maser Series silver in the tank. Turn the tank from side to side. Let it sit on each side no longer than an hour. Once you have coats all the tank, or all sides you want coated, pour out the rest. The next day, you are as good as gold.

[slikwilli420]

Pete, you sound like you are ready to take the Pepsi challenge on this stuff.

I don't want to got the acid route, but will use Evaporust which I have had really good success with. Will that still work?

You willing to send a quart my way gratis? If it does as you say, I will sing from a mountain top.

[Stev-o]

I'm surprised we have not heard of this product before...

http://masterseriesct.com/

[drumstyx]

...that sort of thing doesn't just happen...I think they might owe you a tank...

[slikwilli420]

I had $100 into the original purchase price, chemical stripping at another place and some previous brazing work. Guy said he would cut me a check to make me whole and to get out of his hair. I obliged.

That cash should help me get the other tank derusted, coated and painted.

[calj737]

Its really not that difficult. I wish someone here would do as I suggest, come back and tell everyone how well it worked. Then there wouldn't be such worry and such destruction. A rusted tank, start by pouring in phosphoric acid. Leave it in a couple days. You can get it at the big box stores. It is not expensive. After that, pour it out and  blow air inside the tank until it is dry. Let it sit for a couple days, airing it every so often. Then pour maser Series silver in the tank. Turn the tank from side to side. Let it sit on each side no longer than an hour. Once you have coats all the tank, or all sides you want coated, pour out the rest. The next day, you are as good as gold.

There are numerous rust converting/sealing products that work very well. I don't see anything particularly unique about why this particular product is THE best? Caswell, POR-15 and others all do exactly as this product describes. Maybe, the only advantage over Caswell that I see is that Caswell is a 2-part where this appears to be a single stage product. But like Caswell, it too hardens completely.

Personally, I don't know whether a rock hard interior surface is a benefit on a track bike; I'd defer to the racers for their experience and recommendations about it. Cost-wise, its the same as POR and Caswell. If you have great experience with it, use it. But it hardly seems to be an epiphany product to me? 

[bwaller]

Bad deal man. I'm the one who suggested a rad shop in the first place but there was no need for that mess.

[drumstyx]

I had $100 into the original purchase price, chemical stripping at another place and some previous brazing work. Guy said he would cut me a check to make me whole and to get out of his hair. I obliged.

That cash should help me get the other tank derusted, coated and painted.

That's fair, glad they didn't hang you out to dry after that.

[ekpent]

 Just for fun Matt can you take a picture from the front and maybe the underside also.Thing is really spread apart. Glad they paid you off at least and now you have a cool piece of garage art  Bet the guy working on it had a major OH SHIZZLE moment,sure they don't like ruining peoples things.

[Terry in Australia]

They claim some gas vapors were hidden in the rust and it exploded. He also mentioned he had not checked to see if the vent was working properly. This tank has been stripped and soaked more than once with non-flammable products and I just don't see any way on God's green earth what he is telling me is the truth.

Did the dude's nose get longer as he was telling his story mate? Ha ha, it should have. That damage is not as a result of the combustion of a tiny amount of gas fumes hiding in the rust, (which wouldn't have been present anyway) but rather, when he pumped the compressed air in to test if it was sealed. How do I know? I've done it myself, trying to use compressed air to pump the dent out of a CB750 tank. (which doesn't work, by the way) I caught mine in time and was able to pull the compressed air and pull the two sides of the tank back into the middle, but I reckon yours is too far gone?

A radiator is a pressure vessel, and as such, is designed not to deform under pressure, whereas a gas tank is designed to hold fuel and is vented in case of any pressure buildup inside. My guess (and I'm certain of this) is that the "Technician" hooked up the compressed air and walked away for a moment, while your gas tank was turning itself into a balloon.

Anyway, you got some money back and you have another tank, so no biggie. Do you have a bore scope camera? I bought one years ago and it's really handy for looking at the insides of gas tanks. If you do, poke it inside your replacement tank, and if it doesn't look like the dark side of the moon, give it a wash out with that Evapo Rust stuff (looks like a good product, I might have to buy some) and call it good. If it's cratered, don't weld it, get some of that stuff that Pete's talking about. Cheers, Terry.    

[Lostboy Steve]

Shop calls today and said they blew my tank apart and it's destroyed. I'm literally at a loss for all words.

Pressure test gone out of hand?

That's my guess. These tanks aren't exactly stress proof. Which is why I said I wouldn't solder for structural strength. After my tank was powder-coated it didn't hug my frame right. I wound up using a ratchet strap to squeeze it back together. Imagine what a few psi of air could do...


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[Lostboy Steve]

They claim some gas vapors were hidden in the rust and it exploded. He also mentioned he had not checked to see if the vent was working properly. This tank has been stripped and soaked more than once with non-flammable products and I just don't see any way on God's green earth what he is telling me is the truth.

Did the dude's nose get longer as he was telling his story mate? Ha ha, it should have. That damage is not as a result of the combustion of a tiny amount of gas fumes hiding in the rust, (which wouldn't have been present anyway) but rather, when he pumped the compressed air in to test if it was sealed. How do I know? I've done it myself, trying to use compressed air to pump the dent out of a CB750 tank. (which doesn't work, by the way) I caught mine in time and was able to pull the compressed air and pull the two sides of the tank back into the middle, but I reckon yours is too far gone?

A radiator is a pressure vessel, and as such, is designed not to deform under pressure, whereas a gas tank is designed to hold fuel and is vented in case of any pressure buildup inside. My guess (and I'm certain of this) is that the "Technician" hooked up the compressed air and walked away for a moment, while your gas tank was turning itself into a balloon.

Anyway, you got some money back and you have another tank, so no biggie. Do you have a bore scope camera? I bought one years ago and it's really handy for looking at the insides of gas tanks. If you do, poke it inside your replacement tank, and if it doesn't look like the dark side of the moon, give it a wash out with that Evapo Rust stuff (looks like a good product, I might have to buy some) and call it good. If it's cratered, don't weld it, get some of that stuff that Pete's talking about. Cheers, Terry.

The evaporust stuff leaves a black oxide I'm not sure what the people who have used it do with that. I suppose wash it out?

Everyone has a method. I still like electrolytic removal after a good shake with paint thinner and screws. Then whatever repair is necessary.




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[BPellerine]

I have seen a 50s Norton tank that had been dry for years explode and lift into the air about 8ft when a guy I knew was trying to braze it,it was a rare tank and he was heartbroken.bill

[Lostboy Steve]

Here's one I did for a member.

Had to install a patch from the inside because it was so badly thinned. Once welded it, it was smoothed out, and leak free.

Did you cut out the bottom first? I'd like to see how you did the internal repair. Nice job.


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[Terry in Australia]

I have seen a 50s Norton tank that had been dry for years explode and lift into the air about 8ft when a guy I knew was trying to braze it,it was a rare tank and he was heartbroken.bill

What was in it Bill, Nitro Glycerine? Most fuel is good for maybe 6-12 months tops nowadays, and if it's been flushed a couple of times like the OP says, I reckon you could drop a match in it with no fear, but even if you did, it wouldn't do any damage like what's in the pics. That's air pressure. Cheers, Terry.

[slikwilli420]

My dad has a buddy with an engineering background and he is sure that the tank ballooned because the acid they use was full in the tank and the flux/solder combination can cause a reaction that if not vented will result in expansion. Since I know the cap was on at the time that energy had nowhere to go and boom, chemical reaction. It's peculiar that the repair shop didn't think of this anytime in the over 30 years of repairing such things.

[calj737]

My dad has a buddy with an engineering background and he is sure that the tank ballooned because the acid they use was full in the tank and the flux/solder combination can cause a reaction that if not vented will result in expansion. Since I know the cap was on at the time that energy had nowhere to go and boom, chemical reaction. It's peculiar that the repair shop didn't think of this anytime in the over 30 years of repairing such things.

It's as Terry stated, these gas tanks are vented, radiators are not. Rads are designed for pressure. Whether it was a chemical reaction or compressed air that caused that failure, its all down to venting.

So that's a clue to you that your fuel vent was still not clear  This may have caused you all types of fit racing later. Silver lining perhaps...

[calj737]

Here's one I did for a member.
Had to install a patch from the inside because it was so badly thinned. Once welded it, it was smoothed out, and leak free.

Did you cut out the bottom first? I'd like to see how you did the internal repair. Nice job.

I did, 2 large rectangles on either side. A small whizz then, a fresh piece of cold rolled sheet, dropped in thru the filler, positioned, and welded. Flap disk it down flush. The trick is to feather out the weld onto the new material so when you disk it, it comes up flush to the original surface and doesn't leave a crater to fill with bondo.