Author Topic: Gas tank rust - how many pin holes is too many? Tank shop grenaded my tank (Read 8836 times)

Terry in Australia · « **Reply #25 on:** April 22, 2017, 07:40:48 pm »

Quote from: speedwobl on April 22, 2017, 02:19:13 pm

Terry, soldering is soft material and has a tendency to work harden and become brittle when stressed. In addition, solder does not fuse with the parent metal of the gas tank. Brazing works better than soldering and will stand up to higher loading - in fact you will see the petcock bungs on CB tanks are brazed. If you are worried about a repair area springing a leak in a crash your best bet would be to TIG weld the holes as this provides fusing with the parent metal or better yet ... don't crash!

Thanks mate, but I think you missed my point. Sure, any sort of welding is better for joining metal to metal, but when there's virtually no metal left due to internal cratering, you can spend a lot of time chasing holes that you burn with your welder and end up welding a patchwork quilt. Solder works well to fill craters in tin, and was used by industry right up to only a few years ago to make all sorts of fuel, oil and water containers, due to it's sealing qualities.

I'd be much more confident in a tank that's had all it's craters filled with solder then lined with a good quality tank liner, than one that's had the lowest point of a paper thin metal crater held together by a blob of weld. Cheers, Terry.

754 · « **Reply #26 on:** April 22, 2017, 08:16:15 pm »

I cant see the solder fatigueing, unless the metal flexs...and apparently it still seems to be reliable enough for the electronics industry.
I agree with Terry , far less invasive and lower temp than welding or brazing..hardest part is getting it clean.
Hey no one seemed to like the sectioning idea to save a rotted tank?

calj737 · « **Reply #27 on:** April 23, 2017, 04:09:46 am »

Quote from: 754 on April 22, 2017, 08:16:15 pm

Hey no one seemed to like the sectioning idea to save a rotted tank?

And "weld" the sections back together, right? Isn't that in conflict with your concern about welding a tank? The only downside to welding a tank is the person behind the torch tip. Cratering is due to dopes who don't know what they're doing when welding. Controlling heat is a learned skill and easy enough to do on thin, if not paper thin metal. MIG welding that tank would be more challenging, but easily accomplished by tacking, tacking and more tacking. TIG welding or TIG brazing are the best options, and far more durable than soldering up a tank for longevity and sealing.

But I am pretty sure the radiator shop will do a perfectly fine job and Willi will get a tank he can race and maintain as a result.

Terry in Australia · « **Reply #28 on:** April 23, 2017, 04:24:12 am »

Another reply from someone not understanding my post. The "Cratering" that I was talking about has nothing to do with inept welders, but rust. As I said previously, they might be pinholes on the outside, but the inside of the tank will look like a moonscape. There's nothing wrong with TIG/MIG welding, brazing etc on good metal of consistent thickness, but if you're going to attempt to weld a cratered tank from the outside with any sort of welder, you're going to have problems........

calj737 · « **Reply #29 on:** April 23, 2017, 04:27:54 am »

Quote from: Terry in Australia on April 23, 2017, 04:24:12 am

Another reply from someone not understanding my post. The "Cratering" that I was talking about has nothing to do with inept welders, but rust. As I said previously, they might be pinholes on the outside, but the inside of the tank will look like a moonscape. There's nothing wrong with TIG/MIG welding, brazing etc on good metal of consistent thickness, but if you're going to attempt to weld a cratered tank from the outside with any sort of welder, you're going to have problems........

Oh I understood it, I just disagree with it from experience. I do agree tanks that are rotted and chewed up internally are much more difficult to repair. But soldering them won't be any more successful than welding them. If the wall thickness is that eroded, it needs to be replaced or lined.

And being able to weld thin material that is "cratered" is all about skills which aren't sold with the welding machine at the local Harbor Freight and the 110v Flux Core piece of crap many folks buy.

Terry in Australia · « **Reply #30 on:** April 23, 2017, 04:45:58 am »

How much experience do you have welding rust cratered gas tanks Cal? Got any pics of your work? Remember, pics, or it didn't happen.............

Lostboy Steve · « **Reply #31 on:** April 23, 2017, 04:52:39 am »

Some people can fill gaps, and some can't it's just the way god made you, don't feel bad. Lol

I would never solder a tank for many reasons. Mostly because solder isn't structural. If that tank flexes at all you're going to be pissing gas. If it were mine I would electrolytically remove whatever rust I could. Then I'd braze whatever pin holes I could find. Last, I would por15 it just to be 100% sure. I've mig welded several bad tanks with success but it's very difficult and can become a big mess quite quickly. When you work in an industry where people want you to weld thin rusted steel everyday, you get good at fixing little holes and welding junk metal.

Sent from my iPhone using Tapatalk

calj737 · « **Reply #32 on:** April 23, 2017, 04:53:30 am »

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.

calj737 · « **Reply #33 on:** April 23, 2017, 05:02:27 am »

And replaced the floor plates on the same tank that were too rusted out to repair.

Terry in Australia · « **Reply #34 on:** April 23, 2017, 05:44:10 am »

Yep, as I previously posted, you've just demonstrated what usually happens with pics of the classic "Patchwork Quilt", (thank God for grinders!) and of course, where you couldn't pile the weld in, you've welded in new metal, which is a much better idea. Good job...............

BRAD CHIEDUCH · « **Reply #35 on:** April 23, 2017, 07:17:29 am »

I agree with calj, pinholes can be repaired with the right guy on the end of the torch as my picture demonstrates. However, if you have "craters" then the tank will need to be patched and if done properly will be a solid repair. It sounds like you are opposed to the "patch" repair method but I can guarantee that a patch will have a lot more structural integrity than a glob of solder in a corroded crater.

PetesPonies · « **Reply #36 on:** April 23, 2017, 09:33:51 am »

I have nothing good to say about POR15. But master Series is different.

nvr2old · « **Reply #37 on:** April 23, 2017, 11:04:53 am »

I've advocated using a radiator shop for years now, especially for pin holes along the seams. Anything bigger I've had TIG welded. Radiator shops are a great source for confirming they're sealed. They pressure test them and the liner they use is thin. I can't speak for all shops, but I have yet to have a problem. 100% repaired for less then $100. The tank has to be stripped to bare metal, though. The boiling out process ruins paint..but boy, does it determine the areas that need repair.

calj737 · « **Reply #38 on:** April 23, 2017, 01:16:04 pm »

Quote from: Terry in Australia on April 23, 2017, 05:44:10 am

Yep, as I previously posted, you've just demonstrated what usually happens with pics of the classic "Patchwork Quilt", (thank God for grinders!) and of course, where you couldn't pile the weld in, you've welded in new metal, which is a much better idea. Good job...............

::)The metal was torn to bits due to the significant crease that I fixed first. I had to use a patch but metal didn't exist. It was not required due to thinned metal. The floor plates were replaced because they too had enormous sections of metal missing.

I don't pile metal into anything I weld. I add filler to fuse the pieces. I used a flap disk to blend that patch. It was then filled with body filler and primed.

Terry in Australia · « **Reply #39 on:** April 23, 2017, 07:01:27 pm »

Quote from: speedwobl on April 23, 2017, 07:17:29 am

I agree with calj, pinholes can be repaired with the right guy on the end of the torch as my picture demonstrates. However, if you have "craters" then the tank will need to be patched and if done properly will be a solid repair. It sounds like you are opposed to the "patch" repair method but I can guarantee that a patch will have a lot more structural integrity than a glob of solder in a corroded crater.

Nope, not opposed to the patch method at all mate, your pinhole weld pic looks nice, but like Cal, you don't have a pic of the cratered inside, where the thickest part is your weld, even after you grind it flush. The inside will still be badly cratered, so while your welding will probably inspire confidence, it doesn't really add any strength. In that case a patch would be a much better idea. Cheers, Terry.

calj737 · « **Reply #40 on:** April 23, 2017, 07:32:15 pm »

Quote from: Terry in Australia on April 23, 2017, 07:01:27 pm

The inside will still be badly cratered, so while your welding will probably inspire confidence, it doesn't really add any strength. In that case a patch would be a much better idea.

The area welded will be stronger where it's been welded. Welding holes does not repair areas where metal may be thinned due to corrosion. But, as I said above, welding areas that are cratered is quite possible by someone competent. And I guarantee you, that when welded, that area is much stronger than before, craters or not.

And welded is much stronger than soldered. No 2 ways about it.

PetesPonies · « **Reply #41 on:** April 24, 2017, 06:38:31 am »

This is exactly the reasons you want to seal both sides of the welds with Master Series. If you do that, you can forget about problems.

bochnak · « **Reply #42 on:** April 24, 2017, 12:16:00 pm »

I recommend using Caswell. Mix up a very small amount and take care of the pin holes from the outside, then continue to derust. Once derusted, caswell line the inside.

I have used caswell about 8 times in the past few years with zero issues.

Matt

slikwilli420 · « **Reply #43 on:** April 24, 2017, 04:25:05 pm »

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

I have another tank but I don't trust them to try their hand at this one. It looks much more sound inside. I have evaporust and prep n etch at home. I'm thinking try the evaporust and see what happens some it's non acidic.

Thoughts?

Terry in Australia · « **Reply #44 on:** April 24, 2017, 04:35:45 pm »

Well if your tank was that bad mate, it's probably a good thing it was destroyed, all the welding in the world wouldn't have saved it. I've used POR-15 with 90% success (one fail out of 10 or more) and once again, as long as you follow the instructions for any tank liner, you should get a good, permanent result. Cheers, Terry.

PetesPonies · « **Reply #45 on:** April 24, 2017, 04:59:35 pm »

Terry, zero fails with Master Series. It's a much better product.

Terry in Australia · « **Reply #46 on:** April 24, 2017, 05:15:45 pm »

Quote from: PetesPonies on April 24, 2017, 04:59:35 pm

Terry, zero fails with Master Series. It's a much better product.

Thanks mate, it sounds great, if I can find it here I'll give it a try.

PetesPonies · « **Reply #47 on:** April 24, 2017, 05:20:22 pm »

My guess would be you cannot. However, I don't know that for sure. Just add it to your next shipment from the US.

BomberMann650 · « **Reply #48 on:** April 24, 2017, 07:00:28 pm »

Quote from: slikwilli420 on April 24, 2017, 04:25:05 pm

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?

slikwilli420 · « **Reply #49 on:** April 24, 2017, 07:06:29 pm »

Guy said he poured acid in to get more rust out and it exploded. It doesn't add up to me. I'll know more when I get to the shop tomorrow.

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Author Topic: Gas tank rust - how many pin holes is too many? Tank shop grenaded my tank (Read 8836 times)