Suggestions on soldering SS water pipe fitting

Houdini

Houdini

Senior Member
Seems like I fix one thing and then another problem pops up. I thought my petcock on my Stainless Steel water pipe was leaking, but it turns out that the threaded fitting that appears to be welded or soldered to the pipe, where the petcock drain screws into, is the problem. It looks like a leak by one edge where it meets the water pipe.

I could just buy another water pipe, but is there a way to solder it. I don't have any skill in welding, nor the equipment, but I do have a torch. If it can be soldered, what type to use. If this is not a good idea, then I'll just get a new pipe.
 
If it is indeed stainless steel, your best bet is get a new one. That stuff is tough to do when it's new, after you have had coolant and what not through it, it will be very difficult at best.
 
Clean the tube up, put apoxy in the crack and let dry. It should control the leak if you put enough on it and it has something to hold on to. your system if orginal there is no pressure on the leak.
 
Although you don't say how bad the leak is, I get the impression it is not a torrent. I'd take an even easier route than epoxy putty and put a little of one of those radiator sealing products in the cooling system.
I know, I know, there are going to be people lambaste me saying they would never put that stuff in their car. I said "a little" as in, follow the instructions. I've used that type of product for decades (only when needed) and never had it cause a problem. It will plug the leak and likely be permanent.
Forget trying to solder stainless steel.
 
Thanks for letting me know that it would be hard to solder SS. I think my best bet is to just get a new pipe. Thanks again for your suggestions and advice.
 
It is not hard to solder. I was surprised as I had to fix some stainless. I already had the silver bearing solder and I just needed the special flux.

It can be pricey to get all of that. I do enough odd jobs it is worth having the solder and flux. For you it might be cheaper to just buy the part.
 
Kevin is correct. Stainless is not hard to repair, using silver solder. Any good welding shop can do this type of repair. You can also purchase silver solder and flux from McMaster-Carr but the repair cost will probably be cheaper, silver solder is very costly.
 
If it is stainless, then it was probably brazed with a 45% silver brazing alloy which melts about 1100 dgF.

Soldering temperatures are much lower, typically below 600dgF. One product that might work is the 96%tin 4%silver solders which melt at 430dgF. I've seen them at welding supply houses in a little tube for $5. Ask for "430 solder" I think Allstate 430 was one brand.

This should stick to both the stainless and the braze alloy. You can almost "paint" it on with a soldering iron, and watch you don't use too big a heat source. The flux is a simple acid and once it bubbles on the surface, it is active and the solder should melt on the surface.
 
I used to sweat SS with standard solder (No Flux) Go to an older Hardware store and get a small bottle of "Tinner's Acid". If a kid under 35 serves you, he won't know what you're talking about. It's not well known and most people have never heard of it. It's good for radiators too.
Terry
 
I just did a search on "Tinners acid" and Oatey still makes it. Oatey is a large plumbing supply Co. For a small bottle they get under $5.
Terry
 
I used a coated silver solider that is used for food service and it works fine. It has held up on a piece of trim on my Corvette for over ten years. JMHO.
 
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