Joining copper to stainless

[mark bolton]

It was suggested I consider converting my flat pan to a boiler design, running tubes through the bottom of the pan front to back and dropping the bottom of the pan into the arch. This would allow the hot gasses/smoke from the fire to run through the tubes in the sap acting similar to a flue pan.
Has anyone braised copper to stainless? I was thinking of using copper tubes and joining them at the ends to the stainless steel with a bronze alloy. Just wondering if this is possible &/or if the different expansion/contraction properties of the metals would cause a joint failure...

[KenWP]

You have to check but it's seems that brazeing is not allowed for a syrup pan. The bronze rods have been know to contain led. If they pass the food test they probbably would work. You will here on here of guys tig welding and mig and rod welding and non lead solder but never brazeing.

[MartinP]

Just flare the ends and solder them. That is how I made my pans.
Photobucket has pics

[WF MASON]

There was a time when alot of the old syrup pans with copper and bronse fitting needed to be replaced and keeping that connection for the flue pan involved putting that fitting back onto a welded replacement pan, I moved from soldering them to welding them with silicon bronse tig rod ,it wouldn't be something I'd recommend learning to weld on, one metal is sucking up the heat and the other is fighting against it. I always thought the welded steamaway with welded in copper pipes would be something , but I was told you can't weld copper to stainless.

[WESTVIRGINIAMAPLER]

Bill,

Nice looking unit you have in the new Bascom's catalog. Guess you will be working your fingers to the bone now trying to keep up with all the orders.

[mark bolton]

Thanks for the info.
MartinP- great pics, I see you flared the ends, fitted them in then from the ends then joined them in the center.
How did you cut the holes in the stainless and how did you flare the large copper?

[MartinP]

Thanks,
I bought a hole saw that was the same dia as the copper tubes. It looks like one for cutting holes for locksets in doors, it just has bimetal cutting teeth.
To flare the copper, took a piece of alum. pipe same size as the copper pipe. Cut it in half then put the copper thru the holes in the pan and clamped the alum pipe inside tight to the pan. Then ball peen hammer a bunch arount the outside edge that was sticking through. Maybe 1/4" until it matched the pan. Took it back out, tinned with solder and then put in an solder to pan. Same thing on other end, just slide coupling over the middle first. Solder the end then the coupling in the middle.
Have fun, and happy boiling.

[WF MASON]

I haven't seen the new Bascoms catalog , but if my evaporator is in there, I believe I reached the 'PINNACLE' of my career, I must now announce my retirement while being at the bottom of the top in the industry, I'm off to Kroger New York.

[3rdgen.maple]

I seen them in the catalog as well. Funny thing is though on line it says sold out.