What solder should I use?

[Mark Privee]

Hi, I am new to the site and I am making an arch evaporator. I have soldered wire before but never anything else. I use a wood burner to melt the solder but I am not exactly sure what kind of solder I should use. I would think it would need to be non lead solder or maybe have silver in it. I have no idea how hot this thing is going to get but I would imagine that the normal solder would melt. Do I need high temp solder? Do I have to get a torch to heat up high temp solder? I saw a video on YouTube where the guy used copper tubes as an alternative to regular drop flue pan so that is what I am trying to make. I weld a lot but never have I welded stainless steel or soldered it, I was thinking of using regular steel like the guy in the video because stainless is apparently hard to weld/solder. Any info of what type of solder and were I can buy it would be much appreciated. Thanks

- Mark

[psparr]

You need to use silver solder for the stainless. And an acid flux to go with it. I haven't had much luck with it. But I'm a novice. My best advice is to practice with it before committing to your pan.

[Mark Privee]

Are these okay to use?
http://www.amazon.com/HARRIS-SAFETY-SILV-SILVER-BRAZING-ALLOY/dp/B002QN662A/ref=sr_1_3?s=hi&ie=UTF8&qid=1443833485&sr=1-3&keywords=silver+brazing+rod

http://www.ebay.com/itm/NEW-16oz-KESTER-Acid-Paste-Flux-Formula-SP-30-Solder-/191621723558?hash=item2c9d8b75a6

[maple flats]

For SS you want a silver solder and the flux specified by the solder manufacturer for that solder on SS. You might want to contact any of the evaporator manufacturers and see if they sell the solder and flux. Then get a small order and when you get that, search for a larger quantity online for those specific products. The type of SS may play a role too, bright annealed vs mill finish vs whatever. One may do better with one solder while another may need a different one.
You will need a few soldering irons and will likely want a flux called "Sal Ammoniac". When I was soldering a thermometer bushing to a SS pan I used to have, I asked at my local tinshop. The old master there gave me the sal ammoniac, loaned me his irons and his iron furnace (which mounted on top of a 20# propane tank). He was a long time friend who has since gone to his eternal reward. He is likely doing all new duct work for the Lord.

[Zucker Lager]

Hey Mark:
This is a low temp solder that is silver based I've used it for piping on refrigeration systems copper lines up to 3 inch that usually we would use brazing temperature and silver brazing rod like "sillfloss" but we tried this Harris product called Staybright and it held up for years, and the units were large tonnage working hard all day every day. Look around for best price it can be expensive and buy the Harris flux for it. Good luck Jay

http://www.harrisproductsgroup.com/en/Products/Alloys/Soldering/Lead-Free-Solders/Stay-Brite-Kit.aspx

[Mark Privee]

Thanks guys for all the info! The stay bright kit says it has a melting point of 430°F, will the solder melt while i am boiling?

[Zucker Lager]

Hey Mark:
I think they make a few different types of Staybright check and see what their #8 melts at??? If you get things too hot soldering then you might warp things. I think as long as your pan has liquid in it your going to be ok but if you ever run it dry then all bets are off. I've seen old commercial made pans "solderless" after that happened. Jay

[Mark Privee]

Thanks Jay, I will try it. 8 is a bit higher.