soldering stainless with lead

[Watershed]

This is NOTHING to do with stills, or anything that has anything to do with any form of food stuff but I need to do a quick fix.
Will standard lead solder wet stainless steel with a shot of ammonium fluoride flux?

[hummelfahrer]

High Watershed,
The answer is:NO.It won't stick,if it does it will NOT last.
You will have to use silver solder oder TIG-weld it.
Or use a mechanical means of making connections,either by crimping or by using threads.But I have seen rigs built fromSS that used threaded female couplers and just plain ss tubing wrapped with teflon tape and then threaded into the couplings.
Greetings
hummelfahrer

[Watershed]

Awww, might as well wait until I can borrow the spot welder then - broken joint on one of our liq nitrogen dispensers.
cheers

[LeftLaneCruiser]

Hi Watershed,

Sorry for not having jumped in earlier, but i have soldered stainless to copper and stainless to stainless with no problems.
I needed to use a special kind of soldering fluid though. Read on the label "especially for soldering stainless steel" (S-39 rvs).

I found the stuff in the local do-it-yourself hardware store, don't know if it's available in US and or UK.

KJH

[Brett]

personally i wouldnt solder something that handles liquid nitrogen tho

[knuklehead]

This is NOTHING to do with stills, or anything that has anything to do with any form of food stuff but I need to do a quick fix.
Will standard lead solder wet stainless steel with a shot of ammonium fluoride flux?

Sure it will work. I solder stainless with 50/50 using zinc chloride flux, works great. Solder is solder it's as simple as that. If you can solder something with lead free solder then you can solder it with lead solder. Only reason you chose one over the other is the intended application. The most important thing is the flux.

[rectifier]

Remember in a cryogenic application (especially a dispenser which heats and cools many times a day) there is a lot of contraction and expansion. You're not going to want to patch a hole with a different metal, or it will be under a potentially serious strain due to different expansion coefficients... and just start to leak again.

I have worked with quite a bit of LN2, and quickly learned nothing is leakier than using a swagelok fitting made of a different metal or alloy than the pipe... Cryogenic stuff sure acts funny... anything jury-rigged always starts to leak after about a week it seems.

[possum]

I share rectifiers concearn about the differing rates of expansion. I have only used cryo in smallest. Having a big tank leak could get a fella burned pretty bad.


Hope this works out for you.