Sharing stainless work connecting cap to boiler.

[Pyewacket]

Hello folks, building an essence still. Well, I am re-purposing a concentric still and need to attach it to a typical stainless salad bowl. This may be beating a dead horse, but I have had success doing it this way a few times.

Few things.
Some tips when soldering stainless steel to copper.

This is a huge departure from what you know about soldering copper to copper. Stainless steel requires a large amount of cleaning. So you will need to sand and/or use a stainless steel brush, stainless steel wool to get ALL corrosion off the metal. You should never touch the stainless steel soldering area once cleaned. The oils from your fingers will prevent the solder from binding. You will also need to make certain that all sanding debris is brushed off the steel. If you used permanent marker to mark anything on the steel, it must be sanded off before you solder.

This flux is different. I use: http://www.amazon.com/dp/B001HWE9A2/ref=biss_dp_t_asn" onclick="window.open(this.href);return false;" rel="nofollow
LA-CO M-A Liquid Stainless Steel Flux Liquid, 4 oz -- It is not a paste. It is a liquid acid based substance. You will use a clean brush to apply on both the stainless steel and the copper. Do not use any paste flux when joining copper to stainless.

Apply the flux where you want the solder to go. This is not a capillary situation. If prepared properly, the solder will pool and make a strong bond to the stainless. I will show you photos of my stainless soldering and you will see that plenty of solder is used as it pools on the surface and binds to the copper.

Never put the torch flame on the stainless. Heat the copper and let the heat transfer to the stainless steel. Stainless steel scorches at high heat, so keep that flame away. In actuality, the stainless is so thin that it heats up rather fast--even conducted from the copper. In fact, you can use a 100w soldering iron to push fuse solder on the surface of the stainless steel. Although not needed for this application, you can also use a soldering iron to solder two pieces of stainless together.

This a pictorial -- with sub-notes on each photo.