[BeerWelder]

I need to weld/braze/solder several 4" tri clamp ferrules to various kegs and SS pots. I tried a year ago and gave up.

I've successfully soldered smaller fittings to a pot, but never larger fittings or to a keg.

I've tried SiBr brazing with a TIG torch. I can do it on flat surfaces but I can't get nice welds with a ferrule on a keg. I need airtight welds. I've been warned that SiBr is known for having porous welds.

I've tried TIG with stainless rod. Made a mess with that.

How do I weld/braze/solder ferrules onto a keg or pot ? What settings do I use ? Tips ? Tricks ?

[Poland308]

If your going to braze it then use 45% silver. But brazing isn’t a good process for the joint configuration you will have when putting bungs on a keg or pot. They really should be welded. If it’s a SS keg then I’d recommend welding it with 312.

[BeerWelder]

I tried soldering it with a high silver solder. The solder stuck fine. The problem was that I couldn't get the whole fitting hot enough to melt the solder all at once and when I heated one part, the solder ran out of the joint at another place. I can SS smaller pieces no problem. But not a 4" ferrule.

Why 312 ? I was using 316L rod. My problem seems to be welding in the corner of a 90 degree joint more than anything. Especially a circular one.

Here is the pot I am trying to weld on. FWIW, this isn't a high grade SS. In fact, the pot is magnetic and it works with an induction heat source.
https://www.bayouclassicdepot.com/colle ... t-lid-1044

Here is what a 4" ferrule looks like. It is not magnetic.
https://www.brewershardware.com/4-Tri-C ... ory_id=300

[tweake]

with an unknown grade SS, 312 filler or possibly 309 would be best choice, especially when joining to 304 or 316 ferrule.

with welding, a aluminum backing plate that fits really tight works well. but it has to be tight, if it the thin SS buckles and lifts up off it you will instantly blow holes. it also helps stop sugaring.
need a fine sharp point on the tungsten, pulse really helps. but you also need the right sized filler. use the filler to cool it.

buckling the pot is an issue that i don't know how to fix.

getting a perfect fit up makes it a lot easier to weld.

[LtBadd]

To TIG weld you'll have the best out come with a tight fitup, tack 4 places (every 90*) then tack every 1/2" or so all the way around. You need to have a back purge, then weld a short length, move 180* weld another short section. Let cool and then continue.

You can use thin aluminum sheet to build an area behind the ferrule for the purge. Other materials can be used as well to create a tent for the purge, get creative. Use the silver HVAC tape to attach the purge tent, if your far enough away from the weld area duct tape will work.

[TraditionalToolworks]

I think at least some kegs were made of aluminum...if that is the case it would sure explain your difficulty.