Soldering a 1" Lock Nut to Sanke Keg, with Pictures

nicely done quaffer!

Bobby_M said:

The only difference between soldering and brazing as far as I know is temperature required. The filler material always has a lower melting point than the two materials being joined.

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I soldered the fittings on my kettles with great success. I noticed though that I torqued on one too much and it cracked the solder, then leaked a bit. I just resoldered. However, I brazed a few tri-clover fittings to some 1/2 ss tube and can tell you that its MUCH harder than the solder. The joint got cherry red and the flux kinda twinkle a bit and it looked like some fusion was going on. Now I know it wasn't "welded" together, but i was able to grind the joint smooth and there is no visible seperation between the two pieces.

I just came across this post and it really makes me want to try it on a keggle brew kettle. What did you use to keep the element contacts dry? a box?

I think I remember seeing someone basically cutting a hexagon out of the back of a box and soldering it to the side of the kettle around the nut. I'll be doing that to my BK here in the next few days.

When you solder the hex nut on the keg you are not able to dimple it - correct?

If you were to dimple it, is there something that can be soldered on and still be flush enough for the element? Anyone tried this?

On my kettle, I used the dimple method with a 1" half coupler soldered in. The half coupler provided a perfect surface for a silicone o-ring to seal. I used a weatherproof box, almost identical to Kal's installation to cover the connection. It works great, hasn't leaked a drop.

epcgordy said:

On my kettle, I used the dimple method with a 1" half coupler soldered in. The half coupler provided a perfect surface for a silicone o-ring to seal. I used a weatherproof box, almost identical to Kal's installation to cover the connection. It works great, hasn't leaked a drop.

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What size hole did you drill for this. I did the OP's method for my HLT because the 1-1/2 hole I drilled for the coupling was too big so I brazed on a 1" lock nut. I still need to put an element in the kettle and I'd like to do the dimple and braze a half coupling on.

IIRC, it was a 1 1/4" hole for the half coupler using the dimple tool. No need to braze, with the dimple and solder you can get a very strong joint. Check the Soldering Stainless Steel thread in the DIY section. There's a tremendous amount of info in there.

In trying to decide between a flared opening with 1" half coupling and directly soldering a locknut, I think the nut wins. For one thing, the threads are both NPS and there is no question that the gaskets will mate before the threads interfere. Then next reason is that there is more surface area for solder to bond to. Last, no flaring tool needed.