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

[Crabnut]

Hey Quaffer, where did you source the lock nut you used? I am a long way from the east coast, but not that far from Snohomish, here in snowy (???) Renton.

 

[Tiber_Brew]

Thanks, I've read through your thread and your build is awesome! Nice work. I'll be stealing ideas from you as I upgrade my system in the near future

Sounds good. Good luck with your build!

TB

 

[japhroaig]

i have been using 1" couplings from bargain fittings, butt-soldered to kegs with great success. even though they are bigger, i think they are easier to solder than a lock nut. i'll take pics the next time i solder one, but basically cut your hole with a step drill bit, clean up the areas to be soldered with 220 grit sand paper, and solder away. the harris stay-clean (i think that's the stuff) works miracles.

 

[Quaffer]

Hey Quaffer, where did you source the lock nut you used? I am a long way from the east coast, but not that far from Snohomish, here in snowy (???) Renton.

Hello from snowy Snohomish, (almost) neighbor.
I found the nuts at bargainfittings.com.
My kids were out of school today and again tomorrow, on account of inclement weather. I was home on a snow day as well, but tomorrow it is back to the grind for me.

 

[Quaffer]

i have been using 1" couplings from bargain fittings, butt-soldered to kegs with great success. even though they are bigger, i think they are easier to solder than a lock nut. i'll take pics the next time i solder one, but basically cut your hole with a step drill bit, clean up the areas to be soldered with 220 grit sand paper, and solder away. the harris stay-clean (i think that's the stuff) works miracles.

I'd be very interested in seeing pictures of this. Yes, the Harris Stay Clean is what I used as well.

 

[Quaffer]

I can't believe it was November when I did the last one. High time for an update.

The BK got a 1" nut today. It is a Bayou 62 quart s.s. stock pot. I got it for its flat bottom because I plan to whirlpool in my next brewery.

Wise from my last attempt, this time I clamped the nut in place. I used a ratchet tiedown and a piece of scrap wood pushing on a faucet wrench. The wrench was a perfect fit, half is underneath the nut, half is above. This way the nut could not slide out of place. It worked great. In this picture I am finished soldering, ready for cleanup.

Close-up of soldered nut before cleanup.

After cleaning up with warm water and a dish brush, then a wet rag with Bar Keepers Friend.

Different side of cleaned up nut.

This time I used a propane torch instead of the MAPP gas torch I used last time. It was a much better experience. I recommend using a propane torch for this work. Things worked smoothly and there was not much burning of the flux. Of course, I have a lot more experience this time which accounts for some of the easier soldering, but still, I think propane just works better.

 

[HHP]

How has the durability of this solder been? It seems a lot like brazing and I wonder how the durability is compared having it welded?

What kind of solder did you go with this time?

 

[Quaffer]

How has the durability of this solder been? It seems a lot like brazing and I wonder how the durability is compared having it welded?

What kind of solder did you go with this time?

I used all the same stuff as last time, save the propane. Solder is Stay Brite #8.

I can't speak to the durability of the solder. I have heated water only a few times in the HLT (so far so good) and none in the BK.

 

[Bobby_M]

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.

 

[trigger]

I used the same solder on my keg to fasten the 1" locknut and the other fittings. After probably 20 batches they are holding up great. To braze the fittings you need to get an actual brazing material, which basically has more silver in this application. The technique is similar, but the key is that the brazing rod will have a much higher melting point than the silver solder. I tried brazing one of the fittings on my system, and after about an hour of messing aroung with mapp gas I decided it wasn't worth the trouble. If the solder fails I'll just weld the fittings in, but right now it's holding up excellently.

 

[hammis]

nicely done quaffer!

 

[pickles]

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.

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.

 

[runningweird]

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?

 

[TheDom]

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.

 

[homebrewdude76]

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?

 

[epcgordy]

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.

 

[Bsquared]

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.

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.

 

[epcgordy]

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.

 

[Bobby_M]

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.