I finally got around to soldering the "welding spud" I bought a while back from Brewhardware.com
on to my HLT. It was a lot easier to do than I thought and seems to be very strong. I should have done it months ago instead of putting off.
I used the Harris Staybrite kit mentioned many times here -- bought it off ebay. This solder performed fantastic using just a propane torch (with a left-over camping bottle). To make the hole I used TiN
drill bits and my collection of Harbor Freight step bits, finishing with the big 'n
I wound the solder around the boss several times and rested the spud onto the pot with the hole up. Then I heated it from the top as well as a little from the bottom. The solder melted and wicked great. It wet perfect on the inside wall and formed a real nice looking fillet seal around the boss. On the outside, the fillet mostly formed around the spud but left some gaps on the edge where the tank wall curves away from the spud. I even pounded the tank a bit during preparation but I guess it could have used some more. If I did it again I'd wind the solder the full width of the flange. Nevertheless the joint was liquid tight and strong enough to hold up to some moderate wrenching torque.
I'm using this for a digital probe thermometer in my HLT in conjunction with this other fitting rig from BrewHardware.com
. I'm real happy with the result.
I also noticed that with a 1/2" male NPT fitting installed on the outside, you can still get another 1/2" male NPT fitting to thread on the inside. You don't get a lot of threads/turns but it seems like it would be enough for a pickup tube.
These spuds are definitely the way to go. I'll be ordering more now for sure. I say to heck with couplers and weldless kits. I do have the McMaster fitting rig for the 'dimpling tool' too but never used it since the couplers I ended up with were too big OD. I probably won't ever use it and just stick with the spuds.