I wanted to put a thermowell on my mashtun so that I could check the temp without having to keep opening the lid and losing heat. The thermowells I found online were more expensive than I wanted to pay, so......
Here's what I used:
(1) 1/4" OD copper tubing (about 8 inches of it) - $1.25
(2) 1/4" FIP x 1/8" brass compression coupling - $1.75
(3) 2" long 1/8" MIP brass pipe nipple (shank) - $2.00
(4) 1/8" FIP brass coupling - $2.25 (*see below)
(5) two 3/8" stainless steel washers - $0.75
(6) o-ring - $0.25
Total cost = $8.25
(7) are my probe thermometers - I already had these, so not counting their cost.
* = I really didn't want that freaking coupling. All I wanted was a threaded 1/8" brass pipe cap or a simple nut that would thread onto the shank from the outside, but they didn't have either of those things at Lowe's. I bought the coupling just to get the hell out of the store.
I took a lot of pictures as I did this and am about to post them, so here goes....