Apprenticeship Session 33
After the disappointment at the end of the last session, we worked during the week to get the rings ready to go. They weren’t quite perfect, so we did wind up making a few adjustments (namely grinding the ends down so they connected better). But It didn’t take us long to get those finished up.
So the next step in getting the pipe ready was to cut out the plate that covers the one end (the end with the tail) so that it fit the pipe and had a big enough opening to get the key in. It wasn’t to hard to cut the notch for the key, but we first attempted to hacksaw the thin sheet of metal to bring it closer to the shape we needed for the pipe – and then abandoned that approach pretty quickly. It wound up being a lot easier to just grind it down. So we traced on the sheet around the end of the pipe and just whittled it down on the grinder.
Now the pipe is ready to be brazed. The first step was to cut up some old brass bullet casings into small pieces that we would then lash to the pipe lock. The idea is that we need to hold that brass in place as close to where we need it to flow to seal up the joints between the pipe, plate, and rings. So we used a linen thread (which will burn up during the brazingbrazing Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, with the filler metal having a lower melting point than the adjoining metal. Brazing differs from welding in that it does not involve melting the work pieces and from soldering in using higher temperatures for a similar process, while also requiring much more closely fitted parts than when soldering. process) to carefully tie down small “tidbits” of brass in the key areas. It took a lot of tidbits and a lot of lashing to get enough pieces in place to cover all the spots we needed.
And while all this cutting and lashing was going on, we were also working on the lock piece and fullering another neck on it with the guillotine. While it takes it a bit of effort to make that happen, it’s quite a different type of job than lashing the brass pieces to the pipe.
the example 
our current piece
So the last thing at the end of the day was to pack the pipe to prepare it for the actual brazing process. The first thing that got packed was the center of the pipe with the small bits of brass and charcoal. The brass will line the interior and the charcoal will help support the pipe and keep it from collapsing. Then the exterior needed to be packed in clay. The clay needs to be a certain type, stoneware clay I believe, with a bit of sand (you should be able to feel a bit of grit), and horse manure (which adds some fibers that will allow steam to vent out of the clay rather than crack it). You just pack the pipe, being careful not to disturb the brass lashing that was done, in about 1/4-to-1/2-inch thick clay all the way around, including inside the tail part. (I sure hope I got it packed in that tail part good enough.) The clay should have at least 24 hours to dry, so that’s where we left it for the day.
Next session we’ll get to do the actual brazing process which I understand to be “cooking” the clay for about an hour. We’ll also be working on the lock fitting and getting a spring made for it as well. I suspect that’s all we’ll get done and we’ll have one more session to make the key.
This pipe lock has introduced us to some very different skills than we have done in the past. It’s hard to imagine trying this project on our own without some guidance. The North Dakota Folk and Traditional Arts Apprenticeship grant has really allowed us to push our boundaries for sure!
P.S. We were late for our session today as we were hiring a contractor to build our house. Looking forward to getting our own workshop set up soon!