Tuesday, December 30, 2014

Gateway (22)

Post 22 in an ongoing series describing the design and build of a Japanese gate for the Museum of Fine Arts in Boston.

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After yesterday's adventures, I had some time to think about the apparently moist interior of one of the beam chunks I had sliced up. It was seeming a bit grim frankly. I began coming up with a few plans as to how to best proceed, generally along the lines of cutting the joinery parts over/undersize, and letting them dry for a few weeks, perhaps even returning the pieces to dehumidification for a spell. None of which was at all what you might call convenient. Just cutting the joints though in green wood is a formula for loose connections and poor fits later on, and I didn't want that.

So when I got to the shop this morning, the first thing I wanted to do was assess how moist the parts were. And you know what? They weren't moist at all:


Must have been a hallucination on my part. 12% MC at the core is perfect. The wood is evenly dried. Whew! That was a load off my mind, let me tell you.

Okay, back to it. For the next while everything I will be dealing with will be big and heavy, so good thing my back is feeling healthy. Those core exercises seem to be paying off. Today I started in on cutting the main crossbeam, or kabuki. The process is similar to that undertaken with the nose pieces yesterday: careful layout, double checking layout, double checking drawings and looking at layout one more time, and then out comes the Makita 380mm saw:


I prefer this saw to the more commonly available 405mm version they sell in the US, which has a crappy stamped steel base. While the same 405mm saw can be obtained from Japan with the better cast base, I feel the 380 mm saw is a better match for the 110v. motor. It's a sweet machine and highly accurate.

Crosscutting is followed by ripping, using the same 50T blade, and off comes the waste:


I immediately shoved the moisture meter pins in there to check - again, a pleasing result of 12%:


That's such a relief.

Next task was to mortise the beams for some long tenons. I dusted off my Makita 7305L beam mortiser, which hasn't seen action in far too long. I fitted the 30mm chisel and started cutting. Here's a video showing a cut:


With the first bit of mortising, the stress relief kerf in the timber was in an inconvenient place which made it a problem to run two rows of mortises side by side. You can see in the still photo above that the first mortise was started, and then had to be abandoned. So I ran it down the middle and then used the circular saw to rough cut the outer walls:


I followed the same process on the other end of the kabuki, then did the same thing to the two nose ends, where I was able to use the double row of mortises, which vastly cut down on the work required to remove the waste later on:


A closer look:


A 30mm chisel run down in two rows side by side means a 60mm width is mortised, just inside of the target of 2.5" (63.5mm). Convenient - I wish I could say I had planned it that way, but it just worked out 'tis all. I wish the mortiser could cut a little deeper, but 155mm (6.1") deep is a good start at least.

A lot of chopping and paring lays ahead on those parts, but I put them aside for the time being as my neighbor Joe showed up, who was, it turned out, persuadable in terms of helping me schlep a couple of larger timbers over the jointer and through the planer. I promised him beer, and duly delivered afterward. I may have understated the nature of the task, but he was game.

Before the fun could begin, I first mounted an Aigner extension on my jointer outfeed table:


You can see that the bar has 4 mounting holes. It came with two holes. The factory ones, which are anodized, happen to be in a position such that a hole drilled through the table edge would run right into a casting web, which would be highly undesirable - there would be no place to put a nut onto the mounting bolt. I hate shit like that. So I had a local machinist make a couple of new holes in the mounting bar. I wish Aigner would supply a bar with no holes, or supply one just to fit Martin jointer tables. Oh well.

Anyway, it took all of 5 minutes to drill and mount the bar and extension table:


With the extension in place, I end up with a fairly long jointing surface:


A bit more than 14' (4.3m) in fact:


It was very helpful to have that additional support on the outfeed, as we were jointing 8"x9" (205mmx230mm) timbers, 10' (3m) long. They weren't light, not in the slightest degree.

After a bunch of grunting, snorting and other manly stuff, you know, we had a pair of clean and square timbers - these are going to be the rear support posts for the gate:


It's nice to have a planer and jointer which can handle these sort of tasks. I've tackled this job in many different ways in the past, but will choose to run the material over stationary equipment any time it is feasible to do so. My body can just manage the task - Joe was looking decidedly hunched and creaky afterward, though the beer seemed to perk him up. His help was invaluable.

The rear support posts, by the way, will be parallelogram-shaped, so the above milling was simply the initial step. I'll let the parts sit for a week and then tackle the phase 2 milling.

Tomorrow I'll be digging into the main posts. The last day of 2014 should be a fun one, with more timber 'rasslin' ahead.

Thanks for dropping by the Carpentry Way. Comments always welcome. Post 23 up next.

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