Post 5 in a series describing the design and construction of a Japanese garden entry gate for the Museum of Fine Art in Boston. Post 1 can be found here, with subsequent posts linked at the bottom of each entry.
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I dropped by the drying facility just a couple of miles up from my shop, where they had moved the Port Orford Cedar timbers in position to go into the dehumidification room. The timbers will remain in dehumidification for several months before going on to vacuum kilning. Most of the material is either quartersawn or rift cut, so I didn't need to worry too much about degrade as the wood dries, however with the largest sections the end grain runs in a semi-circle on the section and thus cracks would likely propagate on at least one face. A good way to mitigate this effect is to kerf the face that will shrink the most, and my larger cicular saw with a rip blade fitted is well-suited to the task.
Here's the stack I wanted left out of the dehumidification room - in particular I needed to deal with the two main posts on the bottom of the stack:
Three of the four bonus 9"x17" pieces needed kerfing - here's the first, with the kerf offset to align to the peak of the grain curve:
Not sure what, if anything those might be of use for, but they may as well get dried with the rest.
Then onto the main task. The saw was at maximum depth of cut, which enabled it to just reach the center of these 11" thick columns:
Done - these were nice sticks, perfectly clear as far as I could see:
There is the matter of the 17' long, 9"x17" beams - missing from the shipment (hence the 'bonus' pieces mentioned above) - which will be getting milled up in Oregon early next week. I should have those a week after that and expect, based on what I know of the log sizes the timbers will be cut from, that they will probably require kerfing before they go into dehumidification. So, I'll be back with the saw once more in a few weeks.
After the material has been in dehumidification for a month or so, I will bring some wedges over and tap them into the kerfs to help them along the process of opening. I'll return every month or so to tap the wedges in a bit more as required. As the timber dries and shrinks, the kerf opens to a wedge shape, and this opening accommodates most of the tension created by the drying process. Later, when the drying is complete and the material dressed to shape, the wedge-form sliced opening up the beam will be filled in with a slice of wood.
The wood is quite wet still, but it was nice to run a saw through such butter after the bubinga slice up of the other day, not to mention the rosewood I've been working for the past while.
So nice that spring is finally here!
All for today - thanks for dropping by. On to post 6
Chris;
ReplyDeleteBeautiful spring flowers.Ones I have are purple and white.Need the heat!
J.T.
Thanks J.T..
DeleteI can thank my wife for flowers, as she planted dozens of bulbs in our front yard. I'm intrigued to see what pops up next.
~C
Ginger taps. On no more than three occasions. I won't say how it is that I came to know this. Monthly intervals is just right for POC.
DeleteMichael,
Deletegood comment. Yes, you certainly don't want to overdrive the wedges or you could propagate a crack from the bottom of the saw kerf. Also have been there and done that before.
~C