Friday, November 25, 2016

Pennsylvania spice chest 5, triangular trenches

The other day after making all the grooves and dados etc. I actually also glued up the carcase.
Ever since I have begun making a dry assembly before actually applying any glue, my glue ups have been rather uneventful, actually the have gone reasonably smooth and according to plan with a minimum of fuzz.
I'll be the first to admit that I earlier on viewed this dry assembly idea as an unnecessary modern invention made to slow down any process. But it seems as there is some sort of merit to it.

The dividers will all be rounded on the front edge, and in order to easily make a nice smooth transition from the horizontal to the vertical dividers I decided to use a system of a triangular trench.

I saw a spice chest on the Internet, where the builder had employed this method, and it looked pretty easy. The idea is that instead of a regular flat bottomed dado you make a V shaped trench. Then on the corresponding divider you make a triangular edge. This edge will fit in the trench and cause a smooth transition of the rounded front. Technically it could be used in any type of front, but I figured that there was no need to get fancy and push my luck.

The method suggested in the Internet build was straight forward, but it requires a single jig. This jig is nothing more than a straight batten planed at a 45 degree angle. You then place this batten right next to the line where you would like your trench to start.
After a little bit of experimentation I found out that the best method was to start by chiseling vertically down the middle of the trench. Since I had laid out all my trench lines as center lines It was just a matter of following those.
I gave the chisel a good whack and buried about 1/8" or a little more in the wood.
When the center line had been chiseled, I supported the back of the chisel on the 45 degree batten. A tiny touch of the mallet ensured that the tip of the chisel was biting the wood followed by another whack game me close to desired depth.
When I was satisfied that I had more or less reached the required depth, I moved the batten to the other side of the trench and repeated the angled chiseling.

Making a triangular trench.

4 comments:

  1. It looks like a good technique. It will be cool,to,see if it turns out.

    ReplyDelete
    Replies
    1. I had to choose from a glamour shot showing a nice finished trench, or this that shows the setup. I have imposed a limit of maximum 1 picture on myself.

      I have high hopes that it will end up working.

      Cheers
      Jonas

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  2. I think some Japanese construction techniques use this triangular trench method. It should look very nice. But I wonder if the trench is needed for any structural purpose then maybe it won't be as strong as a dado. Like maybe the two pieces that have the triangular trench and support the divider might be pushed apart, leaving a gap at the joint. Looking forward to seeing the result.

    Matt

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    Replies
    1. Hi Matt

      I am pretty sure that it won't be as strong as a dado for the exact reasons that you mentioned. But for dividing the inside of a spice chest it will be more than strong enough.

      One of the downsides to this triangular trench method is that it seems more difficult to make the corresponding piece accurately. I guess it could just be the tools and equipment that I have out here combined with the not 100% flat stock though.
      Or maybe it is just lack of practice.

      Brgds
      Jonas

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