Friday, June 16, 2017

3rd Annual June Chair Build - IV - The Seat Blank

I now have one seat blank that is pretty much ready. The main problem I see is my battens might be a bit too narrow for what I intended, but that wood is what I had to work with. I think I have an idea that will solve the problem.
One seat blank done.
I know, it doesn't look like much, yet. I've joined the two boards together with a slight gap between them. Hopefully this will mitigate any thought this chair will have for splitting after I install the legs. There should still be some room for wood movement this way.

Jeff gave me a comment on an Instagram photo I posted that he would like to see how I do the sliding dovetail with the toolset that I have. I have done a few sliding dovetails before, and I think I would probably do them the same even if I had more tools, except that a router plane sure would make this easier.

I don't have photos of how I made the battens. I made them with a 10 degree slope on each side. This is pretty easy to be accurate on. If you can plane a square edge on a board, you can also plane any angle on the edge you want. It is the same process.


Since I don't have one, I make do with a chisel instead. Here's a visual tutorial:
First mark where the batten will go.

I then clamp the batten upside down as a saw guide.

The batten holds the saw at the perfect angle.
I removed the handle from my Ryoba as it is in the way, but I think you could do this with about any saw. I once did it with a crosscut panel saw.

Here's a short video of how this works:

Sneak up on the line, then repeat for the other side of the batten.
One note here: I'm not doing tapered battens here. If I were, I could just cut to the lines I marked, then push the batten in a bit farther to tighten it up. With straight battens like these, I had to come it a bit on my second cut, or the dovetail would be sloppy and loose, as I measured from the widest part of the batten. I'm not sure of a good way to measure this, but a little guesstimation got me there in the end.
Here I'm starting to chop out the waste. I want a nice crisp edge, so I start by chopping out half the waste, then half of that until I can't go halfsies anymore.

Half of the waste...

until I get to the line. Then clean it up a bit and come in from the other side of the board.

With the edges done, I go bevel down to remove most of the waste.

I'm not too worried about how it looks yet, just don't get too aggressive.
If I had a router plane, I would pretty much start using it at this point. I might have used it to take the last couple of shavings at the edges of the board, but I also might not have. It depends on my mood.

Also, it is important to take a moment here and sharpen the chisel and/or router plane. A new edge will make this easier and more accurate.
Now I start taking down the high spots until it starts to look nice.

It is starting to look nice, but I need to check that the depth is enough not to get in the way of the batten.

I check that with both my marking gauge,

and some kind of straight edge. You can see here I have a ways to go still.

That's better.

Done! Does it fit?

Yes! First try.
I have to say I enjoy doing these with only a chisel and a saw, but with these two chairs there are a total of eight of these excavations that need to be done. A router would come in handy. But even if I had money burning a hole in my pocket to buy a new one, I still could probably get these all knocked out this way before the mailman would show up with a new tool.

Speaking of new tools, I need to get a brace or a new drill to drill the holes for the legs in the next post. The cheap Chinese corded one I have does not have enough torque to drive my 3/4" bit through pine. Unbelievable!

15 comments:

  1. This is great, Brian, thank you! You make it look easy, even without the router plane. I've been leaning towards using screws but you've convinced me to do the dovetails.
    Jeff

    ReplyDelete
    Replies
    1. Wow! Good luck, and don't blame me if it doesn't turn out!

      Delete
    2. Haha! No worries, I'll know it's time for more practice.

      Delete
    3. This joint with a chisel is actually great practice for chisel control. I like to use the same technique for tenons, lap joints, rabbets, etc. It really is amazing all what one can do with the humble chisel. Often times I feel like it's faster to do one of these kinds of joints with a chisel that is at hand rather than get out a specialty tool.

      Cheers!

      Delete
  2. Nice write up on the sliding dovetails Brian. This is something I have yet to try.

    The seat looks good and solid. Can't wait to see what you come up with for this chair.

    ReplyDelete
    Replies
    1. Thanks, Greg. It looks a lot harder than it is.

      The seat feels plenty stiff. But stay tuned, there are still plenty of opportunities for me to screw this up.

      Delete
  3. Hi Brian,

    great project! You used the time well being absent from Hohenems! As You've build a chisel shoulder plane once, now you have to make a chisel route AKA Old Womens Tooth. Just a thought.

    Cheers
    Pedder

    ReplyDelete
    Replies
    1. Now there's an idea! I briefly considered using a router I made from a sharpened screw head into a piece of wood, but this was too big a job for that, I think. But an old woman's tooth made out of a 2x4 and a chisel sounds like the perfect thing. I still have another chair seat to go, so maybe I'll do that.

      Thanks!

      Delete
  4. Thanks to your help, my first two sliding dovetails are complete and good enough for me to be happy with them. I tried a panel saw first, about a 10ppi rip, but it didn't cut well and I didn't keep it aligned with the guide very well. Some chisel work fixed it right up though. The 2nd attempt was with a Japanese style saw with the handle removed. It was much closer off the saw. A little tuning, but not much.
    The panel is pine, about 19" across and 3/4" thick. It looked easier to fit a tapered sliding dovetail than a straight one, so that's what I went with, about 1/8" narrower at the front. It seemed good to hide it from the front so the dado stops about half an inch from the edge. I chopped it out like a mortise for about an inch to make room for the saw to work.
    Great coaching, I really appreciate it!!
    Jeff

    ReplyDelete
    Replies
    1. Great news! This joint really isn't that scary. I prefer the tapered ones, just like you did. That way, if things are a little sloppier than intended, it is a simple thing to tighten them up. Do you have pictures somewhere?

      Delete
  5. Thanks. No pics yet, but I'll take a couple and let you know.

    ReplyDelete
    Replies
    1. OK, I think there are now 3 pics on IG. Another first, but not as fun as the joinery.

      Delete
    2. It looks perfect! Did you use a router plane on the bottom? I forgot to mention it, but the scrap you used as a sanding block is the perfect thing when sawing with a panel saw. Just use it to press the saw against your guide, and your cut will be in the perfect place. I find I don't need it when using a Japanese saw, but this goes much quicker with a panel saw.

      Delete
    3. Thanks! A low-res image with a filter really tightens up the joinery. I used the second batten pressed against the panel saw, but it just didn't want to cut. Maybe because it's filed to rip, maybe just technique. Eitherr way, the Japanese saw was much better. I was *very* thankful for my Veritas router. Would have been trying the Paul Sellers chisel thru a 2x4 otherwise.

      Delete