Tuesday, November 14, 2017

Slab bench

The final piece of the slab is 14" wide and 39" long and I am going to use it for a bench.  Scrounging around, I found enough pieces of cvg douglas-fir for a base.  Two leg assemblies will be joined with a stretcher.  Here is one dry fit:


I don't usually describe my construction techniques because it doesn't seem all that interesting but often I pick up tidbits in the descriptions in other blogs, so here goes.  These tools plus my miter box are what I used:


I chose the angle on these legs by eye and then used a bevel gauge.  Since the most critical cut on these angled tenons is the shoulder, I created knife lines and then cut them on my miter box.  It takes no extra time and ensures precision.  After that I sawed out the tenon at the bench.

As I've written before, I use a hybrid method for making mortises.  I lay them out in pencil but only use a center line because I drill them out on my drill press. 


Then it takes only a couple of minutes to finish them with a wide chisel, using the edges of the holes as guidelines.  Yes, I should be using a mortise chisel, and someday I may, but this method works so darn well it's hard to give up.

I cut the through mortises for the long stretcher the same way:


If you look closely at the mortise on the right, you can see a hint of the original drilled hole in the center.  This is what makes this method so convenient; the guideline ensures a perpendicular mortise that fits snugly with little or no trimming.

I use the drill press mostly out of force of habit but it would be just as easy to bore the hole with my brace and bit.  There are some things in hand tool woodworking that seem almost magic to me and one of them is that you can bore holes at precise angles completely unguided with no more than some sort of reference like a bevel gauge or square.  There is no need to have a drill press. 

I always peg or drawbore my mortises; it's a belt and suspenders thing.  If you think about it, in a drawbored joint the thing that matters most is the shoulders of the tenon.  They need to be dead on for both appearance and strength.  The peg holds the tenon tight.  As long as the peg holds, the snug fit of the tenon doesn't matter; only the shoulders matter.  You lose the mechanical strength and glue strength if the fit is poor.  I know that some woodworkers who drawbore don't even bother gluing their tenons but I do, as I don't see a reason to give up the redundancy.

2 comments:

  1. I figure the glue is good for the first 150 years and the peg keeps it good for another 200 before restoration is needed. :-)
    Sincerely,
    Joe

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  2. Andy,

    I peg or draw bore almost every M&T, glue if pegging, no glue when draw boring. No real reason for no glue when draw boring other than it is easier. Picking between using a peg or draw boring is simply do I have enough "meat" in the joint to draw bore. If I do that is my preference.

    It's good to see the "tick-tock", It is always interesting to understand the how. Nice work.

    I have a full boxed set of Jennings bits from a #4 to a #16. A couple of the larger one's snail is worn so much they stop pulling after 25mm or so. I just received a set of new Jennings pattern bits from TFWW. I expect their first use will be a run at doing a few mortises your way.

    ken

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