Well, the good news from down here is that despite various non-woodwork distractions, I have been able to find a few hours more. Not quite as much to show for it as last week, but I have now made up my mind about the back and how it will go. I don't seem to have taken as many photos as usual either - sorry!
I've done several more minor repairs to places where the tongue had broken off, by trimming back and gluing on a fragment cut off an offcut.
I've sanded all 11 back pieces, on both sides, to clean them up a bit. (It's cool enough to have the vacuum on, to use with an Abranet hand pad. Nice and dust free.) I remembered that, about a decade ago when I made a batch of knotty pine boxes, I treated all the knots and resin pockets with sanding sealer, reasoning that it's basically shellac, which is what knotting is, and then a coat of water based polyurethane. I've not seen any resin problems on those boxes. As I still have enough sealer and poly, I'm doing the same on this project and have already sealed the inside of the back. I'll give everything a sanding and a first coat of both before assembly.
Having decided that the back will indeed be made of 3/8" thick matchboarding, I was able to cut the rebates where it will fit. These are 3/8" deep and 1/2" wide. Since they are on the verticals, with the upper end hidden under the top board of the bookcase and the lower end hidden on the floor, the rebates can run all the way through, with no messing about making them stopped.
Out of all the options available I took the line of least resistance and used the same onion plane as before.
It's not really necessary but I did mark out the width and depth first. The first piece had some big wavy knots at the edge, so I took the precaution of carving away some of the hardest bits with a chisel before planing. This helped.
Just for a change, I planed some of the depth with a more basic rebate plane. This particular one has no maker's name on it but does have a nicely fitted boxwood sole from a previous owner. It's the first wooden plane I bought.
I think it was a bit quicker too, easier to hold straight and a close fit to the size of rebate required. It's not hard to plane down to a line.
Both planes could take quite thick shavings, which is what you want to do really, unless you have a use for fine wispy firelighters.
Here's a really dull shot of a bit of planed rebate, showing that the surface through the knot is not as smooth as I would aim for on a table top or a picture frame, but is ok for a hidden constructional detail:
And there was another one of these to go in the garden refuse bin:
One thing I have been wondering about is how to fix the boards on. The old cupboard had two nails on the ends of each board every board had two splits where the nails had been. From the scars I can see that they were thickish headed nails. I trimmed the splits off when cutting the boards to length.
So, should I just use one nail per board or can I get away with two? I have plenty of thin, bendy panel pins in various lengths, which I don't think would put up much resistance to a bit of sideways pressure. And these boards are probably about a century old and might not do much seasonal movement now anyway. I don't want them dislodged if the user slams a heavy book or box into place, so two pins would be more secure.
Opinions and suggestions welcome!
