Thursday, September 1, 2011

Woodworking for The Inept, Part Two

The next day, I took my creation out to see how well it fit:

Okay, I could work with this! I knew I'd have to adjust the inside curve, of course, and I knew the piece would be too thick. My only real error in fitting was that I cut wide to the right, although not nearly as wide as it appears here. I made some marks on the piece and took it back in for adjustments.

I enlarged the inner curve with a drum sander on a Dremel, and smoothed the outer curve with a sanding block. I cut what amounted to a small wedge off the right side, and then took the piece out to re-check it. It looked okay, but it was hard to be sure because it was still too thick. So I took it back in and sanded the piece down a bit from the back, being careful to keep the front and back sides parallel.

Sadly, I was so busy keeping the front and back parallel that I allowed them to get just a bit too close. I really should have stopped halfway through and checked my progress against the existing piece, but I was so eager to get it done that I ended up letting myself in for more work. I'd overdone it by less than one-sixteenth of an inch, not much, but enough so that I had to shim it out to the proper level. I didn't have any 1/16" stock handy, but I did have some nice stout paperboard.

This is archival backer board, designed to keep things like pictures and comic books stiff in a plastic bag. It's rigid and fine-grained. Plus, it's just under one-sixteenth of an inch thick. Ad hoc!

Those of you who have been following this blog for a while will no doubt be shocked at my proposing to use a paper product as part of a long-term repair. You may be asking: Is he really under that much pressure to get this done? Has he lost interest in the project? Where's the danged lolcat already?

The truth is, I'm not proposing to use a paper product. I'm proposing to use an epoxy-impregnated paper product. I've learned from experience that when you impregnate a material with liquid epoxy, the material becomes nothing more than a vehicle for the epoxy. It wouldn't be a good idea to put it where it would be exposed on its face, because it would still look like paper, and would be subject to abrasion over time. Laminated to the back of a piece of wood, however, and with only its edge exposed, it would as a practical matter serve as well as an equivalent volume of WoodEpox.

Plus, I had to mix up some LiquidWood anyway. You will recall that last time I mentioned that the plywood I'm using for the new piece is not weatherproof. It's interior plywood, so the glue holding the plies together is not waterproof; the wood is thus subject to delamination over time. To forestall this as long as possible, I was planning to give the piece a good epoxy bath, so it was a simple matter to slip the paperboard in there at the same time, getting the impregnation and lamination done all at once.

After all the hoops I had been jumping through unsuccessfully to get the epoxy to cure thoroughly overnight without needing further heat-curing, this time I just followed the basic procedure, letting it induce for ten minutes, letting the piece soak for about a half hour, then taking it out, wiping off the excess, and letting it sit at room temperature overnight. I figured since there would be very little penetration, and thus very little epoxy mass, the need for further curing would be inevitable.

The next morning, the piece was fully cured, with absolutely no hint of stickiness. Ah, irony.

I couldn't help noticing the effect the epoxy had on the wood: it looked varnished. I filed the observation for future experimentation. Now that the varnish I used on the kitchen cabinets has been outlawed here in California, I'm going to have to find some reliable substitute. The junk that's available now certainly won't do.

Cutting the impregnated paperboard to shape convinced me of its resilience; I couldn't cut it with an X-Acto knife. I had to bear down on it hard with a bare single-edged razor blade to get it to cut cleanly. That indicates that it's harder than birch or poplar.

Once it's painted and part of the casing, the impregnated paper will be indistinguishable.

It was time for one final check for fit:

As the kids say, woo-hoo! The profile and height are now perfect. It still looks wide on the right, but that's due to the perspective. With all that's going on with this piece already, once I've puttied up the gaps, it'll blend right in. . .uh, except for one little detail.

The grain on the new piece is going the wrong danged way! It would have been simple enough to orient the piece so that the grain lined up, but it never occurred to me. Well, as I said, I've never done any real woodworking before, and this proves it. You can be sure that I won't make this mistake next time this kind of thing comes up.

Not that this is a truly harmful error, not with all the other things going on with the casing. Still, I will have to take extra steps to ensure the grain difference is not readily apparent.

I'll do the actual attaching of the new piece a bit later. First, I want to do a little work on the area underneath it. In the meantime, remember: there's no problem that a little epoxy and sandpaper can't fix.

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"Our minds are one: I feel what you feel; I know what you know."


  1. This is the BEST "Old House" Restoration blog ever! It is written by someone that knows how to explain in detail how to do whats needed without confusing the reader. If your restoring an old home this is definitely the guy to follow. Rob Spencer knows his stuff and takes his time to do it right the first time. Thanks for taking the time to do things right and making it easier for those that are following in your footsteps! (Woodstimesthree)


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