Saturday, November 5, 2011

I'm Cuttin', I'm Drillin', I'm Paintin'

With the junction cuts successfully executed on the cap pieces, the next step was to trim the other ends even with the sides of the casing. To do this accurately, it was necessary to attach the cap pieces to the casing first. This is because there was a chance of the pieces' moving slightly when attached, so cutting them afterwards helped ensure that the cuts will remain accurate on the finished casing.

Of course, I wanted to do my best to keep the pieces from moving at all as I attached them. Proper positioning was necessary to keep the pieces in proper alignment at their junction. Happily, I had gotten a good idea of how to get this done from re-attaching the rehabilitated cap piece on the east casing. From that experience, it only took a week of obsessing on the subject to come up with a good procedure.

The first step was to pre-drill the holes for the mounting screws through the cap pieces. To get the screws located properly, I marked where the cap pieces meet the backing piece on each end of the bottom of each piece, transferred these marks to the top, and then drew a line to connect these marks on both pieces. Then, I drilled five holes perpendicular to the top in each piece along these lines. Doing it this way ensures a good angle for the screw through the backing piece safely back from the front edge, but still far enough forward that the screws won't poke through the back of the casing and provide another avenue for the elements to enter.

The diameter of the holes through the cap pieces is large enough so that the screw threads only touch the sides, and do not engage them. This is so when the screw is driven, it will go right into the backing piece, and not just pull the cap piece away. In such a situation, the screws' entire holding power comes from the threads biting into the backing piece, so the holes in the piece to be attached need only be small enough to keep it in alignment.

I have frequently mentioned the virtues of pre-drilling, especially in old wood, to prevent splitting the wood. In this case, however, I did not pre-drill the holes into the backing piece, because if they were even slightly off-center with the holes in the cap piece, the cap piece would be pulled out of position. I felt safe screwing right into the wood in this case because the screws I used have a "drill point", a little slot cut into the tip that provides some cutting action and some clearance for the wood displaced by the screw.

The second step in getting the cap pieces installed properly was to do as much assembly as I could beforehand. To this end, I inserted screws into position at the first and last holes, positioned so that the tip was even with the bottom edge. In that way, all I had to do was to put the pieces in place, hold them there with one hand, and drive the screws with the drill in the other hand.

And so, with everything as thoroughly thought out as I could think of, I ascended the ladder with the cap pieces and the drill. I was nervous, because attaching pieces of wood in proper alignment is another one of those tasks at which I have not had great success in the past. This time, however, all my preparation paid off.


Now it was time to mark the ends of the cap pieces for trimming. I took my trusty carpenter's pencil, all nicely sharpened, and marked the cutting location on each piece as precisely as I could.

I removed the cap pieces, took them back to the garage, took a deep breath, and made the cuts. Then, I took the pieces back to the casing and re-attached them.

Wow, what a relief at last to have this done! I've been fretting about this task for months, ever since I realized I'd have to do it. And I had done it as well as I could possibly have hoped, i.e., with a minimum of patching necessary to bridge the gap.

It may be difficult to see clearly in this picture, but the horizontal placement is perfect; the two pieces meet flush at the crest. There is a bit of a gap that opens towards the front, but as it turns out, this is due to the slope on the backing piece not being constant along its whole length.

As is quite obvious here, the slope lessens considerably at the far left; this pulled the back of the left piece down just a bit on the left side, which is what caused the gap at the junction. Happily, it will be a simple matter to putty both gaps up imperceptibly.

With the cap pieces now well and thoroughly made, I took them right back off again in order to do some final preparations. Before I could get to those, however, my plans changed suddenly.

I was planning to wait and prime both casings at the same time, but just after noon, I learned that there was an 80% chance of rain the next day. I did not want the unprotected wood on the east casing to get wet, because then I'd have to sand again. I couldn't start painting right then, because the sun was shining directly on the casing, so I had to wait until the sun went down behind the trees. This gave me only about 45 minutes to work before dusk. I just barely made it, although it was pretty dark by the time I got to the apron under the sill, so I couldn't inspect my work until the next day, before the rain started in earnest.

Not bad, if I do say so myself. It's far from perfect—as I've said, I didn't have time for perfection—but I'm very gratified to see how well the top of the casing came out. The cap pieces look just fine from this distance, and the patch in the apron is, as I had hoped, imperceptible. The variances in sheen visible in places are due to differences in how the primer penetrates the putty compared to bare wood; these will be eliminated by the top coat.

* * *

. . .to boldly go where no man has gone before.


  1. Every good scout knows it pays to be prepared!

  2. Wow, filling in all the gaps! What's a squirrel to do in the fall? Fall back :-)


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