Got Wood?

A very old project is finally taking shape.

Our third floor has never looked quite as nice as the other two. We suspect that it was originally unfinished, with just a basic floor and walls, minus the nice carved trim that was used elsewhere. The baseboard trim and door trim were/are just basic flat boards. We removed that basic trim several months ago when the oak flooring was installed, and we've stored it all in the garage ever since.

Our plan had always been to replicate the nice trim from the lower floors. But of course, that molding isn't available anymore. It was either carved onsite when the house was built, or ordered from a molding-supply company. Either way, it's been out of stock for... oh... about a hundred years.

No problem. We'll just make our own. Seriously.

One of our first heavy-equipment purchases was a Jet JPM-15 planer/molder machine. This is a noisy, vicious, and ludicrously dangerous woodworking machine that turns flat boards into custom-made molding and trim pieces.

The planer/molder works by spinning one, two, or three sharp knives at high speed while the wood passes underneath. Depending on the shape of the knife(s), you can cut any pattern you want. You can buy ready-made knives in all sorts of pretty patterns from molding-supply places, but none of them had knives that matched our existing trim.

So we bought a length of blank knife steel with the intention of cutting and grinding our own knives. It's very heavy and (duh) very sharp. You cut off a length of the knife blank and then grind it into the pattern that you want.

I spent a few days grinding my first knife and got pretty close to matching our molding pattern. Unfortunately, there are some small curlicues in our molding that I wasn't able to duplicate. I could get close, but my grinding wheels were too wide to duplicate the smaller details. So off I go to find narrower grinding wheels.

No luck. None of the building-supply stores or woodworking shops had what I needed. Dead end.

So I took the knife blank to a local cabinetmaker, along with a section of our old trim, and he agreed to cut a custom knife to exactly match the trim. It took him a few days and a few hundred dollars, but it's a perfect match.

Or at least, I thought it was. At first, I matched up his knife against the sample piece of molding I'd given him, and it was very, very close but not quite exact. No problem -- he got a lot closer than I did, so I can't complain about his workmanship. Then I flipped the knife around and held it up against the trim again, and it was an absolutely perfect fit. Guess what? Our trim is not actually symmetrical. It's slightly different on the left and right sides. More evidence that the original molding was probably not machine-made.

Now that I've got a perfectly-matched knife blade, I'm out of excuses. Time to fire up the beast and make some sawdust.

The planer/molder spins very fast, so you have to be careful about balancing it. I bought some scrap pieces of hardened steel from a local metal shop and cut and ground them to make counterweights. We have a hyper-accurate scale in the kitchen (for weighing food), so I weighed the knife and then weighed the two counterweights so they'd all match. It took a few trips back and forth between the bench grinder in the garage and the scale in the kitchen, but they're all within 0.5 grams of each other now. That's about the weight of a pinch of salt. That'll do.

The next step was to take the old redwood molding we'd reclaimed and rip it down to size. The molding we're matching is exactly 5 inches wide, but the plain baseboard trim we removed from the third floor is about 5-1/2 inches, so we had to trim off the excess. The edges were pretty ragged anyway, so ripping it all on the table saw helped smooth out the edges anyway.

I admit I stood back a bit and covered my face the first time I started up the machine with the new knife and counterweights in it. It's like starting a helicopter in your garage, but one with with heavy steel knives on the rotors. It makes a lot of noise -- and even more sawdust -- and if it's not balanced correctly it bounces menacingly. But everything worked okay. So far, so good.

I practiced on a few scrap pieces of pine first, just to see if it worked. And it does! Kind of. My first practice pieces had some high and low spots in them, as if the knife had dug too deeply in places.

That's because it had. I had to adjust a set of metal and rubber rollers that hold the work piece down so that it doesn't bounce on its way through the machine. Once that tweaking was done, the next practice pieces came out much better. Time to try the real thing.

At first, I started with short (2-foot) pieces of reclaimed trim. Then I moved on to the larger pieces, until we finished with two huge (10-foot) strips that used to live upstairs in Kathy's office. It's a slow process, and you can't really see it working until the wood starts to come out the other end (by which time it's too late to fix anything), but overall I'm pretty happy with it.

We've now got nearly 100 feet of newly made reproduction trim. That's barely half of what we need, so we'll have to buy some stock lumber and cut a lot more. But now that we've got the hang of it, that shouldn't take more than a day or two.

We're especially happy that we were able to reuse the exact same pieces of redwood trim that came out of these rooms initially. It's just being turned into something a little bit nicer.