Scratchstock/bead scraper technique advice needed

[bsa441]

Just made a scratchstock for beading some bed rails. I am having trouble getting clean cuts. The cutter wants to wander just a bit and I get a lot of tearout at the edges of my bead, and the cut is rough at the edges. The bead itself seem to be pretty good, but I think that's because it is getting burnished by the cutter.

What are important factors in scratchstock use? I am trying to bead poplar. Maybe that's not a very good wood for beading. Are vertical cuts more difficult? I have essentially vertical cuts on each side of the bead. Is the cutter steel choice really that important? I am using an old hose clamp for cutter stock, but maybe I need to find an old saw blade. Do I need to burnish the cutter edges as I would a cabinet scraper blade? This would be almost impossible, given the small dimensions of the cutter profile. Is there usually some cleanup work done on scraped beads with chisels/gouges/sandpaper?

Thanks for all your help.

John Snow

[Roger King]

Hi, Don't claim to be an expert, but here's my 2 cents worth...

The blade on a scratch beader should be of pretty food steel, something better, at least than a hose clamp. I use old blades from my Stanley knife. (the replaceable blade type). Grind off most of the edge, and put the profile on with a dremel or similar grinder tool. Should be a slight bevel to the grind to make an edge. After a few passes on a medium stone (on the face) to do away with the burr created, you're all set. When scratching, start with light cuts, I increase the depth of cut by repositioning the blade, sorta' like using a router bit. A little at a time. Also, important to scratch with the grain of the wood, if possible, this will make for a much smoother surface. I have made several things with this set up and used it on various woods, with success, cross grain is a little harder to master. good luck...

-roger-

[whit3rd]

Good for you! I like beaded edges myself (really crave them for my next bookshelves) and router bits are all the wrong size. Not the manufacturer's fault, really; carbide is all the rage, and you can't make the delicate beads with carbide cutters (not enough edge support, the carbide breaks).

Best steel for this might be an old dull file blade, or maybe a saw blade (hacksaw is easiest to work with), because you want high-carbon steel. Flexing of the blade will cause a rough cut, you want the steel behind the edge to be rigid (and the edge stays sharp longer). As far as I can tell, the right procedure is to cut many shallow passes, and because it's usually with the grain, you have to be careful the fence doesn't wander.

My next project (one of 'em) is a high-angle (60 degrees) plane for beading. I've considered using a metal body rabbet plane with a custom-ground blade, too, but the rigidity of a wood plane with a thick-ish blade should do fine. And it's a lot of work to make a blade that hits the rabbet plane's adjustment mechanism.

[bsa441]

Well, duh! I have a Dremel Moto Tool, and cast-off saw blades. Sometimes it just takes a little whack by someone else to get my brain working.

Also, do you think the better steel will result in less tearout in poplar, especially in the sap wood? I guess the only thing to do is try.

Thanks for the advice.

Juano