Scratch Stock - Simple, Easy, Effective (Photo Tutorial)

[Hank Knight]

I needed to put a small bead on the edge of a curved skirt for the hunt board I'm building. Because of the curve, my side bead plane wouldn't work, so I decided to make up a little scratch stock for the job. Several people have posted questions about scratch stocks recently, so I took the opportunity to turn yesterday's project into a photo essay for those who haven't used scratch stocks before. As you'll see, they're simple, easy to make and very effective tools.

All you need is a block of wood, a bolt of some sort and a blade. I started with a piece of 8/4 hard maple, a 5/16" machine screw with a knurled head and an old card scraper.

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock011Small.jpg

Cut the block to a convenient size and chamfer the edges for comfort. Then drill a hole for the bolt. The bolt engages the cutter and keeps it locked in place, so where you drill the hole depends on the size of your stock and the placement of the cutter.

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock018Small.jpg

Then saw a kerf in the block to house the cutter:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock026Small.jpg

Tap the hole for the machine screw:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock023Small.jpg

Next, prepare the cutter. I made mine from an old card scraper, scoring it with a Dremel tool and snapping it off. Clean up the edges with a file and cut the profile. You can cut just about any reasonable profile you need for your work. Mine is a simple quirk and bead - a little over 1/8". I used a 1/8" chainsaw file:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock028Small.jpg

Hone the edges of the profile dead flat and sharp. I took mine through the Arkansas grits up to surgical black. I don't have a stone small enough to hone the inside edges of the bead. I tried wrapping a piece of fine wet-or-dry sandpaper around a screwdriver shank, but it dubbed over the edge and ruined it. I recut the profile and just honed the flats. It worked fine:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock034Small.jpg

I found that my saw kerf was too wide for the cutter. I was afraid I'd get chatter, so I made a shim out of brass shim stock. The non-business end of my cutter extends past the edge of the block so I bent the shim around the edge of the cutter to protect my hand:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock031Small.jpg

Here's the assembled scratch stock:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock037Small.jpg

To use, set the cutter so the profile extends beyond the edge of the block and lock it down with the screw. Reference the cut by keeping the edge of the block in contact with the workpiece and pull or push the stock along the edge. Start with light pressure and adjust the angle of the stock to get a clean cut. A well sharpened cutter will actually give you shavings instead of sawdust. Look closely at the image below and you can see the shavings curling away from the cutter:


http://i50.photobucket.com/albums/f343/hankknight/ScratchStock005.jpg


Keep repeating until you cut the full profile. Be aware of the grain direction. If the cutter begins to tear out or chatter, change the angle and/or the direction of the cut. After you get the cut started, you can increase the pressure on the stock, but you really don't need to muscle it. Just keep a nice steady pressure and repeat the cut until you get there:

http://i50.photobucket.com/albums/f343/hankknight/ScratchStock010.jpg

Easy peasy. You'll be surprised at how easy this is and the quality of the cut you can get with a well prepared cutter. Mine required almost no sanding.

Hope you found this useful.

Hank
Scratching away.

[Rob Lee]

Hi Hank -

Excellent article - clearly written and appropriately illustrated. I'm also glad to see you tapping wood - few people believe how strong threads tapped into wood are.

Cheers -

Rob

[Hank Knight]

Thanks Rob. I hope this isn't too basic, although I didn't appraciate scratch stocks until I actually used one. Then I learned how easy they are to make. Maybe this will encourage others to try it.

Hank

[Bob Easton]

Superb! Just the right blend of text and pictures. I've read many descriptions and a couple of articles about scratch stocks, but few as clear and concise as this one. THANKS!

[John Dykes]

And that's why I contribute here at Sawmill!

- jbd in Denver

[Dan Bertenthal]

Thanks, Hank. I've seen articles on scratch stocks before but this is so straight forward that I'm finally going to do it. Thanks for your insight,
Dan

[Zahid Naqvi]

That's great Hank, I think I am going to try making one soon. I have a need to draw a bead on some table legs I am making these days.

[Mark Koury]

Thanks Hank for this quite nice pictorial essay!

About a year ago I purchased a Bronze Beading Tool from LN. I have never been able to get the kind of results that I anticipated inspite of sharpening and at one point even trying to turn a hook on one of the blades. Seeing your results gives me the notion that I’ve been pusing too hard. Practice - Practice - Practice! (Soon I’ll retire and have the time! :D)

Mark

[Dave Anderson NH]

Nice tutorial Hank. One thing I'd mention though for folks who don't have a tap set at home. You can tap a wood like hard maple by looking up the correct root diameter in any book containing a listing of bolt and thread sizes. Drill the appropriate sized hole and working carefully you can use the bolt itself to tap the threads. Note that you should back the bolt out of the hole after every few turns. It's not elegant and it won't make as nice a thread as a tapped thread, but it will work and be servicable.

[Denis Tranchemontagne]

Looks like a good project this weekend.

Thanks for sharing

[Hank Knight]

Nice tutorial Hank. One thing I'd mention though for folks who don't have a tap set at home. You can tap a wood like hard maple by looking up the correct root diameter in any book containing a listing of bolt and thread sizes. Drill the appropriate sized hole and working carefully you can use the bolt itself to tap the threads. Note that you should back the bolt out of the hole after every few turns. It's not elegant and it won't make as nice a thread as a tapped thread, but it will work and be servicable.


Dave,

Good tip. I've used a bolt to cut threads too. If you cut a groove in the bolt threads with a triangular file parallel to the shank it turns the bolt into a tap of sorts. Each thread cut by the groove becomes a thread-cutter that cuts the threads instead of compressing them in. Look at the tip of a self-threading screw for the idea. It works pretty well, especially in hardwoods like maple.

Hank

[whit richardson]

Nice work up as others have said. It would be great if this forum had stickies for good examples like this one or a separate "library" of how-to posted by members.

thanks again.

[Hank Knight]

Thanks everyone for the compliments. This was a fun little project and rewarding because it works so well. I did the tutorial to show that there's no magic involved and that it's really an easy technique that produces good results. I enjoyed doing the write-up and photos. I hope you can use it. Let me say that I learned this scratch stock configuration from Garrett Hack, so I can't claim credit for it. I probably should have given him credit in the tutorial.

Hank

[Michael Peterson]

Thanks Rob. I hope this isn't too basic, although I didn't appraciate scratch stocks until I actually used one. Then I learned how easy they are to make. Maybe this will encourage others to try it.

Hank

I've grown up in the shadow of an uncle and grandfather who were expert carpenters/woodworkers, but they didn't pass any knowledge on to me. I've spent the last few years learning what lap joints, dovetails, panel saw etc all have to do with a finished piece of wood/furniture, and this is EXACLY the type of article I've needed in my mentorship. You along with the other kind people who have taken the time to invest in my informal education have helped fill a huge void that leaves me content and empowered at the end of a finished jewelry box or shelf. Thank you!