Wooden Threads

[Bob Glenn]

I bought one of those wood threading kits from Woodcraft, with the screw cutter and matching thread tapping tool. The set works well, however, my most recent project using wood screws, will occasionally get wet in the rain. The last and first time this happened, the screw swelled, making it impossible to remove until it dried out.

I have been using cherry and walnut for the screws and usually poplar for the nut.

My question........Could I help this situation by soaking or applying a boiled lindseed oil / mineral spirits mixture to the screw threads? I'm thinking this would seal the pores of the wood. My concern is the screw sticking after that.

[Cliff Rohrabacher]

In a word: No.

The only think I have ever encountered that really seals wood up so it can't take on or lose water is a 2 component catalyzing urethane. It can't be used in threads cause it builds up fairly thick as well as penetrating very deep.

[Jim Becker]

I agree with Cliff. Wood is what it is and by its nature, it's going to swell when wet or in heavy moisture. And there is no such thing as a total seal, although shellac will help relative to ambient moisture more than any other type of finish...and it can go on thin.

[Keith Outten]

You can make bolts and nuts from Dupont Corian with your threader that will work well even underwater.

.

[Cliff Rohrabacher]

You can make bolts and nuts from Dupont Corian with your threader that will work well even underwater.

.

How cool is that? Is the stuff strong in that application?

[Neil Lamens]

Hi Bob:

Wood nuts and threads outside..........nah!!! Are you able to design using a hanger bolt, and press fit with a dab of epoxy, a nut inside your shaped wooden nut????

Neil

[Keith Outten]

How cool is that? Is the stuff strong in that application?

Cliff.

You bet! Corian fasteners are plenty strong, probably stronger than wood simply because they don't have any cross grain to deal with. I've made them in 5/8", 3/4" and 1" diameters from various Corian colors. Since you can't buy Corian dowel rods you have to glue two 1/2" thick pieces together then rip them on your saw and turn to size before threading. Making the nuts and heads is done the same as wood. I have also made wooden open end wrenches to fit the bolts. I recently made a Corel Draw drawing of an open end wrench so I can start making them on my ShopBot CNC router.

Laser engraving the bolt heads makes a unique business card that won't ever be thrown away :)

.

[Gary Keedwell]

. Am I missing something here?. Not meaning any disrespect...just a little confused. ( per normal) :confused: Will the nut and bolt be visible?
How about using an insert? You can thread the wood ...then screw the aluminum inserts and that should help stabilize the wood. When an aluminum thread strips out, I drill the hole a little bigger and re-tap the hole and then use a stainless steel insert. The insert is actually two threads in one . The outside thread to screw into new hole and the inside thread will accommodate the original Male thread.
Just thinking outloud...:)
Gary K.

[Bob Glenn]

Thanks for all the feed back guys. To answer a few questions posed here. Yes the screws and nuts are visible. I am an eighteeth century re-actor making windsor chairs at festivals. I have made a work bench with a large vise using wooden screws. I also have made a spring pole lathe, mentioned here in another thread. I have used the 1 3/8's inch screws in the head stock and tail stock with the lathe centers mounted in the end of the screws. We had a storm come through during a festival and the lathe got wet. I only had time and canvas to cover my tools and chairs.

I think I will try the shellac option to slow the absorbsion process a little.

Thanks for the help. Bob

[joe greiner]

Have you tried soaking the screw blank before cutting the threads? After drying, might be somewhat loose, but later wetting shouldn't produce interference. To prevent expansion, the entire screw would have to be airtight, I think, as the humidity will otherwise find its way to the threads.

Joe