Spindle taps

Re: Spindle taps

john lucas

Particle board doesn't thread very good. If you use wood at all you need to seal it with a good thick finish to prevent leaks through the wood.

I find the best thing for vacuum chucks is plastic decking material. You have to plane off the little grain ridges that are cast into them, or you could mount it on the lathe and turn it flat. then drill and tap your hole. Mount that on the lathe and true up the face. Then cut a groove to fit some PVC pipe. You can buy pipe adaptors , or pipe couplers in various sizes that are perfect for vacuum chucks. I used a 4" coupler for one and a 4" to 6" for another one.

Re: Spindle taps

George Balock

I find that UHMW polyethylene works great for some of my smaller vacuum chucks. It drills and taps great.

Re: Spindle taps

Tom Gall

I don't think threading particle board would work very well. Are you referring to MDF? Wouldn't recommend that either unless you mount on a faceplate. I have quite a few MDF chucks made years ago and you have to seal the hell out of it....I used 3-5 coats of Deft lacquer (brushed on and sanded) and I think they still leak a little. About 5 years ago I found this stuff at a reasonable price (3/4"x12"x12") and it is available in larger sizes (up to 4'x8')..... but the shipping will probably kill you. Works great!

https://freckleface.com/shopsite_sc/store/html/product848.html

Re: Spindle taps

Dick Coers

Particleboard would be a poor choice. But I have not seen any rated at very dense. The core is always more porous than the skin and would not tap well.

perhaps stabilize, then tap

John K Jordan

There is a way to tap porous materials including soft, punky wood - stabilize it with super glue: drill a hole a bit undersized, soak inside the hole with thin CA and allow to cure repeating until it won't take any more, drill the hole to the proper size for tapping, soak again with CA, tap.

Caveats:

- It may take a lot of CA glue.

- The fumes are horrible.

- The exothermic reaction of curing CA can generate a lot of heat.

I've done this with plenty of smaller threads but my experience does not yet extend to lathe spindle-sized threads like 1-1/4"x8.

Another way I've tapped soft wood is drill a hole, glue in a plug of harder wood with wood glue, drill and tap the harder wood. Haven't tried this with MDF or particle board but It might work ok. Might even work better if the plug had a flange turned on it first. This an "egg chuck" I made by tapping a hard Dogwood plug glued into a piece of soft cedar:

Also, the construction "lumber" we just used on the outside of our house (for siding, battens, and trim) is a manufactured wood product that looks like particle board but it is quite hard and dense, cuts cleanly. Pieces I left out in the rain over the winter do not appear to be degraded. I suspect a piece of that would tap nicely.

JKJ

Re: Spindle taps

Dennis in Southern Oregon

When I made mine a few years ago, I used scrap Corian sheet material. It is strong, and is easily tapped and turned. It mostly comes in half-inch sheets, but can be cemented with epoxy to produce thicker structures. I used a disk for the spindle end and a ring for the outboard end. Each was grooved to accept a short length of large PVC pipe. The final assembly was trued up by trimming the outboard ring on the lathe.

I obtained a lifetime supply of scrap Corian for free by visiting a local bathroom contractor. "Scrap" pieces ranged in size up to about 12" x 20".

Re: Spindle taps

Dennis in Southern Oregon

Actually the PVC "pipe" was PVC couplers. I made chucks using 6",4" and 3" couplers.

Re: Spindle taps

Mark Paulley

All thanks for the help, I apologize for my reference as

dense particle board I meant the MDF type of product.

I will follow up on several of your recommendations

Thanks