UHMW Router Sub fence

[George Bokros]

I use UHMW for a sub fence on my router table. I recently read that a zero clearance sub fence will reduce tear out when making rails and stiles for cabinet doors. My question is how hard is it on the router bit to cut the profile cut through that material. My sub fence is like either 3/8 or 1/2 material. I did it for my table saw insert but that was thinner.

Thoughts and comments please.

TIA

George

[Curt Harms]

UHMW should cut easily. But here's another thought, especially for cope cuts. Either cut the rails a little wide or better yet (for me) leave stock wide enough for two rails plus a bit, make the cope cuts then rip to width and and remove any tearout. This leaves really clean joints. I've tried doing the backer thing with scrap and got it to work, but going overwidth and ripping away any tearout has produced cleaner joints. Just my experience.

[David Thompson 27577]

You'll have no trouble routing through the plastic -- it's actually fairly soft stuff compared to most hardwoods.

But not that most rail and stile bits are bearing-guided. So you'll find it impossible to get the bit through the UHMW to the point that the bearing is flush with the front face -- the bearing will prevent the through-cut.

The best I've been able to do, is to cut partially through from each side of the plastic, then use either a drill or a saber saw to cut a hole for the bearing. Then I can run the bit through completely.

Kindof a PITA, but perhaps worth it.

[glenn bradley]

UHMW has always machined very well for me. I have not noticed any excessive wear on the cutters. I do use something cheaper like scrap for ZCI sub fences on the router table though. My ability to get an already cut sub fence back into a reasonable position for re-use is more effort than it is worth to me. I have prepared a pile of pre-cut sub fences from scrap and so just grab another piece once one is worn out. I use a Forstner bit to drill a clearance hole (outside the desired ZCI area) for the bearing. Each one is good for 3 positions of so. then I flip it and get 3 more and then toss it.

[Steve Ryan]

You can also try HDPE, less$$. Are you sticking before you cope? I cope first, stick second. Any tearout gets removed in the sticking process.

[George Bokros]

I am referring to the tear out when sticking. I don't get much on the cope cuts.