Maybe epoxy renew on zero clearance is a bad idea

[sean meltvedt]

For a while I have been thinking it’s a great idea to use leftover epoxy to renew my zero clearance throat plates. Well I’m now reconsidering-as this blade is decided trash with 25 of 40 teeth damaged or missing. I checked on my other saw and sure enough, some minor chipping on that one as well. So-I’m thinking the old epoxy would be cheaper to throw away😳
Is anyone else doing this without damaging blades?
Cheers
Sean

467200467201

[Rick Potter]

Haven't tried it yet, but I have been meaning to use some just on the part of the insert where the leading teeth go. I don't see a need to cover the whole slot.

Since epoxy seems to be a problem, I wonder if Bondo would be better? It stays fairly soft.

[Doug Garson]

I just cut a piece of scrap wood and glue it in, never had a problem. Have done this on table saw zero clearance inserts and crosscut sleds. Also glued pieces of wood into radial arm saw fence to renew it.

[Michael Schuch]

I had never considered rejuvenating my zero clearance plates with epoxy. It sounds like a good idea at first thought. Thank you for sharing your experience to save the rest of us some heart ache!

[Alan Schwabacher]

That looks bad, and I would not have expected simple epoxy to be so hard on carbide teeth. Did you perhaps use a metal-filled epoxy like JB weld?

Fitting in a piece of wood is a good solution, but it's more bother here with an internal kerf than it would be on the edge of a single runner sled.

[Kevin Jenness]

I've planed and sawed through marine epoxy fills and gluelines for years without seeing any tool damage. What type of epoxy did you use?

[Myk Rian]

I can't believe the epoxy did that. There's something else going on.

[Lee Schierer]

I can't believe the epoxy did that. There's something else going on.

From the photos, it appears that the saw blade is not centered on the opening in the throat plate. Any sliver of material that gets between the blade plate and the opening in the throat plate will push the teeth into the steel of the throat plate. I would try to adjust the trunions or table top so that the blade is centered better on the opening in the throat plate. The only other alternative would be to increase the width of the opening in the throat plate.

[Steve Demuth]

I have updated zero clearance tools using epoxy mixed with shavings from a jointer or planer for years. Never had any damage to saw blades or router bits as a result. Also, like many folks, I turn objects on the lathe that are heavily epoxied, often using carbide insert tools. Again, never damaged a tool with the epoxy. So, I think something else is going on with your situation.

Was the epoxy properly mixed and fully hardened? "Gummy" epoxy can raise hell with tools in odd ways by building up on them and creating highly variable and off-axis forces. I can imagine that breaking brittle carbide teeth under the wrong circumstances.

[Frank Pratt]

I can't believe the epoxy did that. There's something else going on.

This. Epoxy just isn't that hard. So many others have been doing this for ages with no problem. Are you sure the blades were not chipped prior to the epoxy work?

[John TenEyck]

I use a replacable insert in my ZCI, but for my RAS table I fill the over worn groove with Bondo since it cures in 15 o 20 minutes. No issues with blade life that I can tell.

John

[sean meltvedt]

To answer some of the questions-the pictured plate was originally the ICS plate that was last used on the PCS so they don’t share the exact same curf. The epoxy is West 105 with either the 206 or 205 hardner. When I cut through my plates, I just park the fence on top of the plate with 1/2-1 inch of clearance between the fence and the blade. I’m wondering if the fact that the plate has a little bit of rattle room somehow allows a tooth to be damaged. If the damaged piece gets between the epoxy and the next tooth… then it’s all downhill from there. I too have cut through tons of epoxied pieces with no issues-that’s why I’m so confused as to the mechanics at play here. I’m still not sure exactly what caused it.

[johnny means]

From the photos, it appears that the saw blade is not centered on the opening in the throat plate. Any sliver of material that gets between the blade plate and the opening in the throat plate will push the teeth into the steel of the throat plate. I would try to adjust the trunions or table top so that the blade is centered better on the opening in the throat plate. The only other alternative would be to increase the width of the opening in the throat plate.

What steel? The throat plate is phenolic.

[Dan Cameron]

Ive repaired the ZC slot on my sled several times using Bondo. No blade damage I have seen.