[maryjo]

Need to know why when I use my Typhoon bits and stones it dulls my carving tools. I knew about the sandpaper problem but I wasn't prepared for the other power bit and burrs to cause the same problems.Is there any way to prevent this

[Nancy-ID]

Maryjo,

I'm not sure what you mean but guessing I would say you are referring to what I have experienced. After using the power tools on a carving then switching over to your knives etc., you find the carving harder to do??? I think it has to do with the term, "work hardened" ? Sort of like if you pound on aluminum it actually gets harder. I think that is what is going on, not the tools becoming duller. Hey! Anybody out there really know what causes this?

[Thomp]

Nancy

i think your on the right track with the hardening from hammering on it, also consider the heat friction, each will harden the wood only supervisally deep that is depending on how hot or hammered of a treatment it got.

[Paul_Guraedy]

The explanations of Nancy and Thomp seem to be the logical answer. I wonder if it might also be something about the manner in which the power tool is used.

I ask this because I have noticed exactly the opposite effect. After having used a rotary power bit, the wood seems to have actually softened. I find the same thing with roughouts.

[AlArchie]

MaryJo, what kind of wood are you carving? If driftwood or other "found" wood, it may not be the power bits themselves that are causing your dulling problems. Both these types of wood are notorious for having grit both on the surface and imbedded in the wood. Plus, your typhoon bits may be forcing surface grit into the lower wood fibers.

A second thought might be that you are carving much harder wood with the typhoons and stones. Those harder woods will dull tools ground for work in say, BASSWOOD.

Some hardwoods actually do get hardened by high temps. Better quality hickory tool handles are often "fire hardened", but these are treated with much higher temps than would be generated by normal friction from rotary tools, unless you are actually "smoking" your pieces by holding the burrs too hard on the work piece.

I've also noticed that when using high speed router bits on pine or other woods with highly aromatic sap contents, the router bits will "burn" some areas with high pitch content,and these heated pitch areas actually glaze over with a hardened smear of pitch. These areas get "hardened" enough so they only reluctantly accept stain, and may require sanding to remove the glaze. If you are carving pine, cedar, spruce, arbor vitae, pinion or other coniferous woods, that may be part of your problem.

My guess is that you are using the power bits on either found or really hard wood. Then the dulling would be likely due to either imbedded grit or carving on harder, more abrasive wood than the grind on your hand tools is designed for.

Al

[maryjo]

No Archie I'm using Basswood.I never thought about the wood fibers being compressed and hardeding the wood.Maybe after I do my roughing out with the foredom I'll try soaking the wood with water.

[Lynn O. Doughty]

Even if the bits did scorch the wood it would only be on the surface which, while maybe a little more difficult to carve away than whats underneath once it's gone the remainder is just as it was originally. Maybe you just have a bad piece of wood. I've been fighting a battle with a chunk I bought from a guy a year ago and the next time I see him I'm going to let him know about it!!!

I think whats in play here is that rough surfaced wood has a tendency to dull sharp edged tools. Just as some use brown paper bags as the last step in sanding their carvings you can only imagine what a sawn surface of a cutout would do to a polished knife edge. Guess thats why we have to resharpen them. The first thing I do when beginning a new piece is to carve off all the surface wood that has been roughed up by the bandsaw. Only then do I reach for my best carving tool to begin the actual carving.

[mdallensr]

I agree with Lynn. Wood doesn't work-harden the same way metal does, and any change in the carving properties would be superficial. I think any "grit" embedded in the wood from Typhoon burrs or other rotary tools would do more than dull tools. It would put a serious nick in the tool that would be visible. I'd bet on a hard piece of wood or even a different species of wood. We have a problem in Ohio of mixing basswood with buckeye at times, and you can't always tell the difference by looking at them. Mike

[Hi_Ho_Sliver]

Bits will get dull too, eventually...and sometimes like was said, a buildup of pitch...which can be burned off...(not real high heat tho!) I think maybe the way you use a bit can have a lot to do with it....I have a couple that I was in a hurry and started "hogging" wood and they got pretty dull on me fast!