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Hey all,

I trimmed the excess off of a Honduras Rosewood backplate today. Honduras is some pretty splintery stuff, it seems. I had some minor tearout at the two widest spots on the lower bout when the laminate trimming bit passed these spots. Nothing that will matter after the rout for binding and purfling is done. I alway use climb cuts in the appropriate spots to try to mitigate this. After seeing what was going on I applied some CA to the back all the way around to try to help things. Just wondering what everybody does in this situation to stop tearout.

Here's a pic showing the very small tearout spots.

Chris.

I use the RoboSander and finish off with a hard sanding block continuing on with the block to true up the sides. I don't use the router as much any more.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Thanks Todd,

My first thought was that it was time for a new flush trimming bit. Lucky for me the tearout wasn't worse.

Never have tried a RoboSander. (yet)

Chris.

there is also a trick with tape . Did you climb cut or rout?

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

John,

I did both climb cut and rout, depending on where I was on the back plate. Didn't try tape.

Chris.

John, what is the tape trick?
Thanks, Mike

i use a spiral downcut bit in my laminate trimmer with the adjustable guide bearing that came with it.

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sweat the small stuff.

Chris: One nice set of Honduran.One thing I find that helps when cutting binding channels is to make the first cut shallow. Try about .025 to .030 thou. and then cut to your full depth. Also,your bits can never be too sharp.....!!!
Tom

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A person who has never made a mistake has never made anything!!!

if you place some tape with the grain in the fragile areas this helps to support grain and help to avoid tear out . Todd's advice will work but you can nibble these areas down with the router. If you climb cut you must be very aware of the feed rate as you can cause compression fracture and routing can tear things out from the attack angle of the cutter.
Flush , downward or upcuts will all do this if you exceed the feedrate . I have a vid on You tube that discusses this . http://www.youtube.com/results?search_q ... g+jig&aq=f the tape is mentioned as are a few more techniques . hope this info helps

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

All of these tricks will work(most of the time)....for me, on splintery stuff I have been sanding flush, it's quick, easy, and so far fool-proof.

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Gwaltney Guitars

It doesn't help for flush trimming the back, but for cutting the binding and purf channels you can scribe the back with a gramil and the sides with a round marking gauge before routing.

-jd

Thanks everyone. All these responses are very helpful.

Chris.

train termites

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it