# Porter-Cable dovetail jig tearout



## fishlore (Oct 28, 2007)

I get terrible tearout cutting dovetails and box joints in white oak with my PC jig. Is this because the horizontal board on top gets cut away? Do I neet to re-trim this sacrifice piece after each use? Is it possible that the wood I'm using is too dry? I have a cheap moisture meter and it is off the chart dry. I seasoned the wood myself with a room dehumidifier.


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## Hamlin (Dec 25, 2005)

Giving this thread a bump.


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## Gary696 (Jan 28, 2006)

fishlore said:


> I get terrible tearout cutting dovetails and box joints in white oak with my PC jig. Is this because the horizontal board on top gets cut away? Do I neet to re-trim this sacrifice piece after each use? Is it possible that the wood I'm using is too dry? I have a cheap moisture meter and it is off the chart dry. I seasoned the wood myself with a room dehumidifier.


Make sure your backup board (your horz. board?) is tight against your work piece. I would think if it is tight and nothing is moved, you shouldn't have to make a fresh backer cut each time.

Gary B


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## bobj3 (Jan 17, 2006)

HI fishlore

Many push the bit to hard that's to say trying to cut the slot in one pass in hardwood,,,white oak is one of the hard ones to get a clean cut,,,dovetails must be cut in one pass but box joints can be made in two or more passes stay in the rule 3/8" in one pass, yes it will take longer but you will come out with a nice clean slot..

The blind dovetail are always cut 3/8" deep the norm but if you are cutting through dovetails switch to a 8 deg. or 7 deg. bit this will get you a nice clean pass..

A backer board will help but the Oak will dull bit in a heart beat so once you see a bad cut replace the bit with a new cutter....



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fishlore said:


> I get terrible tearout cutting dovetails and box joints in white oak with my PC jig. Is this because the horizontal board on top gets cut away? Do I neet to re-trim this sacrifice piece after each use? Is it possible that the wood I'm using is too dry? I have a cheap moisture meter and it is off the chart dry. I seasoned the wood myself with a room dehumidifier.


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## fishlore (Oct 28, 2007)

Thanks. I'll watch the bit for sharpness and be more careful with the backer board. I take it that low humidity in the wood isn't part of the tear out problem.


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