windstorm

Happy New Year everyone! I need some advise on reducing tearout on my Porter Cable 4212 dovetail jig. I'm making box joints (my 1st attempt) on 1x6 red oak & the tails are fine, but I'm getting tearout on the pins. My spacer board is snug and the 1/2" router bit is sharp (new), and it's a little frustrating. I understand that some tearout is expected. Any advise is appreciated. Thanks.

Rob

Whenever I make dovetails or box joints, I use one of two methods. Usually with the dovetail jig I scribe a line across the surface of the wood at the depth of the cut, deep enough to score the wood fibers to eliminate tear out. If I'm making box joints on the table saw, I use a scrap of wood as a backer and move it along with the stock so there is a fresh face for each cut.
Here are a couple of marking gauges...

http://www.rockler.com/product.cfm?page=11305

http://www.rubylane.com/shops/bridgepast/item/3998

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chesterboyd

Rob had a good suggestion but let me suggest putting some scotch tape over the area before you rout it.I know you said you had a good back up board, but the tape may help.Also, can you rout the tails a little shallow, so you have your assembly stand a little high and you can sand out the tear out?Lots of luck and happy new year.

windstorm

Thanks to both Rob & Chesterboyd. I scribed my line on my two outside cuts & taped over them & no tearout! I also used a 1/2" shank bit & this seems to be sturdier during the cut (who knows, maybe less vibration). I also routered in 1/8" increments & while it took a few more passes, it was like cutting butter. Problem solved!