[dualquads]

I have a project that I want to include box joints in planed down 3/4" red oak. I have never tried this type of joinery before and will be using a PC jig. Made a few test joints using 3/4" ply and the results weren't good (tear-out and chipping mostly due to a dull router bit I think). I bought a new carbide bit and ready to try the oak. Would it be advantageous in reducing tear-out to (1) only rout say 1/4" deep or so per cut and make several cuts increasing the depth each time, or (2) pre-cut the joints by hand or on the table saw and finish with full depth routing?

Thanks!

 

[ryan50hrl]

Use a thin backer board behind or next to where it's breaking out if you can so that the oak has support

 

[snookfish]

I'm sure others have had a much different experience than me but I have never had much luck with box joints on plywood. I always seem to get more tear out than I expected. Maybe my blades were not sharp enough but when I did the joints on solid wood and had a backer they came out fine.