Flush Trim Router Bits
Spread open the pages of most woodworking magazines, including Popular Woodworking, and you’ll find projects built using face frames. Woodworkers go about building face-frame projects in varying ways.
Contributing editor Troy Sexton constructs the face frame then builds and fits the cabinet to that frame (See American Cabinet, Popular Woodworking April 2008, issue #168). I tackle a face-frame cabinet from a completely opposite direction. I build the cabinet then design my face frame to fit that case.
The one technique we both have in common is that we build the face frame larger and wider than the cabinet. The frame overhangs the case by at least 1/8″. That’s so we can trim the frame to exactly fit the case. And how do we trim the frame? With a router and a flush-trim router bit.
The next question is which flush-trim bit. Yesterday I received a new catalog from a router bit company. I begin thumbing through the pages and was intrigues by a newly designed flush-trim bit , at least this was the first time I had seen this design. This bit has a glue-reservoir area that bridges a glue line in order to eliminate glue buildup on the bearing. Do we need this feature?
Also, do we need spiral-upcut and downcut flush-trim bits. Router bit manufacturers have touted these bits for years. Spiral flush-trim bits are supposed to provide a cleaner cut. How about downshear flush-trim bits? This style bit has been available for a while. Is this design something we should have in our bit arsenal?
For years, I’ve used a basic, straight flush-trim bit and it’s served me fine. I guess I’m set in my ways because I don’t see the need for these somewhat specialized router bits. I’m not saying that the next time I need to replace my flush-trim bit I’ll stay with my old standby, but I’m perfectly satisfied with the job the basic bit is doing.
So, how do you trim face frames to the case? Do you have a favorite flush-trim router bit or technique for flushing the face frame to the cabinet? Leave a comment and let us know how you’re trimming frame-to-cabinet joinery.
Oh , and a tip I picked up from Troy was to always do my flush trimming using a climb cut. That technique keeps you from ripping out the wood as you trim. That’s what makes the results using an ordinary flush-trim router bit equal to the newer designs.