Router Bit Size

[scamp]

I am making my own perfling using layered veneers so I can get the colors I want. Black, green, black. I want to use the finished perfling around the inner and outer ring of the rosette. I want to buy a router bit that matches the thickness of the perfling so it can be used to cut out the rosette as well as create the channel for this inner and outer perfling ring. My perfling has a thickness of 0.065 inches. My question is…. What router bit size should I get. Should it match the thickness of the perfling or should it be a bit less ( like 0.060 ) since I suspect the finished channel might be slightly wider than the dimensions of the bit.

Any help appreciated

[tippie53]

Your chances of that are slim , if you have a circle jig use a smaller bit and widen it with adjustments. it will be ore versatile. If you need , lets say .187 and you use a 3/16 cutter, If you have any runout , and you will that .187 will be wider than you planned.

[scamp]

Your chances of that are slim , if you have a circle jig use a smaller bit and widen it with adjustments. it will be ore versatile. If you need , lets say .187 and you use a 3/16 cutter, If you have any runout , and you will that .187 will be wider than you planned.

Thanks John. I was asking because I have seen a few examples on line and by some people on this forum that suggest using a “properly sized” bit to both cut out the basic rosette as well as make the accurate channel for the inner and outer perfling ring of the rosette. Seems like it should work well if you could get the exact right size router bit but as you say…. That is hard to do. That’s why I asked. Seems like the routed channel will be a bit wider than the dimensions of the bit. How much larger? Who knows.

[Kevin Sjostrand]

1/16" should work fine.
Get it and test it on scrap. You want a good fit but need room for the glue. You can always open up the channel but you can't put the wood back.

I use a 1/16 for regular BWB purfling you can buy that varies between .055 and .063 or so. It works fir me.

When installing chamfer the bottom edge of tiu binging a little so it goes in easier.

[scamp]

1/16" should work fine.
Get it and test it on scrap. You want a good fit but need room for the glue. You can always open up the channel but you can't put the wood back.

I use a 1/16 for regular BWB purfling you can buy that varies between .055 and .063 or so. It works fir me.

When installing chamfer the bottom edge of tiu binging a little so it goes in easier.

Thanks. A 1/16 router bit should be easy to find and experiment with. I thought you were the guy on the forum who was using this technique.

I found a 0.055 router bit on the LMI site they claim you can use directly for their B/W/B plastic perfling. Unfortunately I suspect it would be too small for my custom perfling.

[Kevin Sjostrand]

I have the .055 bit and i find it too tight for .063 purfing

[Stray Feathers]

I usually find I have to rout inner and outer edges of each channel, which takes some fiddling and smaller bits are sometimes needed. You can find them but Lee Valley is one easy place to get some of these downcut spiral bits: .025, .032, .040, plus 1/16, 3/32 and 1/8. Depending on how many you order you may get free shipping. I also use them for routing for mother of pearl inlay. Bruce W.

[rcnewcomb]

PreciseBits.com is another good source for specialty bits.

They also have a reference on cutting shell with feeds and speeds at the bottom of the page.

[MaineGeezer]

If you want an exact width, you'll need to make two passes with an undersize cutter. Small cutters flex under cutting loads and will cut oversize, and possibly somewhat unevenly.

[scamp]

Thanks for all the feedback.
Great to have some additional venders for these bits as they are sometimes hard to find.
Also...Interesting comment about making two passes with a smaller sized bit first.
I can see how putting pressure on a smaller sized bit will make it wobble and hence create a wider cut.
As usual, I will try some experiments taking into account all the excellent comments and pick a path.

Regards
Scamp