Another router question

[musicdog400]

I am planning a hollowbody guitar, and I am a bit nervous about the router and tearout when cutting the binding channel. I see people suggest bump cutting and climb cutting, where you cut the curves from the opposite direction.

 

So with climb cutting, you are really moving the router in the opposite direction from which it is intended to be used. Correct ?

[ohspyro89]

I'd honestly suggest against climb cutting if you aren't experienced. Routers have a terrible tendency run with the wood, especially during climb cutting.

 

The wood that you'll have the worst experience with tear outs will be figured woods. I've never really had any huge issues with woods that weren't figured. A good sharp bit is essential too. After they dull, they tear out like there is no tomorrow!

 

If you haven't used the climb cut before, try it out on some test pieces!

[tedmich]

I find that nice 4 flute milling cutters can leave a much better finish than most router bits for simple cuts, and they aren't much more expensive. No std shanks though so you need a 1/4" bit to get a 1/4" shank. MSC Industrial has a nice Kenametal bit for $13, 4 flute solid carbide ( MSC #: 71335137) and you can also get one coated with TiAlN (MSC #: 74210394) for about the same price. The coating helps lubricate and stop resin/pitch from sticking/burning onto the bit.

 

Grizzly has some similar bits too.

[MahaloVision]

One thing that helps is to chisel, sand, and/or plane away as much excess plate as possible before doing the routing. Too much plate will give the router bit more tendency to rip out chunks of top. On your first pass, you'll have to do some climb cutting anyway - think of running the router "downhill" from the apex of the curves of the bout towards the waist and the head/tail sections.

 

A good router jig makes the process easier, by the way. I've built a Fleischmann type parallel arm jig that works great, but a lot of other people use the vertical router on slides approach too. The method of using a router table with a doughnut spacer to hold up the side is workable, too - as in the Benedetto book.

[Tomm Williams]

Do not attempt any binding channel cutting without cutting lots of scrap first. This will go a long way towards building your confidence before you stick that $300.00 top into the router!!!!!

I use the Luthiers Mercantile carriage router and it works great. If your just getting started and can't justify such an expense, at least buy an upper brand router like Dewalt or Milwaukee. Make sure you get the best bits you can afford and the easiest way to avoid tear-out, no matter which direction you cut, is to make numerous small passes rather than one big cut.

 

DO NOT DO THIS WITHOUT PRACTICE!!!

[musicdog400]

Thanks all. I do think I will take the plunge and buy the binding cutter jig. I also read that coating the edge with shellac can help hold things together.

 

I suppose there were instruments with binding before there were routers. So there probably is a slower way to do this without power tools.

[MahaloVision]

Yes, a Gramil or Purfling cutter. Basically a knife with a guide, sort of like a mortise gauge. The knife marks the line, and you chisel it out. Just that simple.