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Binding channels. My binding stock is 0.08" thick. 1/4" tall (not that this part matters). My purfling is 0.024" maple (x2). So I am pushing 0.128". I've done this before, but it seemed then (and now ) to be a bad idea. Had a few kerfed lining chip-outs. Question is, would you use a deeper ledge for purfling and make the main cut 0.08"?

Only reason I am asking is because its a lot more setup work...

Are you bending bindings at .080"? I usually thin binding close to .065" and cut my channels at .060".
.080" too thick for easy bending, IMO.
Ken

yes, already bent (fox bender).

I personally cut a stepped binding channel. It doesn't take that long to change a bearing and adjust the depth. Maybe 2 minutes on my SM binding setup. I also feel cutting a binding channel over an 1/8" deep can seriously compromises the integrity of the linings especially if they are kerfed. I make my own ebony bindings and prefer them to be about .084"x .250" including the purflings.

PS It helps to have two body cradles. That way I just swop cradles once the router is adjusted for the second cut.

Best, M

Ok. Makes sense. What is a body cradle?

I agree on depth of cut issue. Just curious what others thought

Yes, definitely stepped channels for me as well. I don't want to be removing any more from the body/lining area than is necessary.
Ken

Body cradle
http://www.bluescreekguitars.com/shop/i ... -d0LICypy3

Definitely.

Yeah, thinner bindings are a lot easier to deal with, especially since they'll flex a bit when gluing to squeeze out gaps. But I really like the look of short, thick bindings (like .200" tall, .080" thick, heavily rounded), so I usually just tough it out. It also depends on the wood. Curly maple is friendly even at .080" thickness, but .080" purpleheart has to be bent perfectly or there will be gaps.

As for the current guitar, I'd say go ahead and cut the second ledge. In the future you could use double sides or thicker linings to get more meat. I do use a single channel if I'm using a single veneer purfling, but any more than that gets a separate channel.

I do stepped channels too and I use 0.080" thick binding. I do my bending on a hot pipe and 0.080 binding works fine with that approach for me. I like the look of the thicker binding too.

I rout the purfling channel, change the bearing, and then rout the binding channel. I determine which bearings to use by doing test cuts on scrap first and fitting the purfling and binding to those channels with allowance for glue. The purfling from LMI and SM can vary slightly in dimension from one piece to another and within in the same piece, so I do the test cuts and fits for each guitar with the exact purfling pieces I plan to use.



I'm not clear on how you are using the two cradles. Why do you swap cradles to make the second cut?

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

My setup uses an adjustable cradle that holds the sides of the body perpendicular to the table. The router simply travels up and down as it follows the back or top contour.

I'm not clear on how you are using the two cradles. Why do you swap cradles to make the second cut?[/quote]

The sides of the guitar are pretty much perpendicular to the guitar top. Not so on the back especially if I'm doing a Manzer wedge which is pretty much a standard feature on my guitars. If I didn't have the second cradle I'd have to readjust my single cradle and or set the router up twice for each side.

Ok, got it now. I wasn't clear on the sequence of cuts, but it makes sense now and eliminating two router set ups would be nice.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I still don't quite get it ... surely , on a wedge guitar, altering the perpendicularity of the sides is going to compromise the width of the cut , with a consequent variation in the visible width of the binding/purfling ? Won't the rebates be slightly wider on the treble side than the bass side?

I think the "two cradles" would allow you to set one for the sides being perpendicular when the top is being cut and the other set so it is perpendicular when the back is being cut. With this you can set to cut the binding height and width, cut the top using one cradle, pop the guitar out and put in the other cradle to do the back without having to re square the body every time you flip the guitar (at least that is my take on it and it would save some time if you have the space).

To the main question I use .08" binding and cut the binding channels first then do a shallow step door the purfling.

Exactly!!

Exactly!!

Stepped channels for me as well. It's more work but worth it, IMO.

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George :-)

Assuming a stepped ledge (one for purfling, the other for binding), I think the question of which one you cut first depends on what type of router guide system you use, and how it indexes off the guitar sides and plates. When the indexing point indexes off a surface already routed, that throws off calculated depths. Testing on scrap is super important.

I use the LMI binding router tower and a Stew-Mac cutter with bearings. It works really well, but all the stuff I mention above is important to plan for with my system. It might be less important with other systems that index off larger or different parts of the sides and plates.

Well. Spent day working out cut depths and so on. It still never fails to amaze me that a specific combo of bearing etc does not always result in expected cut depth. I understand issues with side registration. And I'm using a new dewalt with excellent bearing runout specs. But it's always more than I expect. Top and back dome play a role too in geometry. Best to just cut and check. Zero in. Went with ledges for purfling. Looks great.

Thank you

Mike