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If the binding is a bit taller than the purflings, (0.27” vs. 0.25”) can I cut the binding channel to match the purfling and plane the excess .02” off the binding after glue-up?



Also, do I make any thickness allowance for the glue layers, e.g., between the sandwiched binding and purflings, when calculating the rabbet thickness? Thanks.

Joe

#1 yes you can, it's easier.

#2 You need to be aware and accommodate for swelling with wood glues. Test fit on scrap, make notes. Modify your depth if necessary. It's a good idea to leave the bindings slightly proud, they're easier to scrape flush than to scrape the top, back, or sides down to the binding. Test on scrap first (make a nicely bound wooden jewelry box)

Thanks Terry.

Joe

I am looking at the picture above - doesn't the binding channel need to be stepped ? or can it also be cut like this ? It looks easier to cut this way.

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It's this new idea from recent decades that everyone gets a participation award. - MUX

@John. On my first and now on #2 I have done with the step for the purfling. I am considering doing like this on the next.
For the binding I have chosen 2 mm padouk but I think next time I will chose 1mm; much easier to bend and if needed one can always add another thin veneer on the inside .

While I agree its a good idea to leave them pround on top, there's a lot of guys who scrape the sides down to the bindings - only a few thou though.

The issue is that if you scraspe the bindings, it's really easy to get bindings that are not even in thickness and it's pretty obvious.


To the op, typically the purflings aren't the full depth like the binding. The binding and purfling channel is usually L shaped.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

If you are using full-height purfling lines, you should be okay. If using the shallow purfling lines you'd have to make sure that the tape or whatever pushed down on the purfling. The taller binding may in some instances create an angle that would cause the clamping force to miss hitting the purfling. One way around this is to do purfling first and then glue the binding. But that's a lot of tape.

I've been doing it like in the picture for over 40 guitars now with no issues yet.

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Been there, done that- now I bring the sides down to the bindings if necessary.

Cheers
John