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I've been building for about a decade now, but I've never cut a soundport. I was asked to cut a soundport into my next build and suddenly realized I'm not sure how that's done.
Is it cut before bending the side, or after? Is it reinforced somehow on the inside? If so, how?
I don't suppose there is a tutorial somewhere documenting the process, is there?
Thanks.


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Most people reinforce the interior of a sound port with a bent piece of wood matching the interior radius. I typically cut the sound port after the box is enclosed.

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http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=25805&p=347681&hilit=sound+port#p347681

Here's a past thread that has some useful information for you.

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Steve Smith
"Music is what feelings sound like"

I did an oval soundport after the box was closed, using a set-up like this http://www.luthiersforum.com/forum/download/file.php?id=15283&t=1, but using a guide bush in the base of my (smallest) router, so the template was oversized.
Reinforced the side behind the area with crossgrained veneer before the box was closed.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Have not done any sound ports, but use 1/64" aircraft plywood to reinforce on-board pre-amp control box cutouts. Strong and flexible.

http://www.nationalbalsa.com/birch_ply_p/1641224bp.htm

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Ken Cierp

http://www.kennethmichaelguitars.com/

Thank you all for your help. Consensus seems to be laminate a reinforcement on the inside, bend, then cut with router/coping saw/Forster bit.
Any reason not to cut while the side is still flat? That seems easier.


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I bend first then laminate the reinforcement

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Steve Smith
"Music is what feelings sound like"

Here is one I added to a guitar. New construction would be very similar except I would bend, fit and glue my reinforcement pieces before closing the box and then cut the hole after.

http://howardguitars.blogspot.com/2015/ ... uitar.html

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I always cut mine flat first and then bend the side. My main reason is that I bind my soundports and it's just a whole lot easier to do so flat rather than trying to get a good 3d bend.

What do you glue the binding in with? I'm surprised that the seam from one end of the binding to the other doesn't open up when the side is stretched and compressed into the bend. Do you do a scarf joint there? What part of the hole do you put this joint? I would guess one of the endgrain sides would have the least distortion. . .

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I've learned from that one. I do make a scarf joint at the widest part of the oval. I then make a tight fitting plug to fit into the hole before bending. The tight bond does loosen but once cooled it is back to solid. With the plug in place, nothing moves to where it shouldn't.

Is the plug side thickness and glued in? You wouldn't have a photo would you? That might save me from asking several more poorly formed questions. . .

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I don't think I have a photo that I can think of. I can try to remember to snap one next guitar.
But to answer your question, yes, the plug is full thickness/depth. In fact, I often just use the hole cutout piece. If I use a 1/8" bit to cut the hole, it usually fits nice and snug once binding/purfling is in the hole. If it is a bit loose, I just shim the edges with some binding tape.
It's not really rocket surgery. You just need something to hold everything in place while the glue cools back down.

Thanks!

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.