Official Luthiers Forum!

I am in the middle of a build ..box is closed and my customer has just emailed me asking whether or not it is too late to add a soundport.
I have never done a sound port in a guitar and I am certainly apprehensive about adding one to an already closed box.
Are there those of you who have added a sound port to an already closed box?
What might be the pitfalls I should be aware of?

Thanks in advance for any reply,
regards,
jack

Jack;
When I need to add a port I pick the location-mark the center of the hole with a awl (anything with a sharp point)
Then because most ports are cut into a curve of the side I bend a piece of scrap (or sand a thick piece of wood) to match the inside curve(radius) to hold inside the guitar while I drill the hole to prevent tearout.
Works for me -but you may need someone to help to hold the inside pieces .

Mike

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Mike Collins

I think a lot cut the soundhole after the box is closed (...strikes me as easiest) EXCEPT that they knew there was going to be one & probably added a couple of reinforcing laminations to the inside before closing. (I expect this could still be done, & maybe some don't bother if it's to have a stiff "ring" for trim.)
I cut mine with a router collar & template clamped to the guitar (saw the method on a Tony Karol posting).

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Dave
Milton, ON

I do mine after I do the pore fill - dont want any of that falling in either !!!!

But I have added one to guitars totally after the fact - i simply glued in some cross grain supports thru the hole.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Sorry, no video Filippo, but there's no magic. The only thing on this one was that it was so long, the bit exited before the ends were complete. Had to drop the bit some to finish the ends. Other than that it was real straight forward... almost foolproof way to do it I think. Thanks again to Tony!

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Dave
Milton, ON

Made in Canada Eh !!!!

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I do it the same way as Dave. The only thing that is brutal is binding it. Generally I put in a tall binding and plane/scrape the excess away. It is no fun doing that through the inside of the guitar's sound hole.

So on ports that I bind I cut it before the last plate goes on. That way I can get inside to clean up the inner binding.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I've made 2 acoustics with soundports and both have been done after the box is closed, and without interior support. I'm not saying don't use support, I'm just saying that it is doable.

Let us know how it goes!

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Jake

~Make a joyful noise unto the Lord~

Many thanks for the replies; I would have believed that it would have been better to cut the port prior to bending,certainly before the box is closed, but apparently there are plenty of folks who do it after the box is completed.
Thanks for the thoughtful advice,
regards,
jack

I added an oval soundport after closing up a rebuild. I didn't want to take the chance with a drill or a router...for fear of a "catch and tear" scenario.....so I used my flex shaft and a med. 1/2" drum sander to slowly work through the side upper bout, work it to near shape and then used a fine drum to finish the edge to proper shape....I then used a 3/8 dowel with 220 grit to slightly clean up and slightly round the edges. Worked great for me.
Kent Bailey

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Wood Creations by Kent A. Bailey
EXCELLENCE IN SCULPTURE, CARVING, LUTHIER, ARCHITECTURAL MILLWORK AND DESIGN

http://www.kabart.com

One of my students added a port to his reso after the fact, when it turned out to be choked due to insufficient soundhole area. He glued in some side reinforcement, and used a flex shaft and burr (iirc) to cut a more or less round hole. He kept enlarging the hole until the sound stopped getting better, and the neatened it up a bit. He then made a surround for it, and that brought it back down to about the ideal size.

I usually drill the port before putting in the liners, but after bending the side. I like to reinforce the inside with a cross grained wood piece, and back that up when drilling from the outside. I drill the hole a bit bigger than I'm going to want it.

For a surround, I drill the correct size hole along the grain in a block of the same wood I'm using for the binding. I make something that looks like a spool on the lathe, with the center the same size as the hole I drilled through the block, and flanges on either end. This is cut in two in the center, and the two ends inserted into the hole in the block. This allows me to turn the outside concentric with the hole, and to a slight taper. I wrap the outside of the ring (it's actually an inch or so long) with veneer, glued on with Titebond, and wrapped tightly with rubber bands to clamp it. If I'm using two colors of purfling, I do this in two steps, to be sure both are tight.

The mandrils are removed from the ends, and the whole thing wrapped with sticky-back sandpaper, to work the hole to the correct taper. Then the sandpaper is removed, and the surround glued in. This can be trimmed off after the glue dries, and shaped up to look nice.