Questions about making a sound port

UkeforJC

UkeforJC

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Dear all,

I am planning to make a sound port on the side of the Stew-Mac soprano ukulele that I am building.
So, I want to ask how important/necessary it is to have a patch inside the side?
I am only making a small port using a Dremel 4000. Maybe 1" in diameter.

If a patch is absolutely essential, how do you make it? Do you have to bend it like bending the side?

Thank you
 
Mandolin builders use medical guaze saturated with Titebond glue to reinforce the area around the F-holes. Keep in mind that you should reduce the size of the soundhole if adding a side port. As the soundhole has already been cut in a Stew-Mac kit, the only option you have is to bind the inside of the soundhole to reduce its size.

Brad
 
Thanks Brad.
By the way, what is the reason for reducing the size of the soundhole?
 
The size of the soundhole vs. the volume of a body is an important design criteria. There are formulas to calculate the optimum soundhole diameter for a given body size. I am assuming that the soundhole in the Stew-Mac kit is the optimum size for that body. If you add a side port, you will effectively be increasing the size of the soundhole which may have an effect on how the instrument sounds. When I add a side port to the side of an instrument, I subtract the area of the side port from the area of the soundhole and make it that much smaller. Remember the adage in lutherie, "Everything matters and everything is related".

Brad
 
Absolutely it need to be reinforced. I've used both Spanish cedar, bent and fitted between the kerfings, or carbon fiber. If you are staying with an inch or smaller I have not found it necessary to reduce the size of the sound hole by much at all in order to get good results from the side sound port.
 
Thank you!! Brad, Chuck, for sharing the information.
I think I definitely should add some reinforcement at the side of the port.
I don't have any equipment to bend any wood. So, is there any simple way to bend the wood patch?

Chuck, I read it somewhere that you mentioned that the patch should be 0.06". Is it correct?

Brad, the method, "using medical gauze saturated with Titebond glue", have you done it before? did it work out ok? I assume that it is just a piece of gauze soaked in a lot of titebond. Is it correct?

Thank you guys.
 
I did a search on the relation of soundhole size to body volume. I found some formulas, and the concept makes a lot of sense.
What I find surprising is that "travel" ukes with their shallow bodies do not seem to have smaller soundholes. Is this just for the familiar looks? What actually happens if your soundhole is too big?
 
Things that make sense in theory do not always work in practical application. I have done significant experimenting with sound ports and have not found side sound ports of any size on MY soprano ukes make any real dramatic difference. It is another matter with tenor ukuleles however where port and sound hole sizing seems to be more critical. I admit, I have not exhausted the subject by any means, just my practical experience.
 
I have used the gauze- glue reinforcement on 86 mandolins, 9 arch top guitars and 5 arch top ukuleles over a 26 year period with good results. I picked up the technique from Roger Siminoff's book on building a mandolin. That said, it is an inelegant solution, a thin piece of wood would look better, especially if you do not bind the side sound port and you use a wood of a contrasting color. An easy way to do it, go to a Woodcraft store and buy some thin wood veneers. You can use veneers of different colors, use a couple of layers and they will bend easily to shape. Use a piece of formica as a gluing caul.

As for the size of the soundhole vs. the volume of the body, the astute observer will notice that there is considerable variation in soundhole sizes in instruments that work quite well. I can only conclude that there is a fairly wide range that will work. I only try to stay close to designs I know work well. If the soundhole gets too big, the instrument will lose projection. You decouple the back and sides from the top and the voice of the instrument becomes weak. One possible explanation for the travel ukes is by bringing the back closer to the top, you increase its response to the top, allowing a larger soundhole.

Brad
 
Thank you all for the information.

So, does the position of the sound port matter ? I have seen so many different disigns and the positions of the sound port are all over the side.
The size of the sound port I plan to make is abour 1 inch.
 
Moore Bettah Ukuleles said:
Things that make sense in theory do not always work in practical application. I have done significant experimenting with sound ports and have not found side sound ports of any size on MY soprano ukes make any real dramatic difference. It is another matter with tenor ukuleles however where port and sound hole sizing seems to be more critical. I admit, I have not exhausted the subject by any means, just my practical experience.
Click to expand...

I have wondered whether you reduce the sound hole size on your tenors when you add a side port. Hard to tell with the photos.
 
For the sound port to do its job it should be aimed at the players head when the uke is in the normal playing position. That said, when the player looks down, they will be looking into the interior of the uke, so make it pretty inside.

Brad
 
I have built 5 or 6 tenors with sound ports, and i didn't reduce the sound hole size. They all sounded great.
If your sound port isn't that big, i don't think its a big deal.

I prefer to place them on the upper bout just above the waist. For me, when they are placed on the lower bout, they become muffled by my arm and/or body.......it really depends on your posture and how you hold your uke.

Jake Maclay
Hive Ukuleles
http://www.hiveukuleles.com/
 
ralphk,
What kind/strength Ammonia and ratio of hot water did you use? I've seen Ammonia used to fume White Oak for a Stickley style finish but that was some super strong stuff from a printer supply house.
 
Tarhead said:
Get a plastic bag of rice or lead shot an use it as a gluing caul to help the thin patch to conform to the shape you want.
Click to expand...

Hi! Tarhead,
do you mind to illustrate more about using a bag of rice? Pete Howlett also suggested using a sand bag to me in my other thread.

Did you guys mean, just take two bags of sand/rice/or whatever powder and put the side and veneers in between two bags, and clamp them together?
so, the flexibility or softness of the sand/rice bag can protect the wood from the clamps?

Thanks..
 
UkeforJC said:
Hi! Tarhead,
do you mind to illustrate more about using a bag of rice? Pete Howlett also suggested using a sand bag to me in my other thread.

Did you guys mean, just take two bags of sand/rice/or whatever powder and put the side and veneers in between two bags, and clamp them together?
so, the flexibility or softness of the sand/rice bag can protect the wood from the clamps?

Thanks..
Click to expand...

If the piece of wood you are lining the port with is very thin and you place it with the long grain perpendicular to the sides you may not need clamps at all. The weight of the sand/rice/beans/shot/etc will hold the piece in place and conform to the inside curve of the upper bout while the glue sets up. If you need to clamp it, get a piece of wood wider than the bag of rice or beans or sand or lead shot, etc and put it between the clamp head and the bag so the loose material doesn't get skwooshed to the edge of the bag. No need for another bag of stuff on the outside of the upper bout.

You could also make a clamping caul out of wood to match the inside curve too....or make 2 upper and 2 lower while you're at it and then you'll be able to hold the sides in a body mold. Then all you would need is a piece of plastic wrap or waxed paper between the call and the piece of wood.

You also may be able to just clamp the piece in place with some clamps if your sides aren't to deep for your clamps and forget all this other stuff. It ain't rocket surgery.:D
 
Tarhead said:
If the piece of wood you are lining the port with is very thin and you place it with the long grain perpendicular to the sides you may not need clamps at all. The weight of the sand/rice/beans/shot/etc will hold the piece in place and conform to the inside curve of the upper bout while the glue sets up. If you need to clamp it, get a piece of wood wider than the bag of rice or beans or sand or lead shot, etc and put it between the clamp head and the bag so the loose material doesn't get skwooshed to the edge of the bag. No need for another bag of stuff on the outside of the upper bout.

You could also make a clamping caul out of wood to match the inside curve too....or make 2 upper and 2 lower while you're at it and then you'll be able to hold the sides in a body mold. Then all you would need is a piece of plastic wrap or waxed paper between the call and the piece of wood.

You also may be able to just clamp the piece in place with some clamps if your sides aren't to deep for your clamps and forget all this other stuff. It ain't rocket surgery.:D
Click to expand...

Hahaha...thank you man, for the illustration. That was great.
 
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