Kumalae repairs

I recently aquired a 20's era Kumalae soprano that is in suprisingly good condition, but it does have a couple of cracks in the back and the glue joint has come apart between the back and side for about 2". I was wondering what material you would recommend for cleats to repair the cracks, I have some Sitka spruce but no Koa. Can you recommend a place to get small pieces of Koa?
The main question I have is about the soundboard, it appears the string tension over the years has pulled on the bridge and caused a dip in the soundboard between the bridge and the sound hole. I was hoping someone here would have ideas on how to straighten it and prevent it from happening again

As the Kumalae is built out of koa, that would be the best material to use for repairs. If you send me a PM with your address, I can send you some scraps. As for the potato chipping, those ukes were built so lightly that is to be expected. It may be a good idea to install a light bridge patch to stabilize the area.

Brad

Every old Kumalae I have seen including mine had that dip in the sound board above the bridge. Kumalae used very thin tops which gave them such a great sound but compromised rigidity. Contrast that with the Indonesian Ponos which had thick tops but muted sound.

Mahalo nui loa for the answers, I had suspected the very thin soundboard may just be prone to the bowing/"potato
chipping" (that is the perfect term for it, I'd never heard it before). Thanks Brad for the offer, I've sent you a PM. What strings would you recommend? It seems I've heard some say that Worth makes a light string for old ukes, do you think they may help?. Thanks again guys I really appreciate your input.

The koa is on the way, sent USPS Priority mail. Keep in mind that rare earth magnets are a quick and easy way to apply clamping pressure to internal cleats. I think the Worth strings are a good idea. Let us know how things turn out.

Brad

I know I have mentioned this site before and it may not be held in the highest regard, but I was impressed with the amount of free info he provided on his site.

He uses an improvised "bridge doctor" to flatten out the sound board and transfer the load to the tail block. Breedlove uses something similar on thier guitars now.

http://www.ukuleles.com/BuildingHowTo/ukuleleBD.html

olgoat52 said:

I know I have mentioned this site before and it may not be held in the highest regard, but I was impressed with the amount of free info he provided on his site.

He uses an improvised "bridge doctor" to flatten out the sound board and transfer the load to the tail block. Breedlove uses something similar on thier guitars now.


http://www.ukuleles.com/BuildingHowTo/ukuleleBD.html

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Thanks for the link, there is a lot of info there. The "bridge doctor" looks like an interesting idea for a future build (8string maybe?), but this is a vintage uke and I just want to restore it as close to original as possible.

kenikas said:

Thanks for the link, there is a lot of info there. The "bridge doctor" looks like an interesting idea for a future build (8string maybe?), but this is a vintage uke and I just want to restore it as close to original as possible.

Click to expand...

I understand but even with very old Martin guitars, once the top started to collapse, there really weren't may alternative other than improving the support, bigger braces, larger bridge plate, all of which is not exactly restoration activity.