Double Bass Loose inner lamination on Kay

[layrepairs]

Hi,

I was hoping someone may have some advice on this Kay (1949 by serial number).
I'm attempting to repair this for someone who retired and needs to sell it.

It was left for a long period in a poor environment and delaminated all over the place.
I have the front off and the lamination issues repaired. The neck is in fine shape.

However, the back inner laminate layer is really bad. A big section of it is released
and the corner even broke loose. I have tried to get glue under the lamination and put
weight on it with the front off and the sides in place - largely no success. I can't really
clamp it without forcing the C upward even more and I'm concerned it will end up twisted
or just even more broken. For example, are the other corners likely to let go soon and
should be all reglued anyway?

How hard would it be to completely disassemble so I could try to clamp the back layers?
I understand it would be very hard to get back together without some frame.
If not, what is the best method? Sand bags both under and above?

I don't have any vacuum gear.

Thanks

 

[james condino]

That is a very clean loking 1949!

If it was my project: finish everything on the top and then glue it back on (hot hide glue only!!!!). Then remove the back and fix all the issues on it. That way you have a frame (the rib galand) to hold everything together while one of the plates is off. If you take everything completely off, it gets a bit squirrely trying to align all the parts again especially in the springtime when the weather is changing every day.

I tried to do this last year without removing the back; it had never been off and was attached very well. I made a giant "go-bar" deck that screwed down to the corner blocks. Everything was going great and I had about 25 go bars in place under tension and the loose back sections gluing under pressure.....until all that pressure completely blew the back off the ribs and left me with even more of a mess. Good luck and keep the photos going- those early postwar years are my favorite!

j.
www.kaybassrepair.com
www.condino.com

 

[Paul New]

That looks a lot like mine, the finish and everything, and it's supposed to be from 1951.

 

[Jake deVilliers]

That looks a lot like mine, the finish and everything, and it's supposed to be from 1951.

They appear to have had a pretty stable work force at Kay and were fairly consistent, especially with their finishes. I imagine they would go out of their way to keep their finish guy happy, as he was the 'face' of the business.

 

[layrepairs]

I've been working on this at a snails pace but the front is nearly stable.
I used hobby shop 1/16 and 1/32 inch basswood to repair the laminate because that's what I can find local.
Its certainly too late now but does anyone know what Kay actually used on the lamination layers?
I'm not great at identification of woods but the inner lay does not look like spruce, birch or maple.
Is it poplar?

 

[Jake deVilliers]

I've been working on this at a snails pace but the front is nearly stable.
I used hobby shop 1/16 and 1/32 inch basswood to repair the laminate because that's what I can find local.
Its certainly too late now but does anyone know what Kay actually used on the lamination layers?
I'm not great at identification of woods but the inner lay does not look like spruce, birch or maple.
Is it poplar?

You're doing fine. They used a lot of different woods. I've seen birch, maple and poplar.

I would be more concerned with soundness than the correctness of the inner ply species!

 

[james condino]

Midwest Ply makes most of the specialty thin plywoods that most model shops sell; you can order it in endless thickneses and material combinations. There are a whole bunch of online build it yourself skateboard supply websites that also offer veneers in much thicker
Layers than traditional woodworking supply places that are also great for grafting. I usually make them up as needed for the job by resawing and running the pieces through the small thickness sander.

By the early 1950s, Kay used tulip poplar for the inside layer of their plys. It tends to have major adhesion issues and falls apart very easily compared to the models from the 1940s that have the maple inside layers. Those are very user friendly on repair days. I'm in middle of a technology challenge right now; I'll try to post some images of my new vacuum mold system for re arching and repairing the ply plates soon.

J.
Kaybassrepair.com
Condino.com

 

[Jake deVilliers]

Midwest Ply makes most of the specialty thin plywoods that most model shops sell; you can order it in endless thickneses and material combinations. There are a whole bunch of online build it yourself skateboard supply websites that also offer veneers in much thicker
Layers than traditional woodworking supply places that are also great for grafting. I usually make them up as needed for the job by resawing and running the pieces through the small thickness sander.

By the early 1950s, Kay used tulip poplar for the inside layer of their plys. It tends to have major adhesion issues and falls apart very easily compared to the models from the 1940s that have the maple inside layers. Those are very user friendly on repair days. I'm in middle of a technology challenge right now; I'll try to post some images of my new vacuum mold system for re arching and repairing the ply plates soon.

J.
Kaybassrepair.com
Condino.com

Right on - vacuum bagging would be a great solution for delaminating Kays.

 

[layrepairs]

Finally have the inside front laminate repaired. I cheated in one spot with the grain at an angle.

Does it look good enough to glue it back on and then pull off the problematic back?

Thanks for the help again.

 

[layrepairs]

Finally have the inside front laminate repaired. I cheated in one spot with the grain at an angle.

Does it look good enough to glue it back on and then pull off the problematic back?

Thanks for the help again.

So, after years of neglect, I finally got back to work on this Kay.
I believe it is a C-1, serial number 21074.
I don't have a proper shop any more but I'm attempting to get her fixed anyway.
I will need some help with a few mistakes.

I was missing screws and ordered some #4 x 3/8 round head brass and those seemed to fit perfectly:

I think it needs just a Sharpy on the repaired front. However, I still have issues with the bouts. One I found after putting back together which is far from perfect. It seems like ~1/3 of the outer layer of of the the upper bouts is still spongy. I think it is just the outer layer. Should I split it and use an art palette knife or is there some simple way to inject hide glue under the problem? I'm pretty certain I can put pressure on it.

I have more issues with the bouts too.

Thanks as always.

 

[Steven Ayres]

First, for the pinstriping, touchups using a Sharpie is not uncommon, but they fade quickly. Dilute sign paint will last much longer.

Reviewing this thread, I'm not really clear on exactly what problem you're trying to address or where it is. My first guess is that by "bout" is you mean "rib," meaning any of the side panels connecting top and back. If you have delaminating ribs, do you have loose edges (most likely where the upper rib meets the C rib)? Or are the edges good, and you're able to press on a rib and it feels soft ("spongy")? Am I correct that by "outer layer" you mean the finish ply on the rib? (This would be the top one of five.) Can you share photos to illustrate your problem more specifically?

 

[layrepairs]

Yes, the one of the upper ribs, right side facing the bass. About a third of it still feels spongy. I failed to note this before reinstalling the front. I would have clamped it prior to this if I had noticed. The end near the neck sems to be good. It's as if the outer ply is no longer glued down, about 4 inches basically all the way front to back

. Perhaps stressing it a bit more during clamping caused it or more likely I just failed to notice. See the darker grain cracks slightly bulging.

 

[Steven Ayres]

That looks like it could be water damage. I don't think you'll be able fix it without taking it all apart and relaminating the rib. As long as it doesn't buzz it'll be fine.

 

[KUNGfuSHERIFF]

If you had clamped the ribs too tightly, they’d be bulging out near the center. What was shown is what some of us call rib cancer. Possibly too much urea in the glue. I don’t envy you.

 

[layrepairs]

Attempting a wedge method.

 

[layrepairs]

That looks like it could be water damage. I don't think you'll be able fix it without taking it all apart and relaminating the rib. As long as it doesn't buzz it'll be fine.

Hey, thank you for being supportive.

 

[layrepairs]

Hey, thank you for being supportive.

 

[layrepairs]

So, after ignoring this Kay for almost a year, I put the strings that were with it when I got it back on and the same bridge. It does "tune" and didn't just pull apart leaving it a few days. However, I have some serious problems. Some easy to fix. The bridge is badly warped. Some serious steam and clamps made it only a bit better. If you look closely at the picture, I had to shim the feet with basswood about 3/16 to get it even close. Oddly to me, the A string is low.
I know how to do the basics for a new bridge with adjusters.
There is a what I would call a hockey puck disk under the sound post, looks original from Kay. It seems that the post needs to be very near the front/upper part of this support disk. Is it atypical they had this disk rather mis-centered?
The tailpiece has this Kay original coat hanger wire with two cap nuts. I feel like this should be left original but the "tail nut" grooves are off by at least an 1/8 inch to the G side. That could be from my previous work but it looks sort of original. I feel like I should get a "blank tail nut" and more it "left" (E side).
If you look closely, there is also about an 1/8 inch off the end of the finger board greater on the E side than the G side.

So, one big setup question: If there is a string angle off the bridge to the tail piece, is this important? Would moving the indent slots on the tail nut (like $8 for a blank) so it is more centered and slightly changing the slots in a new bridge bring it into alignment? I have done several bridge adjusters in the past. I can drill 'n tap.

Pic is how Kay C-1 serial number 21074 is today.

 

[Steven Ayres]

So, after ignoring this Kay for almost a year, ....

I would caution against getting attached to any factor in the old setup: start fresh to do it properly.

You have one of the maple-top C-1s, built to replace the discontinued Orchestra and Student basses, using cheaper materials to hit a lower price point amid postwar inflationary pressure.

Because the height of the bridge is related to its distance from the nut, it's not unusual to find an old bridge is not appropriate to the setup we want. A bent bridge can often be straightened temporarily, but it's best to replace it, and not scrimp on the cost. The position of the sound post will naturally change with different placement of the bridge, and it's also not unusual to find that a bridge has been set up for shorter mensure, which can make the unmoving post-reinforcement disk seem inappropriate. I've seen posts set too close to the bridge more than once as well. So the whole system starts with setting your mensure, typically 41.5-42".

The saddle grooves develop over time — they weren't there when the instrument was new — and a poor setup can leave a misaligned tailpiece. The answer is a new saddle, which I would do as a matter of course, and not in maple, as the C-1 typically has. It's important to address alignment before the setup. Be sure to carefully check that the neck and endpin are aligned center-on-center (don't rely on the saddle); any deviation indicates a neck-joint problem that will only worsen.

The Kay tailwire may be an endearing quirk for some, but to maximize the voice of this instrument professionals typically replace it with a proper modern tailgut.

 

[layrepairs]

I would caution against getting attached to any factor in the old setup: start fresh to do it properly.

You have one of the maple-top C-1s, built to replace the discontinued Orchestra and Student basses, using cheaper materials to hit a lower price point amid postwar inflationary pressure.

Because the height of the bridge is related to its distance from the nut, it's not unusual to find an old bridge is not appropriate to the setup we want. A bent bridge can often be straightened temporarily, but it's best to replace it, and not scrimp on the cost. The position of the sound post will naturally change with different placement of the bridge, and it's also not unusual to find that a bridge has been set up for shorter mensure, which can make the unmoving post-reinforcement disk seem inappropriate. I've seen posts set too close to the bridge more than once as well. So the whole system starts with setting your mensure, typically 41.5-42".

The saddle grooves develop over time — they weren't there when the instrument was new — and a poor setup can leave a misaligned tailpiece. The answer is a new saddle, which I would do as a matter of course, and not in maple, as the C-1 typically has. It's important to address alignment before the setup. Be sure to carefully check that the neck and endpin are aligned center-on-center (don't rely on the saddle); any deviation indicates a neck-joint problem that will only worsen.

The Kay tailwire may be an endearing quirk for some, but to maximize the voice of this instrument professionals typically replace it with a proper modern tailgut.

Ordering a new saddle and bridge. Would you remove the two cap nuts and sort of edge over the holes? Thanks for all the advice.