Double Bass Exploding bass help

[dooleyblu]

Hello all,

I just bought this bass and I am in the middle of regluing the back. The bass was dropped on the endpin and the block broke loose and the back started to pop off. After hearing about these exploding basses, I decided to pop off the back and re-glue/support before it continues to explode. I re-built and re-glued the block, but now I am trying to decide how much else I should re-do. Another layer of perfing? re-bluilding the rest of the blocks? or just filling in the gaps and sewing it up? How can I post my pictures?

Thank you

 

[dooleyblu]

I have set up a Kodak picture gallery. I can send you an invatation to see thew bass if you like.

Thanks,

Kevin

 

[Matthew Tucker]

To get a meaningful response here, fill out your profile so people can see what your experience is or isn't, and post the pics on this site.

 

[dooleyblu]

I am an accomplished woodworker, I am not a luthier, I am not a real bass player, I just play one at Church. I bought this bass because I most likely broke it when I was looking at it and I would like one for the studio. So far, this has been a great learning experience in woodworking.
Here are some pictures of the bass. I have removed the perfing from the back edge and will they will be replaced with new wider perfing. I have chiseled the neck block to a smooth, flat surface. I have not yet decided to add a full block of wood to replace what I chiseled off and make it look like the tail block, or just add corner bracing to top and bottom to increase the attachment area. I want to sand off the newspaper around the F hole and add backing material. I would like to reinforce the perfing on the top. I do not know if I should add a second layer or add small blocks equally spaced that will encompass the original perfing.

My questions are:
1. Full block of wood or corner bracing on the neck block
2. What would be the proper material for the F hole reinforcement
3. What would be the best way to reinforce the top perfing

Thank you for any input you can offer. Remember, “You break it-you buy it”

 

[Matthew Tucker]

That's the ticket. Its not often we see a bass with the front on and the back off!! I'll leave the real luthiers here to help you, but its "purfling" not perfing!

 

[mje]

That's the ticket. Its not often we see a bass with the front on and the back off!! I'll leave the real luthiers here to help you, but its "purfling" not perfing!

I think he's actually talking about the linings, not the purfling.

 

[dooleyblu]

The word I was originally looking for was kerflings (kerfed-linings). so yes I am wanting to replace/reinforce the linings. I have looked for a complete list of terms but have not yet found one. Here is a picture of what I was thinking about.

 

[mje]

The word I was originally looking for was kerflings (kerfed-linings). so yes I am wanting to replace/reinforce the linings. I have looked for a complete list of terms but have not yet found one. Here is a picture of what I was thinking about.

That's what I thought. From what I understand, you don't want to use that style of lining on a bass, or make them too thick, but I'll defer to the luthiers on this one.

 

[dooleyblu]

I really do not want to take off the original lining from the top. Should I just add a second layer of lining.

I was only thinking of making a few small notched blocks.

Here is a picture.

 

[arnoldschnitzer]

Why do you want to reinforce the linings at the top joint? That will adversely affect the tone.

 

[Matthew Tucker]

Look at the pics in the Upton Bass Hospital Invalid Link Removed. The Full German Restoration has some good pics, although that bass has outside linings as well.

You'll see that the linings you've got are pretty standard, if a bit damaged. And to my eye, the corner blocks look a bit chunky ...

I think you could just replace or restore the damaged linings in spots so there's a uniform gluing surface.

 

[dooleyblu]

Hello All.,

Thank you Tucker for your interest. I have replaced the lining for the back and cleaned up the side post. I did not take them down too much, just rounded the off nicely. I think I am ready to glue on the back. I still have not decided to re-enforce the neck block. If I do anything I think I will just add the support blocks. After adding the new linings the profile of the ribs dose not match the back so I added some spreaders so that the profiles matched. I will add string to them so I can pull them out when I am done. I do not know if this built in stress is a bad thing, or just natural.

Putting it all together. I have a novice violin maker friend to help me glue it together. He suggest working one edge around gluing and clamping as we go. I am thinking that we would work from the neck block down to the tail.

Is there a more proper way of doing this?

In the picture, I added some tricks like adding the foam shelf lining to my clamps and a modification to what someone else suggested about keeping hide glue. Instead of putting it in small cups, I put it in Ziplock baggies. When I need some more glue, I clip the refrigerated baggie to my beaker of hot water and dip my brush right into the baggie. It works great!

I‘ve got to go, thanks.

I do not have internet at home so I will check any posts in a few hours before I glue.

 

[Matthew Tucker]

I have never glued a back or top so I am not speaking from experience.

Our luthier in Sydney said that he puts the glue on all over, clamps the top, then even if the glue has gelled he re-activates the glue with a paintbrush and a little very hot water or a hot knife.

But I think the method you describe is how most people would do it.

The sometimes-controversial Traeger starts at the end block and works his way north to the upper corners, then glues the neck block, checking alignment of the fb, NSEW, then finally the upper bout seams.

The bracing idea looks fine as long as you are sure you can get them out of the F holes later!

Good luck, send pics!

PS your glue looks nice and clear ... mine always looks grey and snotty. I wonder why?

 

[dooleyblu]

Hello all,

Last night we tried the plan and totla failure. no intimate contact at all. I have a new plan, I have jelled the glue in thin sheets and will cut into strips. put them in joint and activate with steamer. close gap and clamp.

I also spayglued sand paper on to both sides of a thin peice of tin. stuck that into the gap and sanded both ribs and back togeather for intimate contact. I will show pics.

Got to go, dead battery.

Thanks Mathew,

Kevin

 

[dooleyblu]

Last night everything worked out as planned. the alignment block worked great. except one string got caught under the sidepost. D'oh

More later1

 

[dooleyblu]

Matthew wrote

PS your glue looks nice and clear ... mine always looks grey and snotty. I wonder why?

I used Behlen Ground Hide Glue
Traditional luthier's glue that creates stronger wood joints than bottled liquid hide glues, and allows disassembly later with a hot knife. Granulated, for dissolving in water using our Electric Glue Pot. Gram strength is 256. 1-pound container.

Chow