Dissolving Animal Glue

JtheJazzMan · #1 10-27-2006, 06:05 AM

Hi i have a bit of a strange (and frustrating

) situation on my hands. On the top and bottom of the bass there are small cicles of plywood glued on where the soundpost sits and im trying to remove them in order to improve the tone of the bass, as i beleive they are soaking up the sound.

I have managed to remove the bottom piece by soaking it in methylated spirits. I think its animal glue, and the spirits did soften the glue, but it still took some effort to pry the piece off.

The piece on the top however is proving to be a real pain. I cant get a tool with enough leverage to pry it off, or get it at an angle to pry it off - and i cant even see what im doing!

I cant even think how to apply heat to it to soften it. Im very hestitant to keep chipping away as it will do a messy job and im afraid ill crack the top

Has anyone used any solvents/ or has any techniques for dissolving the glue right off? any help is appreciated

Chasarms · #2 10-27-2006, 08:54 AM

Once the soundpost punches a hole through the back, you should be able to get a tool in there pretty easy to remove the other patch.

I guess it's too late now, but there's probably a reason those post patches were there.

All that said, I have nothing to offer as to how to remove the patch that is on the top. But, if after being such a smart a$# I may ask, why do you believe that the post patches are choking the tone of the bass? I have seen many wonderful sounding basses that have a post patch.

Bob Branstetter · #3 10-27-2006, 09:22 AM

I totally agree with Charles. Removing those patches is not a good idea. You should also consider that any solvent that will disolve the glue on the patches may also disolve the glue that holds the plys together under the patch. Prying is another no no. You are just as likely to break loose a layer or two of the plys as you are getting that patch out.

peasandhoney · #4 10-27-2006, 12:21 PM

without seeing the patches for myself, it seems to me that they were an improper repair. that is, i would never use plywood at the patching material. removing AND replacing these might be a good idea (and a hell of alot of work). the best bet for removal would be a very sharp plane and tons of patience. no solvents will work on hide glue (if someone used plywood, i wouldnt expect to see hideglue either). but if it is, heat and moisture are key. in very demanding situations i also use DIF wallpaper remover (cut down and only as needed in extreme cases). it has enzymes that work on the organic matter in hideglue. WARNING: moisture and heat may adversely effect the wood of the instrument! and the DIF must be neutralized (with hydrogen peroxide) and cleaned away thoroughly or any new joint may fail.

Chasarms · #5 10-27-2006, 01:23 PM

Quote:

Originally Posted by peasandhoney

without seeing the patches for myself, it seems to me that they were an improper repair. that is, i would never use plywood at the patching material. removing AND replacing these might be a good idea (and a hell of alot of work). the best bet for removal would be a very sharp plane and tons of patience. no solvents will work on hide glue (if someone used plywood, i wouldnt expect to see hideglue either). but if it is, heat and moisture are key. in very demanding situations i also use DIF wallpaper remover (cut down and only as needed in extreme cases). it has enzymes that work on the organic matter in hideglue. WARNING: moisture and heat may adversely effect the wood of the instrument! and the DIF must be neutralized (with hydrogen peroxide) and cleaned away thoroughly or any new joint may fail.

I'm guessing the patches were there from the factory. My Shen has a back patch that was there on day 1. I think it is fairly common with ply basses.

Bob Branstetter · #6 10-27-2006, 01:25 PM

Quote:

Originally Posted by peasandhoney

the best bet for removal would be a very sharp plane and tons of patience. no solvents will work on hide glue (if someone used plywood, i wouldnt expect to see hideglue either).

It's going to have to be a mighty small plane to fit through the ff holes! Unless I totally misread what JtheJazzMan is saying, he is talking about removing removing the platforms that the soundpost rests on (to prevent the to post from poking a hole in the plywood) and doing it without removing the top to gain access. They are very common in plywood basses and serve a very useful purpose. BTW - the solvent for hide glue is water.

JtheJazzMan · #7 10-27-2006, 05:35 PM

Thanks for the help everyone. First off the front and back are solid wood with ply sides, so im not worried about solvents affecting the wood....just as long as it does notget onto any of the other glued areas. also the soundpost shouldnt punch through. i know another person with a bass from the same company and he does not have any patches

You are correct Bob, the patch is on the inside of the bass, on the top piece, so a tool has to get through the F hole and curve up to touch the inside at the top.

The reason i am trying to get them off is that the best sound will be produced if the soundpost is touching the front and back directly....small patches of soft plywood and glue only adversely affect the sound. The bass is too quiet for a solid wood full size bass.

So heat and moisture is the best bet? im stumped how i can apply heat to the area in such a cramped and confined area

Bob Branstetter · #8 10-27-2006, 08:13 PM

Quote:

Originally Posted by JtheJazzMan

So heat and moisture is the best bet? im stumped how i can apply heat to the area in such a cramped and confined area

Trying to do what you want to do without removing the top is an invitation for trouble any way you look at it. What is this bass? maker? brand? country?

JtheJazzMan · #9 10-28-2006, 04:21 AM

Its a prima, but dont worry anymore, i got it off!

i simply keep soaked it in a metho soaked rag for many hours, and then i put a chisel on a handle through the endpiece hole to reach the piece.

ill post up when ive pieced the bass back together whether its made a difference

Jeff Bollbach · #10 10-28-2006, 08:32 AM

Good luck fitting the soundpost!

Bob Branstetter · #11 10-28-2006, 10:50 AM

Quote:

Originally Posted by JtheJazzMan

Its a prima

Now I'm curious. I did an internet search and couldn' find any Prima brand bass with spruce top and maple back with plywood ribs. In my 45+ years of working on basses, I've never seen soundpost reinforcement patches from the factory on the top and back of any bass that wasn't laminated. If yours has a non-plywood top and back, (assuming you can get a sound fitted)I would seriously worry about soundpost cracks in the future. Manufacturers of low end basses seldom add anything that isn't absolutely needed.

JtheJazzMan · #12 10-30-2006, 12:56 AM

well the results are impressive. theres far more "oomph" in the tone when you hit a note, plus the notes sing a lot more. most importantly what i was looking was the tone of the G string. MUCH more depth, its great.

i understand this project carries risks, but i certainly wouldnt be happy with a dull tone - or living with a bass that wasnt given the opputunity to play to its full potential. until such times as a crack spoil my day im going to enjoy the bass