Glue removal on dino bones

[holdinghistory]

A few weeks ago I picked up a few Edmontosaurus ribs and two fibia. Was working on getting a bunch of trilobites prepped, but finally getting around to starting on them. They all look like they have been covered in elmer's glue, guessing as a field consolident. I have some acetone I was thinking of using to remove the glue, and then I had planned on using some Paraloid B-72 to reconsolidate the bones. I am concerned about whether the bones will all fall apart if I do an acetone soak, especially if some of the smaller pieces will soak up the liquid and disintegrate. Not sure the safest way to do it, so I am starting with one of the more solid looking ones. Any suggestions? 

 

So far I have just been scribing off the matrix and some glue chunks with an Aro until I get close to the bone.

[frenchy2]

I would consolidate using B-72 on the other side and when solid,  flip it over and just dab a small area with acetone and clean the bone just a little at time.  This will take patience I'm afraid.

[Ptychodus04]

Scribe/pick off as much as possible before you go to the acetone. White glue turns into a mass of sticky boogers when solvent is applied. 

[holdinghistory]

2 hours ago, frenchy2 said:

I would consolidate using B-72 on the other side and when solid,  flip it over and just dab a small area with acetone and clean the bone just a little at time.  This will take patience I'm afraid.

That is a good idea, I will start working on it! 

 

2 hours ago, Ptychodus04 said:

Scribe/pick off as much as possible before you go to the acetone. White glue turns into a mass of sticky boogers when solvent is applied. 

I have been taking off everything dry, but some of the dirt seems very saturated with the glue and the scribe mostly just makes little holes the size of the tip. Should I try to take that off too, or would it get easier with an acetone application?

[Ptychodus04]

9 minutes ago, holdinghistory said:

 

I have been taking off everything dry, but some of the dirt seems very saturated with the glue and the scribe mostly just makes little holes the size of the tip. Should I try to take that off too, or would it get easier with an acetone application?

 If there’s room to get a dental pick into the nasty matrix without hitting the fossil, try to peel off pieces. If not, you will probably have to go to acetone.

[Harry Pristis]

 

Here's what TFF member 'oilshale' had to say about white glue:

"Don't get me wrong - Elmer's White glue is a great stuff for glueing wood and can be also great for "hardening" crumbly fossils!

"But I fully agree with Harry's opinion (even so I am a polymer chemist and my job is to develop white glues and other latices....): I would never use a white glue unless the fossil is wet, crumbly and the substrate is porous and can't be dried before consilidation!

"There is no way to remove this white glue once dried (not even with solvent). It will form a dense polymer layer on the surface without penetrating much into the substrate (white glue are tiny polymer particles dispersed in water with a particle size of around 1µm, so the penetration depth won't be much).

"Butvar, a Polyvinyl butyrate (the company I am working in is also producing these polymers, of course different brand names) in this respect is much better (will penetrate better and can easily be removed by solvents).

"I do have a couple of fossil fish which were mistreated by someone else in such a way. Since the substrate was almost nonporous (diatomaceous earth!) and quite soft (and may be also the amount of white glue and concentration used was too high) there is now a thick slightly yellowish polymer film on top. Unfortunately, this is not all: The film shrinks and now peels off (with bones attached to the polymer film of course)!
Thomas"

 

Based on these remarks, I think your best bet is to peel away whatever excess glue you can with a scalpel or Xacto knife.  As Ptychodus04 cautioned, acetone will make a mess of the dried white glue.

[RJB]

Wow!  My prepping heart goes out to you.  The best of luck to you and fossil.

 

RB

[holdinghistory]

Thanks all! I am taking a break from this particular piece to work on some of the easier ones first, and then will try and tackle this one slowly. Close to done with one of the fibula.

[crabfossilsteve]

If indeed that is Elmer's Glue would not a soak in water be the solvent to use to soften/remove the glue?

 

[Ptychodus04]

52 minutes ago, crabfossilsteve said:

If indeed that is Elmer's Glue would not a soak in water be the solvent to use to soften/remove the glue?

 

 

Once white glue (PVA emulsion) of any variety sets it is effectively irreversible. No solvent will completely remove it and at best will turn it into a sticky goo that still has to be mechanically removed.

[Harry Pristis]

 

 

Just a thought . . . white glue will soften with heat.  You might try try heating the exterior glue drips with a heat gun or hair drier, then plucking the bits of softened polymer with a forceps.  I've not had occasion to try this, but it's a better idea than acetone.

 

 

[holdinghistory]

Hmmm, I will have to give that a try. I am wondering if I could shave it off much more easily with a scalpel if it is a little warm.

[holdinghistory]

One Fibula is done! Not really any glue to remove, but my first dinosaur prep job finished. Here are the befores.

And the afters.

[RJB]

That looks purty dang good now!

 

RB

[Ptychodus04]

Well done! 

[Haravex]

Good job 

[JohnBrewer]

On 09/11/2017 at 10:57 PM, holdinghistory said:

One Fibula is done! Not really any glue to remove, but my first dinosaur prep job finished. Here are the befores.

And the afters.

Superb job!

[LordTrilobite]

Great job on the prep, that looks really good.