Seeking Glue Removal Advice

[uncoat]

 

Hey there, im hoping some of the clever folks here might be able to offer some advice on a prep im working on. Im currently prepping a large 150 - 200 pound block. In the initial prep, a part of the block cracked and opened up a small crevice. This crevice did not beak completely into two pieces, it was still held together by the un removed matrix surrounding the fossil. At the time, i didn't want this to slowly shake into a bigger crack or lose pieces due to the vibration of the air tools. There was/is a lot more prep to do and between prep and flipping over a large block i was worried about loosing pieces. So i filled this gap with super glue with the idea that i could reverse this later on and join the two pieces together much tighter so the crack would disappear or be less noticeable.  As the prep continues, im getting closer to the time when im going to have to re glue the pieces. The problem is that a lot of small pieces of the fossil are glued back on around the area of the break. So i need to figure a way to dissolve the glue at the break but not in the area around the break. Normally i would place the entire fossil in a tub of acetone to dissolve the glue from the joint and then glue the two pieces back together. But since there are a lot of small, non descript pieces close to the break, im reluctant to do this. I already tried poring acetone over the break to try to separate the two pieces but this didnt work. This would all be easier if the fossil was not so large, heavy and hard to move.

 

I may end up having to soak the whole thing in acetone to dissolve this joint but i want to avoid this if possible. Does anyone have any suggestions for alternate ways to remedy this problem? 

 

Hard to photograph this fossil so here is a basic drawing of the problem.

 

Nick

 

[Bobby Rico]

Welcome to the forum. I can call the  Prep Jedis for advice @Ptychodus04 and @RJB

[Thecosmilia Trichitoma]

@steelhead9

[caldigger]

2 hours ago, Bobby Rico said:

Welcome to the forum. I can call the  Prep Jedis for advice @Ptychodus04 and @RJB

Something tells me The Force isn't going to work in this instance. 

[Ptychodus04]

Your drawing didn’t attach (from what I can see on my phone). Are you removing the matrix on one side of the crack? If so, scribe away as much as you can and use a local application of acetone to loosen the bone fragments. 

 

You can also abrade the super glue with dolomite.

[uncoat]

4 hours ago, Ptychodus04 said:

Your drawing didn’t attach (from what I can see on my phone). Are you removing the matrix on one side of the crack? If so, scribe away as much as you can and use a local application of acetone to loosen the bone fragments. 

 

You can also abrade the super glue with dolomite.

I noticed that the pic disappeared , i just put one back up. Yeah I have tried applying acetone to the area that needs loosing but the area is large enough that it drys too fast to loosen the glued joint. I may have to figure out some sort of hoist to hold the rock in the air, then dip the tip that needs to be removed into acetone.

[Ptychodus04]

1 hour ago, uncoat said:

I noticed that then pic disappeared , i just put one back up. Yeah I have tried applying acetone to the area that needs loosing but the area is large enough that it drys too fast to loosen the glued joint. I may have to figure out some sort of hoist to hold the rock in the air, then dip the tip that needs to be removed into acetone.

Can you just scribe as much matrix as possible prior to dealing with the glue in order to have a lighter load to deal with?

[Bobby Rico]

@uncoat drawing.

[Bobby Rico]

7 hours ago, caldigger said:

Something tells me The Force isn't going to work in this instance. 

“Much to learn you still have “ 

[uncoat]

13 hours ago, Ptychodus04 said:

Can you just scribe as much matrix as possible prior to dealing with the glue in order to have a lighter load to deal with?

Yeah so far that's the plan but i was hoping someone here might be able to suggest an alternative to that. Even after that is done, its still going to be heavy enough it will be difficult to lift and position. That might just be the best way to do it though.  

[Randyw]

Is there a way to tie an acetone soaked rag or yarn around the break? That way the acetone would stay in contact and you could keep wetting it to keep it damp until it desolved some of the glue? Without knowing any of the details of the piece that’s all I can come up with

[Ptychodus04]

You may have to chalk it up to “lessons learned”. Next time when you glue a crack, clamp the joint (even if you have to use straps).

[Mark Kmiecik]

You could build a dam around the jointed part with a material attached directly to the matrix that is impervious to acetone, like an epoxy, and fill the dam with acetone. Once separated the epoxy can be prepped away and the two parts rejoined with suitable adhesive.

[Phevo]

Couldent you build a Dam like Mark advised? 

 

I use a putty around My specimens for silicone casting and that works well

[uncoat]

 

22 hours ago, Randyw said:

Is there a way to tie an acetone soaked rag or yarn around the break? That way the acetone would stay in contact and you could keep wetting it to keep it damp until it desolved some of the glue? Without knowing any of the details of the piece that’s all I can come up with

Thanks for the suggestion. This seems do able given the size and shape of the fossil. I will have to try this.

 

16 hours ago, Mark Kmiecik said:

You could build a dam around the jointed part with a material attached directly to the matrix that is impervious to acetone, like an epoxy, and fill the dam with acetone. Once separated the epoxy can be prepped away and the two parts rejoined with suitable adhesive.

I considered this. I have used a wax called " carbo wax" (I think?) in the past to build a dam as you suggest or to prep fragile areas of a fossil. In this case the fossil has a distinct curve to it and if i did this, i would have to do it in small sections due to the curve. This would make it hard to tell when all the glue was dissolved in each section. Initially i  was thinking it might be more work then necessary but now its seeming like it might be a good option. 

 

Thanks for the good alternative suggestions. I still have a little time before i need to do this so its good to have some options to think about.