Green River Skate Prep Question

[Angelh]

I am a complete novice to everything fossil-related.  My family found an awesome fossilized asterotrygon on a huge beautiful slab with a couple of knightia.  (That's my research talking.}  I see that the overwhelming majority recommend butvar in a solvent, so that is my plan. It seems that all the posts refer to brushing it on.  It seems, to me, like this would displace the tiny bones. ?  I was assuming that spraying it on would be better.  Could someone give me some advice on that?  Also, I don't want the slab to split (it certainly has several splits on the edges.) Do I just apply the butvar to the fossils or also to the sandstone to stabilize and seal it?  I included a photo to show the size of the sandstone slab.

[Ptychodus04]

Welcome to the forum!

 

Great find! You can use Butvar B76 or Paraloid B72 as a stabilizer. The Paraloid is a bit harder and a little cheaper but both are acceptable. Mix it with acetone in a ratio of one part Paraloid to 50 parts acetone by weight (you don't have to be exact).

 

I brush it onto delicate specimens using high quality artist brushes. You're not technically brushing it. You're really letting the brush draw the solution up and then lightly touching it to the specimen with a brushing motion. If you make a lot of contact with the specimen, you will displace the bones and/or scales on specimens from this layer. I would use thin cyanoacrylate  (superglue) to hold the delaminating layers together. Simply stand the slab on end and let the glue run into the cracks. Do this slowly so you don't spill it onto the surface of the slab. It will significantly darken the matrix and you don't want this. The glue will keep any cracks from worsening.

 

[hadrosauridae]

Listen to Ptychodus advice, he knows well how to prep GR fossils!

[jpc]

3 minutes ago, hadrosauridae said:

Listen to Ptychodus advice, he knows well how to prep GR fossils!

I agree.  Great slab, by the way.

 

[Angelh]

Thank you so much for all the information!

[Crusty_Crab]

So I don't have a fraction of the experience that others seem to have with Green River preps, but what is the purpose of applying butvar or any other compound? The slab looks beautiful, what is the evidence that it is degrading and therefore requires a stabilizer? Butvar or paraloid are commonly applied as stabilizers, when necessary. I suppose they can be applied for aesthetic purposes to get the "wet look" but most people seem to prefer a more natural look. If the objective is to provide a protective barrier to UV, I would maintain the best protection is to store it in the dark, away from UV sources rather than rely on a coating. Is there any reason to believe that it will degrade without an overcoat? Keep in mind that museums are full of fossils that had been overcoated in a misguided attempt to preserve them, only to find that the overcoat is far more damaging, as well as a barrier to any molecular studies in the future. Like I said, I don't pretend to have a fraction of the knowledge that others have, just genuine questions.   

Edited September 29, 2021 by Crusty_Crab

[Ptychodus04]

19 minutes ago, Crusty_Crab said:

So I don't have a fraction of the experience that others seem to have with Green River preps, but what is the purpose of applying butvar or any other compound? The slab looks beautiful, what is the evidence that it is degrading and therefore requires a stabilizer? Butvar or paraloid are commonly applied as stabilizers, when necessary. I suppose they can be applied for aesthetic purposes to get the "wet look" but most people seem to prefer a more natural look. If the objective is to provide a protective barrier to UV, I would maintain the best protection is to store it in the dark, away from UV sources rather than rely on a coating. Is there any reason to believe that it will degrade without an overcoat? Keep in mind that museums are full of fossils that had been overcoated in a misguided attempt to preserve them, only to find that the overcoat is far more damaging, as well as a barrier to any molecular studies in the future. Like I said, I don't pretend to have a fraction of the knowledge that others have, just genuine questions.   

 

Often, fish from the Sandwich bed (aka Split Fish) are quite flaky and require stabilization. Honestly, I'm of the opinion that all fossil bone requires stabilization for long term preservation unless curated for a specific purpose. There may not be obvious physical damage that occurs but the bones degrade over time when removed from the ground.

 

This is a debate that preparators have been having forever.

[hadrosauridae]

2 hours ago, Crusty_Crab said:

So I don't have a fraction of the experience that others seem to have with Green River preps, but what is the purpose of applying butvar or any other compound? The slab looks beautiful, what is the evidence that it is degrading and therefore requires a stabilizer? Butvar or paraloid are commonly applied as stabilizers, when necessary. I suppose they can be applied for aesthetic purposes to get the "wet look" but most people seem to prefer a more natural look. If the objective is to provide a protective barrier to UV, I would maintain the best protection is to store it in the dark, away from UV sources rather than rely on a coating. Is there any reason to believe that it will degrade without an overcoat? Keep in mind that museums are full of fossils that had been overcoated in a misguided attempt to preserve them, only to find that the overcoat is far more damaging, as well as a barrier to any molecular studies in the future. Like I said, I don't pretend to have a fraction of the knowledge that others have, just genuine questions.   

 

Split layer fish bones can be blown off the matrix with a hard breath!  I have a some that you can see the "dust" that used to be bone laying on the shelf below it.  ITs just falling off from humidity and temperature changes in my house.  But those arent anything special, I'm not concerned if they vanish.  Anything you want to last, needs to be consolidated.  

 

The only down side is that it changes the matrix color slightly.  It doesnt make it look bad, but you have to coat the whole surface so it looks even.  But its nice to be able to touch it without your hand being covered in the shale dust.

 

Edited September 29, 2021 by hadrosauridae

[Ptychodus04]

12 hours ago, hadrosauridae said:

The only down side is that it changes the matrix color slightly. 

This is why I apply it with fine artist brushes. It’s the easiest way to keep the consolidation material only on the fossil.  

[RJB]

On 9/28/2021 at 2:32 PM, Ptychodus04 said:

Simply stand the slab on end and let the glue run into the cracks. Do this slowly so you don't spill it onto the surface of the slab. It will significantly darken the matrix and you don't want this. The glue will keep any cracks from worsening.

Be careful with this part.  It really hurts to learn this the hard way.  Been there done that

 

RB

[Ptychodus04]

1 hour ago, RJB said:

Be careful with this part.  It really hurts to learn this the hard way.  Been there done that

 

RB

I guess I should have said: Carefully stand the slab on its end.