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Masp

Consolidation for matrix fish / dino bones

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Masp

 I need some advice for consolidating these 3 fossils. 

 

#1

 

The Enchodus fang/jaw itself is fine, however the sandy matrix Is the issue, especially because it’s messy for display because tiny grains keep falling off, etc. What would you reccomend for consolidating that?

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Masp

#2 best way to go about cleaning this tyrannosaur bone? For consolidation, do you recommend pva, acetone etc. 

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Masp

#3

 

Same goes for this sauropod femur.  My issue is that it’s very fragile and the base already broke off.  The surface with the predatation marks is fine, so maybe I can leave that alone, but the rest of the fossil may need consolidating. 

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Masp

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snolly50
19 minutes ago, Masp said:

The Enchodus fang/jaw itself is fine, however the sandy matrix Is the issue, especially because it’s messy for display because tiny grains keep falling off, etc. What would you reccomend for consolidating that?

At the end of my recent Mosasaur jaw prep, I coated the entire piece with dilute PVA. This worked very well and did not noticeably change the appearance of the matrix. Your piece is held in the same type of Moroccan matrix, so it should work for you as well.

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Manticocerasman

I would advise consolidating with Paraloid B-72 . those are pellets to be disolved in aceton. then you drench the fossil in the mixture, the aceton then evaporates and the paraloid reconsolidates in the fossil or matrix.

this proces is also reversible and sealing of the fossil with paraloid also helps against pyrite decay.

 

there are a few threads on this forum on how to use paraloid.

 

 

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Masp
11 minutes ago, Manticocerasman said:

I would advise consolidating with Paraloid B-72 . those are pellets to be disolved in aceton. then you drench the fossil in the mixture, the aceton then evaporates and the paraloid reconsolidates in the fossil or matrix.

this proces is also reversible and sealing of the fossil with paraloid also helps against pyrite decay.

 

there are a few threads on this forum on how to use paraloid.

 

 

Now is this coating just for the matrix and coating the fossil itself too correct?

 

Also what’s the difference between Pva and paraloid b-72?

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Manticocerasman
8 minutes ago, Masp said:

Now is this coating just for the matrix, or do you suggest coating the fossil itself too?

 

Also what’s the difference between Pva and paraloid b-72?

PVA or wood glue is a white glue that you commonly find in most DIY-stores , it is often used diluated with water to preserve fossils. this is an easier alternative for Paraloid B-72

 

 

 

As for Paraloid: https://en.wikipedia.org/wiki/Paraloid_B-72

 

I would use both possibilities on the whole pieces , fossil and matrix. Exept from extra gloss on the fossils, you wouldnt see much visual difference after treating them.

 

 

 

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snolly50

The PVA I utilized is B-15, commercially known as Vinac. It comes in the form of tiny beads which are dissolved in acetone in a concentration to achieve the desired viscosity. It is my understanding that White/wood glue does contain PVA, but it is merely one on the components. Vinac is solely PVA.

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Ptychodus04

Use pure PVA (vinac), Paraloid B72, or Butvar B76 dissolved in acetone (1 part plastic to 50 parts acetone). I would suggest brushing it on for these specimens in the event that there are unknown glue joints. If they are soaked, the acetone will likely dissolve the glue.

 

Here's the confusion using the acronym PVA without any other info...

 

  • PVA in white glue (elmer's, wood glue, etc) is polyvinyl acetate in a water suspension (probably... it can also be polyvinyl alcohol in water suspension) plus any number of unknown ingredients.
  • PVA used in fossil conservation is pure polyvinyl acetate dissolved in acetone or ethanol (plus nothing else).

There's a big difference in the characteristics of a PVA suspension vs. a PVA solution (regardless of the unknown ingredients in "white glue").

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RJB

What I found with white glue years ago was that it felt sticky on days where the humidity was high.  Thats when I stopped using it.  Good luck

 

RB

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Walt
4 minutes ago, RJB said:

Thats when I stopped using it.  Good luck

You or @Ptychodus04 mentioned one time that it was old school to use egg whites.  Is that a total no-no?  Doesn't hold up?

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RJB
1 minute ago, Walt said:

You or @Ptychodus04 mentioned one time that it was old school to use egg whites.  Is that a total no-no?  Doesn't hold up?

It wasn't me.  Ive never even heard of that.  Interesting idea though, but yeah, I would think that egg whites would not hold up?

 

RB

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Walt
8 minutes ago, RJB said:

It wasn't me.  Ive never even heard of that.  Interesting idea though, but yeah, I would think that egg whites would not hold up?

I know that the proteins in eggs and milk form some of the strongest bonds anywhere.  Probably yellows, though....

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RJB
16 minutes ago, Walt said:

I know that the proteins in eggs and milk form some of the strongest bonds anywhere.  Probably yellows, though....

Yeah but, what about moisture? What about sittin around for 100 years?  What about insects? 

 

RB

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Ptychodus04

Old glues used any number of ingredients to stick two things together. Just because it works doesn't mean it's a good idea. You can give yourself a tattoo with a sewing needle and a ballpoint pen but I wouldn't suggest it. :P

 

Proper conservation goes well beyond the lifetime of the person applying the product. Decades ago, people used shellac, lacquer, and glues made from all kinds of animal parts. None of these are considered appropriate for conservation due to their breakdown over time and the inability to reverse the application. This is why we lean towards one of the plastic polymers (Polyvinly acetate, Paraloid, or Butvar) in acetone as a glue and consolidant. They are indefinitely stable and reversible.

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Walt
4 minutes ago, RJB said:

Yeah but, what about moisture? What about sittin around for 100 years?  What about insects? 

 

3 minutes ago, Ptychodus04 said:

Old glues used any number of ingredients to stick two things together. Just because it works doesn't mean it's a good idea. You can give yourself a tattoo with a sewing needle and a ballpoint pen but I wouldn't suggest it

I was just curious :)  Now I'm off to get a tattoo removed.......

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RJB
11 minutes ago, Ptychodus04 said:

Old glues used any number of ingredients to stick two things together. Just because it works doesn't mean it's a good idea. You can give yourself a tattoo with a sewing needle and a ballpoint pen but I wouldn't suggest it. :P

 

Proper conservation goes well beyond the lifetime of the person applying the product. Decades ago, people used shellac, lacquer, and glues made from all kinds of animal parts. None of these are considered appropriate for conservation due to their breakdown over time and the inability to reverse the application. This is why we lean towards one of the plastic polymers (Polyvinly acetate, Paraloid, or Butvar) in acetone as a glue and consolidant. They are indefinitely stable and reversible.

I dont care what anyone says about you Kris,  your ok in  my book, and purty dang smart too.    :)

 

RB

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jpc

Ptychodus is spot on in all this stuff.  

 

Another fun thing about shellac is that t never really sets to total dryness so it attracts and holds on to dust.  

 

But egg whites??@!!  Yikes.  That is just an invitation for an insect/mold invasion of a collection.  

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Walt
3 minutes ago, jpc said:

But egg whites??@!!  Yikes.  That is just an invitation for an insect/mold invasion of a collection.  

:shrug: Somebody on TFF mentioned it.  I found it curious too...

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RJB
21 minutes ago, jpc said:

Ptychodus is spot on in all this stuff. 

Im gunna knickname Kris,,,,,,,,,,,,,   Spot  :)

 

RB

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Walt
5 minutes ago, RJB said:

Spot

And this, is how legends are born! :yay-smiley-1:

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Ptychodus04
32 minutes ago, RJB said:

I dont care what anyone says about you Kris,  your ok in  my book, and purty dang smart too.    :)

 

26 minutes ago, jpc said:

Ptychodus is spot on in all this stuff. 

That says a lot coming from you two. :D

 

 

4 minutes ago, RJB said:

Im gunna knickname Kris,,,,,,,,,,,,,   Spot  :)

 

RB

Just what I need... :P

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Masp
20 hours ago, Ptychodus04 said:

Use pure PVA (vinac), Paraloid B72, or Butvar B76 dissolved in acetone (1 part plastic to 50 parts acetone). I would suggest brushing it on for these specimens in the event that there are unknown glue joints. If they are soaked, the acetone will likely dissolve the glue.

 

Here's the confusion using the acronym PVA without any other info...

 

  • PVA in white glue (elmer's, wood glue, etc) is polyvinyl acetate in a water suspension (probably... it can also be polyvinyl alcohol in water suspension) plus any number of unknown ingredients.
  • PVA used in fossil conservation is pure polyvinyl acetate dissolved in acetone or ethanol (plus nothing else).

There's a big difference in the characteristics of a PVA suspension vs. a PVA solution (regardless of the unknown ingredients in "white glue").

 Thank you!

 

I’m going to coat the entire enchodus jaw w/ matrix as snolly50 suggested, but for the tyrannosaur fossil,  do you suggest cleaning off the orange and green gunk with a popsicle stick or dental tool first? And then for the sauropod femur,  should I coat the entire thing, or leaving the surface with the predatation marks be?

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Ptychodus04
44 minutes ago, Masp said:

 Thank you!

 

I’m going to coat the entire enchodus jaw w/ matrix as snolly50 suggested, but for the tyrannosaur fossil,  do you suggest cleaning off the orange and green gunk with a popsicle stick or dental tool first? And then for the sauropod femur,  should I coat the entire thing, or leaving the surface with the predatation marks be?

 

Yes, I would remove as much of the offending material as possible with a pick. As for consolidation, there are two schools of thought.

 

  1. Every fossil bone requires stabilization in order to prevent possible deterioration in the future, even if it is not currently evident. This school would say to consolidate the entirety of the specimens in order to fully stabilize them.
  2. Only fossil bone that is currently unstable or deteriorating requires stabilization. This school would say, only stabilize if the bone is brittle or crumbling. If it is not, leave it alone.

 

The saurapod bone needs consolidation based on both schools of thought based on your description of it being brittle and having already broken. I would apply consolidant to the entire piece. The theropod vert is another story. Is it stable? I tend towards school #2 in my preparation. If the bone is strong, it stays as pure as possible. If there's a chance of something coming off, it gets consolidated. For example, I have worked on tons (literally) of material in the Perot lab that is VERY stable and does not require any consolidation, but almost every fish I have ever prepped needs it due to their particular bone structure, preservation, and propensity to flake..

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