Fossil Stabilization

[Scottnokes2015]

Hi everyone,I'm new tho this so I rely on the many experienced views on here. I recently collected a small slab of Menard Limestone that is littered with different types of bryzoans,brachiopods and crinoids stems and beads. The thing is, its very fragile and I was wondering can I spray it with matte acrylic spray like krylon or is there something else better,thanks

Scott

[jpc]

Try to get some vinac... it is available from the Black Hills Institute and a small dose will last you a lifetime.You have to dissolve it in acetone, but it does a great job.

[Fred]

I think jpc provides an excellent suggestion here. An alternative option for you could be Paraloid B-72, also to be dissolved in acetone.

If you consider one of these options, don't let the fact that you have to dissolve it yourself scare you off, this has advantages too. Because you can play with the concentration, you can actually make a solution that is as thick or thin as you want it to be to fit your needs. Just make sure you handle the acetone in a well-ventilated environment (outside for example), and bear in mind that it is highly flammable.

Edited April 27, 2015 by Fred

[jpc]

excellent advice from fred

[rejd]

Another vote for paraloid b72. As stated, it is a very versatile option. I use it a lot and it works great. I usually make a concentration of 5-10% weight to volume for consolidation. Maybe show is a picture of the piece you need to consolidate.

[Scottnokes2015]

Thank you everyone for your Advice,that's a great help. I'm currently a forensic student and have very limited budget and I'm not able to Afford the vinac once the shopping goes on. Is there a PVA spray I can get from hardware store our hobby lobby like the krylon sprays, thanks again everyone

[Fred]

Krylon spray and the likes contain half a dozen compounds that were never developed nor intended for fossil conservation. I would strongly advice against putting anything like that on your fossil.

A relatively cheap alternative to our former suggestions could be a pure form of PVAc in dispersion, namely water resistant 'white' wood glue (D3), if you can find it in a small quantity or get it from someone (you only need a tiny bit). Here it is mainly applied to porous fossils, however. I have no experience applying it to the limestone you're talking about.

It's a water-based solution. Add additional water (e.g. 10 units of water for 1 unit of glue) or twice that amount to make it thin fluid, then apply with a brush or soak if the slab can take it.

As I said, I have never tried this on the kind of rock you have, so... at your own risk

[Wrangellian]

I use white glue (WeldBond) diluted only about 2-3 times water per unit glue, or even 1 to 1 depending, and it works fine on shale. Not sure about limestone, but I imagine it will work not too differently than the shale... You have to be careful though as it is not so easily reversible like the acetone-dissolved stuff is. I have been thinking I need to find some B-72 and start using that as well, however, as I do make mistakes occasionally and hate it! and although white glue is somewhat reversible in water (reluctantly - can't count on it), my dry shale specimens can fall apart upon submersion in it.

The benefit to white (non-toxic) glue is I can precision-apply it with my FineLine applicator into cracks rather than slathering the whole visible fossil surface in it too, and then if any spills out I can lick it clean (then wipe my tongue off on a cloth!) The drawback is it dries slower so I have to carefully put clamp(s) on and let it dry, if that is needed, but this can be beneficial too as I have more time to make adjustments before it dries.

Crazy glue on the other hand dries very fast and bonds to your skin better than to the rock, and crawls out all over the fossil surface, but it usually also soaks into things more readily. I would only recommend it in the field when you are in a hurry.

Edited April 29, 2015 by Wrangellian

[Harry Pristis]

Let me quote:

Here's what 'oilshale' had to say about white glue (wood glue is just another polymer formulation):

"Don't get me wrong - Elmer's White glue is a great stuff for gluing 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 consolidation!

"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"

[Scottnokes2015]

Ok thank you, I think I'm going the order a small sample of what the black hills institute of paleontology use, Vinac, which is also dissolved in ascribe.

Does acetone it's self not damage fossils?

[Auspex]

...Does acetone it's self not damage fossils?

Only insomuch as some cracked fossils that are barely held together by mud may disarticulate if soaked too long.

Acetone can be very damaging to you, though: use only with plenty of ventilation and avoid prolonged skin contact. Oh, yes, it is highly combustible, too.

[Wrangellian]

I should be careful: I have not and would not recommend slathering the surface of any fossil in white glue, especially less-diluted white glue! All I can say is it works fine on shale fossils when I use it to piece together cracked fossils and keep it off the visible display surfaces (outside of fossil) - on the broken surfaces that need to be bonded and letting it soak into cracks and such (as long as the cracks are tight and not held apart by debris though this is where most of my frustration arises). I can't speak for anything else. I have heard from people who make up a 5-gallon bucket of dilute (10-1?) white glue and just routinely dunk their fossils in it! That's not how I would go about it...

[Scottnokes2015]

Ok,I'm in agreement,I wouldn't just dunk fossils inn such as total immersion. I think when I get this vinac, I'm going to mix a little amount and just do a couple light coats all round.thanks for the advice Auspex, I will take much caution and make sure I dint get it on me or down me. I'll probably get one those all inn one disposable overall and do. All out side. I really appreciate you guys helping me,I'm so new to this hobby,that there is much to learn,thanks again

Edited April 29, 2015 by ScottNokes

[Opisthotriton]

A little acetone here and there is not something super scary; acetone is nail polish remover, so obviously people get it on their hands and are ok. That said, lots of exposure, either on your skin or breathing the fumes, is not good for you (or your liver). So don't worry if you splash a little on your hand, just wipe it off then wash it off. Don't breathe too close to the acetone. A lungful of acetone fumes is nasty. Nitrile gloves would be handy so you don't get the vinac solution all over your hands. And wearing an apron is a great idea because once you get vinac on your clothes, it's pretty much there permanently. You can try using pure acetone to remove the vinac from clothes, but the acetone will weaken the cloth fibers. I get vinac on my fingers all the time (peels right off when it dries), but I'm very careful to not get it on my clothes!

But yes, acetone is not a good thing to breathe or soak your fingers in if you can avoid it. Safety first is always best. It will take a few hours or more for the soaked teeth to fully dry, so try to leave them outside or in a well ventilated space for as long as possible (and try to keep dust from settling on them while the surface is sticky).

[Scottnokes2015]

Ok thank You for your Advice,it's pretty much what I thought. How long does it take to dry on the fossil itself

[oilshale]

Only insomuch as some cracked fossils that are barely held together by mud may disarticulate if soaked too long.

Acetone can be very damaging to you, though: use only with plenty of ventilation and avoid prolonged skin contact. Oh, yes, it is highly combustible, too.

In very rare cases, acetone or pure alcohol can damage the fossil. Happened to me with a fossil from Fiume Marecchia (Pliocene near Venice, Italy). The substrate there is very soft - the slab started to swell and delaminated.

Thomas