Some questions about Vinac, acetone

[Minerva8918]

Hi everyone!

I recently bought a pint Vinac (well, the Polyvinyl Acetate bead equivalent from BHIGR) and some acetone to stabilize some trilobites, trilo-bits, and trilo-butts that I collected from West Virginia in the Needmore Formation. I've read through the topics about Vinac and other consolidants here on the forum, but there are a few things I still have questions about, so I would really love your help.

At the moment, I don't intend on using very much Vinac solution because I'm only going to be using it to stabilize/consolidate some pieces that I plan on sticking in the mail for some friends.

• I bought some natural bristled paint brushes, and I was going to go the route of 'painting' a very dilute solution of Vinac onto the pieces. Would a small glass jar with a metal lid (like a baby food jar) be sufficient, or should I use something larger? I have a 16 oz salsa jar (glass, metal lid), but since I wasn't planning on using very much at the moment, I wanted to ask if something smaller would be better.

• Would a baby food jar lid (or aforementioned salsa jar lid) have any sort of seal that could potentially get eaten up by the acetone and end up mixing with the Vinac solution? If so, would that affect the integrity of the Vinac? If any seal does dissolve, would the lack of a seal make the chance of spillage higher?

• All of the pieces I'm mailing still have shale matrix attached to them. The thickest slab is about 1/2 inch thick. How will I know if/that the Vinac has penetrated the entire piece?

• How long does it take to completely dry? I've read that setting things that have undergone Vinac treatment on wax paper is okay. Is that still good advice?

• I have used super glue on a couple of pieces that broke while trying to extract them. For future reference (if I get around to putting Vinac on those), would the acetone in the Vinac solution weaken or otherwise negatively affect the bond between the pieces glued together? I used Gorilla brand "Impact-tough" if that is useful information.

I'm sure I will have a lot more questions throughout my journey of fossil prep, but I'll start with these. Thank you!

[Harry Pristis]

My bias, but "painting" is not the same as consolidating. If they were my trilobites, I might match the jar mouth with the largest specimen that I want to dip into the Vinac solution. That is the only way to be certain that the shale has been penetrated.

Acetone will weaken the rubberized gasket on a baby food jar, but the acetone in the jar will evaporate before you need worry about contaminating the solution. Acetone will weaken or dissolve most glues, some quicker than others.

I recommend a cardboard beer flat as a drying rack because the cardboard will absorb any excess Vinac solution. See other tips for consolidating fossil, including inverts, here:

http://www.thefossilforum.com/index.php?/user/42-harry-pristis/

[Malcolmt]

I use a jar about the same size as a baby jar. It originally had some kind of spice in it and has a metal lid with nothing else in it. I find that is a good amount to mix at any point in time. I like to use a clear glass jar so that I can see the clarity of the solution. Vinac beads will take some time and shaking to dissolve completely. Always stir before using. No matter how well I tighten eventually the acetone will evaporate but the good thing is you can just add more acetone and it will dilute nicely.

I tend not to soak for consolidation but then the matrix I collect is generally not in too bad shape.

Use acetone in a well ventilated area and be careful in that it is highly combustible.

Brushing is okay for saving flaking exoskeletal material on trilobites but as Harry indicated it is not really going to consolidate weak matrix.

For consolidation I use a pipette or syringe to apply the vinac solution and do it in multiple applications. You are generally trying to get the solution into all the cracks and crannies and to pretty much become the structure holding the trilo exoskeleton together hopefully from underneath.

The acetone will weaken the cyanoacrylate.

I always dry fossils on cardboard

Edited December 23, 2015 by Malcolmt

[ZiggieCie]

OK here's my 2 cents worth; I just went out and checked my B-72 in acetone solution. It is 6 months old. I have it in a mason canning jar with the two piece lid and the rubber/silicone rubber gasket is fine with no noticeable evaporation yet. I have a smaller amount mixed with alcohol in a small jelly jar with the rubber gasket they come with. You don't have the same concerns with the alcohol as with the acetone. The diff is mostly that the acetone dries faster. For us small usage types either should be fine, museum class work has many needs that we don't.

Here is a link for B-72 but the vinac is almost the same.

to dissolve it use a small pouch of cheese cloth and hang it in the Ac/alch by the lid. It is fun to watch it dissolve out. If you just dump the pellets in they are harder to dissolve and can clump up.

http://www.connectingtocollections.org/wp-content/uploads/2014/02/Davidson_and_Brown_2012_Paraloid_B-72-_Practical_tips_for_the_vertebrate_fossil_preparator.pdf

[Xiphactinus]

I mix up my vinac in an old laundry detergent bottle. It's easy to shake up to mix it if it separates. If I only need a bit, I just pour it into the lid and any leftovers go back into the bottle when done.

[jpc]

I mix up my vinac in an old laundry detergent bottle. It's easy to shake up to mix it if it separates. If I only need a bit, I just pour it into the lid and any leftovers go back into the bottle when done.

I do too. You gotta use a number 2 plastic (USA recycling numbers) and wash the bottle out very well. The acetone will eat through other plastics. You can also buy small Nalgene bottles form outdoor gear stores. That is good. I mix mine with a magnetic strirrer, but before I had that, it takes a week or so for the stuff to dissolve. The cheesecloth method mentioned above is good. And shake it up every now and then.

Something to keep in mind if you plan to dunk a piece in vinac, or coat it completely, is that any other vinac that is already on the specimen will dissolve the liquid vinac before the liquid gets into or onto the specimen.

[Minerva8918]

Thank you to everyone who has responded. I really appreciate the info everyone has shared! Happy holidays

[jpc]

If you do soak things, it is better to dry them on wax paper. If they drip vinac, this will easily peel off the wax paper, rather than sticking to paper or cardboard.

[Harry Pristis]

If you do soak things, it is better to dry them on wax paper. If they drip vinac, this will easily peel off the wax paper, rather than sticking to paper or cardboard.

I have consolidated thousands (literally) of fossils and have never had one stick to a beer flat. I do have, however, more than a few beer flats with stains from draining Butvar B-76. Perhaps Vinac behaves differently. I suspect that wax paper, like slow drying, is a superfluous flourish to the basic process.

[jpc]

well, my fear can't argue with Harry's experience.

[Ptychodus04]

I do too. You gotta use a number 2 plastic (USA recycling numbers) and wash the bottle out very well. The acetone will eat through other plastics. You can also buy small Nalgene bottles form outdoor gear stores. That is good. I mix mine with a magnetic strirrer, but before I had that, it takes a week or so for the stuff to dissolve. The cheesecloth method mentioned above is good. And shake it up every now and then.

Something to keep in mind if you plan to dunk a piece in vinac, or coat it completely, is that any other vinac that is already on the specimen will dissolve the liquid vinac before the liquid gets into or onto the specimen.

Me 3! The detergent bottle is the way to go!!

[squali]

After trying unsuccessfully to mix Elmers with acetone , I finally got some PVA from Black Hills a month ago. (PVA B-15 Beads)

I was used to the water based dilution, but as Kris pointed out to me in a different post, the acetone based mixture is way easier to remove.

The ratio I came up with is a 1/2 dry ounce of PVA to a cup of acetone based on their bulk mixing directions of 1/2 pound

of beads to make one U.S. gallon of consolidant concentrate. You can thin it more depending on what you use it for. If I'm attaching micros to a slide I dilute it by half. They sell it as 1 U.S. pint so you should weigh it out. Whatever you use to store it in, DO NOT use the empty paint cans you can buy at the hardware store. The gray coating they put inside breaks down in acetone. I guess everyone uses latex paint these days.

Beer Flats used to have some kind of wax coating if I remember right?

Edited December 26, 2015 by squali

[Harry Pristis]

. . .

Beer Flats used to have some kind of wax coating if I remember right?

I don't know if those flats are coated -- could be. If they are treated with something, it does not impair the cardboard's absorbency. It may even enhance its absorbency. Flats are manufactured for a one-time use so they may be not only organizers, but also napkins.

Here's an image of a flat I used for a short while. I don't remember what bone drained the prodigious amount of consolidant in the middle (the darkest stain). Whatever it was, it separated without sticking. Lesser drains follow the round contours left by the cans. The smallest drains leave just a spot. Try one, you'll like it.

[Minerva8918]

After trying unsuccessfully to mix Elmers with acetone , I finally got some PVA from Black Hills a month ago. (PVA B-15 Beads)

I was used to the water based dilution, but as Kris pointed out to me in a different post, the acetone based mixture is way easier to remove.

The ratio I came up with is a 1/2 dry ounce of PVA to a cup of acetone based on their bulk mixing directions of 1/2 pound

of beads to make one U.S. gallon of consolidant concentrate. You can thin it more depending on what you use it for. If I'm attaching micros to a slide I dilute it by half. They sell it as 1 U.S. pint so you should weigh it out. Whatever you use to store it in, DO NOT use the empty paint cans you can buy at the hardware store. The gray coating they put inside breaks down in acetone. I guess everyone uses latex paint these days.

Beer Flats used to have some kind of wax coating if I remember right?

Thank you SO much for the dilution, squali! Math is not my strongest point...so that was extremely helpful. I'm keeping mine in a glass jar for now since I'm not using too much at the moment. I'm using it to consolidate trilobites and the shale matrix they are in. I'm hoping to avoid any sort of glossy sheen on the shale, which I read can happen when the solution isn't dilute (diluted?) enough.

I took Ziggie's advice and used cheesecloth to dissolve the PVA beads in the acetone. I was actually slightly worried that it wouldn't dissolve correctly because in my attempts to sit the cheesecloth with the beads so that the bottom was the only part in the acetone, I accidentally dunked the whole thing ! But I just checked a minute ago, and it all dissolved. Yay!

Thank you so much again to everyone who has posted here. You've been enormously helpful!

[Ptychodus04]

Thank you SO much for the dilution, squali! Math is not my strongest point...so that was extremely helpful. I'm keeping mine in a glass jar for now since I'm not using too much at the moment. I'm using it to consolidate trilobites and the shale matrix they are in. I'm hoping to avoid any sort of glossy sheen on the shale, which I read can happen when the solution isn't dilute (diluted?) enough.

I took Ziggie's advice and used cheesecloth to dissolve the PVA beads in the acetone. I was actually slightly worried that it wouldn't dissolve correctly because in my attempts to sit the cheesecloth with the beads so that the bottom was the only part in the acetone, I accidentally dunked the whole thing ! But I just checked a minute ago, and it all dissolved. Yay!

Thank you so much again to everyone who has posted here. You've been enormously helpful!

I'm less scientific with my mixtures. I mix my acetone to PVA ratio simply by volume for each. 20 parts acetone to 1 part PVA, unceremoniously dumped into a jug, shaken (not stirred) for a solution with a similar viscosity to vegetable oil. The dissolution process takes a few days but ultimately, everything dissolves.

Then, I cut my PVA solution with an equal part of straight acetone in small batches to give me a consolidant with a ratio of 40:1. This soaks in well and allows a deep penetration with multiple applications before the surface turns really glossy. If I have to consolidate the specimen that much, I use straight acetone to remove the surface PVA to provide a more matte finish.