Whale vertebra - how to...

[outdoorsman555]

A friend took me out to a spot on a creek he owns where you can find Miocene-era fossils. Found several whale bones, all black in color, except this large vertebra which is all white.

 

My friend said I needed to stabilize the white ones, as they would crumble over time otherwise. Looking through the various posts on here I bought some butvar, but found a couple methods that people talked about for use.

 

Completely submerge the fossil, paint brush on the solution, or use a turkey baster to squirt it on? Not sure how to proceed. After dissolving the butvar into acetone, which method is the best for vertebra? If I submerge it, which sounds like it might be the best for stabilizing (as it would permeate to the core), how do you move it from the submersion tank to a spot to dry? It doesn’t fall apart once you set it in butvar/aceatone solution for a while?

I have let the vertebra dry for several months now. This is my first attempt at preserving a fossil so any tips/suggestions would be appreciated. Thanks in advance.  

 

 

[sharkdoctor]

Submersion works well, but can waste consolidant and generally requires a nail board or pin board. It is overkill for this piece, I suspect. However, submersion can make the piece pretty rugged!

 

You can make a nail board by running small nails through a sheet of plywood at the corner of every square inch. Once you flip the board, you have enough "pins" or points to rest the fossil on while it dries. You may get a small amount of sticking, but generally not enough to strongly bond the bone to the points of the pins.

 

Most likely, your friend means bones that are actually white. White fossil bones from the east coast generally means that they have been exposed to acid and/or strong weathering. They generally become very friable once they are white.

 

The bone in the picture looks very stable in comparison to a strongly weathered bone. Brushing on a coat or two of consolidant should work well. Start by pouring some into the spongy bits, or using a soaked brush several times on the spongy bits. 

[Ptychodus04]

I have to humbly disagree with the advice from @sharkdoctor

 

I've been consolidating various types of fossils for decades with many different methods. Submersion is always preferred when possible. I only brush or drip consolidation material onto a specimen when soaking isn't possible, or I'm spot treating an area during prep. Anything requiring spot consolidation can't be soaked or everything you locked down during prep will come off.

 

I would definitely consolidate your bone. I say this because the cancellous bone is not filled in with minerals (very common in more recent fossils). This makes the specimen inherently brittle.

 

There's no such thing as wasting your solution. Even if all your solvent evaporates, you can simply add solvent to the plastic left behind and you're good to go. I submerge specimens until there are no bubbles coming out. This is the only way to know that the consolidation material has penetrated to the center of the specimen. Removal is easy, slip on some kitchen gloves and grab the piece, letting the big drips fall off. Don't hold it too long or you'll stick your gloves to the specimen. Set the specimen on a cardboard flat to dry. The piece may stick to the cardboard. If this happens, and some cardboard comes off with the fossil, simply wipe a bit of acetone onto the area to remove the cardboard fibers. Easy peasy.

[outdoorsman555]

Follow-up post (yea, its taken me awhile), mostly to just double check me, and help anyone in a similar situation.

I couldn’t find any Butvar-76, so I ended up buying “B08SY Resin” which said it was a Butvar-76 equivalent. I mixed it at a ratio of 10 grams of resin powder to every 100ml of acetone to get to a 10% mixture. I’m not really sure that’s correct. I had originally found how to mix it on some datasheet, but now I can’t seem to find that again… Maybe someone smarter than me knows if that was the correct formula and mixture ratio???

I slowly added the resin powder directly to the bottle of acetone, then put the top back on and let it sit for a day. I shook the bottle up a bit the following day, and poured it into a large pot.  The mixture was quite a bit thinner than expected. It basically wasn’t much different in viscosity than plain acetone. Is that right? I dipped all the items I have, until the bubbles stopped. Pulled them out (with junk tongs I have) and let the excess liquid run freely back into the pot, which with water like viscosity, looked like most of the mixture coming back out of the fossil. I put them on parchment paper (not wax paper as I found later wasn’t as good), and let them dry. Certainly, it seemed like some of the resin permeated the fossil, but is it enough? As you can see from the photo of the color of the fossil changed, so its not white anymore, so I think its ok. Thoughts?

[Fin Lover]

I'm not familiar with the resin you used, but I believe 10% is too high with Paraloid or Butvar.  That's why they look shiny now.  But, as long as there isn't a white sheen showing, it shouldn't hurt anything (and that is only an aesthetic issue).  You may be able to remove some of the resin with plain acetone, if you want to get rid of some of the shine.

Edited August 6, 2023 by Fin Lover
Reworded

[outdoorsman555]

Yes. I did remove some of the shine with some plain acetone. I think I found some documentation that said 2%-10% was a normal ratio for stabilizing fossils with Butvar-76, so it is probably on the high side at 10%. Just trying to do my best on preserving what I found. 

[Fin Lover]

I've seen 2-5% a lot on here.  Luckily, it's easy to remove if you use too much.