Wet fossil stabilization

[Drenthe]

Dozens of articles written about stabilizing crumbly specimens but I have yet to find someone who can make me feel confident about a solution. 
I kayak rivers and find tusks and crumbly bones on the sandbars. They are wet or at least half wet from contact with the ground. 
The stabilizer must dry quickly, be reversible and work on a wet specimens. Currently I leave most of them where I find them because I cannot come up with a good solution.

[caldigger]

@Ptychodus04 @Uncle Siphuncle

[Ptychodus04]

Any Davidson at the AMNH recommends Rhoplex WS-24 for consolidating wet specimens. 
 

Your other option is controlled drying. Wrap your wet find in a towel and dunk it in the river. When you get home, wrap it in another towel (dry) and put it in a closed cardboard box for about a month. When you come back you should have a dry tusk you can stabilize with Paraloid. Don’t seal it up too well or it will mold. The point is to slow the drying so it dries out at the same speed inside as on the surface, thus reducing cracking.

[caldigger]

So You're saying I shouldn't  just stick it in the microwave in high for 20 minutes? 

[Uncle Siphuncle]

I’m not in love with Elmer’s glue, but some thin it and use it as a cheap and readily available alternative for field stabilizing wet specimens.  But I try yo do something more like Kris mentioned.  Either way, good to take pics before lifting to help with reassembly should part of it crumble.

[Ptychodus04]

13 hours ago, caldigger said:

So You're saying I shouldn't  just stick it in the microwave in high for 20 minutes? 

Probably not the best plan.

[Drenthe]

Most of the tusk and some of the bones fall apart as soon as I disturb them. The large tusk wasn’t as much of a problem but the smaller tusks, teeth and bones are unsalvageable if I can’t find a quick consolidator. The bison skull in this photo literally melted into mush. 
I need something that will dry within 30 minutes. I will check out the rhoplex. Thanks

[Drenthe]

I checked out the rhoplex but i don’t think it will dry fast enough. I am on the river for 6-8 hrs before I can get out again so unfortunately I am limited by time. Floating the river at night isn’t any fun. Especially if I hear water roaring ahead.

[Bob Saunders]

I can't other to say that some wood turners put wet wood in a paper bag with wood chips and saw dust and put it up on a rafter to dry. so maybe along with the wet towel some chips etc. may help but change often. Another is like Menards sells a moisture absorbing bags to help control wet areas and basements. Although I have read that they are not good around some metals. When they become saturated just dispose of them. 

[Ptychodus04]

For things like the bison featured, dint try to remove it from the soil. Excavate around it and make a plaster jacket. This will protect the bones in transport and will also provide the slow drying required.

 

Pleistocene fossils are often sub-fossil bone and are extremely fragile when wet. The jacket and the matrix will help them greatly. Granted, this may not be a kayaking event with all the required materials.

[Drenthe]

3 hours ago, Ptychodus04 said:

For things like the bison featured, dint try to remove it from the soil. Excavate around it and make a plaster jacket. This will protect the bones in transport and will also provide the slow drying required.

 

Pleistocene fossils are often sub-fossil bone and are extremely fragile when wet. The jacket and the matrix will help them greatly. Granted, this may not be a kayaking event with all the required materials.

 

3 hours ago, Ptychodus04 said:

For things like the bison featured, dint try to remove it from the soil. Excavate around it and make a plaster jacket. This will protect the bones in transport and will also provide the slow drying required.

 

Pleistocene fossils are often sub-fossil bone and are extremely fragile when wet. The jacket and the matrix will help them greatly. Granted, this may not be a kayaking event with all the required materials.

They dry well in my climate. I sometimes use Elmer’s glue to seal them and the glue allows it the moisture to slowly evaporate from the bone. I paint Paraloid b72 on the exterior of my larger wet tusks leaving the core untouched so that moisture can evaporate slowly through it. 
it’s just the field stabilization that is giving me fits. 

[Drenthe]

You are correct. They are not old enough to be technically fossilized. That is a blessing and a curse. I abandon a lot of nice ice age bones, teeth and tusks because they have already started to crumble. Guessing there isn’t really anything I can do for them. The weight of plaster would crumble many of them.

[Ptychodus04]

10 hours ago, Drenthe said:

You are correct. They are not old enough to be technically fossilized. That is a blessing and a curse. I abandon a lot of nice ice age bones, teeth and tusks because they have already started to crumble. Guessing there isn’t really anything I can do for them. The weight of plaster would crumble many of them.

If you excavate enough matrix with the fossil, the plaster will simply hold everything in place until you get to open the jacket and start prepping. This is a tried and true method that hasn't changed since the 1800's. There's a process that needs to be followed in order to be successful but I have recovered some otherwise unrecoverable fossils by employing a field jacket. There are some fossils that are just too weathered to be collectable no matter the process.

 

If I have a fragile specimen in the field, I uncover the bare minimum bone in the field in order to understand the extents of the specimen and then section it into manageable sized blocks for jacketing. You will be amazed what you can recover by doing this.

[FossilDAWG]

I have a question that might fit with this thread.  I once found a 2-3 foot long Baculites with iridescent shell in a clay matrix (Coon Creek Formation). Unfortunately it was in a creek bank, almost at water level, and as I tried to dig around it to make a pedestal the excavation continuously filled with water that came up from the ground.  The clay and the fossil were also completely water-logged.  Needless to say, the Baculites disintegrated into small fragments as soon as I tried to undercut the pedestal.

 

My question is, is there anything I could have done, such as a consolidant or glue, that would have worked relatively quickly (as we were working under a time constraint) to hold together a soft and waterlogged specimen?  Or should I just moved on and not wasted time trying to save the fossil?

 

Don

[Ptychodus04]

23 minutes ago, FossilDAWG said:

I have a question that might fit with this thread.  I once found a 2-3 foot long Baculites with iridescent shell in a clay matrix (Coon Creek Formation). Unfortunately it was in a creek bank, almost at water level, and as I tried to dig around it to make a pedestal the excavation continuously filled with water that came up from the ground.  The clay and the fossil were also completely water-logged.  Needless to say, the Baculites disintegrated into small fragments as soon as I tried to undercut the pedestal.

 

My question is, is there anything I could have done, such as a consolidant or glue, that would have worked relatively quickly (as we were working under a time constraint) to hold together a soft and waterlogged specimen?  Or should I just moved on and not wasted time trying to save the fossil?

 

Don

I would suggest jacketing the specimen prior to undercutting your pedestal. This will give it stability while you undercut. Widen your trench so you can freely excavate horizontally under the specimen and dig a couple channels through the pedestal. Now, you have to work fast (it helps to have an assistant here). Prepare your plaster bandages and bail out your trench. Wrap your bandages around your original jacket and through your channels. Continue to bail water from your excavation while the plaster sets. At this point, you should have stabilized your specimen enough to allow you to break the supports and remove your jacket without damage.

 

For long, thin jackets, it is advisable to integrate a 2x4 or 2x2 (depending on the length and thickness of the jacket) into the plaster bandage wraps for additional support to prevent flexing of the jacket.

[FossilDAWG]

Thanks.  I'll try to remember to bring appropriate supplies if I ever get a chance to collect there again. 

 

Don

[Ptychodus04]

A field jacket is the most underutilized arrow in the collector's quiver I have ever seen. I just got done looking at a mosasaur that was collected mostly without a jacket and I am still lamenting what could have been.

[ParkerPaleo]

I'm not certain of the correct term but I carry 'plaster cloth' in my field pack just in case I need to make a quick jacket.  Bought several cases from government surplus years ago.  I know its available at larger art supply stores as well.  Very handy when you don't have time or ability to bring large amounts of plaster/burlap.

[FossilDAWG]

One more question, will plaster bandages set if they are in contact with water, or if the fossil is water logged?

 

Don

[Ptychodus04]

On 12/2/2019 at 2:16 PM, ParkerPaleo said:

I'm not certain of the correct term but I carry 'plaster cloth' in my field pack just in case I need to make a quick jacket.  Bought several cases from government surplus years ago.  I know its available at larger art supply stores as well.  Very handy when you don't have time or ability to bring large amounts of plaster/burlap.

I also have some plaster bandages ready to go. They are really convenient, just get them wet and apply. For small jackets they are great.

 

On 12/2/2019 at 2:31 PM, FossilDAWG said:

One more question, will plaster bandages set if they are in contact with water, or if the fossil is water logged?

 

Don

Plaster will set if the specimen is wet. It will theoretically set underwater if you have a dry enough paste so the water that gets absorbed is used for the reaction. In practice, I wouldn’t expect it to work.