Fossilhunters fish prep

[Ptychodus04]

I think it is disarticulation at the front. I could be wrong, but I held it in my hand and it didn't look like a partial on top of a complete.

 

Losing bits of fish is pretty common with Green River specimens, especially the small ones. The bones and scales are super fragile. Consolidating as you go will help.

[Pagurus]

Thanks for posting your fish prep. You're doing well, and your care and patience is clear. I'm also prepping largely with xacto knives, for better or worse. Occasionally I'll stick a sewing needle in the collet of an xacto knife, using it like a pin vise. It usually works well. I've tried dental tools and use them or a scribe to remove matrix more quickly, but I've occasionally removed more than I intended to. Sharpened chain saw files have been recommended here, but I've never tried them myself. Seems like a good idea. Whatever you use, it's important to keep the tool sharp. I've noticed that my xacto blades cut through the 18-inch layer more easily after I've sharpened them on a honing stone. Still slow going, but a little easier and less apt to do damage to the fossil since I'm applying less pressure. I have a bandage wrapped around the knife handle to give my fingers a break. Be sure to rest your hands now and then. I usually just blow away the dust but I've found that a little plastic desk fan is helpful too. I've never tried it, but I think a little fish tank air compressor would be useful, without the noise of a larger compressor. Some of those little aquarium air pumps are pretty quiet. I hope you're having as much fun uncovering those fifty-million-year-old fish as I am. You're doing great!

 

Mike

[fossilhunter21]

42 minutes ago, Pagurus said:

Thanks for posting your fish prep. You're doing well, and your care and patience is clear. I'm also prepping largely with xacto knives, for better or worse. Occasionally I'll stick a sewing needle in the collet of an xacto knife, using it like a pin vise. It usually works well. I've tried dental tools and use them or a scribe to remove matrix more quickly, but I've occasionally removed more than I intended to. Sharpened chain saw files have been recommended here, but I've never tried them myself. Seems like a good idea. Whatever you use, it's important to keep the tool sharp. I've noticed that my xacto blades cut through the 18-inch layer more easily after I've sharpened them on a honing stone. Still slow going, but a little easier and less apt to do damage to the fossil since I'm applying less pressure. I have a bandage wrapped around the knife handle to give my fingers a break. Be sure to rest your hands now and then. I usually just blow away the dust but I've found that a little plastic desk fan is helpful too. I've never tried it, but I think a little fish tank air compressor would be useful, without the noise of a larger compressor. Some of those little aquarium air pumps are pretty quiet. I hope you're having as much fun uncovering those fifty-million-year-old fish as I am. You're doing great!

 

Mike

Thank you for the information @Pagurus.  

Edited May 12, 2021 by fossilhunter21

[fossilhunter21]

5 hours ago, Ptychodus04 said:

I think it is disarticulation at the front. I could be wrong, but I held it in my hand and it didn't look like a partial on top of a complete.

 

Losing bits of fish is pretty common with Green River specimens, especially the small ones. The bones and scales are super fragile. Consolidating as you go will help.

Yeah now I think it looks more like it's diarticulated than it being two fossils. Thanks. 

Edited May 12, 2021 by fossilhunter21

[fossilhunter21]

Wow! Pins are so much better than exacto knifes! They may be slower but it's worth it to use them and lose few small peices rather than lots of big pieces with a knife.     Thanks for the tips guy's.    

Edited May 13, 2021 by fossilhunter21

[Ptychodus04]

Yup. It is slower but better. You have to keep them sharp though or you are likely to gouge the fish.

[fossilhunter21]

Here I is after some more work. 

Just to let you guys know I will not be able to work on it much in the next couple days because I am tying to give my hands a bit of a break.  

[Ptychodus04]

This looks like a Diplomystus. The pectoral fin is high on the side of the body in relation to the pelvic fins. Good job so far.

[fossilhunter21]

15 minutes ago, Ptychodus04 said:

This looks like a Diplomystus. The pectoral fin is high on the side of the body in relation to the pelvic fins. Good job so far.

Thanks for letting me know.  

Edited May 19, 2021 by fossilhunter21

[fossilhunter21]

I haven't been able to work on it much lately, but this is how it's looking.

 

[hadrosauridae]

slow and steady wins the race!

[snolly50]

@fossilhunter21 It's probably already been mentioned, but worth repeating for this type of prep. Take a break! The repetitive fine motion in using a pin vise can wreck your hand. It's easy to get engrossed in prep and go too long. Make yourself stop every few minutes and you will avoid that worrisome strain.

[Ptychodus04]

I finally have this fish figured out. What appeared to be the pelvic fins are actually the dorsal fin with some of the more anterior rays displaced. This is definitely a Diplomystus with the orientation of the fish ventral side up.

[fossilhunter21]

4 minutes ago, Ptychodus04 said:

I finally have this fish figured out. What appeared to be the pelvic fins are actually the dorsal fin with some of the more anterior rays displaced. This is definitely a Diplomystus with the orientation of the fish ventral 

Wow that is way different than I thought. 

 

Thanks for helping figure it out.   

[fossilhunter21]

I have been working on it for a few more hours, and here is how it's looking. 

[fossilhunter21]

After a few more hours this is looking even more like a fish.

Edited May 25, 2021 by fossilhunter21

[hadrosauridae]

Looking better and better! Its bigger than I originally thought.  Youre doing a great job. Keep it up!

[Ptychodus04]

Looking good!

[Ludwigia]

13 hours ago, fossilhunter21 said:

After a few more hours this is looking even more like a fish.

 

Yes it certainly is. Good work!

[fossilhunter21]

I have some softer fish, and even if you just touch them a little bit then they break. Is there any way to harden them while still under the matrix?

[fossilhunter21]

Here it is after a couple more hours.

[hadrosauridae]

12 hours ago, fossilhunter21 said:

I have some softer fish, and even if you just touch them a little bit then they break. Is there any way to harden them while still under the matrix?

 

Not that I have discovered yet.  I tried using a super-thin mixture of consolidate, but it only goes a tiny distance before the matrix soaks it up, and then youve got matrix glued to the fossil which only makes the prep harder.   

[Ptychodus04]

On 5/26/2021 at 8:06 PM, fossilhunter21 said:

I have some softer fish, and even if you just touch them a little bit then they break. Is there any way to harden them while still under the matrix?

 

Applying some Paraloid B72 50:1 solution will harden the bones without hardening the matrix too badly. If you use much, as @hadrosauridae mentioned, you will harden the whole thing.

 

If you can get a small amount exposed, you can apply small amounts of Paraloid as you expose the fish. This will significantly lengthen the prep time required as you have to let the solution completely harden before proceeding. If you rush it, the plastic will pull the fish off the matrix.

 

Another option is to heavily consolidate the entire piece by soaking in the Paraloid solution. This will consolidate all the matrix and the fish. You can then use acetone to remove the plastic from the matrix above the fish. This will effectively stabilize the specimen without permanently hardening the matrix. No matter how you go about it, these are slow preps.

[fossilhunter21]

So how do I store the solution?

[Ptychodus04]

I store mine in a mason jar with Saran Wrap under the lid to keep the acetone from eating away the seal.