Green River fish preps

[Alex S.]

Hey everyone. I just got back from my first of hopefully many Kemmerer fish trips.

My wife and brought home loads of fossils that's I'll highlight in a trip report.

I brought home 2 larger fish one which the what said was Phareodus which seems to be complete.

 

 

 

i need to glue it down and then prep it from the top but wanted to pick everyone's brains primarily @Ptychodus04 and @RJB but I'm open to all input.

 

I am planning on mixing a thick bit at solution and painting it on the highlighted areas the dark line being the vertical crack underneath the fish then clamp them. Is this the right idea?

 

I was also wondering if I should paint the exposed fish with a thinner solution before I glue it down? I've also got this other fish my wife found that's barely exposed so I haven't ID'd it yet, that is cracked in the same way.

 

 

 

 I'm curious about dry time when I got home there was some condensation on other pieces from being wrapped up.

 

While these were seemingly dry should I wait awhile before glueing them up?

 

Thanks for all your knowledge and expertise.

[RJB]

I'm going to wait for Kris @Ptychodus04 on this one.  He does an excellent job at explaining things.

 

RB

[Ptychodus04]

You’re thinking along the right path. You can use thick Paraloid for your glue.

 

Make sure your pieces are free of all rock fragments. Then brush on your glue, fit, and clamp. Allow several days to fully dry. 
 

I would not coat the exposed fish before gluing as you take the chance of slightly changing the alignment of the 2 pieces.

 

As for drying time for the rocks, it can take a few days to weeks depending on how much rain they got recently before your trip and how thick your slabs are. If you can safely unwrap them, this will speed up the drying.

[Alex S.]

Thanks Kris, that makes a lot of sense. I had another question about prepping a branch from GRF I had expected to see darker coloration in cross section at the edge of the slab but it appears to be the same color as the host rock. Is common and how would I go about preparing it? 

[Ptychodus04]

That doesn't actually look like a branch to me. There are often random bumps and ripples in the rock. This looks like that to me. There should be some kind of carbon film if there's actually a plant present. It may be that there's something deeper that is causing the ripple. What does the cross-section look like? 

[Alex S.]

Here's a photo of the cross section. It's by my thumb right where the vertical dark line is.

[Ptychodus04]

I think that you just have a deformity in the rock but there could be something hiding in there. There's nothing obvious on the cross-section but plants can be tricky. I would scribe down from the surface of the bulge a bit to see if you run into a carbon layer. Plants can really deform the rock and then get crushed paper thin. They really are a PITA. I have a bottom cap piece that showed a tall bulge with nothing in cross-section that would up being a reed with a flower bud on the end but I had to go fairly deep to find the plant.

 

Edited September 30 by Ptychodus04

[Alex S.]

Good to know I'll do that. Thanks for the advice. I am still waiting on my zoic trilobite scribe I ordered 2 months ago so I'll hold off until I get that so I have a bit more control than my Dremel p290.

[Alex S.]

I've spent several hours under the scope on my wife's fish and heres where I'm at so far

 

I think it's a Phareodus but I'll keep working on it. So far the matrix is pretty nice with a slightly harder layer right above the fish but it's separating fairly well from the scales. To my great delight I managed to find a tiny fry right above the big fish that I managed to extract in 2 pieces 

 

 

Sorry for the poor micro scope photo I don't have a trinocular scope or a good alternative for photos so I'm stuck holding my phone against the eyepiece.

[trilobites_are_awesome]

looking Good!

[Alex S.]

Thank you! Between my PhD and renovating a house I haven't much time to do any serious prep but it's nice to make some progress.

[Ptychodus04]

16 hours ago, Alex S. said:

I think it's a Phareodus

 

I think it's a Mioplosus.

 

The dentary position is wrong and the pectoral fin is too high on the body and too small for Phareodus. Also, the dorsal fin would be more posterior. Phareodus has thick scales as well where Mioplosus has thinner, more delicate scales like your specimen.

 

It's looking good. My only bit of advice would be to stabilize as you go. This will help lock the scales down and help keep the small bones from popping off. I'm working on a Sandwich Bed Diplomystus currently and I have to stop and stabilize every couple of minutes or the fish peels off the slab... I hate prepping Sandwich Bed fish!!! 

[Alex S.]

Thanks Kris! That was my second guess. Yes I've been stabilizing but I need to do it more frequently. The bit prepared underneath the spine had popped off when she split it and I tried to put some paranoid on and then stick the piece down so the scales would be on the fish when I prepped down too it but it didn't work.

[Ptychodus04]

19 hours ago, Alex S. said:

Thanks Kris! That was my second guess. Yes I've been stabilizing but I need to do it more frequently. The bit prepared underneath the spine had popped off when she split it and I tried to put some paranoid on and then stick the piece down so the scales would be on the fish when I prepped down too it but it didn't work.

 

I'm using one of my smallest scribes to uncover the scales on my current prep and I'm stabilizing after removing less than 1 square centimeter of matrix. Use a very thin solution (max 50:1) to keep from building up a ton of paraloid and making your prep harder. 

 

Gluing scales back on is tough. You have to use a thicker paraloid solution (15-20%) and clamp the pieces together tightly for several days. Prepping this isn't fun but you can usually save most of the scales this way.

[Alex S.]

Good to know I definitely think my paraloid solution is too thick then ~20:1. My scribe finally shipped so I should get it in the next couple weeks but until then I've been using the Dremel p290 to get close and a pin vise to finish it off and have been thinking the Dremel probably transfers too much vibration. I'll keep the gluing the scales back on method in mind thank you.

Edited October 9 by Alex S.

[Alex S.]

I had some more time today to work on my fish. It is coming along well.

The scales on the bottom half keep popping off but it'll still but it'll stop be a nice fish in the end.

[Ptychodus04]

Looking good. Mio's have some of the most delicate scales of any GRF fish. Even 18" Layer Mio's are tough to prep.

 

I'm feeling your pain on the large Diplo I'm prepping. I'm in a spot where I only get a few millimeters uncovered before I have to stop and consolidate... and this is using my Balaur scribe turned all the way down with the .5mm stylus!!! I hate my life. 

[Alex S.]

Haha I'm glad to know it isn't just me. The Balaur is on my dream list of scribes it seems awesome.

[Ptychodus04]

5 minutes ago, Alex S. said:

Haha I'm glad to know it isn't just me. The Balaur is on my dream list of scribes it seems awesome.

It's amazing for really fine detail work.

[trilobites_are_awesome]

@Alex S. Hows the fish prep going?

[Alex S.]

@trilobites_are_awesome it is going well. Today is the first time I've had a chance to work on it. Between a PhD and a home renovation prepping time is hard to come by. My zoic trilobite finally came in which has been wonderful. The scales on the top of the fish. (Bottom of the plate refused to stay on but all in all I think it's coming along nicely.

[Fossildude19]

Fixed the orientation for you.

Coming out nicely!

 

[Alex S.]

Thank you!

[trilobites_are_awesome]

Very nice!

[Alex S.]

The prep is finished on the mioplosus. I should've kept track of my time but I think it was around 15-20 hours. Here's one of my wife proudly holding her fish.and here is a close up.this was a very informative prep for me. I lost a decent amount of scales, initially had glue that was much too thick and unfortunately went too deep in a couple places. Regardless I am still pleased with it and think that it'll make a nice display piece at around 22cm. 

 

Kris @Ptychodus04 I had a question about trimming down matrix. I have a wet tile saw that I use for lapidary would that work. or do I need to use a hack saw or something else so I avoid getting specimen wet?