How to prepare a fish fossil from the Green River Formation

[Dapalis1]

paleotools also sells the crystal mark swamblaster air abrasive units. (i know it sounds like i work for the guy or something. but i don't. i just have been very happy with his service and products)

Brock

Hi Brock,

I contacted Bill Murray yesterday and he replied very kindly today. He advised me to go for the Micro Jacks. He told me that the Micro Jack does very detailed work. So it sounds like it's a great tool.

I believe i need a compressor to get it working? Forgive me for my silly questions but i don't really know what it runs on. I assume that an air scribe runs on pressure and thus i need a compressor or something like that ???

Thanks,

Dapalis1

[screweduptexan]

Ahhhh...this makes me want to go back to Wyoming to go fossiling. There is so much for me to learn!

[ebrocklds]

yes, you will need an air compressor. even though bill said a micro jack is better for detail, i would suggest you get a paleo-aro, as they are much more versitile. the microjacks just don't move very much material very quickly. so if you have a fish that is more that a few mm down it will take much more time. get one with a nice sharp tip and a steady hand, and you should be able to get all the detail you want on GR fish. i like longer stylus for mine so that i can get down into small holes and cracks on dinosaur bones.

Brock

[Dapalis1]

Thanks ebrocklds

Actually i just received the package. I purchased the Microjack 5 along with a very thin and long stylus.

I attached some pictures of the work that i have done so far on the fish.

As you can see the head came out disarticulated. There is still a very thin layer covering the specimen but it is extremely hard to remove.

How do you usally do to remove that very thin layer in between the fish bones...? Cause it takes a while to chip it away with a chain saw file.

And moreover in some areas like on the head, the tool is not very convenient to chip in between the bones...because of their shape!!

Let me know what you think about that!

Thanks,

Dapalis1

[ebrocklds]

Dapalis1, that is where an air abrasive unit comes in handy. another trick that will take some small pits of rock off, is a brown art gum eraser.

https://www.archival...cture%20970.jpg

i am not sure how else you can get it off.

Brock

[Dapalis1]

Dapalis1, that is where an air abrasive unit comes in handy. another trick that will take some small pits of rock off, is a brown art gum eraser.

https://www.archival...cture%20970.jpg

i am not sure how else you can get it off.

Brock

Thanks!!

And what about the thin layer covering the back bone? Cause the shape makes it very slidy and thus it it hard to chip the matrix away around and on the backbone.

As you see, the rock left on the fish consists of a very very thin layer that is hard to remove.

I mean in between the fish bones, there is not even enough space to insert an art gum eraser..!

Dapalis1

[Auspex]

Thanks!!

And what about the thin layer covering the back bone? Cause the shape makes it very slidy and thus it it hard to chip the matrix away around and on the backbone.

As you see, the rock left on the fish consists of a very very thin layer that is hard to remove.

I mean in between the fish bones, there is not even enough space to insert an art gum eraser..!

Dapalis1

The bones need to be imbeded in the matrix for strength and stability; if you undercut them, the bones will break and/or fall out. Try rubbing the area with an art gum eraser; this is standard prep for split-layer fish, and is also used to "clean up" 18" layer fish after removal of excess matrix.

[ebrocklds]

just scrub the surface of the fish with the eraser, following the ribs so you don't break them off. on smaller fish it is sometimes hard to not damage them when you are cleaning the last bits of rock off. even an air abrasive will blow off pieces of ribs. i have only cleaned the verts with an abrisive unit. i don't know of any other way to do it.

Brock

[Dapalis1]

just scrub the surface of the fish with the eraser, following the ribs so you don't break them off. on smaller fish it is sometimes hard to not damage them when you are cleaning the last bits of rock off. even an air abrasive will blow off pieces of ribs. i have only cleaned the verts with an abrisive unit. i don't know of any other way to do it.

Brock

Hi Brock,

You are right it's pretty hard to work on very small fishes like this one!

You mean you never use the air abrasive to clean the ribs or other small parts? Cause it would blow off pieces of ribs ..? So why do i need an air abrasive if it only works for the verts...?

The bones need to be imbeded in the matrix for strength and stability; if you undercut them, the bones will break and/or fall out. Try rubbing the area with an art gum eraser; this is standard prep for split-layer fish, and is also used to "clean up" 18" layer fish after removal of excess matrix.

What do you mean by "undercut them"? As you can see in the pictures i just tried to scratch the matrix away along the ribs to bring the skin to light. It turns out the skin is located underneath so i gotta "dig" a little bit deeper in between the ribs to bring the skin to light. It's pretty hard to go in between the ribs for such a small fish...and rub the skin in between...

Where can i get an "art gum" eraser?

Thanks,

Dapalis1

[coprospector]

Are you kiding me ? 1000 bucks for these tools. Wouah That's a lot of money. :rolleyes:

Do you think that it is worth buying them for someone who is going to prepare mostly fossil fishes from the Green River?

Or should i settle for the chainsaw files for now?

I work in a paleo lab in western colorado.I use a #3 air scribe.I bought mine from paleo tools.com.this tool works very well for extra fine matrex removel.useing a very light touch.The tool was around 350.00 good price for what it does.I also use a head magnifier that is almost a must.I hope this helps every one.jayincolorado.

[coprospector]

Thanks ebrocklds

Actually i just received the package. I purchased the Microjack 5 along with a very thin and long stylus.

I attached some pictures of the work that i have done so far on the fish.

As you can see the head came out disarticulated. There is still a very thin layer covering the specimen but it is extremely hard to remove.

How do you usally do to remove that very thin layer in between the fish bones...? Cause it takes a while to chip it away with a chain saw file.

And moreover in some areas like on the head, the tool is not very convenient to chip in between the bones...because of their shape!!

Let me know what you think about that!

Thanks,

I use a #3 micro jack and go slow taking my time.I work in a paleo lab in western colorado.I use the scribe on fish and teeth.a head magnafier(sp) is a must.jayincolorado

[DDD]

I'm very new to this, learning to prep Green River fish after a trip to Warfield Fossil Quarry back in late August. I started my first attempts to remove the matrix covering the fish with a Dremel electric engraver, replacing the bit with a much finer, sharper one from an engraver pen. That worked fairly well, especially working under a binocular microscope and proceeding very slowly and patiently. Even then, though, I noticed that the vibration from the engraver, even when turned to the lowest/finest setting, caused some damage to the finer details in the fossil.

After talking with Bill Murray at PaleoTools I met with him at the Denver show a few weeks ago and got to try out a few of their air scribes. Within a second of touching the Micro Jack to one of my specimens I was sold. I bought a PaleoTools Micro Jack #4 on the spot. I'm powering it with a Craftsman 6-gal, 150-psi compressor (~$169) and that works just fine.

Here is my first 'practice' prep on a broken Diplomystus with the Micro Jack.

Dan

[tracer]

by golly, i think you've got it!!

[joshuaborcher]

well i do my own work depending on how hoard the rock is you might be abel to get away with what i use I use a dremal with a small wire brush attactment on the slowest stting

[Dogdare]

I realize this is a fairly old thread, but I have a question more related to preparing the matrix (if I'm using the proper term), rather than the fossil itself. Many of the fish fossils that my son and I exposed from the Blue Moon Quarry will take little prep in order for us to be happy, but I was wondering about reducing the size of the surrounding matrix around the fossil so that it can be properly displayed, either in a frame or a display box.

I thought I read somewhere that the stone can be easily cut with a jigsaw. I have a number of partial fossils, exploded fish fossils,...so I don't mind some experimentation, but I thought I'd ask first to shorten the learning curve.

thanks,

Herb

[Auspex]

Herb,

I have trimmed that shale with nothing more than a hacksaw. If you have lots to do, you could rent a tile saw from a home improvement center to save time and effort, but a chrome-molly, 18 tooth hacksaw blade is just a couple bucks, and it goes through soft shale pretty quickly.

[Malcolmt]

I currently cut these with a diamond bladed tile saw. I have also cut them with a hacksaw before I owned a tile saw.

[Dogdare]

Thanks guys, it confirms to me that I can cut it fairly easily. At this point I'll make some practice cuts with my existing tools and see how it goes. I appreciates the responses.

Herb