Trilobite Prep

[Ptychodus04]

I just finished up a prep for @Fossil-Hound of some E. rana trilobites from Penn Dixie. It was a lot of fun and they were cool to prep. I got to really put my Micro Jack to work!

 

Here are a few pics of a before and after.

 

[DevonianDigger]

Nice work! Those look familiar!  

[Fossil-Hound]

@Ptychodus04  @DevonianDigger You're one to talk! 

[RJB]

Nice job.  I myself find that the smaller the prep job the less I want to do it?

 

RB

[Ptychodus04]

1 hour ago, RJB said:

Nice job.  I myself find that the smaller the prep job the less I want to do it?

 

RB

 

The small jobs are often not worth the tooling up time for sure. This was not one of those. Jason sent me a big box of these to prep. I put around 15 hours into them.

 

Of course, I've never turned down a prep job because it was too small. In fact, I've never turned down any prep job!

[joshuajbelanger]

Very coo!  I just found a ton of calymenid trilos from Kentucky, and as soon as I get a day off I'm gonna start prepping them.  These are my first trilos, any pointers?

[Ptychodus04]

1 hour ago, joshuajbelanger said:

Very coo!  I just found a ton of calymenid trilos from Kentucky, and as soon as I get a day off I'm gonna start prepping them.  These are my first trilos, any pointers?

 

Go slow. Rushing will ruin a fossil. What tools to you have? What matrix are the trilobites in?

[joshuajbelanger]

I have air abrasion and air scribes-problem I think is the matrix.  It's in Kentucky Dolomite.  Seems to be the stickiest matrix I've ever dealt with.

[Ptychodus04]

Do you have a binocular microscope? I have found that 10x under the scope is wonderful for prepping sticky matrix with a small scribe or abrasive.

[RJB]

No preparator likes 'sticky'!!!   Im with kris, take your time and be patient.  Put it aside once you get tired or your eyes start going wierd on you and give it a few days.  Always looks better with a new look at it a day or so later.

 

RB

[joshuajbelanger]

Yes sir, I have numerous stereo and regular microscopes.  I haven't used a scribe under it yet, I usually do really delicate work by hand with the scope, but I'll give it a try.

 

yeah, I'm used to really loose limestones, so this dolomite is definitely something new.

 

i don't use the abrasion too much, but I can see where it's going to be useful here.  What do you guys usually run your psi at for something tough?

[Ptychodus04]

I'll push it as high as 90 psi.

[FossilSloth]

On 7/9/2017 at 3:14 PM, Ptychodus04 said:

Do you have a binocular microscope? I have found that 10x under the scope is wonderful for prepping sticky matrix with a small scribe or abrasive.

Can you give me an example of a binocular microsope setup? Like the model of microscope, and how it's set up, relative to the air blasting cabinet? 

[Ptychodus04]

My scope is from Amscope. I don't recall the model number but it is a dissecting scope on a small boom stand.

 

I don't currently have a blast cabinet. (Have not been able to sneak that into the budget yet) Mist if the abrasive work I do is pretty small scale and shirt duration. So, I just stuck my shop vac hose by the piece and suck most of the abrasive up that way. Larger scale abrasion is done outside.

 

If you are using a microscope with a cabinet, you would want your objective lens to be very close to the glass if the cabinet in order to give the most working room inside the cabinet.

[Malcolmt]

Here is some rough drawings for a blast box that I use, I did these up for a friend a few years ago.

 

You generally use a barlow lens to increase the working distance for your scope but it reduces the magnification  proportionally.

 

BlastBox Page 2.pdf

 

BlastBox Page 1.pdf

[FossilSloth]

I have to change the plexiglass on my blasting box frequently so I wouldn't want a microscope lense to be anywhere near it 

[Ptychodus04]

What if you switched to plate glass instead of plexi? You wouldn't need to change it out as it doesn't scratch nearly as easily.