First “prepped” echinoids

[Shaun-DFW Fossils]

I am new (12-14 months) to hunting for fossils and even newer to trying my hand at prep work. I have zero tools and I’ve mostly dabbled with a few air scribes doing volunteer work cleaning dino bones at southwestern Adventist university, who has a massive collection. But my friend let me practice with his air abrasive tool, which I had not used before. I was pretty happy to get these three hemiaster whitei echinoids prepped after finding them in Fort Worth. He advised me to hold the tool at least an inch away and do slow horizontal back and forth motions to blast away the tiny particles of matrix (and a few larger chunks) I had to free up. I managed to not chip any of them, thankfully! I will be trying my hand at some larger macrasters next. One of them still needs just a little work near the bottom. 

[Wrangellian]

Looks like you did pretty well! It's tempting me to get into prepping, but on the other hand I know it's not cheap, needs space, and practise, and the things I have that need prepping will probably be more difficult than these echies. Anyway, keep at it.

[Shaun-DFW Fossils]

38 minutes ago, Wrangellian said:

Looks like you did pretty well! It's tempting me to get into prepping, but on the other hand I know it's not cheap, needs space, and practise, and the things I have that need prepping will probably be more difficult than these echies. Anyway, keep at it.

Thank you! I agree with your assessment..until I have more time and space (and money), I’m planning to mostly share/donate in exchange for the ability to use others equipment for now. Nothing is free, that’s for sure!

[Wrangellian]

Whatever you can do to make it work. 

Nothing is cheap! (at least nothing that's worthwhile is cheap)

[FranzBernhard]

8 hours ago, Wrangellian said:

Nothing is cheap! (at least nothing that's worthwhile is cheap)

But the best things are free!

Franz Bernhard

Edited January 6 by FranzBernhard

[Wrangellian]

21 hours ago, FranzBernhard said:

But the best things are free!

Franz Bernhard

I don't know, I think that's more an exception than a rule. 

[hadrosauridae]

Very nice prep results!  Do you know what powder you were using for the air abrasion?

[Balance]

So is air abrasion just a tiny sand blasting set up? I’m imagining an air brush paint set up shooting baking soda through it?? 
 

Jp

[jpc]

35 minutes ago, Balance said:

So is air abrasion just a tiny sand blasting set up?

 

yes

 

I’m imagining an air brush paint set up shooting baking soda through it?? 

 

I think some folks here have created exactly that
 

signed, The Wyoming JP

 

[Jaybot]

What psi would you use with baking soda and a paasche airbrush style air eraser?  I'm trying to get started in air abrasion fossil prepping.

[Kane]

Depends on the matrix and the specimen. Not a good idea to exceed 50 psi, but I’ve done it many times on account of Paasche’s poor flow issues.

[Ptychodus04]

On 1/5/2024 at 8:24 PM, Shaun-DFW Fossils said:

He advised me to hold the tool at least an inch away and do slow horizontal back and forth motions

 

 

Good job on the prep. I prefer a slightly elliptical motion over a direct horizontal motion. This helps me catch stuff at slightly different angles and also keeps you from "burning" the specimen at the end of your linear motion. With an elliptical motion, you never stop moving the nozzle with abrasive flowing. Using a horizontal motion, you stop at each end of your stroke. You have to time the stop of your motion with cessation of abrasive flow in order to keep from hitting both ends of the line for a longer duration.

 

On a sturdy fossil, this isn't as big of a deal but on a delicate specimen, it's the difference between prepped and destroyed.

[Shaun-DFW Fossils]

3 hours ago, Ptychodus04 said:

 

 

Good job on the prep. I prefer a slightly elliptical motion over a direct horizontal motion. This helps me catch stuff at slightly different angles and also keeps you from "burning" the specimen at the end of your linear motion. With an elliptical motion, you never stop moving the nozzle with abrasive flowing. Using a horizontal motion, you stop at each end of your stroke. You have to time the stop of your motion with cessation of abrasive flow in order to keep from hitting both ends of the line for a longer duration.

 

On a sturdy fossil, this isn't as big of a deal but on a delicate specimen, it's the difference between prepped and destroyed.

Thank you for the insight! Sounds good!

[Shaun-DFW Fossils]

On 1/7/2024 at 8:36 AM, hadrosauridae said:

Very nice prep results!  Do you know what powder you were using for the air abrasion?

Aluminum oxide mixed with glass beads (I believe). And the oxide is reused so it’s even softer against the echinoids. Sorry for the delay, I don’t always get notifications despite my settings here

Edited January 8 by Shaun-DFW Fossils

[Ptychodus04]

18 hours ago, Shaun-DFW Fossils said:

Aluminum oxide mixed with glass beads (I believe). And the oxide is reused so it’s even softer against the echinoids. Sorry for the delay, I don’t always get notifications despite my settings here

Be really careful with that abrasive. Both of them are hard enough to damage all but the toughest invertebrate fossils.

[Shaun-DFW Fossils]

I was able to use the “sand blaster” where I volunteer at a local university (which has a big dino bone collection) on more echinoids, mostly hemiaster but some heteraster as well. They use dolomite, which I found to be too soft for the more dense clumps of matrix, but it worked great on echinoids with modest amounts of presumed sand caked onto the outer shell. Here are a few I prepped, the first batch I attempted to blast after the 3-4 individuals I prepped a few weeks ago. These are all from the same goodland formation spot. 

[Coco]

Very nice !

 

Coco

[Shaun-DFW Fossils]

3 hours ago, Coco said:

Very nice !

 

Coco

Thank you! 

[Shaun-DFW Fossils]

Here’s a pic with natural light. I didn’t like how my kitchen light worked out in the last pic. 

[SPrice]

Looking good. So now you're a preparator besides a Fossil Finder Extraordinaire.

[Shaun-DFW Fossils]

51 minutes ago, SPrice said:

Looking good. So now you're a preparator besides a Fossil Finder Extraordinaire.

Thank you! I’d say both are a work in progress, but it’s still easier for me to find them than to prep them!

[Coco]

Good prep !

 

Coco