Prepping a Dinosaur Vertebrae

[Welsh Wizard]

Hi

 

I’ve recently acquired this dinosaur vert. I’ve started prepping it but it’s a right pain. The bone is a similar colour to the matrix, the matrix smears and the bone is soft. I’ve been using s combination of pens and dolomite but it’s really tough to work out where the matrix ends and the bone begins. Any help is welcome.

 

I think it’s an iguanodon dorsal but may be from an ankylosaur. Time will tell.

 

 

 

 

[Welsh Wizard]

Progress so far

 

 

[Manticocerasman]

looks like a tough one, is chemical prepp mabey an option? is the matrix limestone?

 

 

[Ptychodus04]

That looks like a right foul pain in the posterior! What kind of magnification are you using? I've found 10x to be helpful when there's no good separation between matrix and bone. Also, dropping a bit of Paraloid on what you know is bone can help the task. It will darken the bone a bit so it is easier to see what's matrix and what's bone.

 

I've also found that lowering the angle of your scribe helps when the matrix is soft and sticky. You are basically rubbing it off.

[JohnBrewer]

Don’t envy you, Nick!

[Welsh Wizard]

7 hours ago, Ptychodus04 said:

That looks like a right foul pain in the posterior! What kind of magnification are you using? I've found 10x to be helpful when there's no good separation between matrix and bone. Also, dropping a bit of Paraloid on what you know is bone can help the task. It will darken the bone a bit so it is easier to see what's matrix and what's bone.

 

I've also found that lowering the angle of your scribe helps when the matrix is soft and sticky. You are basically rubbing it off.

 

Thanks

 

Thats really helpful

 

No magnification yet but I do have a magnifying light which I could try. I think the challenge is getting some contrast. I was thinking of covering in KOH and leaving to see if I could get the smeary clay of.

 

Paraloid is really weird as the bone seems to suck it up and look the same but I keep adding it.

 

Using the scribe like an eraser is a good idea which I’ll try.

 

Ill keep you updated as I progress although it will be a slow process.

[Welsh Wizard]

3 hours ago, JohnBrewer said:

Don’t envy you, Nick!

 

Thanks John

 

Its good fun when it’s over. I’m not really a prepper but you do switch off from things and it’s quite relaxing.

 

N

[Welsh Wizard]

8 hours ago, Manticocerasman said:

looks like a tough one, is chemical prepp mabey an option? is the matrix limestone?

 

 

 

Thanks for the reply 

 

The matrix is largely clay - from soft clay to rock hard clay with pyrite. I was thinking of given KOH a try

[Ptychodus04]

@Welsh Wizard, KOH should do well on the softer clay for sure. Be careful as it will also get into any cracks in the bone and remove the clay. If that’s what’s holding the very together, you’ll end up with a pile of bone chunks. I would not pile it on and let it sit for hours before checking it.

 

Also, you you have experience with strong bases? They can be more dangerous than an acid because you don’t feel their effects as quickly.

[JohnJ]

10 minutes ago, Ptychodus04 said:

@Welsh Wizard, KOH should do well on the softer clay for sure. Be careful as it will also get into any cracks in the bone and remove the clay. If that’s what’s holding the very together, you’ll end up with a pile of bone chunks. I would not pile it on and let it sit for hours before checking it.

 

Also, you you have experience with strong bases? They can be more dangerous than an acid because you don’t feel their effects as quickly.

Presoaking in water (if practical) can limit the intrusion of the KOH or any buffered acids used to neutralize the base.

[Welsh Wizard]

Thanks John and Kris

 

Ive no experience of using KOH for fossil prep but years of experience of working with strong acids and bases. I am a Chartered Chemical Engineer but haven't worked directly with chemicals for quite a few years.

 

I must admit I do try to avoid chemicals at home as it's not just the handling, it's also the storage and disposal, all of which can give you a headache.

 

Nick

[Welsh Wizard]

Trying out Potassium Hydroxide flakes.

 

[Welsh Wizard]

Hi all

 

Just a quick update.

 

The KOH had no effect on the matrix so I asked my friend Craig Chivers to have a look at this as well when he prepped the ichthyosaur.

 

He’s made some great progress but during prep work it’s still proving very difficult to distinguish the bone from the matrix. We think that matrix is a phosphate based cement that has bonded and blended with the bone surface.

 

Anyway, with that in mind, here are some further pictures.

 

Nick

 

 

 

[Natalie81]

10 hours ago, Welsh Wizard said:

Hi all

 

Just a quick update.

 

The KOH had no effect on the matrix so I asked my friend Craig Chivers to have a look at this as well when he prepped the ichthyosaur.

 

He’s made some great progress but during prep work it’s still proving very difficult to distinguish the bone from the matrix. We think that matrix is a phosphate based cement that has bonded and blended with the bone surface.

 

Anyway, with that in mind, here are some further pictures.

 

Nick

 

 

 

Looking great!