Bones extraction

[Pixpaleosky]

Hi,

I am in need of advice in order to remove these bones from the field.

For scale, the rib size is about 30cm and is going to the top pf the picture.

My issue is that the matrix is a mix of sand and clay, very soft, and the bones are extremely fragile.

Ideally i would like to remove them with the matrix but it would need to be stabilized otherwise it will fall apart.

I am thinking about putting a lot of starbond on bones and matrix all around to solidify everything ? But then how to remove the plate ? By the way is it possible to remove matrix sticking to the fossil if it has been "starbonded " ?

 

[Troodon]

Currently on a field trip and several have removed big hadrosaur ribs around 90 cm using plaster.   The best technique is to clear the matrix around the rib and pedestal it.  Use an adhesive where cracks occur.   Cover the rib with aluminum foil with an overlap on the sides.   On light items, like your rib, a quick drying plaster roll wrap will be fine and is easy to apply.  A couple of layers works fine try to get it a bit under the rib so it grabs the bone.  After the plaster hardens undercut the rib as much as possible and it should come out in one piece 

 

Starbond is a good stabilizer but one of the hardest to remove if heavily applied and I dont recommend it.  It will come off but takes lots of work.  A field adhesive like PaleoBond PB4417 is designed to be field applied with easy removal but the plaster technique is best 

 

[Ptychodus04]

Matrix stabilized with Starbond can either be scribed off, softened with acetone and picked off, or abraded off. None of the processes are enjoyable in any way. I often have to deal with this as sometimes, fossil bone is too friable to adequately stabilize with Paraloid during prep. I apply Starbond, allow it to set and attack it with a combination of scribing and abrasive. Granted, this is only where I have no other option and only in very small areas.

[Pixpaleosky]

Thank you @Troodon and @Ptychodus04 Do you think i can grab the piece of bone on the left at the same time with a larger pedestal at the top ?

what kind of fabric is best for the plaster ?

For the cracks adhesive on the field, would you recommend pb4417 or pb0002 ?

I have a small bone coated with starbond with a bit of dirt to remove on its head. I could use acetone plus scribbing ?

[Ptychodus04]

You can make the field jacket as large as you can easily handle. You want to remove as much matrix as possible and still have a stable pedestal.

 

Strips of burlap soaked in plaster are cheap and effective. You can buy ready made rolls that have plaster in the burlap and all you do is get them wet. As stated above by @Troodon make sure to cover the exposed bone with foil to keep the plaster off. I like PVA B15 or Butvar B76 for a field stabilizer personally. You can use Paraloid B72 but it is harder so, not as easy to remove later. I’ve never used the Paleobond stabilizers.

 

For your small bone, can the fossil withstand the vibrations of the scribe? What size scribe do you have? How small is the bone? Is it robust or rather gracile? Well preserved or poorly preserved? This is hard to answer because there are so many variables.

[Troodon]

If you don't want to use ready made plaster rolls for your specimen,  like Ptychodus64 said burlap straps with plaster works great and was used in the rib photo.  The rolls for small applications are easy to use.   I use PB2 on cracks where strength is needed and the other where a wider application is needed.  Minimize the coverage where PB2 is used helps in prepping.  Acetone softens all these adhesives.

[Pixpaleosky]

Many thanks to both of you, i will let you know how it went, I shall go back on the field next month and i will certainly have a ton of questions again :))

For the small bone i will make a picture once unwrapped soon