Advice for how best to glue back a scapula

[NevadaHunter]

Hi all, I have this slab that is composed of a mix of sandstone and clay matrix. One side is more heavily composed of sandstone while the other half is more clay. In the sandstone side is a well preserved mandible from Aepycamelus sp. seen from the lateral aspect. It was crushed along the sagittal plane allowing us to see the medial, lingual aspect of the other side of the mandible from behind. Because the mandible is crushed, I feel this piece would be best suited at a slab specimen, if you guys have any opinion please share. Now, the clay rich side appears to not have preserved as well but there is an intact scapula that was already cracked badly and after jacketing and transport, the pieces shifted a bit. How best should I address this? I was thinking using paranoid B-72 but was hoping if any of the masters here have any insight or advice. 

[Mike from North Queensland]

Best of luck. my only suggestion is start from best end clean and debris from between cracks and glue as you go remembering that some pieces will need to be reattached before others or will never go into place. Lots of patience and at least its all there not spread well by a bulldozer like one of my skull projects where I only found half the bits after hours of seiving loose dirt.

   

[Ptychodus04]

I would suggest a 50% B72 solution (1 part acetone to 1 part B72 by weight) to glue these pieces together. It will take some time to fully set but will provide a very strong bond. Stabilize the bone first with a 50:1 ratio of B72 (50 parts acetone to 1 part B72) this gives a roughly 2.5% solution. It will soak deeply into the bone. Then, apply the 50% solution to one sided of the break. join the two pieces together and slightly pull apart and put back together a couple f times. this creates tack and allows the B72 to hold tighter. Allow the piece to fully set before moving on to the next piece. You can work in sections (taking into account the advice from @Mike from North Queensland). Don't work yourself into a place where your combined pieces don't fit together. If you do, simply brush a bit of acetone onto one of the joints to release the B72.

 

This will result in a far stronger bond than if you employed cyanoacrylate and it is indefinitely reversible in the event you ever needed to take something apart.

 

For the cracks in the mandible, drop some 2.5% solution into them to stabilize the edges of the bone before you prep it to keep it from crumbling.