What's the Best Glue for Fossil Repair?

[ConnorR]

Hi everyone! I just got a 20" mosasaur (Prognathodon?) jaw piece in the mail, and unfortunately it was split into 3 pieces. Fortunately, the breaks are fairly clean, with a few small fragments broken off, and the pieces fit right back together. If anyone has experience with this sort of thing, what kind of glue do you think will work the best, and what application method would you use?

 

 

Edited November 30, 2022 by ConnorR
fixed error

[rocket]

oooou, bad, but it will survive!

First check if the stone is fragile and sandy (sometimes the jaws are). If, you need to stabilize with very runny superglue. Afterwards it is possible to fix it with superglue (not so runny) when it fits perfect. This is how I repaired breaks like this

[hadrosauridae]

I recommend A super thin super-glue product from Paleo Bond, called PB-02.  You will only needs a few drops.  First, drop the glue into each broken end, let it soak in, then set.  After each broken end is consolidated, then you should only need a drop or 2 to glue each piece back. 

 

I typically hold parts together with a tiny amount of pressure then count to 60.  It would help to blow on it also (water is a catalyst to start the bonding).  After its reassembled and the glue has had time to set (give it 24 hrs for full cure), then I would go over every crack you can see and put in PB-02.   Lastly you can also do a complete consolidation with Butvar B-76 dissolved in denatured alcohol.

 

PS- after looking at your pic enlarged, I would recommend finishing the prep of this before gluing!  The main break looks to be along an existing separation, and there are others large breaks with sand glued into them.  If you super-glue the sand, it will make it much harder to finish the prep later.

Edited November 30, 2022 by hadrosauridae

[BobWill]

I agree with using superglue. I also have used a product called Q-bond that includes superglue with a filler to use for any gaps you have. I have heard of people using ground up matrix for the same purpose but if you don't have any this stuff is great. Mechanics use the black filler to repair engine blocks since it holds up to extreme heat. It also comes with a gray filler that can be used on other items. You can build up a clay dam to hold the powder in place and just drop some of the liquid type of glue onto it and let it soak in. Add it in layers if the gap is large, then paint it if necessary. It sets very quickly and gets very hard. I found it at an auto body paint supply store.

[ConnorR]

I have 16 ounces of Starbond Medium laying around, so I think I should use some of it. But per hadrosaur's and rocket's advice, I'm buying some super thin CA to consolidate the material first. I'm doing final surface prep in the meantime, but there's some consolidated crushed matrix that's holding it together in some places, so I think that I'll leave that alone.