Help in Repairing Keichousaurus

[keich1]

I've owned a sweet Keich that came from China via Germany in the mid-20th century.  In our last move, it was broken. The photos attached show the main break point with missing vertebrae. The next photo shows the cross-section, just for the sake of proving authenticity (you can see how the matrix striae curve around the bone as well as the details of the spine in cross-section). As I was lucky enough to find the missing vertebrae I placed the pieces together in the next photo and held the pieces in place in the final photo to show how it should look when finally repaired.  My question:  What adhesive should I use to repair the matrix and is there something different I should use to glue the delicate piece with the vertebrae into place?  Many thanks to all for any experience/advice.

[Huntonia]

Well superglue is a favorite of many as a convenient and strong adhesive. It's worked pretty well for me so far but I've never used it on something this large. Perhaps an epoxy of some kind would work. Some of our members with more experience will probably be of more help.

[keich1]

Thanks Huntonia. I didn't want to try Superglue because:

1. I don't know its long term effect on small bones and

2. I'm not sure if it will hold porous matrix together.

We'll see what others say since I don't want to experiment. Appreciate your input!

[Bobby Rico]

I would use a a good quality think superglue. Place a little bit of glue along the middle of the break . Too much Glue and it will keep the join apart just like bricks and mortar. Clamp the join and leave for a day.. I also would consider backing the plate with a board or mesh and thin  resins to stop future damage. Good luck 

 

Do not use any expanding glues they will do no good.

[minnbuckeye]

28 minutes ago, keich1 said:

2. I'm not sure if it will hold porous matrix together.

 

For what is is worth, I just visited @sseth's fossil fish quarry. Trying to be ahead of the game, I brought a bottle of super glue to quickly repair damaged fish. Multiple attempts were made during the visit, all ending in failure. The matrix is very porous and would not allow the glue to join the pieces. Once at home, Paraloid was applied to the fish to preserve them. When dry, super glue was applied to the ends. This time, a great adherence took place. So if the rock is porous, maybe seal the end before gluing. 

 

 Mike

[Ptychodus04]

Superglue will hold this matrix together. I have used it on broken keichosaurs in the past. Glue the small bone fragment on and then apply glue to the larger joint. Clamp the two pieces together and let them sit for a day clamped. This will form a very strong bond.

[ParkerPaleo]

If your matrix is really porous, you can use a thin/penetrant superglue on the edge first, then bond the pieces with the thicker epoxies.  

[keich1]

54 minutes ago, ParkerPaleo said:

If your matrix is really porous, you can use a thin/penetrant superglue on the edge first, then bond the pieces with the thicker epoxies.  

 

3 hours ago, Bobby Rico said:

I would use a a good quality think superglue. Place a little bit of glue along the middle of the break . Too much Glue and it will keep the join apart just like bricks and mortar. Clamp the join and leave for a day.. I also would consider backing the plate with a board or mesh and thin  resins to stop future damage. Good luck 

 

Do not use any expanding glues they will do no good.

Great ideas. Fiberglass mesh? Thanks!

[keich1]

56 minutes ago, ParkerPaleo said:

If your matrix is really porous, you can use a thin/penetrant superglue on the edge first, then bond the pieces with the thicker epoxies.  

Will give superglue a try first and if it just gets absorbed add epoxy. Thanks for the idea!

[keich1]

1 hour ago, Ptychodus04 said:

Superglue will hold this matrix together. I have used it on broken keichosaurs in the past. Glue the small bone fragment on and then apply glue to the larger joint. Clamp the two pieces together and let them sit for a day clamped. This will form a very strong bond.

Fantastic info! Just what I was hoping for. Thanks so much!

[Bobby Rico]

45 minutes ago, keich1 said:

 

Great ideas. Fiberglass mesh? Thanks!

I added to the back of my keichousaurus over 15 years ago. Sorry couldn’t remember the name of the material I used was called but fibreglass probably very similar. I can add a photo?

[keich1]

8 minutes ago, Bobby Rico said:

I added to the back of my keichousaurus over 15 years ago. Sorry couldn’t remember the name of the material I used was called but fibreglass probably very similar. I can add a photo?

Please do share a photo! Thanks.

[dsalles]

I would only use glass fiber fabric for smaller fossils. I once wanted to reinforce the back of a nice Aspidorhynchus from Solnhofen. The slab was very thin and the fish was about 50cm long. Polymers (glues) shrink when hardening - about one cm per meter.  The result was that the slab curved like a bowl. 
For large surfaces, it is better to use a sandwich construction: Stone slab - reinforcing adhesive layer (possibly with gas fiber fabric) - stone slab (or if I don't have a suitable matrix, take plywood or a cement fiberboard).  Then thin slabs do not warp.

 

[Ptychodus04]

IMHO, this repair is so small that adding a backing is not needed. A strong glue bond and easy treatment in the future should be more than adequate to keep this piece together indefinitely.

[keich1]

 

On 8/5/2020 at 4:12 PM, Ptychodus04 said:

IMHO, this repair is so small that adding a backing is not needed. A strong glue bond and easy treatment in the future should be more than adequate to keep this piece together indefinitely.

Thanks to all for the advice. I used evo bond super glue. The results were not as elegant as I would have liked, but more than adequate. Hopefully this will last another 250,000,000 years! See photos.

 

Edited August 7, 2020 by keich1
Additional photo

[Ptychodus04]

3 hours ago, keich1 said:

The results were not as elegant as I would have liked, but more than adequate.

This isn't an easy thing to master. One would think that simply gluing two pieces together would be a no-brainer but it takes a bit of practice to really get the joints tight on a consistent basis.