Paraloid/Acryloid question

[Wrangellian]

Can anyone tell me whether this kind of glue (B-72) will hold up under freezing temperatures? I had the idea to prep out one of my local shale fossils using the freeze-thaw method, but I have glue in the part of the fossil that I want to keep intact. I don't want to subject it to freezing temps if the glue won't hold up. The plan is not to soak the whole piece, just apply a bit of water on the (unglued) side I want to freeze, either outside this winter when it goes below freezing, or in the freezer.

[JohnBrewer]

That’s an interesting question. I’m looking forward to the answers too. 

[Ptychodus04]

It shouldn’t have any issues with freezing temperatures. Once the solvent has evaporated completely it should be quite stable. Granted, I have never tested this. You may want to glue a scrap piece and toss it in the freezer for a few days.

[Wrangellian]

I might do that... thanks

[oilshale]

I would guess the B-72 being stable, but if there are some hollow areas where the water can penetrate into it, it will break.

[minnbuckeye]

Living in Minnesota, cold temps are common. My  specimens that have B72 applied show no worse for the wear. Granted, I have been collecting for a total of 4 years. what will happen in the future is yet to be seen.

 

 Mike

[Wrangellian]

20 hours ago, oilshale said:

I would guess the B-72 being stable, but if there are some hollow areas where the water can penetrate into it, it will break.

I would hope that the glue has filled all the space but I guess pockets are possible. I intend to avoid water going anywhere near the glued part of the fossil.

 

12 hours ago, minnbuckeye said:

Living in Minnesota, cold temps are common. My  specimens that have B72 applied show no worse for the wear. Granted, I have been collecting for a total of 4 years. what will happen in the future is yet to be seen.

 

 Mike

You let your fossils be subjected to freezing temps?

[minnbuckeye]

I am "allowed" only so much to be displayed in the house. The rest is delegated to the first floor of my unheated barn. Again, no ill effects of the cold have been noticed. Hopefully that continues.

@Wrangellian

[RJB]

Hi Wrangellian, I have some fossils that were in a shed for 10 years here in Montana.  Got lower than -20 degree's at times in the winter.   I did use super glue and it has held up fine.  Ive never used B72 but am assuming that it would be fine too?  Good luck

 

RB

[Ptychodus04]

42 minutes ago, minnbuckeye said:

I am "allowed" only so much to be displayed in the house.

 

I think it’s tine to renegotiate the terms of your lease. 

[ynot]

9 hours ago, Wrangellian said:

You let your fossils be subjected to freezing temps?

I would think it is the moisture in the rock combined with cold that does damage. If the rock is dry the freeze should have no effect.

[Wrangellian]

I know, but if some have glue, I wonder how they would be affected. Guess I'll find out...

Also I've realized that bringing a cold fossil into the house is not such a good idea because it gets immediately wet from condensation!

[Wrangellian]

If anyone's wondering, I put a scrap piece with B-72 into the freezer for a few freeze-thaw cycles and it did not fall apart. Only when I threw it back onto the scrap heap did a piece break off, but I don't there there was much glue holding that part on.

BTW a rock sure does accumulate condensation on being taken out of the freezer back into the warm house!

[Ptychodus04]

On 11/29/2017 at 9:41 PM, Wrangellian said:

If anyone's wondering, I put a scrap piece with B-72 into the freezer for a few freeze-thaw cycles and it did not fall apart. Only when I threw it back onto the scrap heap did a piece break off, but I don't there there was much glue holding that part on.

BTW a rock sure does accumulate condensation on being taken out of the freezer back into the warm house!

 

That's a very good test. Warm air on a cold fossil... stinking latent heat of condensation.