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[Ranger_Dave]

I have a few, and am going to get some more tomorrow, leaf impressions in sandstone. There might be some fish there too. It's only 70 million years old and the sandstone didn't quite make it to the stone part yet. The specimens are very fragile and crumble if handled roughly. So, my question is, does anyone here know what I can do to make them a bit less fragile? I know that many fossils are saturated with some kind of liquid to harden them. What do they use?  Thanks.

[rocks2dust]

Paleobond is what I've seen generally recommended in Internet chatrooms for fragile material. It is removable, which is very important to many collectors. There may be other, similar brands out there by now. You'll want to keep with the fossil a note of which stabilizer you used, in case it needs to be removed in the future. The Smithsonian uses polyvinyl butyral in acetone, which may be cheaper (see their fossil prep web page) and is also easily removed.

[Ranger_Dave]

These are just leaf impressions, not of much value. The polyvinyl butyral and acetone sounds affordable. I might try that. I'd still include a note saying it was stabilized if I ever sell any.

[Ranger_Dave]

From the research I've done in the past few days, I think PVA (polyvinyl acetate or white glue) would be the best for what I'm trying to do. The ratios have ranged from 3 parts water to 1 part glue up to 5 to 1. Since I'm trying to stabilize sandstone the more diluted, and thinner, ratio sounds like it might work. I have some plain sandstone, from the same place, that I'll experiment with. I'll post pictures next week.

[peruano]

Back in the day, we used diluted white glue to stabilize fragile whale bones for a museum exhibit.  The bones had been buried for 20 years and  in places where the bone was highly vascularized or very porous, it tended to crumble on contact.  We diluted the glue and just kept drizzling it in until no more was absorbed.  Because of all the water in the glue it dried very slowly allowing it to penetrate into the bone before drying completely.  The nice thing about white glues is they can be removed by soaking if needs arise. 

[Ranger_Dave]

Thanks. This seems a cheaper way than the new superglue formulations and less toxic than mixing with acetone. The leaf impressions are very crumble. Not much pressure and they fall apart. I'll try the white glue and water mix on Tuesday or Wednesday. Now I just have to find a paleobotanist to ID them for me.

[Redrummd]

How about that liquid wood hardener sold at Home Depot?  It really works on porous wood so I suspect it would do the same to sandstone....

[Ranger_Dave]

Interesting..... I'll be at Home Depot this weekend. I'll look at it. I got some plain sandstone to practice with.

Today I soaked, for at least 2 hours, a few pieces in a 4 to 1 ratio of water to glue. The pieces appeared to be soaked through. I tried to break off a corner and it was very fragile. That was wet. I'll see how it hardens overnight.

[Ranger_Dave]

It worked. In the morning the pieces were.... well.... rock hard. 

[rocks2dust]

As most fossil preservation sites point out, white glue does yellow and shrink over time and though it can be dissolved by soaking in water, doing so (or even accidently getting wet or repeatedly exposed to wide swings in humidity) can cause further damage to some fossils, ripping it apart from its re-expanding. It is the cheapest solution if you aren't concerned about long-term preservation.

[Ranger_Dave]

These are just leaf impressions, not a T-Rex skull. I don't believe they are worth the expense of the other methods. Now, if I got lucky and found a nice, complete, fish fossil I would definitely use the better methods.

[Jhon P]

I think this is what Michael is talking about. I have stabilized buckeye burl wood for knife scales. Works best under vacuum

[Ranger_Dave]

Interesting.... I do some woodwork too. That might come in handy for several things.

If anyone wants plans for a very cheap, and easy, bird house, let me know. It's  made out of one dogeared cedar fence board.

[irockhound]

You can buy sodium Silicate by the gallon on the web.  It used to be called Water Glass in the old days.  I does a good job at penetrating porous materials and from reading on it, if you heat it afterwards it can crystalize like Quartz.  They used to dip eggs in it to seal the shells and preserve the eggs longer back before a lot of refrigeration was available.  I would imagine it would work well for fossils.