Stabilizing Matrix

[xonenine]

I've enjoyed reading alot of the prep stuff, 'specially Terry Dactyl and 32fordboys threads.

I'd like to know a little bit about what people do w the hash plates or fossils left in clay/mud/shale when you want to stop them from drying out and crumbling, or seperating from the strata when they dry out.

Products for marble as has been mentioned sound promising, and so do the stabilizers I have looked up for fossil repair and rock/cab stabilizing.

Is it just better to claim your fossils from matrix like this or is there a generally accepted practice?

The most I've done with anything like this is brush on some diluted white glue.(My particular white glue left solidified residue that sparkled on the samples, very unsatisfactory attempt it was)

Thanks, Carmine

Edited December 15, 2010 by xonenine

[bear-dog]

To recieve the best help,you may want to add what type of matrix you want to stabelize.

[Terry Dactyll]

xonenine.... Ive seen fibreglass resin and matting used to good effect to stabilise matrix from the back...although i havent had to do it yet myself...

[xonenine]

Some of the stuff that becomes the most crumbly for me is composed of crushed fossils and crystals.

That was another question, really.I am encountering alot of matrix that seems to be all fossil and crystal.Is there a name for this?

But mostly I was wondering more about a penetrant type material, for the muddier shale I pull out most times right at water level, still wet and muddy.

And aslo to bring out the color in the thinner brachiopods.I have plenty of buffing tools, w a couple of dremels.Carmine.

Edit:being I can't work w air tools here, it's more than timely that I can trade a few hours when I like with a mechanic freind to plug in at his shop.Really looking forward to trying to pull some branching corals out of hiding, seems more affordable if I'm bartering compressor time and just buying a gun.

Edited December 15, 2010 by xonenine

[Terry Dactyll]

PS...You want to google Paraloid as well... which is plastic beads disolved in acetone at various strengths... that is used to stabilise lots of fossils and bone...

[xonenine]

Thanks, never heard of that one, I'll read, should have mentioned I'd read 'bout the BUTVAR a little, so far, too.

[John]

But mostly I was wondering more about a penetrant type material, for the muddier shale I pull out most times right at water level, still wet and muddy.

Wet matrix is a tricky problem. Both Butvar and Paraloid will turn white and not bond well if the matrix is wet.

One way to get around this would be to soak the fossil in acetone, assuming this won't break it apart. Acetone is very hygroscopic, meaning it readily absorbs water. Depending on how wet the matrix is, you may have to soak it in fresh chemicals more than once so that you can be sure the water is completely replaced. If you've successfully replaced all the water in the matrix, you can either allow the fossil to dry or begin to add a stabilizer like Butvar or Paraloid. Both stabilizers are soluble in acetone so they will penetrate even if the matrix is still wet with acetone.

On the other hand, if your fossil is both wet and crumbly or unstable, then you have the classic preparator's nightmare on your hand. There are chemicals used to stabilize wet wood and similar materials, but they are expensive and pretty hit or miss. Some are essentially water-based waxes, others are alcohol-based.

A lot of the time, professionals encountering this kind of situation just wrap the fossils in many layers of newsprint so that the water in the matrix can evaporate extremely slowly. They then set the specimens aside for as long as a year or more and, if done right, the resulting pieces have minimal cracking and breakage. Paleobotanists are big on this technique because almost any kind of penetrating sealant can damage the delicate leaves on a piece of matrix, making them harder, or even useless, to study.

[xonenine]

Thanks for so much info on the subject John, alot of these methods being described sound like alot of fun for me, having been a painter for over 20 yrs, 'mongst other things.I appreciate the answer.

[jpc]

Wet matrix is a tricky problem. Both Butvar and Paraloid will turn white and not bond well if the matrix is wet.

A lot of the time, professionals encountering this kind of situation just wrap the fossils in many layers of newsprint so that the water in the matrix can evaporate extremely slowly. They then set the specimens aside for as long as a year or more and, if done right, the resulting pieces have minimal cracking and breakage. Paleobotanists are big on this technique because almost any kind of penetrating sealant can damage the delicate leaves on a piece of matrix, making them harder, or even useless, to study.

I was gonna suggest exactly this. I've never done it myself, but I have heard from pros who have that this works well.