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[DE&i]

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Edited October 2, 2014 by DarrenElliot

[tooth_claw]

Good save! The paraloid reacts with the water in the PVA to make the white skin that you saw- I see this in the field on moist/damp fossils. You can just treat the specimen with Paraloid the same way that you used the PVA, it will dry rapidly, be resistant to ambient moisture and is easily reversed (as you found!) if it is too shiny or if a bit needs to be reglued. Your fossil just needs to be dry before the paraliod will soak in (acetone can 'chase' out moisture in some cercumstances.

I loves me some Paraliod, it is such a good, dependable product.

[DE&i]

I really appreciate your input, first hand knowledge. So much material information is difficult to find. I think the major mistake I was making was due to trying to keep the costs down. I had this vision that if I applied as much diluted PVA as possible it would increase stability to the bone.Then only requiring a thin coat of paraloid.

Do you think if I apply paraloid straight onto the bone it would soak in,resulting in multiple coats needed.

Regards,

Darren.

[tooth_claw]

Yep- I treat all of our fossils with paraloid dissolved in acetone.

A quick application of pure acetone will break the surface tension and allow the paraloid mix to penetrate into the bone, try to repeat the process until the paraliod has penetrated deep into the specimen to avoid a shell of paraloid surrounding unconsolidated bone (I have seen specimens where this has happened, you can hear crunchy nioses as the crumbled internal bone sloshes around in the 'shell'..it is horrible)

Paraloid consolidation can begin to look a bit dry after a few months, you can simply re apply the mix and let it go again, it is endlessly re-dissolvable and extra applications do no harm at all.

Paraliod mixed into a thick sludge works very well as a glue, mixed thin it penetrates bone faster. You can re dissolve dried paraloid residue in your jar by adding more acetone. You can thicken a thin mix by adding more paraliod.

Actually, a lot of this has been said in the forum before, look up Paraloid in the Preparation section and you will find out more.