Giving fossils wet look

[connorp]

I only prep with hand tools at the moment so I can rarely get all the matrix off a fossil. However, when wet, the matrix is usually impossible to see and the fossil looks very well prepped. Is there a coating I can use to keep the fossil looking wet? I’m looking to try this on trilobites in particular.

[Uncle Siphuncle]

I like low sheen, or none.  When I want to accent a fossil, I coat it with beeswax dissolved in turpentine.  You can adjust concentration to control gloss.  If you go a little heavy, hit it with a hair dryer and wipe with a paper towel.  

[Natalie81]

Linseed oil is also an option. Mostly we give it a little layer of paraloid B72, that gives a slightly darker color and strengthens the fossil

[Ptychodus04]

I wouldn’t use an oil as it isn’t easily reversible. A coating of Paraloid B72, Butvar B76, or PVA B15 will do it and is easily removed.

[Kane]

If the colour matches, shoe polish and a quick buff is commonly used in the fossil trade to mask scuffs/dings and bits of matrix. It is reversible. Some Ordovician trilobites from Russia have been treated with floor polish to give them a sheen. In some cases, abrasion with sodium bicarbonate will polish the shell surface, which might be a more natural route as it is derived from the normal operations of preparation.

[Uncle Siphuncle]

Here is an example of an ammo I hit with beeswax.

[connorp]

2 hours ago, Kane said:

If the colour matches, shoe polish and a quick buff is commonly used in the fossil trade to mask scuffs/dings and bits of matrix. It is reversible. Some Ordovician trilobites from Russia have been treated with floor polish to give them a sheen. In some cases, abrasion with sodium bicarbonate will polish the shell surface, which might be a more natural route as it is derived from the normal operations of preparation.

I actually just ordered some sodium bicarbonate yesterday as it was recommended as a good abrasive to use with a stiff brush. So we’ll see how that goes. I also do need to stabilize the trilobite in question, so hopefully Paraloid gives it the sheen I’m looking for.

[Kane]

14 minutes ago, connorp said:

I actually just ordered some sodium bicarbonate yesterday as it was recommended as a good abrasive to use with a stiff brush. So we’ll see how that goes. I also do need to stabilize the trilobite in question, so hopefully Paraloid gives it the sheen I’m looking for.

For sodium bicarb, the grocery store baking soda is perfect. Do show us the trilobites prior to your chosen treatment plan as some may not stand up well to stiff brushing (risk of breaking or scratching). 

 

Oh, and I forgot to mention the cheapest (and least appealing) method of all: Nasenfett. It's a very old "technique" of rubbing the sides of your nose (not the inside!) and applying the skin oil to the specimen. 

[connorp]

It actually snapped in half last night unfortunately. I was able to glue it back together pretty well though. I’m going to stabilize all the surrounding matrix first before I touch it again and then slowly go from there.

[connorp]

From what I read I dissolved 25 g of Paraloid B72 in 500 mL of acetone. Is this the right ratio for consolidation? And should I just apply it to the surface of the rock, or let it soak (and for how long in that case)?

[Natalie81]

You need a thin solution.  I apply paraloid B72 with a brush, you can repeat after drying if necessary

[connorp]

On 6/5/2019 at 7:12 AM, Natalie81 said:

You need a thin solution.  I apply paraloid B72 with a brush, you can repeat after drying if necessary

Yup. I ended up trying the ratio I mentioned above, and the piece seemed fully consolidated (or at least enough) within 3-4 minutes.