Non glossy consolidation

[JohnBrewer]

Folks, I need an archival consolidant that doesn’t dry glossy. The problem is the plant material I want to protect from flacking is sorta clay/soft shale. Even 5% w/v Paraloid in acetone is giving a glossy appearance. Not too bad on the fossil but looks horrible on matrix and fossil. In fact to increase contrast I like it on the fossil. Coating just the fossil isn’t an option. 

 

@Ptychodus04 @RJB @jpc @Harry Pristis

[-AnThOnY-]

I've noticed on some of my things that butvar will cause a glossy appearance on the matrix at a lower concentration than on the the fossil itself.

[snolly50]

I have used "acrylic sealer" sold in crafts stores. This clear coating is available in a matte finish. It is marketed as a protective coating for floral and ceramic projects. However, it will still impart some gloss. I have used it on Green River fish. Any form of acrylic is generally eschewed by fossil folk as they fear "yellowing." Modern acrylics all tout themselves as "non-yellowing. I have fish plates coated 30 years ago - they look fine. I once used it on St Clair fern plates in an attempt to contain smudges from the dark matrix. This was a disaster. No smudges, but the lovely contrast between the white fossil and the dark matrix was greatly diminished. 

 

Good luck, your mileage may vary.

[Ptychodus04]

@JohnBrewer, I have 2 options for you. 1, if possible, coat the whole thing with Paraloid to stabilize then remove surface Paraloid from matrix using straight acetone rubbed on with a clean, lint free cloth. This usually has a positive outcome but is labor intensive.

 

Option 2 is for me to ship you some PVA beads that you can dissolve in denatured alcohol. The solution making process is longer as the alcohol is a weaker solvent than acetone and the drying time once applied to the specimen is significantly longer as the alcohol isn't as volatile as acetone but the alcohol will give you less sheen on your finished product.

[DPS Ammonite]

I have a similiar question. Will Butvar 76 dissolved in ethyl alcohol be less glossy than when it is dissolved in acetone? How pure does the ethyl alcohol have to be?

 

@Ptychodus04

[Innocentx]

2 hours ago, snolly50 said:

I have used "acrylic sealer" sold in crafts stores. This clear coating is available in a matte finish.

I tried this(matte finish) and found it unsatisfactory. Even though thoroughly dry, it attracted and held dust and lint.

[snolly50]

14 minutes ago, Innocentx said:

Even though thoroughly dry, it attracted and held dust and lint.

That sounds awful, certainly a result that would make the product unsuited for any purpose. Did you apply the product to wood? I know that some woods produce substances that prevent some finishes from ever curing. An undercoat of shellac is the universal fix for this issue.  I recently finished a walking stick with spray-on polyurethane. After months it remained mildly sticky. I brushed on some shellac and it's now like glass. Of course, it would be wise, especially in terms of use with precious fossils to test out any "treatment" on a scrap, dispensable piece.   

[Innocentx]

16 minutes ago, snolly50 said:

Did you apply the product to wood?

No. It was a fossil I thought was special. Will acetone remove acrylic?

[DPS Ammonite]

9 minutes ago, Innocentx said:

No. It was a fossil I thought was special. Will acetone remove acrylic?

Look at acrylic spray label to see if they recommend a solvent to clean dry film.

 

Contact manufacturer to see if their chemist can recommend a product.

 

See this article about cleaners to remove various coatings from concrete: https://www.everything-about-concrete.com/removing-concrete-sealers.html

[Innocentx]

Thanks, @DPS Ammonite.

[snolly50]

58 minutes ago, Innocentx said:

fossil I thought was special. Will acetone remove acrylic?

Ouch! Sorry it was a fossil! Doren, @caldigger was able to reverse the mischief I did to one of the St Clair plates mentioned above. This was a couple of years back, he reported that he successfully utilized acetone. Perhaps he can provide more detail. DPS Ammonite's recommendation to consult the maker is also a great option. Good luck.

[caldigger]

Whatever brand John used for the St. Clair plates seemed to clean off fairly well with acetone. The white on the plants stayed on although I am sure some definition was lost.

Not a big fan of the shiny fossil thing.

[Ptychodus04]

17 hours ago, DPS Ammonite said:

I have a similiar question. Will Butvar 76 dissolved in ethyl alcohol be less glossy than when it is dissolved in acetone? How pure does the ethyl alcohol have to be?

 

@Ptychodus04

I’m not sure if Butvar is soluble in alcohol but if it is, it should have the same results as PVA. You can use denatured alcohol from your local hardware store.

[steelhead9]

Can you explain why coating just the fossil is not an option. With a very fine sable brush, I can coat even the finest bones on a keichousaurus. A picture might enable us to help you better. 

[rfarrar]

Have you tried an artist's workable fixative - the type used to stabilize charcoal or pastel artwork? These aerosol coatings work to stabilize many different fossils and rock types, often without the shiny matrix after-effect. Different brands give differing results, so you may need to experiment a little. A slightly glossy matrix, after spraying with the fixative, can often be toned down by a light rub with an art gum eraser.

[JohnBrewer]

23 hours ago, Ptychodus04 said:

@JohnBrewer, I have 2 options for you. 1, if possible, coat the whole thing with Paraloid to stabilize then remove surface Paraloid from matrix using straight acetone rubbed on with a clean, lint free cloth. This usually has a positive outcome but is labor intensive.

 

Option 2 is for me to ship you some PVA beads that you can dissolve in denatured alcohol. The solution making process is longer as the alcohol is a weaker solvent than acetone and the drying time once applied to the specimen is significantly longer as the alcohol isn't as volatile as acetone but the alcohol will give you less sheen on your finished product.

Option one looks like the job. Thanks Kris!

[JohnBrewer]

4 hours ago, steelhead9 said:

Can you explain why coating just the fossil is not an option. With a very fine sable brush, I can coat even the finest bones on a keichousaurus. A picture might enable us to help you better. 

Because the matrix is incredibly fragile. Even handling the matrix is a risk. A picture won’t help as it wouldn’t show the fragility of the matrix. You may ask how I got them home. The matrix is a clay/slate so more stable wet than dry. The drying was done slowly to minimise crumbling. 

[JohnBrewer]

2 hours ago, rfarrar said:

Have you tried an artist's workable fixative - the type used to stabilize charcoal or pastel artwork? These aerosol coatings work to stabilize many different fossils and rock types, often without the shiny matrix after-effect. Different brands give differing results, so you may need to experiment a little. A slightly glossy matrix, after spraying with the fixative, can often be toned down by a light rub with an art gum eraser.

I want to use something that is used industry standard, archival and very fluid to get into cracks by capillary action. 

[JohnBrewer]

23 hours ago, Ptychodus04 said:

@JohnBrewer, I have 2 options for you. 1, if possible, coat the whole thing with Paraloid to stabilize then remove surface Paraloid from matrix using straight acetone rubbed on with a clean, lint free cloth. This usually has a positive outcome but is labor intensive.

 

Option 2 is for me to ship you some PVA beads that you can dissolve in denatured alcohol. The solution making process is longer as the alcohol is a weaker solvent than acetone and the drying time once applied to the specimen is significantly longer as the alcohol isn't as volatile as acetone but the alcohol will give you less sheen on your finished product.

I have PVA beads in the form of Paraloid Kris. Is that the PVA you’re thinking of?

[Ptychodus04]

2 hours ago, JohnBrewer said:

I have PVA beads in the form of Paraloid Kris. Is that the PVA you’re thinking of?

I believe Paraloid is different than the PVA I use (McGean B15). Do you use Paraloid B-76? My understanding is that this is typically what is used on fossils. If so, it is actually ethyl methacrylate (I think) abs may not be soluble in alcohol.

 

McGean B-15 is polyvinyl acetate.

 

 

[fifbrindacier]

If i'm right, you can use 1g of paraloid for 50g of acetone.

[steelhead9]

19 hours ago, JohnBrewer said:

Because the matrix is incredibly fragile. Even handling the matrix is a risk. A picture won’t help as it wouldn’t show the fragility of the matrix. You may ask how I got them home. The matrix is a clay/slate so more stable wet than dry. The drying was done slowly to minimise crumbling. 

Have you tried heavily consolidating the back and sides, but not the front of the fossil? Do you have an air abrasive unit. Consolidating the matrix with paleobond penetrant stabilizer will  leave a glossy sheen. This sheen can be removed by air abrading the surface of the consolidated area on a very low pressure setting with your air abrader. It dulls the gloss but does not remove the consolidating qualities. This does not work well with paraloids as it tends to turn the surface milky white.

[JohnBrewer]

23 hours ago, Ptychodus04 said:

I believe Paraloid is different than the PVA I use (McGean B15). Do you use Paraloid B-76? My understanding is that this is typically what is used on fossils. If so, it is actually ethyl methacrylate (I think) abs may not be soluble in alcohol.

 

McGean B-15 is polyvinyl acetate.

 

 

Yep P-76

[JohnBrewer]

7 hours ago, steelhead9 said:

Have you tried heavily consolidating the back and sides, but not the front of the fossil? Do you have an air abrasive unit. Consolidating the matrix with paleobond penetrant stabilizer will  leave a glossy sheen. This sheen can be removed by air abrading the surface of the consolidated area on a very low pressure setting with your air abrader. It dulls the gloss but does not remove the consolidating qualities. This does not work well with paraloids as it tends to turn the surface milky white.

@steelhead9 Yeah, as soon as I’d done the front of the matrix with 5% I hit the back and sides with 25% Paraloid. 

 

I do have an air abrader and like your idea. I’d have to import the paleobond as I’m in the U.K. but it does sound a useful thing to have around. 

 

Anyway folks i tried Kris’ option 1 using ethanol to remove the glossiness but retain the consolidation properties. I used a paintbrush. Kris I do dissolve Paraloid in ethanol but a low mixes. Takes an age to dissolve but I find keeping a small bottle in my trouser pocket throughout the day (warmth and agitation) helps. I do add a small amount of acetone sometimes too say w/v/v 10% Paraloid/20% acetone and 70% ethanol 

 

[Peat Burns]

On 6/27/2018 at 8:07 AM, Ptychodus04 said:

I’m not sure if Butvar is soluble in alcohol but if it is, it should have the same results as PVA. You can use denatured alcohol from your local hardware store.

Butvar is soluble in alcohol. I use 100% EtOH. Very slow to dissolve.