What concentration of Butvar 76 should I use?

[KimTexan]

My Butvar 76 arrived yesterday.

I need to know what concentrations of it to make for my bison prep.

Most of the bison was in pretty decent shape and not terribly fragile, but the skull is a different story. It had a few tree roots growing through it and was split in a few places. 

I do not know what concentrations to make of butvar 76 to stabilize the very fragile parts and also to glue back some broken pieces.

1. What concentrations do I need to make for the project? Ideally I would like to know the grams B76 to milliliters of acetone ratio for each use.  

I’m a complete novice at this sort of prep. My prep up to this point has been on invertebrates in matrix. This is a vertebrate in dirt. I don’t even know where to begin. I’d categorize myself as next to clueless.

I’m trying to educate myself with lecture videos and articles, but I haven’t found anything on concentrations or dilutions for different use or applications of bone prep and stabilization.

 

I have some very novice questions. Please humor me in my utter ignorance. 

 

Parts of the skull are very fragile and thin. I’ve left the mud and dirt in place where it is most fragile. So I need to stabilize it before I attempt to remove the dirt, which then stabilizes the dirt in place too. This seems like it’s going to be insanely tedious.

 

2. How do I remove the dirt while it is essential stabilized in place with the bone? I assume I will add a little acetone to the dirt to weaken the b76 and try not to add too much so the I destabilize the bone.

 

Is that the gist of how it works? If that’s the case I can work with that and figure things out as I go. I’m good with my hands and problem solving. 

 

I do understand that I need to have ventilation while doing this. I haven’t worked that component out yet. I do not have a hood or cabinet of any kind. I’m considering building a small make shift cabinet of sorts. I can wear a ventilator type mask. The N95, but I don’t know if those work for fumes like acetone.

3. Do N95 masks work for fumes like acetone?

4. Any suggestions on ventilation?

 

Any helpful tips, guidance, reference articles or materials would be appreciated. I’m currently trying to read through some of Amy Davidson’s stuff on adhesive and consolidants. I haven’t gotten very far though.

 

[Wolf89]

@RJB @Ptychodus04

[KimTexan]

I found an answer to question 1 on the American Museum of Natural History paleo page.

Butvar B76

• Adhesive: generally not used as an adhesive
• Consolidant: 2% to 10% (grams/ml) in acetone or ethanol

So shoot, I can’t use it as an adhesive. Evidently it’s a weak adhesive. I can use the cyanoacrylate, but I am having problems with it penitrating into the bone and sticking. I’m use to the sets in seconds feature. I think it will work if I just clamp it and wait for it to set. Hopefully my clamp won’t stick to it and do damage when I release the clamp. Any suggestions on something to use between the clamp and my bone to prevent that? Tissue paper? It should wash off fairly easily.

I’m not accustomed to having to clamp and wait, but I think it will work.

 

Back to B76 for stabilizing the skull, what is the best recommendation for concretions? 10% maybe?

What if I want to coat the bones I have? While not particularly fragile many have breaks or broken off chips that weren’t recovered. 

I’d like to stabilize the outside of the horn core tip I found before I clean the inside.

What is the best %B76? How long should I let it dry once coated?

[fossilized6s]

I use good old fashion Super Glue on most of my stuff, then B76 to stabilize if needed.

 

Paleo Bond is another alternative for gluing. 

[KimTexan]

2 hours ago, fossilized6s said:

I use good old fashion Super Glue on most of my stuff, then B76 to stabilize if needed.

 

Paleo Bond is another alternative for gluing. 

I think Paleobond is glorified cyanoacrylate, which I buy for a pretty good price on Amazon. $22 for 8 Oz.

[Ptychodus04]

You may want 3 viscositiesbof Butvar. I usually mix 1:50, 1:25, and 1:10 by volume.

 

Butvar can be used as an adhesive but often is not due to its very slow set time (measured in days). I use a 1:2 ratio for a very thick glue. Secure in some way and leave it alone for a few days. It is very strong.

[KimTexan]

 

3 minutes ago, Ptychodus04 said:

You may want 3 viscositiesbof Butvar. I usually mix 1:50, 1:25, and 1:10 by volume.

 

Butvar can be used as an adhesive but often is not due to its very slow set time (measured in days). I use a 1:2 ratio for a very thick glue. Secure in some way and leave it alone for a few days. It is very strong.

 

Thank you very much.

 

The 1:50 for example, would that be 1 gram solid to 49 ml acetone? Which you use for coating or sealing I assume. 

1:25 used for?

1:10 used for stabilization while prepping? 

[SailingAlongToo]

N95 masks are for particulates (dust, silica, etc.) They will not help with fumes.

 

You would need respirator with a vapor cartridge. Lowes and Home Depot sell them. I've also seen them at a few Walmarts and your previously mentioned Amazon has them as well.

[Ptychodus04]

8 hours ago, KimTexan said:

 

 

Thank you very much.

 

The 1:50 for example, would that be 1 gram solid to 49 ml acetone? Which you use for coating or sealing I assume. 

1:25 used for?

1:10 used for stabilization while prepping? 

It is not an exact science so perfect measurements aren't important. 1 tsp plastic to 1 cup acetone gives you the 1:50 ratio. This is used for deep penetration and stabilization. It will sometimes be too thin if you are trying to stabilize cancelous bone. The two higher viscosity solutions are for stabilizing more porous bone. the 1:10 can be used as an adhesive since it is usually around the viscosity of honey.

 

1 hour ago, SailingAlongToo said:

N95 masks are for particulates (dust, silica, etc.) They will not help with fumes.

 

You would need respirator with a vapor cartridge. Lowes and Home Depot sell them. I've also seen them at a few Walmarts and your previously mentioned Amazon has them as well.

I use a P100 cartridge for particulate and vapor protection on my respirator.

[SailingAlongToo]

22 minutes ago, Ptychodus04 said:

I use a P100 cartridge for particulate and vapor protection on my respirator.

 

Yeap, they come in many different combinations including organic vapors, particulates, hydrocarbons, acids, metal fumes, etc. When I teach the OSHA basic "Respiratory Protection" program it's an 8 hour class, not counting the fit testing and medical surveillance required to wear a respirator. My standard cartridge for my personal respirator is a P100 + vapors also.

[Ptychodus04]

14 hours ago, KimTexan said:

 

Back to some of your other questions. My comments will be all in bold. My product of choice has been BcGean B15 (PVA) but Butvar is essentially the same in application.

 

I’m a complete novice at this sort of prep. My prep up to this point has been on invertebrates in matrix. This is a vertebrate in dirt. I don’t even know where to begin. I’d categorize myself as next to clueless.

I’m trying to educate myself with lecture videos and articles, but I haven’t found anything on concentrations or dilutions for different use or applications of bone prep and stabilization. Just to restate, don't get too hung up on the ratios. You're looking for a consolidation viscosity as thin as water so it soaks in deep at first. If needed, go thicker for very porous bone. Most late Pleistocene material is actually sub fossil bone. All bison that I have worked on have been this way and most mammoth material is as well. It all needs to be consolidated to keep it from breaking down. Consolidate even if you think it is pretty stable. If the bones are not too fragile, soak them. If they are very fragile, apply with a dropper or brush, repeating the process several times. You can always remove surface Butvar with acetone if the bone gets really shiny. When in doubt, consolidate. I worked on a mammoth jaw that was very brittle once. Anywhere the cancelous bone was exposed, I poured PVA that was the consistency of heavy cream on it until it started oozing out of cracks on the other side. This completely stabilized the jaw and allowed me to use a very thick PVA solution for the glue as the solvent in the glue solution partially dissolves the plastic already in the bone, resulting in a very strong bond.

 

I have some very novice questions. Please humor me in my utter ignorance. Every preparator was an ignorant novice at one point as well.

 

Parts of the skull are very fragile and thin. I’ve left the mud and dirt in place where it is most fragile. So I need to stabilize it before I attempt to remove the dirt, which then stabilizes the dirt in place too. This seems like it’s going to be insanely tedious. If you have not consolidated these bones during excavation, don't consolidate before cleaning unless doing so will damage the bones. I use Acetone or denatured alcohol to loosen sediments. This allows them to be scraped away. The residual sediment can be brushed away with a toothbrush soaked in the same solvent. This is extremely slow. Welcome to the world of vertebrate preparation. If, as you mention, you need to stabilize in order to keep from damaging the bones, do so with the thinnest solution (mentioned before) and only use 1 application if possible. This will allow the bone to harden some without totally bonding the matrix to it. Then, drop straight acetone onto the dirt and scrape it off with a dental pick. Residual matrix can be removed by the brush method I mentioned earlier. Then add more consolidation solution when the area is clean.

Any suggestions on ventilation? Where are you doing the prep? you really only need some cross ventilation. If inside, open 2 windows on opposite sides of the prep area and put a box fan blowing out of one of them. This will draw the fumes out. Keep in mind, the fan will have to continually operate until all of the acetone has vaporized and been evacuated from the room (takes longer than you think). If you are working in a garage, you can prep near the exterior door and blow the fan across your work area. Once you're finished working, allow the fan to run for a few extra minutes and you can close everything down as you will not be remaining in the work area so the residual fumes aren't an issue.

[SailingAlongToo]

@KimTexan

 

Just keep in mind that both alcohol and acetone are very flammable, but even more importantly, they are explosive in the right mixture / concentration with room air. No smoking, no open flame or exposed heat sources when using these chemicals. 

[Ptychodus04]

2 hours ago, SailingAlongToo said:

@KimTexan

 

Just keep in mind that both alcohol and acetone are very flammable, but even more importantly, they are explosive in the right mixture / concentration with room air. No smoking, no open flame or exposed heat sources when using these chemicals. 

Agreed 110%.

[Harry Pristis]

I agree with Ptychodus04 that a respirator is more than you need if you are reasonably careful.  If you decide to build a containment shelter, you could build a tent of Visquene(sp?) or even with a dollar-store table cover.  If you have a window with a fan to exhaust the fumes, you could position the tent against the window.  You might up-end a folding card table to provide the four uprights for the tent.  Two card tables, top-to-top, might be ideal.  You can line the underside of the upturned table with beer flats which will not adhere to the Butvar.  A tent of this size should accommodate your bones.

 

Adhesives are a matter of choice -- which is easiest to work with?  Will the bone EVER be taken apart?  If not, the range of adhesives expands.  5-minute epoxy is useful for reinforcing thin or cracked bone such as lining a thin braincase.  Remove excess epoxy before it cures with rubbing alcohol or an Xacto knife.  There are a number of non-toxic next-generation glues useful for joins that are permanent.  Be certain to consolidate the pieces BEFORE using any of the glues discussed in this thread.

[Ptychodus04]

As @Harry Pristis said, consolidate then glue. If you do the reverse, the solvent in the consolidation solution will damage the glue bond.

[KimTexan]

9 hours ago, Ptychodus04 said:

Back to some of your other questions. My comments will be all in bold. My product of choice has been BcGean B15 (PVA) but Butvar is essentially the same in application.

 

I’m a complete novice at this sort of prep. My prep up to this point has been on invertebrates in matrix. This is a vertebrate in dirt. I don’t even know where to begin. I’d categorize myself as next to clueless.

I’m trying to educate myself with lecture videos and articles, but I haven’t found anything on concentrations or dilutions for different use or applications of bone prep and stabilization. Just to restate, don't get too hung up on the ratios. You're looking for a consolidation viscosity as thin as water so it soaks in deep at first. If needed, go thicker for very porous bone. Most late Pleistocene material is actually sub fossil bone. All bison that I have worked on have been this way and most mammoth material is as well. It all needs to be consolidated to keep it from breaking down. Consolidate even if you think it is pretty stable. If the bones are not too fragile, soak them. If they are very fragile, apply with a dropper or brush, repeating the process several times. You can always remove surface Butvar with acetone if the bone gets really shiny. When in doubt, consolidate. I worked on a mammoth jaw that was very brittle once. Anywhere the cancelous bone was exposed, I poured PVA that was the consistency of heavy cream on it until it started oozing out of cracks on the other side. This completely stabilized the jaw and allowed me to use a very thick PVA solution for the glue as the solvent in the glue solution partially dissolves the plastic already in the bone, resulting in a very strong bond.

 

I have some very novice questions. Please humor me in my utter ignorance. Every preparator was an ignorant novice at one point as well.

 

Parts of the skull are very fragile and thin. I’ve left the mud and dirt in place where it is most fragile. So I need to stabilize it before I attempt to remove the dirt, which then stabilizes the dirt in place too. This seems like it’s going to be insanely tedious. If you have not consolidated these bones during excavation, don't consolidate before cleaning unless doing so will damage the bones. I use Acetone or denatured alcohol to loosen sediments. This allows them to be scraped away. The residual sediment can be brushed away with a toothbrush soaked in the same solvent. This is extremely slow. Welcome to the world of vertebrate preparation. If, as you mention, you need to stabilize in order to keep from damaging the bones, do so with the thinnest solution (mentioned before) and only use 1 application if possible. This will allow the bone to harden some without totally bonding the matrix to it. Then, drop straight acetone onto the dirt and scrape it off with a dental pick. Residual matrix can be removed by the brush method I mentioned earlier. Then add more consolidation solution when the area is clean.

Any suggestions on ventilation? Where are you doing the prep? you really only need some cross ventilation. If inside, open 2 windows on opposite sides of the prep area and put a box fan blowing out of one of them. This will draw the fumes out. Keep in mind, the fan will have to continually operate until all of the acetone has vaporized and been evacuated from the room (takes longer than you think). If you are working in a garage, you can prep near the exterior door and blow the fan across your work area. Once you're finished working, allow the fan to run for a few extra minutes and you can close everything down as you will not be remaining in the work area so the residual fumes aren't an issue.

Thank you, thank you, thank you!!! I truly, truly appreciate the insight. It is very helpful.

 

 

9 hours ago, SailingAlongToo said:

@KimTexan

 

Just keep in mind that both alcohol and acetone are very flammable, but even more importantly, they are explosive in the right mixture / concentration with room air. No smoking, no open flame or exposed heat sources when using these chemicals. 

I have a one of those 8 hour trainings on chemicals a couple of times. I have to review it yearly. Thankfully I don't have to worry about respirators at work. I use a fume hood. I have a minor in chemistry and make quite a few reagents for our lab. Most are for clinical testing though, but some are still quite toxic, flammable and/or carcinogenic or mutagenic. We have one chemical that weaves itself into DNA. It says it is not harmful, but I personally don't want my DNA woven into.

 

 

5 hours ago, Harry Pristis said:

I agree with Ptychodus04 that a respirator is more than you need if you are reasonably careful.  If you decide to build a containment shelter, you could build a tent of Visquene(sp?) or even with a dollar-store table cover.  If you have a window with a fan to exhaust the fumes, you could position the tent against the window.  You might up-end a folding card table to provide the four uprights for the tent.  Two card tables, top-to-top, might be ideal.  You can line the underside of the upturned table with beer flats which will not adhere to the Butvar.  A tent of this size should accommodate your bones.

 

Adhesives are a matter of choice -- which is easiest to work with?  Will the bone EVER be taken apart?  If not, the range of adhesives expands.  5-minute epoxy is useful for reinforcing thin or cracked bone such as lining a thin braincase.  Remove excess epoxy before it cures with rubbing alcohol or an Xacto knife.  There are a number of non-toxic next-generation glues useful for joins that are permanent.  Be certain to consolidate the pieces BEFORE using any of the glues discussed in this thread.

 

Thank you very much for your input. It is helpful. I have not started on the consolidating. I went back out and spent 4 hours collecting more of the bison today. I did a lot of digging to remove what was on top of the rest of the exposed bones. I am going to be pretty sore. I'm already sore and worn out. I will be working on it later in the week after work.

 

 

 

 

 

[Ptychodus04]

16 minutes ago, KimTexan said:

I went back out and spent 4 hours collecting more of the bison today. I did a lot of digging to remove what was on top of the rest of the exposed bones. I am going to be pretty sore. I'm already sore and worn out. I will be working on it later in the week after work.

 

Excavating will wear you completely out. On one excavation, I was so tired that I couldn’t even pick up my head when we were digging the pedestals for the jacket and I just flopped my head down in the mud.

[KimTexan]

That is pretty tired. I can’t complain though the dirt was beautiful to work with. No clay, rock or shale, just dirt with a sand component.

I’ve had a couple very memorable experiences with extraction or excavating. Once I found a big ammonite in limestone I wanted so bad. I hammered away at it with my 5 lb sledge hammer for maybe 2.5 hours the first day. When I left that night my arms were like wet noodles. I could barely lift them to hold the steering wheel. I was not happy I didn’t get it out.  I went back the next day and worked at least an hour more on it. When it was all said and done I can’t say it was worth the effort. I found a better one maybe 30 feet away that had weathered out already and all I had to do was pick it up. I guess I was being greedy. 

[Ptychodus04]

14 hours ago, KimTexan said:

That is pretty tired. I can’t complain though the dirt was beautiful to work with. No clay, rock or shale, just dirt with a sand component.

I’ve had a couple very memorable experiences with extraction or excavating. Once I found a big ammonite in limestone I wanted so bad. I hammered away at it with my 5 lb sledge hammer for maybe 2.5 hours the first day. When I left that night my arms were like wet noodles. I could barely lift them to hold the steering wheel. I was not happy I didn’t get it out.  I went back the next day and worked at least an hour more on it. When it was all said and done I can’t say it was worth the effort. I found a better one maybe 30 feet away that had weathered out already and all I had to do was pick it up. I guess I was being greedy. 

 

That is the most exhausted I have ever been. We were working almost around the clock for 4 days straight and the temps in the day were over 100 and we were completely exposed without any shade. It was worth it though. It wound up being a new species.

 

I wouldn't say greedy, more myopic. It's easy to get obsessively focused on a specimen. I used to do the same thing. Now, if I'm prospecting an area, I mark the specimens that require more excavation and keep moving until I have searched the whole area. Then, I can decide which ones are worth the effort.

[KimTexan]

The most thoroughly dirty I’ve ever been excavating was up in Wyoming digging in the Lance formation. I was excavating a 52 in Edmontosaurus femur. We were sand blasted all day long by the strong winds. When I got back to our little RV that night I tried to dust and shake off as much as possible before getting in the shower. 

I had sand in my teeth, eyes, ears and nose. At one point in the shower I looked down at the floor and it looked like I was standing on a beach. Evidently I still had a lot of sand on me. After I left it took days to stop finding sand on me or in my hair.

I loved every minute of it though.

[KimTexan]

@Ptychodus04, @RJB and @Uncle Siphuncle I have a couple bison bone questions. One is prep related the other isn’t.

1. Is a tink or clink (higher pitch) noise heard in non-mineralized bones when they’re tapped? Or would that be a possible indication of mineralization?

I went to wash some of the bones to trying to get the grit/dirt out of the finer details before consolidating. When tapped some make a tink or clink sound. I don’t have any modern bone around to compare the sound to. When I washed them off originally they were still damp from being in the ground so there was a lower pitch, more of a thud noise when tapped. 

The horse lower leg bone I found makes the tink noise too now that it’s dry.

 

Is it ok to wash the bones now that they have dried so thoroughly? I went bank and cleaned the fine details on the femur when I was assessing the bite marks. After it was washed I was sitting on the couch right next to it when I heard a loud crack come from it, like the bone had split. I assume as it absorbed the water from washing that it swelled and caused a crack somewhere inside. I can’t see anything outside. It was disconcerting to me.  In light of that would it be better to consolidate before I try to wash out the fine details, vascular holes, small cracks and crevices? Maybe I’m being too cautious.

 

[Ptychodus04]

Hi @KimTexan. Once the bones are dry, you don't want to wet them again. The capillary action draws the water in and causes the bone to expand. Then, the bone has to go through the drying process again. If the bone is soaked through, there can be differential drying (outside drying much faster than the inside) which will cause the bone to crack and possibly crumble. If you need to wet it to clean it up, use denatured alcohol. It will not soak into the bones as far as it evaporates much faster.

[KimTexan]

Thank you so much for responding and me know!!!! I am so glad I asked!

My goodness. If I had realized that I would have been considerably more thorough on the initial wash. I think I’ve made the task more difficult for myself. 

 

Sorry for asking such elementary questions. I’m totally green. I truly appreciate you help and advice!

[Uncle Siphuncle]

1 hour ago, Ptychodus04 said:

Hi @KimTexan. Once the bones are dry, you don't want to wet them again. The capillary action draws the water in and causes the bone to expand. Then, the bone has to go through the drying process again. If the bone is soaked through, there can be differential drying (outside drying much faster than the inside) which will cause the bone to crack and possibly crumble. If you need to wet it to clean it up, use denatured alcohol. It will not soak into the bones as far as it evaporates much faster.

Agreed.  Differential drying sets up internal stresses that relieve themselves in a destabilizing way.

 

I prefer to get stuff home and scrub it while still wet.  If really fragile, I may wrap it in a wet towel till I can get to it.  Stable stuff gets dropped in a 5 gallon bucket and scrubbed w a saddle brush while fragile stuff gets a quick dip or just localized scrubbing w an old toothbrush.  

 

Tusks are the most fragile thing out there, so I monitor drying of them most closely, wicking in Paleobond to arrest cracks as the form, wiping excess away immediately, repeating a couple times a day before sort of vacuum bagging w Butvar for minimum product usage/max coverage.  I do this once reasonably dry, and leave sealed for a day or so for penetration.

 

For small stuff I’m beginning to experiment by doing this in my kid’s vacuum chamber for max penetration.  

 

If I had to put it in Butvar still damp, the frosted look once dry will disappear when wiped w acetone.

 

I use very thin Butvar as I detest high gloss.

[KimTexan]

Thank you Dan.

Vacuume bagging? Is that like placing the item in one of those big zip locks and vacuuming out the air immediately after application of Butvar? Which does what? Slows down the evaporation of acetone which helps the Butvar seep deeper into the bone rather than superficial coating? I’m guessing here.

 

What about the tink, clink sound of bones? Do modern bones make that sound? I’m thinking it must mean some degree of mineralization despite the look and weight seemingly like bone.

I won’t conclude they are until I have someone else’s opinion after seen in person.

I did email Mr. Vance today. I haven’t heard back from him yet. I plan to go to the DPS monthly meeting in 2 weeks. I’ll take some bones with me then and ask around. 

Also, a Mr. Cohen from DPS invited me to go with him to a mammoth prep session in Weatherford.  Evidently he volunteeres for helping with prep now and then. I don’t know the guy, but it’s a good opportunity to learn some stuff.

This bison is a knowledge growing experience.