Butvar questions

[Plantguy]

Hey Guys, 

 

I'm working on trying to mix up some butvar and acetone to put on a tusk tip fragment thats cracking/falling apart.

 

I have had some butvar in a plastic ziplock in the garage for about 3-4 years and never used it. I worked thru the math from some of the other threads and decided that 1 tsp in 8 oz of acetone would get me started and might not be too shiney. About 4 hours ago I put the stuff in a glass jar and its still looking cloudy and I can still see lots of material floating around inside when I swirl it. Will it be completely clear or still somewhat cloudy? I read some threads about it taking a while--not sure what that really equates to. I know some of you are probably dealing with temps much colder but its only 70 here today and overcast at the moment and I'm wondering if this is going to take most of the day for the butvar to dissolve before I can use it.

 

Could butvar sitting in a very hot garage for years and exposed to excessive heat degrade? and that might be part of my problem? Acetone was just purchased last night. Or could I just be impatient as usual? LOL. 

 

Thanks! 

Regards, Chris 

[Ptychodus04]

It looks like your Butvar is still in the process of dissolving. The entire dissolution process can take several days. The final product will be somewhat cloudy but should be completely free of solid bits of Butvar. Storage in the garage doesn't matter. I keep my consolidants in the garage here in Texas. Other than the PVA beads tending to stick together due to heat, there's no issues.

 

If you have more shine than desired on the piece after you consolidate, simply brush on some straight acetone and wipe off. This will remove some of the Butvar on the surface and reduce the shine.

[Harry Pristis]

 

 

It's important to drizzle the Butvar B-76 beads slowly into the acetone.  If you simply dump the beads into the solvent, you will wind up with a 'snot' of plastic which stubbornly resists going into solution.  Even drizzling the beads will not result in quick dissolution.  It takes time and lots of agitation to get the plastic into solution.  Every time I do the mixing I regret that I haven't bought or built a powered mixer.  Once dissolved, though, the plastic will not fall out of solution.

 

 

[Plantguy]

27 minutes ago, Harry Pristis said:

 

 

It's important to drizzle the Butvar B-76 beads slowly into the acetone.  If you simply dump the beads into the solvent, you will wind up with a 'snot' of plastic which stubbornly resists going into solution.  Even drizzling the beads will not result in quick dissolution.  I takes time and lots of agitation to get the plastic into solution.  Every time I do the mixing I regret that I haven't bought or built a powered mixer.  Once dissolved, though, the plastic will not fall out of solution.

 

 

 

1 hour ago, Ptychodus04 said:

It looks like your Butvar is still in the process of dissolving. The entire dissolution process can take several days. The final product will be somewhat cloudy but should be completely free of solid bits of Butvar. Storage in the garage doesn't matter. I keep my consolidants in the garage here in Texas. Other than the PVA beads tending to stick together due to heat, there's no issues.

 

If you have more shine than desired on the piece after you consolidate, simply brush on some straight acetone and wipe off. This will remove some of the Butvar on the surface and reduce the shine.

Thank you both for the additional info! I guess I should line up a couple of other things that need some consolidating that I've ignored. I am no doubt flirting with disaster. I'm also repairing/painting another room in the house and while I wait between those wall repairs to dry and recoat I guess waiting for butvar is nothing to get riled about.We got company visiting soon and the project list gets more entertaining every day! 

 

Thanks again for suggestions/help! 

 

Regards, Chris 

[Ptychodus04]

Eventually, it all will dissolve. You can speed the process by stirring or shaking the solution every day. I keep a base solution ready at all times. I mixed a pint of PVA with a gallon of acetone and shook it every day for a week for about 10 seconds each time. This creates a medium thick viscosity. If I need thicker, I add PVA to a bit of the solution in a jar and stir. This can take around a week to fully dissolve but you will get a strong glue that is about as thick as cold molasses. For consolidation purposes, I take 1 part base solution and add 1.5-2 parts acetone to thin it.

[Plantguy]

1 hour ago, Ptychodus04 said:

Eventually, it all will dissolve. You can speed the process by stirring or shaking the solution every day. I keep a base solution ready at all times. I mixed a pint of PVA with a gallon of acetone and shook it every day for a week for about 10 seconds each time. This creates a medium thick viscosity. If I need thicker, I add PVA to a bit of the solution in a jar and stir. This can take around a week to fully dissolve but you will get a strong glue that is about as thick as cold molasses. For consolidation purposes, I take 1 part base solution and add 1.5-2 parts acetone to thin it.

Appreciate the additional insight. I was hoping to try this first blend on the back of the tusk fragment to get a feel for the absorption process and the sheen. And then potentially move to the other side which already has a nice original satin finish but you can see the cracking going on in the photo below..

A 2nd thicker blend will do the trick on a mammoth tooth fragment that the roots are falling apart badly...The plates/top is mineralized but the base much less so and very brittle/flaky so I was thinking the thicker approach/blend more viscous mix as you had created would be better. 

 

Thanks! 

Regards, Chris 

[Ptychodus04]

I would use an extremely thin solution and give that tooth a bath. It needs a thin solution to penetrate deeply and consolidate well. The higher viscosity is great for holding bits together but thin goes deeper.

 

if you have enough Butvar to submerge the tooth in solution, that’s the route it needs. If you are concerned with the stability, put it in a dish and pour the solution on it.

[megaholic]

Chris, you need to submerge that!  Brushing will do you no good on tusk, or on Mastodon tooth roots.  Also PVA is not Butvar...  Your solution should be fairly strong, and you should let the items fizz until they stop.  About 10 minutes...  Drain and dry in a plastic bag.  You want to flash off the acetone slowly so the item does not get too cold, and give you any frosty white blush, like you get painting on a damp day. You can wipe them with a Q-tip in acetone to remove any shiny areas, but you want a lot of consolidant inside, where it does the most good.  Butvar is my passion, I do all my finds, and have a flawless collection.

 

[Ptychodus04]

@megaholic, while Butvar (polyvinyl butyral) is not PVA (polyvinyl acetate) the application of the two are the same. I have used both extensively in preparation of extremely fragile fossils. 

 

While submersion is best for consolidation, it may not be best for every specimen. Sometimes mammoth tooth roots are held together with nothing but dirt. Submersion can loosen this matrix and in the end, you have a pile of well consolidated scraps. Pouring or dripping is the only application method safe in these instances.

 

This is a judgment call that can only be made by the preparator with the fossil in hand. 

[Plantguy]

1 hour ago, megaholic said:

Chris, you need to submerge that!  Brushing will do you no good on tusk, or on Mastodon tooth roots.  Also PVA is not Butvar...  Your solution should be fairly strong, and you should let the items fizz until they stop.  About 10 minutes...  Drain and dry in a plastic bag.  You want to flash off the acetone slowly so the item does not get too cold, and give you any frosty white blush, like you get painting on a damp day. You can wipe them with a Q-tip in acetone to remove any shiny areas, but you want a lot of consolidant inside, where it does the most good.  Butvar is my passion, I do all my finds, and have a flawless collection.

 

 

3 minutes ago, Ptychodus04 said:

@megaholic, while Butvar (polyvinyl butyral) is not PVA (polyvinyl acetate) the application of the two are the same. I have used both extensively in preparation of extremely fragile fossils. 

 

While submersion is best for consolidation, it may not be best for every specimen. Sometimes mammoth tooth roots are held together with nothing but dirt. Submersion can loosen this matrix and in the end, you have a pile of well consolidated scraps. Pouring or dripping is the only application method safe in these instances.

 

This is a judgment call that can only be made by the preparator with the fossil in hand. 

Thanks guys. I think I get it..I've got butvar so thats the direction I'm heading. Container still has lots of crystals floating in it so its looking like we'll be in swirl mode for awhile.Will keep checking it.  I am concerned a bit about submerging the tusk fragment as I think its just waiting to literally fall apart...so I'm going to try brushing it on at least initially.

 

As for the tooth, the root area is the part that's noticeably unstable and a bit crumbly. The individual plates are separate and I guess its the cementum thats now gone, but the piece is extremely heavy for its size and the enamel seems tough and plates seem very mineralized. The piece with only 3 plates weighs almost 2 lbs!. Having said that it appears there are all kinds of small holes in the plates themselves so I'm going to try submerging it and see if that will take care of getting the butvar inside. 

Appreciate the feedback.  Will post results as I get them. 

Regards, Chris 

 

 

[Wrangellian]

I would think that if your solution is thin enough and your fossil porous or fractured enough, as I gather yours are, you could just apply the solution with a Fineline applicator and it would soak in well enough to hold it together, especially if you're afraid that submerging it will cause it to fall apart. I don't have any experience with your type of specimen, just my shale and sandstone type stuff, but when I use this method I'm often surprised how much I can keep adding before it overflows, so I get the impression it's wicking a ways in.

It's not a perfect tool but it works fairly well (I wish it had an even finer tip). The acetone does not dissolve this type of plastic.

 

[Harry Pristis]

 

 

The Fineline Applicator look like a useful tool.  I've used hypodermic syringes. with or without a needle, for this sort of work.  The syringe is easy to re-fill.  Flush it with a bit of acetone to clean.

 

 

[darrow]

Similar application however I used Butvar B-98 in 99.5% isopropyl alcohol...

Darrow

 

[Wrangellian]

2 hours ago, Harry Pristis said:

 

 

The Fineline Applicator look like a useful tool.  I've used hypodermic syringes. with or without a needle, for this sort of work.  The syringe is easy to re-fill.  Flush it with a bit of acetone to clean.

 

 

This thing holds a decent amount so it requires less frequent refilling (and less frequent jar opening)... the only frustration is that the flow can be difficult to control if you only want a drop (which is why I wish I had a finer tip) and the little bit left in the 'needle' tends to come out as the acetone inside exaporates, I guess, unless you can suck it back in or get the cap back on in time. The only cleaning required is scraping off the resulting buildup inside the blue 'collar', which I suppose could be added back into the jar if you're trying to conserve the stuff.

When I was using syringes I found that they didn't last very long before they became difficult to slide, though that was when I was using diluted white glue, if that makes any difference.

[megaholic]

Chris, 

Just another thing to consider on that tooth, is that you could consolidate it by dipping, or brushing, squirting...as you choose, and if it does come apart as Ptychodus04 mentions, the plates can easily be glued back together with a thick epoxy glue when they are dry. I have had that happen, and re-glued without a trace of trouble.  I have seen others tie string and zip-ties around tusk to hold it together while drying, and consolidating it also.  They would be removed later by rewetting in acetone.  I have not needed to do this with anything personally.  I have reglued mammoth tooth plates. 

Best luck with it...

[Plantguy]

On 11/10/2017 at 8:27 PM, Wrangellian said:

I would think that if your solution is thin enough and your fossil porous or fractured enough, as I gather yours are, you could just apply the solution with a Fineline applicator and it would soak in well enough to hold it together, especially if you're afraid that submerging it will cause it to fall apart. I don't have any experience with your type of specimen, just my shale and sandstone type stuff, but when I use this method I'm often surprised how much I can keep adding before it overflows, so I get the impression it's wicking a ways in.

It's not a perfect tool but it works fairly well (I wish it had an even finer tip). The acetone does not dissolve this type of plastic.

 

 

 

23 hours ago, Harry Pristis said:

 

 

The Fineline Applicator look like a useful tool.  I've used hypodermic syringes. with or without a needle, for this sort of work.  The syringe is easy to re-fill.  Flush it with a bit of acetone to clean.

 

 

 

21 hours ago, darrow said:

Similar application however I used Butvar B-98 in 99.5% isopropyl alcohol...

Darrow

 

 

20 hours ago, Wrangellian said:

This thing holds a decent amount so it requires less frequent refilling (and less frequent jar opening)... the only frustration is that the flow can be difficult to control if you only want a drop (which is why I wish I had a finer tip) and the little bit left in the 'needle' tends to come out as the acetone inside exaporates, I guess, unless you can suck it back in or get the cap back on in time. The only cleaning required is scraping off the resulting buildup inside the blue 'collar', which I suppose could be added back into the jar if you're trying to conserve the stuff.

When I was using syringes I found that they didn't last very long before they became difficult to slide, though that was when I was using diluted white glue, if that makes any difference.

 

9 hours ago, megaholic said:

Chris, 

Just another thing to consider on that tooth, is that you could consolidate it by dipping, or brushing, squirting...as you choose, and if it does come apart as Ptychodus04 mentions, the plates can easily be glued back together with a thick epoxy glue when they are dry. I have had that happen, and re-glued without a trace of trouble.  I have seen others tie string and zip-ties around tusk to hold it together while drying, and consolidating it also.  They would be removed later by rewetting in acetone.  I have not needed to do this with anything personally.  I have reglued mammoth tooth plates. 

Best luck with it...

Thanks all for the additional info and examples. We are still in swirl and wait mode here. Still have quite a bunch of crystals moving around in solution. I'll have to get some applicators/fineline tomorrow as suggested and should be good to start the process. I had some microtips somewhere but they appear to all be gone...I remember some very interesting roguelike Paleobond somehow wicking itself out of a container and creating some fascinating near permanent sculptures on my workbench which included quite a few prep tools.. It is funny now but wasnt at the time. LOL. 

 

Regards, Chris  

[Plantguy]

Just a semi quick update...Its been nearly a month since I started the swirling of the butvar in acetone and it finally got to a point that the mess I created that looked like a snow blizzard in a jar was down to just some flurries so I decided after it completely settled following the latest swirl to try submerging the tusk tip and to my delight only two 3/4" pieces near the end came off after letting it soak about 10 minutes and no more bubbles were rising from the specimen. So I've found some Starbond in the garage that I guess I bought awhile back and forgot about and that should allow me to glue them back on and we should be good to go.....so far so good! 

 

I did also notice something about the tusk tip that has me wondering...I thought the fragment which initially to me looked like a simple pie shaped slice of the larger cross section of the tusk would show concentric tree like rings but when you look at it on end the axis doesnt seem to be in the center and doesnt go to the very tip. And there is actually more of a parabola shaped section and corresponding rings that open downward. Here are some pictures that seem to show the cementum/enamel? on the very bottom/outside layer. Kind of strange but maybe thats the norm and that cementum layer just fell off and it never was elliptical in shape--more triangular as it got near the end. 

More when the tooth gets consolidated. 

 

Thanks again. Regards, Chris