B-76 Wont Desolve

[alej9582]

Can anyone tell me why the B-76 is not dissolving in acetone? Is it supposed to be like this pic below?

 

Alex

[Fossildude19]

Don't know much about it, but there are several posts on the Forum about it. 

 

LINK 1

LINK 2

LINK 3

 

 

Did you sprinkle the Butvar into the acetone, as suggested in Link 1? 

[jpc]

did you pour the acetone on top of the beads, or pour the beads into the acetone?  It should be done via the latter.  It should take about two weeks with daily shaking.  The more you shake it the better.   I have never used B-76 but this is how B-72 an vinac are done.  Same concept.   

[Manticocerasman]

I also use B-72 instead of B-76, but in my experience it takes a while to disolve, often more than a day. Be patient, and shake the pot from time to time.

 

[snolly50]

If you pour the solvent over the beads, the "surface" beads melt together forming a shell; a big, solid clump of plastic. Such a formation has much less surface area for the solvent to contact than does the same volume of individual beads poured slowly into the solvent (each individual bead having a chance to be surrounded by solvent.) With agitation the entire mass you have should dissolve; but it will take a much longer time than dropping the beads little by little. Good luck, have fun.

[alej9582]

Ok guys, I know there will be laughs at my expense but I just have to say it... I was using nail polisher instead of 100% acetone... Please feel free to mock me (for one day only). 

[snolly50]

Yep, a quick Internet query revealed that nail polish remover is between 60 and 79% acetone. So, you are indeed dealing with watered down solvent; although the aloe vera might make your fossils nice and soft.

 

The other factor (just judging from your photo) is the ratio of bead to solvent employed. If that were to dissolve I would guess you would end up with a super thick concoction. Naturally the more plastic to be dissolved the longer it will take, even with straight acetone. 

 

Acetone is super useful, but that stuff gives me a headache. I am super cautious and wear a gas rated respirator when monkeying with it. 

 

By the way, not laughing, you may one day find out some of the "mistakes" I've made.

[alej9582]

Thanks @snolly50! 

[Malcolmt]

Definitely needed to shake vinac multiple times for many days to get it to disolve properly

[alej9582]

Thanks @Malcolmt. Used the procedure that @Harry Pristis posted some time ago and sprinkled the B-76 slowly and shaking constantly. It is disolving perfectly finally!

[Wrangellian]

I use B-72 with straight acetone also but it doesn't take me days to dissolve. I just stir it and stir it. You have to be careful at first as the sticky mass is tough and you have to control it so that you don't jerk it and splash any of it out of the jar! Put the lid on for a little while and come back and stir it again.. squish the blobs against the inside of the glass... Only takes a couple/few hours, not days. Of course do it in a well-ventilated area.

[Ptychodus04]

There’s an amazing amount of experience here.