Get your orders in now for Christmas! Air scribes are FLYING out - are you one of the lucky recipients?
Butvar® B-76 is a thermoplastic, polyvinyl butyral resin. Butvar® B-76 mostly used nowadays in fossil preparation as a consolidant, a semi-matt varnish, a translucent but strong filler material and less commonly as an adhesive.
It can be used as an alternative to Paraloid B-72 as a consolidant or varnish during the current lack of availability of Paraloid B-72. We recommend the 5% wt/vol solution for consolidation, which may need further thinning with pure acetone.
Butvar B-76 as a filler material in fossil preparation: It can be combined with ground matrix to create a natural filler paste, which is rigid when set but easily dissolved or reworked.
It is often best used as a field consolidant or mid-mechanical prep consolidant as it is easier to remove than Paraloid B-72. Butvar B-76 redissolves in acetone or ethanol much more readily than Paraloid B-72 if used as only a temporary consolidant. The matrix isn't consolidated quite as firmly and adhesion with the specimen isn't as strong as with Paraloid B-72. This has it's advantages when working mid prep - the matrix can be consolidated for mechanical removal with an air scribe, but isn't too firmly set.
If using as a varnish, Butvar B-76 has a more matt (much less shiny) appearance than Paraloid B-72 which is often desirable. In this sense, it is similar to Mowithal B30H. If you are familiar with Paraloid B-72, Butvar is much more viscous at 10% wt/vol and so will leave a thicker deposit.
It also has a higher glass transition temperature (62-72C) than Paraloid B-72, making it better suited to fieldwork in hotter climates or storage of specimens in warmer rooms (glass roof, conservatories, etc.).
UK Mainland Shipping ONLY (including IOW, excluding Northern Ireland)
Guaranteed safe checkout