Message text written by "BP - Dwell time 5 minutes."
>Of what advantage is the use of methyl acrylate as opposed to epoxies or
polyester resins? Methyl acrylate has become a buzz word for me, of minimal
substance, and I would like to know what it really means when
preservationists
talk about using methyl acrylate, particularly for injection into masonry.

][<en Follett
<
The methyl methacrylates to which you are referring are either acrylic
monomers or prepolymers. These are low viscosity resins which are reacted
in place to form acrylic plastics. The acrylics have the advantage over
epoxies and polyesters of being clear and UV stable, which the other two
are not. They can be formulated for differing mechanical properties, but
generally are not as strong or chemical resistant as epoxies, nor as
moisture insensitive during application. There has been some very positive
work done using methyl methacrylates in highway repairs and concrete
overlays. Although methyl methacrylate has a very high linear coefficient
of thermal expansion, which would lead one to predict failure under thermal
cycling, they have proven more compatible than expected with concrete.

Another characteristic is their ability to react quickly even under cold
temperature conditions, which is why they are used in concrete repairs to
coolers and freezers. They can smell pretty awful though, so can't be used
in coolers where there is food being stored during application.

Mike Edison