Adhesives

[don dougan <dondougan@zzzzzzzz>]

Hi Jennifer,

I use multiple materials in my work, and joining each one to each other
is different.

However, small unfitted objects are probably best joined with silicone
rubber adhesive, but this is limited to very small and lightweigh (or
very large-but-broad-joining-surfaces and still relatively lightweight
overall) pieces.

If you fit pieces together so they have a mechanical advantage (including
pinning the separate pieces together or carving fitted holes or mating
contours) to strengthen the joint, epoxies work well.

Polyester resins (especially made for stonework) are only suitable for
joining either where the joint will be visible (and needs to be
polished/color-matched) or where it will be imbedded or filling cavities
and the joint is strong even if the resin fails.  Though mixed polyester
colors are more stable than epoxies, most polyesters are not rated for
outdoor use.

When in doubt about future safety or failure, always pin or dowel all
joints and don't rely solely on the adhesive.  All adhesives fail in
various specific combinations of conditions, and you (the maker and
therefore legally the one who is liable) can never know if that condition
will occur to the piece after it leaves your care.

By the way, though cyanoacrylate adhesives (Super Glues) can be used for
some limited
applications where perfectly mating surfaces (such as unbroken chip
replacement or capillary 'bleeding' is needed to reinforce
cracks/fissures), do not use them as the only adhesive at anytime -- they
will eventually fail with exposure to UV light, heat, and even minor
shocks.

Goog Carving (Joining!) to You,
Don

http://www.dondougan.homestead.com/indexdd.html