- Q.When installing stained
vertical cedar siding or fascia trim, what type of glue
should be used for splices and corners? Some
contractors like to dab a little stain on the cut ends
of 3-degree splices or on 4-degree corner miters, but
is there an exterior glue that will adhere in the
presence of an oil-based stain?
A.Jeff Pitcher, vice
president of CP Industries, a manufacturer and
distributor of adhesives for the wood-products
industry, responds: If not for the stain, any
exterior wood glue or exterior-grade adhesive would
work fine in this application. But oil-based stains
could potentially interfere with the glue line, a
problem you could avoid by not using any stain on
the gluing surfaces. If that isn't possible, use
either a solvent-based construction adhesive, such
as PL 400 (Henkel, 800/999-8920,
www.stickwithpl.com) or a
polyurethane-based construction adhesive, such as
Chem-Calk (Bostik, 888/603-8558,
www.bostik-us.com).
Avoid the temptation to use a reactive
polyurethane glue like Gorilla Glue (800/966-3458,
www.gorillaglue.com). While
it's true that this type of adhesive can provide a
sturdy glue joint in the presence of surface
contaminants, its curing process causes it to foam.
Because you won't be able to apply adequate
clamping pressure until the glue cures (nails alone
probably wouldn't suffice), the joints would end up
with unattractive, excessively foamy glue
lines.