Particle board is the wrong "wood" to use for outdoor projects since it
tends to weaken and fall apart when exposed to water. Since you have
already finished the project, an outdoor paint would be fine. Make sure it
is completely cured, about two weeks, before placing outside. Any of the
film forming finishes including paint will be nontoxic once fully cured. If
you really want to go for it, try the epoxy coatings that are made for
marine use. That will completely waterproof it but it is overkill in my
opinion. Lacquer would be the worst film finish that you could use for your
application.

Good Luck.

"Joe_Stein" wrote in message
ink.net...
Hi guys,
I've just finished building a birdhouse from a cheap computer desk (talk
about recycling). It's particle board with the plastic(?) coating that
looks like wood. I'd like to weatherproof it. I thought of just slapping
on multiple layers of paint I have laying around. I don't think the
birds will mind. Comments? Suggestions?
TIA
Joe