Best glue for MiraTec?

[Dave Lewis]

I need to fabricate an exterior trim waterboard. I bought Miratec and the website recommends yellow carpenters glue.

Will Titebond III work OK?

Does the primer need to be scraped / machined off?

[Peter Quinn]

If by waterboard you mean the row of trim closest to the ground that wraps the building, above which starts the siding in most cases, then you should read their install instructions carefully. They prescribe yellow glue for mitered corners on column wraps or corner boards. And yes, for these tite bond III would qualify, type II may also work, and gorilla glue or other urethane adhesive is also prescribed. For long runs of trim they prescribe scarfs or buts and anything over 30' indicates the joints should be gapped and caulked to form expansion joints. Most of the composite trim expands on length due to changes in temperature, so if you butt 45' of plastic trim hard on a cool day in November, it's going to buckle and pull off the building or expand and push off the corner boards in August! Read their install requirements carefully. Miters get glued....but joints caulked and gapped.