To prime or not to prime?

[Raymond Fries]

I am installing 1" rough sawn cedar for trim around windows then painting it a Stone Clay color Acrylic Latex paint which is a darker color. The trim boards will also be sealed to the anderson window frames with backer cord in the gap and covered with polyurthane caulk.

I have read many posts that say to prime all six sides with an oil based primer first.Some say it will prevent bleeding of the tannins.Do I need this with a darker color. The trim that was removed from the room was not primed, painted the same color, and I saw no bleeding.

The other posts say to prime because it will make the wood last longer. I guess some water would wick between where the cedar meets the vinyl siding.

I sure do not mind the extra work, if it is truely beneficial.

I sure would like feedbck from those with cedar experience.

Thanks

[Wayne Lomman]

Prime all surfaces regardless of species. The trim will last much longer especially when the caulk develops hairline gaps which they all do over time. I can't remember the last painted cedar job I did if ever - all mine have been clear finishes - so I will let others comment on bleeding issues. Cheers

[Jason Roehl]

Prime all sides, but don't use an oil-based primer. Personally, I like to use an acrylic solid color stain as a primer, as they are designed to penetrate, "breathe", and to block tannins. They will also remain more flexible than an oil-based product. Then topcoat with two coats of a quality exterior acrylic coating. Or, if you don't mind a little more maintenance, another coat of the solid stain (which would probably get you 8-10 years of service in Indiana).