Damn, had to replace my bunks for yet a third time in 7 seasons!

[WrenchHead]

175 Bass Tracker with TrailBlazer trailer. I replaced my bunks at about 6 years. I used pressure treated 2x4's and covered with original carpet. Now been 4 years and so far so good. Bunk longevity could be related to the area you live in. Here in Florida it is humid most of the year but Arizona is dry. Painted bunks before carpeting is OK if the wood is extra dry before painting. And you have to paint 4 sides plus both butt ends. But if you paint and seal moisture in the wood it will dry rot.

 

[redneck joe]

But if you paint and seal moisture in the wood it will dry rot.

Wouldn't that be wet rot?

 

[slowleak]

I've got two bunk trailers from the 80's, both have original bunks and carpet, both sit outdoors full time. Neither have any sign of any rot.
I've also got a 2007 trailer, with the same configuration, same style bunks, yet those bunks have collapsed on both ends after only 7 years.
All three appear to use pine, all three are 2x4's on their sides wrapped in black carpet with the bottom open.
When I replace the two bad bunks on mine, I coat the wood well with contact adhesive, and glue and tack the carpet in place. The glue plus the carpet backing gives it a barrier from water. The bigger concern with using pine with mine has been warpage, the bunks get wet, the get all twisted out of shape as they dry in the sun at the ramp while I'm on the water.