I have a Venture triple axle aluminum trailer for my Formula 311 SR-1 (~9,000#). One of my bunks/runners has some cracks in it (the other looks and sounds (hammer taps) solid). The current runner is 3" X 8" (as measured) X 12' long with carpet on top. Is there a specific kind of wood for saltwater use that I should be using (replacing with). My gameplan is to inspec both carefully the next time I launch my boat BUT I am thinking of just replacing the "suspect" one.
Thoughts, ideas, recommendations?

I used yellow pine on a trailer project a few years back, used MONEL staples to attach the carpet. Some people swear by cypress, damned hard to find though.

I've always used good ole fashioned pine 2x6's, the trick is to only wrap the carpet about an inch past the corners on the bottom, that way they can dry out, last alot longer doing that, used treated once back in the day, huge mistake

​​​​​​OH yeah, use stainless staples

I’m assuming with that size of boards, your bunks are on edge like mine....not laying flat. I have a 96’ loadmaster aluminum trailer with 3” x 8” x 10’ cypress bunks. A quick check of their (loadmaster) website looks like you can get either cypress wood or already carpeted wood. Their 3”x 8” however only goes to 10’ long. It looks like you can get 3” x 10” in 12’ long. Hope this helps.

Thanks all

Big difference in staple quality: Always use Monel

Like they say, cypress if you can find it. If not, I prefer Fir over pine. Straighter and doesn't warp as bad. I redid mine a couple of years ago with Fir. It's pretty soft wood like pine, but I used Smith's CPES to seal the boards and have had no issues.
By the way, just for fodder, If you use treated wood, you should not use Monel staples. Stated on the back of the box, that they aren't compatible with the chemicals in the wood.

Found this quote on Walmart site regarding Monel Staples. Warning Monel staples should not be used and will corrode with any wood that has been treated with ACQ (pressure treated wood)
Would never have thought that.

We replaced some large ( 4x12x16' ) cypress bunks that were rotten. Here in northern Virginia it was hard to find much comparable. Ended up screwing/gluing two 2x12x16 doug firs together and has worked well so far.

Whatever you do, I'd recommend leaving the lower portions exposed ie not wrapped in carpet so they can drain. And yes, stainless staples!

good luck

Why is treated lumber a "huge mistake"...? That's all I've ever seen used when rebunking a trailer....

Thanks. Brad.
(937)545-8991

You don't want to use treated lumber on a trailer. That advice came direct from Myco years ago when I asked them. THEY use regular pine.

The salt treatment will leak out of the wood as water seeps off the bunks, and will grossly corrode over the metal on the trailer, no matter painted steel, galvanized, or aluminum.

Years ago, I had one of my toolboxes get wet on a crappy launch ramp. I had a number of lengths of 2x6s in there, some salt treated, some not; just to use to build a ramp to change a flat tire (negative angle torsion axle Myco). That wood after it got wet leaked it's salt treatment crap all over that aluminum box and turned the inside to a horrible mess.