Proper lumber and treatment for trailer bunks

[mckinney004]

I have an early 90s 28ft Harris pontoon on a Bobcat trailer that needs the bunks replaced. I recently found out first hand of the corrosiveness of pressure treated lumber with aluminum. So what should I be using for lumber for the new trailer bunks. Planning on using 2x6. Should I be buying untreated lumber and then coating it with spar varnish, oldtimers blend, epoxy, oil based paint, etc? I already have some PT 2x6 leftover from another project. Is it possible to coat it with something that would prevent the chemicals from reacting with aluminum?

As far as the coatings go, are any of the methods I mentioned any better than another. In addition to this project, I'm replacing two transoms in aluminum flat bottom boats. I'll be coating those as well with one of the methods. If they are all fairly equal quality, which is the most cost effective? It appears that oil based paint is by far the cheapest, however I'm not sure how long it will last if used alone. Or am I wrong?

 

[Scott Danforth]

are you boating in salt water or fresh?

if salt water, any hardwood

or cypress if in fresh (can use in salt as well)

do not use PT what ever you do with aluminum. there is not a coating you can do, unless you use bunk slicks or something along those lines.

 

[gm280]

My personal opinion, buy some good straight and as knot free as you can find regular 2 x 6's and apply a couple coats of polyurethane and mineral spirits mixture 50/50. Let it really soak in. Then if you want, paint them with some wood outside type paint like Rustoleum in the color you like. Then carpet them using Stainless Steel staples or Monel staples and install them. They should last for years to come. At least that has worked for me over the years. JMHO!

 

[utfyrfytr]

Just a thought, would the new Trex outdoor deck material work for bunks? I don't think it would ever rot. I'm not familiar with how it is made or if it is solid or hollow. Just thinking.

 

[bruceb58]

Just a thought, would the new Trex outdoor deck material work for bunks? I don't think it would ever rot. I'm not familiar with how it is made or if it is solid or hollow. Just thinking.

Not strong enough.

I just use regular lumber and paint it with latex paint first and then cover with carpet.

 

[gm280]

Just a thought, would the new Trex outdoor deck material work for bunks? I don't think it would ever rot. I'm not familiar with how it is made or if it is solid or hollow. Just thinking.

If it is the same stuff they are now building decks out of, the answer is NO! Those planks are not solid, they have ridges in them on the underside, I guess to save money with the material used. So like bruceb58 stated, they are not strong enough. Go the regular wood route and treat them and paint and they will last a long long time. JMHO!

 

[fhhuber]

Paint has to be COMPLETELY waterproof (including at the bolts holding the board to the trailer) or you are best off not doing it. Like carpet or fiberglass coating most of wood but allowing water exposure through a crack, all it will do is trap water in the wood as it migrates through the grain.

 

[bigdee]

Paint has to be COMPLETELY waterproof (including at the bolts holding the board to the trailer) or you are best off not doing it. Like carpet or fiberglass coating most of wood but allowing water exposure through a crack, all it will do is trap water in the wood as it migrates through the grain.

X2 best not to paint at all b/c it traps moisture. Wood will take quite a few wet/dry cycles the key is drying time.....paint will inhibit the internal drying process. Bolt holes are the first to go. I drill holes larger than bolt and then I drill a weep hole into the bolt hole (through bottom washer) to allow water to escape.

 

[MRS]

Just plain old 2x6 with carpet on sides and top will last at least 10 or more years. Just make sure you mount them nice and solid. Works for me...

 

[bruceb58]

Bolt holes are the first to go. I drill holes larger than bolt and then I drill a weep hole into the bolt hole (through bottom washer) to allow water to escape.

I use lag bolts from the bottom so no bolt holes from the top to absorb water. Plus I hate carriage bolts.