Another "which wood for bunks" thread

[ajgraz]

I did search this forum and others, but still can't decide. So let's discuss this topic some more :redface:

Bunks will be 2 by 6 laid flat, carpet on wood, no glue, Monel staples. Trailer will get dunked in salt 20-25 times a year, hosed down when get home. I'd be happy to get 3 to 5 years service life from the bunks.

So which wood to choose?

Pressure treated

or

Green douglas fir, with one of these treatments:

None
Boiled linseed oil with mildewcide
Oil / latex deck treatment
Alkyd / acrylic deck treatment
Some other treatment (but what?)​

(I did consider redwood, but was unhappy with the knotty, split crap I saw in the lumber yards.)

Thanks

 

[Bondo]

Re: Another "which wood for bunks" thread

Ayuh,... PT, hands down...

 

[1fishbone]

Re: Another "which wood for bunks" thread

First issue:
"Bunks will be 2 by 6 laid flat"

It doesn't matter what wood you use, after a couple dunking s, this will only sag and support the hull where the supports to the frame are located!
But, a lot of trailers are manufactured that way...just glad they don't build houses that way

As for wood, I suggest PT or as I used, dry, rough cut, full size, saw mill finish white oak, standing on end...been there for around 8 years, was covered in carpet but I took off that mold and moisture holding junk carpet and added bunk strips about 4 years ago. Only salt water use.

It also depends how it's supported, mine are supported underneath the wood and bolted to hold them there.
I've seen some where the bolts are the support!
Also, from what I've learned, fresh water rots wood faster than salt water, fresh water has more bacteria, carpet holds/traps moisture.

My 2?

 

[NYBo]

Re: Another "which wood for bunks" thread

But, a lot of trailers are manufactured that way...just glad they don't build houses that way

You've clearly never watched Holmes on Homes!

 

[Evinbuck]

Re: Another "which wood for bunks" thread

Pressure treated will definitly last longer. Just remember to also used galvanized bolts or fastners......same reasoning for using rust proof staples.

 

[I Am Mello]

Re: Another "which wood for bunks" thread

I would go to a mom and pop yard and tell them you wish to pick out some "hard pine" lumber treated of course!

How do you know its hard? It weighs more. This has more strength being you are laying it flat.

There are different treatments. ACQ MCQ CCA ect ect.
Be sure to use stainless fasteners if you buy ACQ treatment, they are horrible on all fasteners except stainless.

All IMHO

 

[fishrdan]

Re: Another "which wood for bunks" thread

(I did consider redwood, but was unhappy with the knotty, split crap I saw in the lumber yards.)

Go to a different lumber yard,,, "lumber yard", not big box store...

When I rebunked my old trailer I looked some really crappy redwood at the big boxes, knots, splits, twists. Took a trip down the local lumber yard and found perfect 10' 2x6's, straight, no knots or splits. Those bunks lasted 10 years and were still in good condition when I got rid of the trailer.

 

[Outsider]

Re: Another "which wood for bunks" thread

Cypress will outlast 'em all ...

 

[Mischief Managed]

Re: Another "which wood for bunks" thread

If you opt for ACQ PT, make sure you isolate the wood and the ACQ-rated fasteners from the metal on the trailer to prevent galvanic corrosion. One of the easiest/cheapest ways to do this is to cut up pieces of plastic, such as the plastic used in those big Sterelite or Rubber Maid storage bins. Cut the plastic into pads sized to fit on top of the trailer's bunk mounts. Also, using a hole saw, cut plastic washers to fit between the fastener washers and the bunk mounts. Thin slices of vinyl tubing on the fasteners will isolate the sides of the fasteners from the holes in the bunk mounts.

 

[ajgraz]

Re: Another "which wood for bunks" thread

I did decide to go with pressure-treated. In fact, after stripping the carpet off my 5-year old PT bunks and trimming a bit off the ends, the wood looks like I just bought it, so I'm reusing them and using the $25 saved for Valentine's Day.

If you opt for ACQ PT, make sure you isolate the wood and the ACQ-rated fasteners from the metal on the trailer to prevent galvanic corrosion. One of the easiest/cheapest ways to do this is to cut up pieces of plastic, such as the plastic used in those big Sterelite or Rubber Maid storage bins. Cut the plastic into pads sized to fit on top of the trailer's bunk mounts. Also, using a hole saw, cut plastic washers to fit between the fastener washers and the bunk mounts. Thin slices of vinyl tubing on the fasteners will isolate the sides of the fasteners from the holes in the bunk mounts.

Awesome ideas. Funny you should mention this, the previous galvanized swivels that were holding up the PT bunks corroded away almost completely...one of the reasons I was maybe considering NOT using PT again.

I already have 3/8", 1-1/4" long stainless lag screws, and I believe I have some scraps of 1/4" starboard laying around (or I could maybe use some scraps of 1/16" silicone rubber sheet) for isolators. As for the lag screws, maybe some small bits of heat-shrink or paint 'em up with liquid electrical tape on the shaft near the head to isolate those.

EDIT: to add to the above, I wound up using some 1/8" thick closed cell neoprene sheet to make 2" by 4" pads between the swivels and the bunks, I punched some 1-1/4" OD x 3/8" ID washers out of some 1/16" thick silicone sheet to go between the lag screw washers and the swivels, and painted the lag screw shafts with liquid electrical tape. If that doesn't galvanically isolate the PT lumber from the bunk hardware, I dunno what will