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I have a 13' RMR with a DRE frame. I'm looking to make a beaver tail for the back to be able to haul more gear.

Does anyone have suggestions on what type of wood to use? Or what to use to coat the wood?

Any and all suggestions are appreciated.
 

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I made mine with 5/8' standard plywood and then rolled/brushed one coat of fiberglass resin on it. I also drilled a bunch of 1/2' holes in it that I then pulled webbing through and knotted to use as tie-down points.
 

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Just make sure you get a plywood with an "x" designation in the name (i.e. ACX or CDX). The X stand for exposure and is designed to be used outside, the other letter designate the quality of the finish on each side so ACX is a higher quality with less defects and a smoother finish than CDX.

The other thing is make sure you use a SPAR varnish, fiberglass is a great add, I have done that on a lot of my beaver tails and side deck but most fiber glass resin in not UV stable so it will yellow over time and it will crack and let water into the plys. That might not be a big issue but the spare with also help with water intrusion.

If you re-coat with SPAR every year or two you will get a long life out of them.

You will probably get some responses that recommend marine plywood which I think is overkill and more expensive than I would want to spend.
 

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Just make sure you get a plywood with an "x" designation in the name (i.e. ACX or CDX). The X stand for exposure and is designed to be used outside, the other letter designate the quality of the finish on each side so ACX is a higher quality with less defects and a smoother finish than CDX.
Try MDO. It's "Medium Density Overlay" plywood. Generally an ABX overlaid with recycled paper. Don't let the "recycled paper" part scare you, it's fairly well saturated with glue. 1/2" MDO is usually used for signs, and 3/4" MDO is usually used for concrete forms--both are outdoor exposures.

I agree with jspoon14, Marine ply is not really needed in this application. You'll get the same glue holding the plies together, but marine ply will generally have fewer voids in the inner plies for strength. You're not looking to keep an offshore rig together in pounding seas...you're trying to keep the groover from holing your raft floor.

Also agree that epoxy resin alone isn't enough to keep douglas fir plywood from checking. if you do glass AND epoxy then you get a lot more strength/stiffness (and cost/effort).

Edit: and in full disclosure, my beaver board is 3/4" marine ply, but I didn't buy it! My brother built it and gave it to me in exchange for using my raft on the Snake about 15 years ago. It's crazy stiff/strong and probably has 9 plies. It's now been in 3 different boats. Top surface was a little gross, so I did my own "MDO" and overlaid heavy kraft paper over the surface with epoxy. The paper looks better than the scarred up plywood. I'd do 3/4" MDO if I built one again.
 

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I make mine out of CDX plywood that is more than 1/2" thick but less than 3/4" thick. I cut round holes for the straps and sand the smoothness into them. Then I lay on a bunch of coats of a mix I found on the internet called "boat soup". It takes a long time to dry completely but the finish has stayed on for over three years now.

Here is the formula
40% spar varnish, 25% linseed oil, 25% turpentine, 10% Jap dryer.

I started off trying it with 25% of each ingredient but since switched to this formula with better finished results. I've also seen on the internet, but have not tried a mix of 1/3rd x 1/3rd X 1/3rd of each without the Jap dryer.

Through my experiments I found too much Jap dryer made the finish kind of dull looking and I like my things to look slick. :mrgreen:
 

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"Micarta"

Try MDO. It's "Medium Density Overlay" plywood. Generally an ABX overlaid with recycled paper. Don't let the "recycled paper" part scare you, it's fairly well saturated with glue. 1/2" MDO is usually used for signs, and 3/4" MDO is usually used for concrete forms--both are outdoor exposures.

I agree with jspoon14, Marine ply is not really needed in this application. You'll get the same glue holding the plies together, but marine ply will generally have fewer voids in the inner plies for strength. You're not looking to keep an offshore rig together in pounding seas...you're trying to keep the groover from holing your raft floor.

Also agree that epoxy resin alone isn't enough to keep douglas fir plywood from checking. if you do glass AND epoxy then you get a lot more strength/stiffness (and cost/effort).

Edit: and in full disclosure, my beaver board is 3/4" marine ply, but I didn't buy it! My brother built it and gave it to me in exchange for using my raft on the Snake about 15 years ago. It's crazy stiff/strong and probably has 9 plies. It's now been in 3 different boats. Top surface was a little gross, so I did my own "MDO" and overlaid heavy kraft paper over the surface with epoxy. The paper looks better than the scarred up plywood. I'd do 3/4" MDO if I built one again.
Very interesting idea using clear two part epoxy and Karft papper for a surface for a beaver board. That is an excellent idea, "Micarta" is what the process is called now, very strong and durable, plus economical(cheap) process to do. How I discovered this, is a friend of mine use to make knives, infact he made a skinning knife for me and used the antler's from a deer I downed for the handle, anyway he would cut square's of Kraft papper or cheep
felt material of different colors for effect and epoxy them together, one at a time using a paint brush to apply the epoxy to each layer he would layer it to about an eight inch thick you can do it to any thickness, one layer or 50 what ever, than press the layers together between two pieces of plywood and clamps, after drying he removed the plywood and your left with this indestructible piece of material to cut and design for knife handles or whatever you want. Modern knife handles, use a commercial product of this material today on very expensive knives. You can take a hammer and beat the crap out of a piece and it holds together. Nice idea to use it on top of a beaver board.
 

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Not to derail but to derail. Has anyone used the micarta or fiberglass overlays mentioned above for side boards? I plan to make some this winter and was hoping to use use something lighter than 3/4" ply maybe with fiberglass I could do 1/2" with a coarse weave glass mighty make a strong board with some texture for anti slippage.
 

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To add to the conversation for those of us who don't know what is reasoning for a beaver board? I thought that was an old school thing that wasn't real needed with modem boat construction.
 

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I use my boards to keep heavy, mostly rocket boxes and water jugs, off the floor and the weight suspended from the frame of the boat. Maybe you don't need them for the really stiff floors on new PVC boats these days.

I would still put something down between the metal boxes and the plastic floor material, like maybe a tarp, to keep them from rubbing.

Everything bags are a good way to replace the need for floor boards.
 
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