How to Treat a Wooden Shelf I'm Building in the Engine Room

[glhotka]

I have a 43' Gulfstar sailboat and want to organize the engine room. The bilge pump is located on a small wooden shelf that is rotting on the edges. I want to build a nice set of shelves to mount the bilge pumps as well as the rear heads shower pump. My intent is to build this out of wood, but the question is what should I treat it with. It will likely be made of red oak 3/4 inch stock and assembled in my workshop then taken to the boat for mounting.
I was thinking of just painting it, but realize that won't protect the wood.
Can I paint it in epoxy? Can I paint it in fiberglass resin without the mat?

What would you recommend and what have you found works best?

Thanks in advance for the thoughts.

[thinwater]

I first read about it for totem poles; I was involved in a totem pole project, researched this subject on the net, and found this:
Protecting woodwork against decay at Sitaka National Historical Park (1993) - Preservapedia
We cooked up the glycol/borate mixture, painted it on repeatadly and heavily, and let dry for a number of days. We then painted the stump with left over marine bottom paint, to provide additional bug protection. It was a great success; that was 8 years ago, and the stumps of the trees we cut are nearly gone, but the totem poles are still hard and undamaged (we dug down a bit and inspected them this summer).

Gougeon Brothers (leaders in the boat/epoxy business) have this to say:
The Effect of Ethylene Glycol and Sodium Borate Solutions on the Adhesion of Epoxy to White Oak and White Pine Samples.
Basically, it can reduce adhesion if the surface is not dry first, which is challenging, since glycol dries very slowly. However, we did not have paint adhesion problems (we did wipe the surface with a fresh water rag to remove glycol from the surface). I suspect the low adhesion (only on the oak) was an artifact of the test method, as others have not reported this.

Alternatively, I bet a pressure treated shelf would work fine, and would last and last. Just not fancy looking, so we don't consider it. Pressure treated wood is not generally seen on boats because it isn't as strong as other things and looks like hell, but it is also quite practical at times. My last boat had some parts in the centerboard hold down that I came to consider sacrificial, and I finally learned that nicely finished oak was a total waste of time. This may be one of those times.

______

The glycol/borate preservative is commercially available, but home brew is dead simple: 70% ethylene glycol antifreeze (concentrate, not 50/50, and get the traditional green sort if you can--it has a borate-based chemistry, and don't use pink PG antifreeze), 30% borax. Heat the glycol on the stove until boiling gently, then slowly add borax until it will hold no more. Do not let the temperature excede 265F (candy thermo) and keep the vent on (it does not stink, but the fumes are potentially dangerous)

[keepondancin]

I wouldn't use oak, it is a hard wood, and putting screws into it will be a pain in the butt. You will be forever cursing it everytime a screw breaks off. I would use a good grade of 5-7 layer veneer plywood, and epoxy coat it. A simple pilot hole wood make installing screws easy, but they would hold.

[s/v Jedi]

I would use a plastic wood like King Starboard.

cheers,
Nick.

[cburger]

Red oak is prone to rot, if you have the choice use white oak. A couple of coats of epoxy will protect the wood just fine, be sure to saturate the end grain really well.

[Jimbo2010]

Originally Posted by keepondancin

I wouldn't use oak, it is a hard wood, and putting screws into it will be a pain in the butt. You will be forever cursing it everytime a screw breaks off. I would use a good grade of 5-7 layer veneer plywood, and epoxy coat it. A simple pilot hole wood make installing screws easy, but they would hold.

Agree

[Shoalcove]

If they are not going to be epoxied to anything else, I'd go to Walmart or similar and buy a cheap plastic cutting board. Cut it to size, screw on your pumps, set in bilge area. No rot, easy to clean, and, I repeat, cheap. On to the next job!

[shorebird]

All good suggestions. Putting screws into oak is fine if you drill the pilot hole properly. For longer screws, an old trick is to use a bar of soap to wax the threads of the screw before turning it in.
Plywood can be a good choice, but edge grain won't hold a screw as well as solid wood.
As posted, epoxy can seal wood well, but ideally, it should be "penetrating" epoxy, which is thinner, and will penetrate further, particularly on edge grain.

[glhotka]

Thanks for the great suggestions. I may go the marine ply route (but starboard/cutting board may be a good option for a smaller project). When you say penetrating epoxy, is there any specific brand I should look for or is this something I can get from a local hardware store? I figure if I can get it at a hardware store over a marine store I will save at least half the cost.

[Jimbo2010]

You don't need marine ply, exterior is fine.

[irwin27destiny]

Look into MAS epoxy.

[Cheechako]

good plywood is often easier to work with. any paint will do, it should out live you in the engine room!

[keepondancin]

Just watch the quality of the plywood. There is a lot of chinese plywood around, and is worse than substandard. Delaminates, filled with voids, lacks glue, etc. Stay away from homecenters, they have a lot of it. If there any wood fabrication businesses around,like cabinet shop, boat builder or repair, even a carpenter or handyman, ask them for scraps. Coffee and an egg sandwich goes a long way. If you are going to do anymore boat projects, it wouldn't hurt to buy a small amount of West, or MAS epoxies, with pumps, so you get the correct metering. Might even be how you mount the shelves in the engine compartment. Doesn't go bad, and you may wind up finding more uses. West System Epoxy web sight has downloads on using West epoxy. Pretty much all the epoxies work the same.

[thinwater]

Originally Posted by keepondancin

Just watch the quality of the plywood.

A quick test for waterproof glues is to leave a scrap in boiling water for 30 minutes; if it doesn't laminate, you're good for this sort of purpose.

[S/V Alchemy]

Originally Posted by s/v Jedi

I would use a plastic wood like King Starboard.

cheers,
Nick.

I would use the same HDPE sheet I use for mounting half the stuff in my steel boat. It melts at a higher temperature than wood burns, and doesn't otherwise rot. You can use a hole drill to reduce its weight, and just through-bolt anything you want to it.

Starboard's pretty much identical. So are the "cutting boards" you can buy for a few bucks at surplus stores.

Wood is great for battens in the saloon and the surround for the head. Otherwise, it's a pain on a boat as far as I'm concerned, and I resort to it rarely.