Introduction/Question

Hello everyone, my name is Mark, AKA Sandflea from the Florida Sportsman Forum. I am building my first boat. It is my own design which is probably dumb, but I just couldn't find plans for what I wanted (plus, I'm more of a figure it out as I go kind of person). I fish a lot around the shallow marshes for reds, trout, flounder, but need a boat that can still cross rough water (St. Johns River) to get to the skinny creeks. My design is basically a watertigh flat bottom catamaran with a small dry cabin to keep equiptment/camping supplies dry, while the deck can take waves, and also easily be rinsed off with a bucket of water after I get out and wade in the marsh mud, then track it back on the boat.


I am building my boat out of 1/2 inch marine douglas fir (and some 3/8) and west epoxy (with some silicone bronze screws, too) and have fiberglass tape for seams (not sure if I really need that since I am also using chine logs at the seams, but I tend to "overbuild, somewhat)

My question: I've heard that Douglas fir tends to "check" or split along the grain. I have bent the wood parallel to the grain to minimize this (and only mild bends) , but will it still check if I only coat with epoxy and paint, OR do I have to use fiberglass cloth over all exposed wood to prevent "checking". I really rather not have to fiberglass the whole boat if I don't have too. btw-the boat will be garage kept when not in use, if that makes a difference.

Thanks for your input!

 

Hi Mark,

Fir plywood will check without a layer of glass over it regardless of where it is kept. You only need 1 layer of the lightest glass fabric you can get.

For your seams use 12 oz. bi-axial glass tape without mat.

 

Thanks, Fisher.

Would I be OK just covering the hulls to prevent leaks? If the deck wasn't glassed, and it checked would that be really bad structurally? I'm not as conserned about it cosmeticly speaking, as long as it doesn't lead to rot or delamination. If the deck had some checking, and water wicked into the cracks, do you think the wood would just dry out between outings? Or would it really start falling apart?

 

The checking will let water in and the epoxy (a plastic) will hold the moisture in. Rot will occur, it will just be a matter of when and how bad. Given our humidity and rains, I would glass the entire thing where ever I could.
As inexpensive as the glass is to your overall costs and labor, I would put 2 layers of glass on the bottom side of the deck and 1 on the top. The 2 bottom layers of glass will strengthen your deck significantly.

 

Thanks for the insight, Fisher...do you get your glass cloth locally or order online? The only glass I've bought so far was a small amount of tape from US Boats to practice with (and it wasn't too cheap). Some of the other places I've checked just didn't seem to know too much about their own stock I need a good source!

 

I get small amounts locally. Larger amounts I get online. You need to shop around as prices change. Try www.raka.com

BTW, I'm not affiliated with them in any way.

 

http://www.fgci.com/

http://www.raka.com

http://www.westsystem.com/webpages/productinfo/guide/index.htm

http://www.masepoxies.com/mas11.htm


Gary

 

Fiberglass Supply, Inc. in Washington state. Most complete inventory of epoxies, fabrics, structural foams, et al around. Good prices.

http://www.fiberglasssupply.com/

Chris

 

Don't know if you have them there, but I get 'glass from the local Ace Hardware, they sell in bulk, and also sell bags of "remnants" as well. For $35 I got enough chop strand mat to do some major bottom repair for my 26 footer, 3 layers on about 60% of the bottom.

 

Thanks to everyone for the the good info.

 

Hi, all!

Fisher, I was talking a few weeks ago to a f'glass and epoxy vendor who suggested that i glass only the top (exterior surface) of my decks (wharram catamaran) and leave the other side of the ply unfinished except for a fungus killer (is cuprinol such??). 'let the wood breath,' was his final comment on the matter. he suggested actually that i leave all but the bilge areas on the inside of the boat unfinished except for anti-fungus treatment. I would be very interested in your thinking on this suggestion.

Thanks,

Tom Arnall
North Spit, CA

 

Sandflea; Try Defender for glass cloth and epoxy.

kloro; Nope, the whole idea of using epoxy is to keep the wood dry forever! Sealing with epoxy, (of nice dry, clean wood) minimizes to a tiny amount the moisture coming and going in the wood. This minimizes movement of the wood, wood that is sealed will not peel your sheathing off. The wood will maintain it's structural properties just as long as it's kept dry. Your salesman is trying to give you half one technology (that of the past century) and half of another (that of the present). We all should know by now that half-a*sed is no answer. Sheath the outside with light glass, coat the inside with three coats of epoxy. She'll be a great boat for a long, long time.

All the best, Tad

 

After you coat the inside with epoxy it is good to paint it with house exterior paint. It has mildewcide and is rated for human contact. The difference is huge. Epoxy tends to create condensation and mildew thrives on it.

 

I painted the lockers on our Catalina 22 with "Killz" mildew resistant paint... and several years later they STILL look like new- Gonzo speaks thew truth in that polyester, vinylester or epoxy resin do nothing to deal with the issue of condensation and mildew.

Maybe there is a fungicide gel-coat somewhere??? Regardless, Killz is cheaper at your local home improvement establishment.

(gonzo do you get paid to answer every post?)