Started Another Duck Boat Build
- Thread starter DaveP
- Start date
DaveP
Active member
I'm making some progress. Boat is 3/4 sanded and faired, all that remains is sanding out half of the hull. Then I plan on applying several coats of epoxy with graphite to the hull. Any ideas on the best why to apply epoxy with graphite?
Sides, transom and sponsons will be painted with Interlux epoxy primer and ployurathane paint.
Sides, transom and sponsons will be painted with Interlux epoxy primer and ployurathane paint.
Brad Taylor (NC)
Well-known member
I've used the graphite thickened epoxy on 6 or so boats now and I've tried foam rollers, squeegees and brushes. I still end up coming back to a 4" brush. The squeegees and rollers don't leave a thick enough coat.
Very nice work on the boat!
Brad
Very nice work on the boat!
Brad
Howard
Well-known member
With the graphite coat I just apply it like a regular coat and go over it a couple times with a foam brush then watch it for sags. I have never used more than 2 coats. It's just to hard to sand. Brad Taylor has used more of it than I have, I think. It's no different than a clear coat imho.
Brad Taylor (NC)
Well-known member
No, I just put it in a flat wide container after mixing to slow down the kick. A plastic paint roller tray works well and the epoxy will peel right out of it once it cures. I tape around the sides however far down I want to go. You may want to mix a little cabosil in for your vertical surfaces if you go over your sides any, otherwise the coating ends up really thin there.
Brad
Ryan Werden
Well-known member
The boat is looking real good Dave. Nice work.
DaveP
Active member
Brad, I"m going to do just the bottom, but planned on mixing some cabosil in just to cut down on the runs. I've got half the hull sanded nice and smooth, the other will be also. In fact I'll have to go over it and rough it up a bit. This is my first time using cabosil and graphite. I used 12 oz biaxial cloth and it took a lot of fairing mix to fill it in and even the over laps. I mixed the fairing mix my self with cabosil and micro-balloons.
charlie foulds
Well-known member
Very nice..!!! Did you fiberglass tape the seams before glassing the hull?
DaveP
Active member
Charlie, Oh yes this is a Bateau boat. Chines got one layer of 12 ounce biaxial tape. Keel and transom got two over lapping layers of 12 oz biaxial tape. Then the hull was covered with 12 oz biaxial cloth over lapped 6" on both sides of the the keel. Plus the keel itself was made out of a single piece of 3/4 X1 1/2 fir. I ripped a V was down the center on my table saw 3/8" deep and 1" wide, put in a few kerf cuts for bending. The V slot was filled with epoxy putty, turned over and set right on top of the keel line, held down with bungee cords. Sides were filletted, then two more over lapping layers of biaxial tape epoxied on top of the keel. Plans call for 1/2" thick fillet at the chines on the inside covered by one layer of 12 oz biaxial tape and two over lapping layers on the inside keel and transom. Then the entire inside hull will be glassed with 12 oz biaxial cloth over lapped 6" at the keel before the frames are epoxied in.
rob paetzold
Active member
Dave,
I can't believe your not done yet! - just kidding
Boat looks great I think you should start teaching duck boat building classes!
I can't believe your not done yet! - just kidding
Boat looks great I think you should start teaching duck boat building classes!
Mike Faught
Member
Nice boat. I have a couple questions about the bottom coating. Why use graphite thickened epoxy? Is it tough, slick, or something else? Will it work on the bottom of a polyester resin boat? I have an original Fatboy that needs some work on the bottom, and this may be the ticket.
Thanks,
Mike
Thanks,
Mike
DaveP
Active member
Mike, I'm not an expert here. What I know about building duck boats I've learned here and on another boat building site. May be the experts will chime in. But you can put epoxy over polyester, but not polyesther over epoxy. There are several additives that can be added to epoxy to create certain characteristics. Graphite powder makes the bottom slick. Alumimun powder increases abrasion resistance. If you are dragging your Fatboy in and out of the water go with an Alumimun mix. These additives are cheap and you don't need much.
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DaveP
Active member
The outside hull is finished. Today it gets flipped over to start on the inside. After fairing, the bottom got three coats of epoxy/graphite. The sides received two coats of Interlux epoxy primer, three coats of Interlux Emeral Green and a coat of cheap flat olive drab spray paint to cover the bright emeral green paint.
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John Robinson
Well-known member
Great job Dave. I was wondering what the benefit of the graphite was as well, slcker in the water, less drag and more fuel efficient? Very clean job and you have passed me like I'm standing still, which is pretty much true this past month.
John
John