Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Re: Strip: Building Bjorn Thomasson's Frej
By:JohnAbercrombie
Date: 4/8/2013, 10:38 pm
In Response To: Re: Strip: Building Bjorn Thomasson's Frej (Erik Jensen)

I have used graphite mixed in epoxy on the bottom of two S&G kayak to give a more durable finish, and toyed with the idea of a black "graphite" hull. Do you know of some data comparing scratch or dent resistance of finishes having different compounds mixed in epoxy?

If you found that graphite gave a more durable finish on your S&G kayaks, yo already have a couple of data points....
I can't answer your question with any real 'data', but I have a few thoughts/opinions/experiences:

1)I've found graphite + epoxy is quite soft (easy to sand into a black dust cloud....)-softer than straight epoxy. The idea of adding graphite to epoxy was developed by the Gougeons (WEST Epoxy) for making low-speed pour-in-place bearings for things like sailboat rudder stocks, as I recall.

2) The 'usual' hull coating is epoxy+graphite+silica (fumed silica aka Cabosil aka 'NoSag'). Graphite for black, silica for hardness. An experiment sanding silica-loaded epoxy will give you an idea of that. I've always found that graphite is more of a dark grey than jet-black color, but it may be the stuff (WEST) I was using.

For sliding off rocks and barnacles, I'm looking for the hardest surface I can easily get, so lots of silica is one way to try for that. The iron oxide is gritty and 'hard' and I don't need a great deal to get a black color, so I can use more silica in the mix.
I've been impressed with how tough the hull on my 'BritBoat' project has turned out to be. It's 6oz glass filled/faired with a good layer of black silica epoxy, coated with 2-part black polyurethane paint (Interlux perfection). So far, so good.....

Messages In This Thread

Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 3/31/2013, 9:53 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 3/31/2013, 10:16 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 4/1/2013, 10:34 pm
Re: Strip: Building Bjorn Thomasson's Frej
Ralph Merriman -- 4/4/2013, 2:55 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 4/4/2013, 4:11 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 4/8/2013, 12:33 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 4/8/2013, 12:46 pm
Re: Strip: Building Bjorn Thomasson's Frej
Erik Jensen -- 4/8/2013, 9:58 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 4/8/2013, 10:38 pm
Re: Strip: Building Bjorn Thomasson's Frej
Erik Jensen -- 4/8/2013, 11:41 pm
Re: Strip: Building Bjorn Thomasson's Frej
Bill Hamm -- 4/9/2013, 2:32 am
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 4/9/2013, 12:32 pm
Re: Strip: Building Bjorn Thomasson's Frej
Bill Hamm -- 4/10/2013, 12:46 am
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 4/20/2013, 12:03 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 4/20/2013, 12:13 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 4/20/2013, 12:18 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 4/20/2013, 12:22 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/17/2013, 12:08 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/17/2013, 12:12 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/17/2013, 12:17 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/17/2013, 12:21 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/17/2013, 12:24 pm
Re: Strip: Building Bjorn Thomasson's Frej
Bill Hamm -- 6/18/2013, 1:24 am
Re: Strip: Building Bjorn Thomasson's Frej
Jay Babina -- 6/18/2013, 3:40 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/18/2013, 9:20 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 6/18/2013, 9:41 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 6/18/2013, 9:50 pm
Re: Strip: Building Bjorn Thomasson's Frej
JohnAbercrombie -- 6/18/2013, 9:54 pm
Re: Strip: Building Bjorn Thomasson's Frej
Björn Thomasson -- 6/19/2013, 5:20 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
Paul Davies -- 6/19/2013, 8:21 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 6/20/2013, 3:00 pm
Re: Strip: Building Bjorn Thomasson's Frej
Björn Thomasson -- 6/20/2013, 3:53 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 7/2/2013, 1:21 pm
Re: Strip: Building Bjorn Thomasson's Frej *PIC*
JohnAbercrombie -- 7/2/2013, 1:25 pm
Re: Strip: Building Bjorn Thomasson's Frej
Don Goss -- 7/6/2013, 11:29 pm
Re: Strip: Building Bjorn Thomasson's Frej
Sean Dawe -- 4/23/2013, 9:12 am