I promised to do a build thread and unfortunately I forgot to take picture during the shaping, but here are some ideas for doing cloth inlay.
I’m building a grom fish for a friend’s son. Started out as a project where I would throw a few left overs together and pop out a vanila fish. Well, the dad and I talked and expanded the project so now it is going to have bells and whistles and cloth inlay and ply keels and carbon load strips and wifi. (no wifi).
First thing you want is good light weight cotton cloth. I have not seen one yet that would bleed with epoxy, so I think you are safe with that. I don’t use any manufactured fibers. Too risky. Get yourself some quality 3M 233 tape which won’t lift in the presence of epoxy. Critical. Use one of your outline templates to lay out your tape line and leave the pencil line showing so the cloth will cover it when you razor cut it.
With cotton you are going to have to deal with wrinkles in the cloth. Two methods I have used are first iron the wrinkles out (preferred) or to use some clamps and weights to pull the cloth tight across the area of the inlay. The second method only works well when you can clamp 360 around the cloth. You need to pull in all directions so if doing say, a nose-only inlay, you won’t be able to clamp from the direction of the tail. See Pic below. The key is to pull the cloth tight across the deck some way so that no wrinkles are there. You will kick yourself if you don’t.
On this little grom fish, the blank is really thin and it is 1 pound EPS (because that is what I had available when starting). So it is floppy and I was concerned about it snapping. So, being a certified genius, I applied some carbon fiber panels to the deck, under the cloth, and will do a nice length-wise strip on the bare bottom. But as you can see, I’m no genius. The black carbon is showing through the cloth. Which pisses me off to no end. I thought about that problem before starting but convinced myself the cloth was heavy enough to avoid that.
So here a few pictures to get started. I’ll show you how I cut the cloth along the tape in the next batch. Right now I’m waiting for the resin to gel and pulling out a new single edge razor. And new batteries in my flash light.
The last pic shows a little clamp I used to pull the cloth in the tail tighter. Just the weight of the clamp, but you could hang some additional weight if needed. Notice the carbon showing through. Pisses me off to no end. Repeating myself. But feeling it.
Further note. I was going to do rail channels in place of no stringer. But when we went to cloth inlay, that could not be done easily. Cotton is hard enough to get to lay flat. Aint gona try to get it to follow a rail channel. Thus the carbon.
I just cut the tape line. My goal is always to cut so that I don’t have to use a pin line to cover. This means you need to do a continuous cut. Don’t lift the razor blade out of the cut. If you have to stop, leave the blade stuck in the cut. You will be cutting a little into the foam. My iPhone won’t take a good pic of the cutting process since I do it in a darkened room. The process is to use a bright flashlight shone upward from the bottom of the board to reveal the darker tape line. 3M green shows pretty well in contrast to the cloth I have used. I have in the past double over the tape with dark blue tape to be sure the tape line would show. But always used the green tape on the foam.
Note, this is not like doing a cut lap where you lift the tape and cut at the corner. The light below reveals the tape line and you just cut straight down.
Another trick to use with really dark cloth is to double or triple stack the tape and cut along the embossed ridge line of the tape stack. More time, more tape, more effort but can be done.
Here is the cut board. You can see the carbon showing through (just pisses me off to no end. Genius )
But the cuts are clean and not pin line needed. Although the dad may ask for one.
Greg Loehr showed me how to use automotive pin line tape on the foam before glassing. Super easy. Just don’t leave it unglassed over night. The pin line material will find its way to the floor and you will be starting over. Lay it out, glass it THEN go home.
One last thing. You may pull up a few beads of EPS foam when you pull the tape up after cutting. You wanted good adhesion and you got it. The remedy is to allow the epoxy to cure hard, then tape over the cloth at the edge of the cut. Yeah more tape. Then use your finger to apply a little light weight spackle over the tears. If you do it all the way around this will soften the hard edge of the cloth and eliminate gaps when glassing. Or while the cloth is soft, you can use a small roller and push the edge down into the foam. Thanks to Sam Barker for that tip.
Whoever is the one who told me about the flashlight trick, I am in your debt. Thanks. You’re a true genius.
OK, you’re on your own, genius. Don’t screw this up with carbon underneath, or substandard tape, or dry cloth, or sloppy cuts. People may be watching.
Actually, post your work. Seriously. I’d like to see it. Use the other thread, though.
Greg, thanks for the thread. Thinking about the people in the path of hurricane Matthew…
What do people think about pre-washing the cloth before measuring and cutting?
When people sew stuff they do this to remove any sizing or excess coloring, and to have the cloth ‘relax’ into its more natural dimensions.
I found out that washing after measuring is not a good idea due to the shrinking of the cloth. I lost six or so inches of length on a six foot piece of cotton.
With cotton, linen or hemp cloth you can go with the let dry then sand over tape to cut lap, with syntetic fiber cloth (PET, PA, etc) it’s a nightmare but those kind of fibers can add lot of durability…
