finishing idea for a NE Dory

As I mentioned in my previous post I am starting my project today and I was just considering the finish on it (yes I know I should probably finish the boat before I think about finish but what the heck...

 

I saw the video on using a decorative cloth under the fiberglass and epoxy layers.. really cool. I like the look of carbon fiber, though the strength is not really needed for my purposes I though maybe I could use carbon fiber as a decorative cloth.. I have never worked with CF before and all the videos I found go over CF with it's own type of epoxy stuff.. would this work the same as a decorative cloth? Or would I need to use whatever resin is required for the CF?

 

Also since I am not really interested in the strength aspect, has anyone found just regular cloth that looks like CF but is just a nornal woven cloth?


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RE: finishing idea for a NE Dory

 

   CF is applied just like glass cloth, using epoxy to wet it out and adhere it to the substrate. Unlike glass, it doesn't turn clear when wet out, so weave pattern is important if you want it to show. I don't know what parts of a dory you'd apply it to, but for the cockpit sole as an example, you could pretty easily apply it using the same methods that are shown for glass: prep the area and sand the fillets smooth, masking tape all around the circumference of the to-be-carboned area, lay your cloth in place and trim to rough shape, overlapping the tape (does the cloth conform nicely, or do you need to turn the cloth 45 degrees so it's "on the bias"?), then wet it out with resin and a squeegee and a light touch, shooting for a fully wet but not shiny coat, indicating the cloth is wet and adhered but not swimming in resin, press all the corners fully into the fillets (the cloth wants to pull away from them as you work it...). Come back the next day and bend the tape up and cut the border, and add a fill coat or two before giving it a gentle wet sand. Repeat the coat and sand until you get the finish you want.

Note black surfaces can reach over 140F on a sunny day. If you're not somewhere pretty far north, make sure you can deal with the hot surface.

RE: finishing idea for a NE Dory

Nothing wrong with thinking about how you're going to finish it before you begin.  For example, if you're finishing "bright" then certain steps definitely need to be taken early on in the game.

As for CF, I've done a few projects with it.  In the past, I successfully used West System to build a CF remote control AC 45.  It took the resin just fine, so I think you're good to go with whatever resin you use.

I don't think there's anything that looks like CF except CF and there's nothing sexier in the sun.  I did stumble across a tutorial about using that soft, spongy boater's non-skid shelf liner and a couple of colors of rattle can to get a similar effect.

The one thing I do have to caution you about CF is that I don't think it likes to be sanded.  So make sure you have enough epoxy to fill the weave before sanding.  I've got some CF and Kevlar that I'm looking forward to using on something in the near future.

RE: finishing idea for a NE Dory

Thanks guys.. I might just give it a try. I want to paint a black waterline, then a Redish or Grey CF from the waterline up to the gunwhales.. then a redish varnish on the interior wood and gunwhales... just thinking though.. I am color blind so I frequently make bad color choices.. (owned a purple pickup truck for two years before someone told me it was purple).   

RE: finishing idea for a NE Dory

Pat, Just a thought, the dory is a very traditional looking design and cf is a very high tech looking product. I can see cf on an oxford shell or cocktail racer but not a dory. BTW, there are several colored carbon kevlar hybrids but cf only comes in black as far as I know  SEEYA Jack 

RE: finishing idea for a NE Dory

Pat, another thought with a little humor this time. If a color blind guy builds a boat with colored carbon kevlar he could very easly end up with a purple truck polling a boat that looked like a clown car so ask someone to consult..... Meant in the spirit of humor. SEEYA Jack  

RE: finishing idea for a NE Dory

You can also get CF/Kevlar weave that's black and red.  Pretty cool looking.  I've had great luck with these guys:

http://www.sollercomposites.com/

RE: finishing idea for a NE Dory

These boats often have traditional forms, but their construction is hardly traditional. If your choice of finish highlights this, that's an aesthetic choice only you can resolve. Regardless, some practical things to consider might be:

-the plank edges. The cf won't easily wrap around square-edged lapstrakes (nor does glass), so at best you'll probably end up applying any fabric to the plank surface, only, and trimming away the cloth that hangs past the lap. Kevlar is terrible here, since it frays when sanded, and you will need to sand that edge.

-weight. Adding cf where the plans call for a simple seal coat of epoxy will add around 3-4 oz per sq yard. It will contribute practically no strength, only a little impact resistance, almost no abrasion resistance, and it will be difficult to patch/touch up/repair.

-application. Kevlar is a trainwreck if you need to sand it at all. It gets fuzzy like a tennis ball. Carbon sands very easily, but the beauty of the weave is compromised if you sand more than 25% or so into the fabric. If your planks aren't fair, or if you apply the cf with any bumps or wrinkles or floating in epoxy, you are stuck using clear resin as a low-efficiency filler until the surface is acceptable.

 

RE: finishing idea for a NE Dory

   I think I am giving up on the CF idea... Not because of the difficulty in getting it to look good but rather because of UV rpotection. We use paint or Varnish to protect the epoxy from breaking down due to the UV rays. If I add CF to the boat I will have no way to protect the epoxy without also obscuring the CF.. which would defeat the purpose.

 

I might look into a "Wrap" type of solution, I have seen them on boats.. but in the end I will probably just toss a good coat of paint on it and get to sailing it rahter than building it.

 

thanks all for your advise... I will have to think of some other project that will benefit from CF. CF is NOT like cheese, it does not belong on everything.

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