cockpit, cabin repair

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cockpit, cabin repair

Postby Blessing » Mon Nov 25, 2013 1:53 am

Hi Everyone,

Thanks for the help on the chainplate question. They will be on the way shortly.

Now I need advice on epoxy or fiberglass. I have several small screw holes, two holes of 4" diameter from instrument removal to repair. Any suggestions or warnings on using items like marine bondo, marine rx, marinetec? Recommendations Please.
Blessing
 
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Re: cockpit, cabin repair

Postby kuriti » Mon Nov 25, 2013 8:33 am

To repair a large hole, i would recommend using epoxy and fiberglass mat/cloth. First, I would tape a piece of cardboard wrapped in cling wrap on the inside of the boat that covers the hole. Cut a piece of fiberglass mat and a piece of fiberglass cloth to fit the hole size. The next step is to wet out the mat and put it in place. You will need to work with the epoxy to thicken it enough with colloidal silica enough not to run, but thin enough to be able to penetrate the cloth. it might be best to thicken it to a very slow syrup consistency to wet the mat and cloth on a scrap piece of cardboard first. Don't soak the mat, just get it wet throughout, excess epoxy will want to run. Once wet lay the mat in the hole and try to insure it touches the existing fiberglass on the edges. While still wet, lay on a layer of wet fiberglass cloth and squigy it into the mat, a roller would be best. Depending on how thick your mat is, you may not need the cloth. basically keep adding layers until you have about a milimeter below being flush with the exterior. Let that kick and get firm. if it drys completely, you will need to wipe it with acetone, then sand it lightly with 80 grit.

it wouldn't be a terrible idea to have a piece of cardboard cut the the shape of the hole handy and wrapped in cling wrap. since it is a vertical surface, there is a high probability the epoxy will start to sag. if you just can't keep it up, then you could just put the carboard over with some pressure and tape it in place. All of this will be messy, so i strongly encourage you to mask the existing fiberglass both in and outside to significantly help clean up. use duck tape or some other non-permeable tape, otherwise you will just epoxy the tape to the boat.

Next,thicken up some epoxy with fairing compound (or just use bondo) even more until you get to peanut butter consistency. Then spread it over the hole and make it as smooth as you can while wet, but just a hair "proud" of the exterior. Let it dry and sand down. i wouldn't use just bondo for a 4 inch hole, too big. for screw holes, just put a piece of duck tape on the back side and use a squigy to fill the hole with bondo. Dry, then sand smooth. All this will need paint not to look tacky. i like West system epoxy and products, but you can use any epoxy for this project if you are going to paint. it is made of vinylester.

that's how i would do it, but there are probably some better ideas out there. should be able to find something online. Lot's of articles will talk about beveling the edges and building up with cloth, but they are usually talking about a hull repair with a thicker substrate. i wouldn't bevel this as you are only working with a thin piece of fiberglass and it won't be taking any loads (it's just cosmetic).

Or, buy a 4 inch compass, problem solved!

Kuriti
kuriti
 
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Re: cockpit, cabin repair

Postby Blessing » Mon Nov 25, 2013 1:18 pm

Thanks, Sounds great.

Iam looking for a 4" compass for one hole.
Blessing
 
Posts: 8
Joined: Tue Nov 12, 2013 4:15 am

Re: cockpit, cabin repair

Postby kuriti » Tue Nov 26, 2013 4:44 am

Two clarifications: i forgot to mention using disposable chip brushes for spreading the epoxy. Also, when i sais "it's vinylester", i meant the boat, not west system epoxy. Don't be scared and have fun, you can do it!
kuriti
 
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Joined: Mon Sep 12, 2011 10:17 am


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