Macgregor 24- pulled out my leaking thru hull speed/depth senders. My plan was to just fiberglass top and bottom but I didn't realize how thick the hull was, so should I cut many,many round pieces to fiberglass in to get same hull thickness or can I fiberglass bottom and fill with epoxy any help is great! Thanks!
fiberglass questions
- Thread starter sailnewbie
- Start date
Need overlap at least 2 x with hole to get bond strength also got to sand prep glass around hole for adhesion usually lay 4"x4" mat of glass wetted up on inside then build outside layer after layer till match then jellcoat but other direction works good too patch on outside still 10 step process
I have this book
http://www.amazon.com/Caseys-Complete-Illustrated-Sailboat-Maintenance/dp/0071462848
It has a section of filling holes in fiberglass boats... and it has a step by step set of pictures to go with the explanation. I've used it and found it very easy.
http://www.amazon.com/Caseys-Complete-Illustrated-Sailboat-Maintenance/dp/0071462848
It has a section of filling holes in fiberglass boats... and it has a step by step set of pictures to go with the explanation. I've used it and found it very easy.
Yeah, use Casey, or check West Systems for instructions. For a proper repair, you will be amazed at the amount of feathering and layering of fiberglass. You'd think that with a bunch of layers of glass and epoxy, you could basically "plug" the hole and have integrity. Nope.
Thanks for the help. I have a lot of experience with fiberglass just not with the water proof aspect of it. Thanks again
I just did this myself. Many different ideas around on the best way to do it. I ended up following the West System's recommendation. After feathering out the hole I figured it made more sense to start with small patches and build with progressively larger ones. West systems recommends the opposite so I went that route.
This is correct. The reason for using the largest patch first is to insure all your other patches stick to first patch which has the maximum surface contact with the repair area with the least amount of irregularities. The first patch will only mechanically bond to the repair surface while the other patches will chemically bond to each other when applied while the epoxy is still green.
Hi sailnewbie
I just remembered a trick that I use that I should have mentioned. I take a piece of visqueen (plastic sheeting) and lay it over the hole on the side of the feathering. Then with a sharpie pen, I trace the dimensions of the feathered hole onto the plastic sheet. Take this back to the work bench and cut out your fiberglass cloth to match the trace... then stack up your successively smaller circles until the stack is the right depth. Then lay some tape (sticky side up) on the edges of the plastic....Only then do you mix your epoxy and wet out the pieces. Lay them right on the plastic sheet and stack them all up at one time. Now take your sheet of plastic over to the boat and with the tape already in place tape the plastic sheet over the hole .... let that set and when you take the plastic off, you will have a very nicely filled hole.
You also need a backing plate on the non-feathered side...
I like to make my backing plate out of vellum (over head projector plastic sheets) taped to the hull. Epoxy does not stick to the vellum. But if you don't have easy access to vellum you can tape a piece of plastic cut from a garbage bag as the backing plate. Something stiff is better but if you can get it to conform to the shape of the hull, then your repair will be fair from the get go and you won't have much after work to perform.
I just remembered a trick that I use that I should have mentioned. I take a piece of visqueen (plastic sheeting) and lay it over the hole on the side of the feathering. Then with a sharpie pen, I trace the dimensions of the feathered hole onto the plastic sheet. Take this back to the work bench and cut out your fiberglass cloth to match the trace... then stack up your successively smaller circles until the stack is the right depth. Then lay some tape (sticky side up) on the edges of the plastic....Only then do you mix your epoxy and wet out the pieces. Lay them right on the plastic sheet and stack them all up at one time. Now take your sheet of plastic over to the boat and with the tape already in place tape the plastic sheet over the hole .... let that set and when you take the plastic off, you will have a very nicely filled hole.
You also need a backing plate on the non-feathered side...
I like to make my backing plate out of vellum (over head projector plastic sheets) taped to the hull. Epoxy does not stick to the vellum. But if you don't have easy access to vellum you can tape a piece of plastic cut from a garbage bag as the backing plate. Something stiff is better but if you can get it to conform to the shape of the hull, then your repair will be fair from the get go and you won't have much after work to perform.
The proper patch has the same lay up and resin as the original part then of course properly done. I know many have only used expoy w/ layers of mat and have not had problems for years. You could prob. Elmer glue a tapered wood plug in a hole and it would last till you got rid of the boat.
No... don't do that.
Use epoxy... keep some white vinegar handy to clean up with in case you get some on your skin or someplace you don't want it. Done correctly the patch will outlast your boat.
Here's the plug I cut for the new through hull
between each layer of glass laid, if you have a small resin roller that can be used, use it cleaning it off in acetone as you will be able to smooth it out and get the air out. If too small an area, then tip with a brush. Try to cut each layer a littler thicker as you fill the hole so it will not overlap coming out of the beveled hole
Once done, spray the area with either black or gray and sand smooth. Any paint left will indicate any valleys which to repair with fiberglass or epoxy. try to use vinly ester resin and not polyester resin for this job if on the hull.
Once done, spray the area with either black or gray and sand smooth. Any paint left will indicate any valleys which to repair with fiberglass or epoxy. try to use vinly ester resin and not polyester resin for this job if on the hull.
Thanks for all input, the job is already done though. I patch it with the resin sold at your normal automotive store and they only have one thickness of clothe and it's thin. On the outside I put 6 layers starting with large down to small and then I cut about 50 circles per sender to fill the hole and then 4 layer on top of that again starting big to small, we just pulled out of water a few hours ago after staying over night and there was not even a drop of water in the hull, amazing as to before the repair there would always be at least an inch of water and now nothing...
Sounds great, keep in mind that the water pressure is very low so you shouldn't have any trouble. In scuba training you are taught that at 33 feet is one atmosphere or 14.7 psi. So if your transducer was say 2 feet deep it would only be about 1 psi. If your through hole fitting was 2 inches in diameter you would have 3.14 square inches so the force on your patch would be about 3 pounds. I think you can sleep at night now.