I tried to post in my original thread but the board already archived it =/
Original post:
http://www.paddling.net/message/showThread.html?fid=advice&tid=1792129
I patched the hole 5 weeks ago, but due to moving for the 2nd time in 5 months I just now got around to sanding it down and paddling it.
It turned out as well as I could hope, maybe better. The inside (3 layers of 5oz kevlar) looks ugly but is structurally stronger then original. The outside is 2 layers of 6oz s glass. I sanded off most of the 2nd layer of glass smoothing and shaping the patch.
Overall I maintained the original shape well, so I’m happy. The white parts are west systems epoxy with thickener as I had to fill in a damaged rib nomex honeycomb core and used it to smooth the contour of the outside hull
I still want to do a skim coat of epoxy to fill in a couple air bubbles I exposed during sanding and add a coat of spar varnish to the outside for a little uv protection.
A question I have is why didnt my glass fully wet out? I dont seem to have a problem with kevlar or carbon, but I have had 2 glass patches not fully wet out. its 80-90% wet out, but you can still see some fibers.
Overall, its not the prettiest inside, but if you painted the boat, it would be hard to tell it was there on the outside
Paddling pics
http://www.dropbox.com/s/uw5yo9dfw0gjqvc/20150622_200156.jpg?dl=0
http://www.dropbox.com/s/b11gu35cxpd5qr0/20150622_202228.jpg?dl=0
http://www.dropbox.com/s/upzv6grru8mqiqc/20150622_201541.jpg?dl=0
http://www.dropbox.com/s/5uwglwn16ul522j/20150622_201531.jpg?dl=0
http://www.dropbox.com/s/zs1n7x0o6ixq9ab/20150622_183123.jpg?dl=0
Repair:
http://www.dropbox.com/s/sl7xc75xz9vhcu4/20150622_183118.jpg?dl=0
http://www.dropbox.com/s/3m6m26t8x19feay/20150622_183113.jpg?dl=0
http://www.dropbox.com/s/paeh1xvrusakxtv/20150622_182824.jpg?dl=0
http://www.dropbox.com/s/f2ngjfr85r86ufm/20150622_182815.jpg?dl=0
http://www.dropbox.com/s/rjxrwb7fkzu9h69/20150622_182810.jpg?dl=0
http://www.dropbox.com/s/bc5w426wqfvbv01/20150622_182806.jpg?dl=0
http://www.dropbox.com/s/8dv9ype9ib2pzvb/20150622_182757.jpg?dl=0
http://www.dropbox.com/s/gk9vttwx9qkhjz8/20150622_182752.jpg?dl=0
http://www.dropbox.com/s/8yhykftj670hzan/20150622_182749.jpg?dl=0
http://www.dropbox.com/s/44ld2e7h1r7wcet/20150622_182706.jpg?dl=0
http://www.dropbox.com/s/f3psdjd9659u2bb/20150622_182658.jpg?dl=0
S-glass fibers are very fine and can be
difficult to wet out. West System is low viscosity and will usually wet out S-glass with patience.
Looks good
Thanks for taking the time to take the photos and post a followup.
Looks like you have a strong repair and maintained the contour of the hull well. I probably would have gone with 2 internal aramid patches, but 3 can't hurt. For what it is worth, I generally ovalize my internal patches by rounding off the corners and they look better that way, at least to my eye.
Regarding the S 'glass, although some satin weaves and heavier cloths can be notoriously hard to wet out, I have not had trouble with plain weave S 'glass cloth of 6 oz weight even when using G Flex epoxy, which is more viscous. I do, however, keep working it with a squeege until I am satisfied that it has fully wet out, which you can tell because it becomes transparent. It also helps to put a coat of epoxy on just before you lay on the cloth.
If you added a thickening agent to the epoxy you used for the initial wet out it would, of course, have made it more difficult.
I think a lot of the visible fibers that you have exposed by sanding will disappear when you add another coat of epoxy.
Ya
Ya, I probably should have only done 2 layers on the inside in retrospect. Its stiff as hell now. lol. Oh well. That is something that Im learning as I go; less is more. This is my ~12th epoxy job and I have slowly been getting the hang of things.
Good up front prep, having everything staged when its time to mix resin, and the squeegee/brushwork motion to get the glass wet out but not distort the fabric… Also, reducing the amount of resin to a minimum has helped me a lot. The first job i did I left a big pool of resin on top that still bothers me >/ Ohh well. All it cost me is an oz or 2.
I didnt thicken the 105 with anything, so my wet out issue was probably me just not squeegeing it back and forth enough. I did lay down a thin-ish layer of resin before laying down the fabric. Also, I laid down 2 layers from 1 pot to speed things up. The resin started to gel on the last exterior layer; I just barely got it wet out which probably contributed to any dry fibers in my last layer.
1 thing, when you are dealing with (relatively) small patches, how do you handle the squeegee so that you dont pull up fibers from the edges of the patch? Do you know of a decent video showing someone doing something similar?
Thanks for your help guys.
yes
If your epoxy was starting to kick as you were wetting out the second layer it would explain the problem.
Since it is so fast to mix up a small batch of epoxy using minipumps, I use very small batches and just mix up more as I need to. Unless I am wetting out a full blanket of cloth to cover an entire hull, I seldom use batches that are larger than 1 pump of resin and 1 pump of hardener. I also prefer the 206 hardener which cures plenty fast in the temperatures I am typically working in. I would use the 205 only if I had to apply epoxy in cool temperatures and had to have it cure overnight.
One way to minimize fraying at the edges of your patches is to use peelply. I almost always do for aramid patches. I don’t always do so for fiberglass.
To reduce fraying I start wetting out the cloth at the center of the patch. As I get toward the edge I just “dab” epoxy onto the cloth using my stir stick, acid brush, squeege, or whatever I am using for epoxy application. Before working the edge of the cloth I wait till the fibers have started to absorb the epoxy. At that point the edge becomes somewhat more resistant to fraying and you can start to gently smooth the epoxy into the cloth.
Good to know
I had peel ply then forgot to use it! Der. That would have been the ticket.
I unknowingly used your method of starting in the middle and dabbing around the edges, but I like your idea of waiting for the glass to absorb a little resin before doing any substantial work around them. Also, you have time when you use 206.
I have both hardeners, but used 205 because ~5 weeks ago it was 68 degrees in the day and ~50 at night. I know 206 doesnt cure much below 60, or at least its extremely slow. Even with the 105, the cure was only about 80% done by morning. I could still leave a fingerprint with a very hard push and could easily dent with a fingernail.
Maybe I’ll glass up a Rudder for myself in the next week or 2 and try out your suggestions. I’ve been loving surfing waves on long island sound, but I get broached somewhat easily without a rudder, even if I rudder with my paddle.
Nice job
It proves, we can keep our Kevlar boats no matter what beats them up !
I have done extensive Kevlar repairs on our Jensen many times as well as our comp cruiser.
jack l