Hey everyone,

I was looking at my fin the other day and realised that there were some small holes on the front of it. It almost looks like a bug has eaten at it. All our other fins don't have this problem but they all have covers and this one does not.

Pics at: www.seabreeze.com.au/gallery/gallery.asp?imageid=3322 and www.seabreeze.com.au/gallery/gallery.asp?imageid=3323

Has anyone experianced this before? Also what it the best product to use to fill in these holes?

cheers
bubs

Bubs, have seen this on leading edge of yacht race keel, caused by cavitation of water across surface.
Didn’t think it would be an issue with windsurfing fins.
We just filled the holes with a top quality product that was real hard and sanded back to a smooth finish.
Guess others who have more experience with these can give you a better idea.
By the way, good photo. If you want to give a better idea next time on size of hole, place a small 5 cent or 10 cent coin next to it for comparison.
Mineral

the 2nd pic has his finger in it...

Yeah. It was hard holding the fin in one hand and the camera in the other. Very hard to get focus on the fin and not things around it aswell, so sorry about that. Good idea about putting the 5c piece in aswell mineral. Thought some pics might hlp as i had never seen it before.

Any ideas about something to use to fill them would still be apriciated. I was thinking hot glue gun or superglue. Anything that i would be able to sand smooth and was also waterproof.

cheers anyway
bubs

hot glue doesn't sand very well...

wouldn't recommend superglue either as a filler.

that aqua knead-it stuff would probably work okay.

Car bog or plastibond, and just give it a light sand to fair it in.
It just looks like a bubble in the laminate thats been exposed.

As Kremlin pointed out last week Aqua Knead-It doesn't work on fins. I did a bit of experimenting myself and am sure it would not stick to anything flexible.

:o will keep that in mind.

well i guess a bit of resin mixed with some kinda filler would be the best option then? i really don't think that hot-glue or superglue would work too well...

Back in my model plane days when we had a big area to fill we'd use bicarb soda, then hit it with superglue and the result would be something that you'd have to file down! It set like the hardest cement you've ever seen in your life. Not sure how flexible it would be, but if you ever want something hard then that's the ticket.

After a couple of goes you learnt to remove any dags of bicarb that you didn't want to stay there, because after you glued it you had a heck of a job trying to get rid of it

Fill it with paint. Goes on easy, easy to sand...

This looks like a manufacturing fault where there has been an air bubble covered by a thing layer of resin or gel coat. I'd repair with fibreglass but if this is too hard then I guess a filler could be used. I have used araldite/epoxy resin that you can buy from a hardware store with success.

Resin and a little bicarb soda or talc. If no resin, some 5 min araldite
will do fine. With enough talc, it'll sand easy to shape and work a treat

A tiny bit of epoxy will do fine (2 part mix) overfill and sand afterwards.

nebbian, model planes you say? Tis what I spend my time doing when I'm not on the water.

PAINT

Have repaired larger damage with resin. For such a small hole, paint goes on easy and sands off easy...

Thanks for all the ideas. We just been repairing a board with some epoxy resin so if we get that back il use that. Otherwise i'll just use some 5 min araldite or paint.

cheers again
bubs

Completely offtopic but...

Edge:
Gliders or powered? I got really into gliders, after a couple of kitplanes I ended up designing and building a flying wing that was the sweetest performing plane I've ever flown, Eppler 193 to 196 (I think!) foil, had the right washout and sweep, mechanical mixer for the elevons, man that thing flew like a dream. Did heaps of maths to figure out all the angles, CG and the like. After that I haven't been into them anymore, if you can design a flying wing that works well then that's the pinnacle in my books.
Also got sick of taking a garbage bag to the slope to pick up all the pieces when the inevitable crash happens

What are you into?

body PAINT... Oh damn, firie bob distracted me - I mean PAINT...

Nebbian,

Doing both really, built myself a kit DLG (discuss launch glider) as well as a few other small electric models, mostly foamies. Got a glow powered .46 low wing ready to fly, we'll see how that goes. Along with a spare room for my 'workshop' and plenty of tools and radio control equipment, I have no problems finding something to do when the wind isn't blowing!

Good to see you've shared the two. Thats 4 people I know that have been flying model aircraft, aswell as windsurfing now

sorry for the hijack folks, I promise it will stop here!

Hey everyone i know this was a while ago but i finally got around to fixing the fin.

We were repairing a board and had some epoxe resin and fast hardener mix left over so i thickened it with some talcum powder and jammed it in the holes. Eneded up finding a whole heap of little ones too, so prity much put the mix all over the front of the fin. Waited till the next day and just finished sanding down to normal shape. Worked a treat.

Bubs