Fiberglass weight

[Chris D]

Hi everyone, I was curious if anyone had an opinion on the fiberglass weight one should use for rudder modifications and for keel repair. I have been reading through the posts of Com-Pac 16, DIY, Sailor's Lounge, and can't seem to find an answer. If this subject has been beaten to death, I apologize, but I can't seem to find an answer. Would it be worth completely covering the keel with fiber glass or just repairing the holes? Already have West Systems 105 and 205 and any advice on the type of fiberglass would be greatly appreciated. Thanks
Chris

[brackish]

I think it is dependent on the size and nature of the repair.  For instance, when I had significant core rot on my Columbia 8.7 where repairs would require taking the glass on the outside completely off, removing then replacing the balsa core, then reglassing areas that were greater than a square foot in size, I tapered all edges and went with the complete system that had been originally used by the manufacturer.  It included specific weight cloth and mat.  The woven roving was on the inside, so I did not have to deal with it.

For large repairs I would call Hutchins and get the original schedule.  For small repairs I usually just use what I have around and I usually have 12 oz. bi axial cloth around.

[Chris D]

Thank you Brackish, that is just the info I was looking for. I just drilled some holes in my keel to let the water out. It's a start.

[MacGyver]

What Brack is saying is right. When I repair at work, I might not specifically use the same weight type that the original manufacturer did, but I do build atleast the same thickness.
What I would do If I were you is inject the holes with 105/205, and 404 mixture to a nice thick consistancy to run through a syringe (West system style syringe, not the medical kind   )
then after injecting the holes, tape (masking tape is fine, old yellow kind) over them to hold the mixture in.

after curing, remove tape, and then sand it down and bevel your glass out, then follow with glass (and 105/205) out to make the repair. Start the repair with the biggest patch first, then the smaller patches. Fair if needed. Seal with a Epoxy Barrier coat, or do Gelcoat, either way..... then bottom paint and good as gold!

Remember to take pictures, everyone here always loves the pictures

Rudder modifications, I ran 3 layers of 4 oz I think...... Pretty stiff when cored in foam and pretty solid I might add. Corners all had overlaps, so super strong.

Mac

[Chris D]

Thank you MacGyver, the more info I have the better. I certainly appreciate the detailed instructions. I will be documenting my journey to post here. Just made a cardboard template of the NACA 0012 to transfer to plywood. I'll try to document that as well. Thanks again. I love this site.

[GeeW]

MacGyver
Thanks for the suggested lay-up for a NACA'd rudder.

Gordon

[MacGyver]

Not a problem,

I will add that when I did my rudder, I did a template, then made several ribs from that template onto the 1/8 plywood I had, cut those out, cut in half, then glued them standiing up to the aluminum plate after it was prepped
Then I used Blue sheet foam from lumber yard to fill in the gaps. The distance between each rib was whatever my sander was, as sanding the foam my sander would stop when it hit the ribs on both sides. If I did it over again, I might try a belt sander and do the sanding outside! LOL

After that, I filled the gaps with some 105/205 and 404, just to get a nice surface for the glass. After a final sanding I glassed it.

The rudder will float up if I want to pull it up, not quickly, but seems to be just right on my CP19/3

Good luck! And definitely take pictures, it is some work, but nice payoff!

Mac