OK, I finished up my first hollow wood about two monthes ago. It surfes great, no problems…until now! I noticed I was getting some water inside, I thought it was the vent leaking but now I noticed a crack along the left side of my fin. I’m not sure if the fin was cracked by the pressure of a bottom turn (I only put one layer of glass on the fin, two ‘footballs’ on each side, and strands of fiberglass as rope…at the time, I thought this was corect…I didn’t know actual fin rope excisted) or by baging against the beach if I lost it in the surf.
Anyway…I don’t want to remove the whole fin to fix it. I feel like the other side is still ‘strong’…why mess with it. Glassing the board went well, but I’m not sure how to go about repairs. Should I give it a light sanding (to rough it up), lay some real fin rope along either side and another football? I also want to add a couple layers of glass to the whole fin…I didn’t know until after it was supposed to be several layers thick. Should I sand down where the crack is and fillit with resin/glass, or just leave it and glass over it??
Please give me some points…I’m running out of glass time (its getting a bit chilly here in NY). Thanks in advance for the tips!!
My solutions to such problems is usually overkill, so I will let others weigh in on your original question. I have another issue.
See picture. A long time ago, after a heated debate, I started to collect, at least assess fins using something called a centroid. The centroid for a homogeneous object, like a plate is the objects ‘geometric center’ and can be used to estimate the center of pressure. Oddly enough, you don’t really need the precise measurements of the fin to get it, just a reasonable picture and a graphics package that lets you read pixel position. Anyway, a quick and dirty analysis indicates that your fin’s centroid falls outside the base of the fin.
If you like, you can post the base and height of your fin and I’ll may be able to estimate surface area. But to do a better job, a better picture is required, and there is no immediate need for that – you’ve got a broken fin to repair.
But this much is worth considering, given the design of your fin, it may break again. However, in the end, you know your fin best and I’m just working on crude pictures, which for all I know, the angle alone made things come out weird.
I’d just sand rough the surface to remove the hot coat, both at the base of the fin and at the first half of the fin. Then cut four rectangular pieces of glass and lam 2 on each side, forming 2 opposite “L”. Let set and hotcoat both sides. Sand and it’s OK.
BTW.: I don’t think that crack is the cause of your water problem.
rope made from pulled strands of cloth is as strong as fin rope as long as you use enough strands. I suspect that that crack apeared as the bottom is glassed in only 4oz and you did not mention adding a patch or two to renforce the area under the fin.
make sure that the board has dried out completely before sealing the crack, I would also check for cracks along the seam where the rails join the top and bottom skins.
Thanks for all the input! No, unfortunatly I did not reinforce the area under the fin…its only one layer of 4oz. About how many strands of 4oz cloth should have I used?
My big question now is (and this always pluages me on repairs) how do I get the area where the new footballs are going to blend with the old area. I want to avoid having a lump where the repair is…whats the way around that??
Neira…I was hoping the crack was the source of my water problem. The bottom planks were ‘wet’ looking after the last few surfs. I’m hoping that the crack was part of the problem but you might be right…it might be the plug.
7 to 9 strands of 4oz should de fine, its really just for ceating a nice smooth contour at the fin base, it also helps to disperse the force a bit.
the real strneght comes from the patches under the fin and the foot ball patches.
there will always be a slight bump, but you can smooth out the transion by making the bottom foot ball patch slightly larger and feathering the edges of both before the hot coat to give a nice gental rise you will hardly notice.
After posting this question, I found out that the crack was minor and it was the plug that was leaking…
So I just recently fixed the fin, but now I have some questions…
First off, here is what I did. I sanded the fin area with about 150/200 grit. Then I glassed the whole fin with two more layers of 3oz glass. After it dried, I lightly sanded and coated it with a smooth coat of resin.
Sanded
Glassed
Sanded and hot coated
First-
I use RR epoxy. When I add the ‘additive F’ the resin clouds up badly, is it possible the additive f is bad. When am I supposed to add it? Is this normal, does the resin usually cloud up after the additive F is added?
Second-
What causes the small ‘bumps’. You can see some in the picture below…
Third- (and most importantly)
After you guys are finished with the last coat of epoxy…what have you been doing to get that shinny look? Leaving it as is or sanding? If your sanding…whats the process to get a nice shine?
1000/2000 grit then polish with a wheel? What type of polish/compound?
It looks like the little bumps or zits are from either dust on the board or dust falling into the wet resin. They will polish out if you start with about #400 wet dry.
As for the cloudiness of the hotcoat, we dont have RR here but when I mix up wax and xylene to make filler out of ATL resin it does cloud up but dries pretty clear and the wax sands out.
Yes this is normal, it will cure clear. you need to shake the can of add F or give it a little heat to get the solids back in to solution, remember to do the with the lid on (had a little accident myself a few days back) If is got any cloudyness afte its cured, its much more likerly to be from mosture or from working the resin too mutch and getting small air bubbles, heating thr resin (before you add the hardner or add F will help with this)
zits, cuase by dust from the brush, bucket or in the air undisolved solids in the resin, see above. will polish out no problem.
two ways, first sand to 120 and give it a poly urethane clear coat, or sand through grits wet 400-1000/1200, add a drop of washing up liquid to the water, wash down area and change water between grits, rub out with posishing compound (surfluster, G4, M3, pearldropsetc), marine liquid wax and buff or if is not going to be waxed pledge furnitur polish will work.
basically the same as poly but you really need to go through the grits thoughly.
two ways, first sand to 120 and give it a poly urethane clear coat, or sand through grits wet 400-1000/1200, add a drop of washing up liquid to the water, wash down area and change water between grits, rub out with posishing compound (surfluster, G4, M3, pearldropsetc), marine liquid wax and buff or if is not going to be waxed pledge furnitur polish will work.
basically the same as poly but you really need to go through the grits thoughly.
Thanks for all the suggestions…I ended up using a Poly Urethane clear coat. It came out great! There was a bit of a ‘haze’ on top when you got eye level with the board…but when looked at from a far or from the top, it looked great. So I just lightly sanded it again and I’m going to apply another coat tonight (inside this time…less humidity). Hopefully this will take care of the surface haze problem.
