Alternative To Fin Rope

General Discussion
1

Does anyone know of a good alternative to fin rope when glassing on fins?

2

Just cut up some fiberglass cloth in strips about 1/2" wide, and about 1.5" longer than the base of your fin. Usually, about 7 strands does the job.

3

7 strands for each side of each fin?

4

Yup, that approximates half a rope (3 strands of rope).

5

I used to pull apart fiber glass cloth into separate strands… then gather a bunch of them together, and use that instead of fin rope. -Carl

6
Quote:
I used to pull apart fiber glass cloth into separate strands... then gather a bunch of them together, and use that instead of fin rope. -Carl

Yep, 10 strands from 6oz cloth makes good roping.

7

Every strand with a bias cut patch provides front to back and side to side support. Several football shaped bias cut patches applied at the base of the fin works better than fin roving which provides support in a single direction which is actually opposite the side to side forces that occur when turning your board.

8

Hey John - I always understood the purpose of the fin rope/woving to be also to fillet the joint. Fiberglass doesn’t make 90 degree turns well (not strong), putting the fin rope in the fin/deck intersection prevents the fabric (e.g. your football shaped bias-cut patch) from having to bend at 90 degrees. So, while your patches are good, putting them over fin rope = even stronger. Yes?

9
Quote:
Every strand with a bias cut patch provides front to back and side to side support. Several football shaped bias cut patches applied at the base of the fin works better than fin roving which provides support in a single direction which is actually opposite the side to side forces that occur when turning your board.

I think both work best whenused together - the rope fills up the space ('twixt fin side and bottom) that’s covered by the cloth.

10

Yes - The first layers will be bent more to fill the joint. Subsequent layers gradually form more of a radius at the base. Using both rope and cloth is a good idea but the thread was alternatives to fin rope? I usually use enough cloth patches (I can’t ever get a perfect oval like my paint program does) to get a pretty thick fillet. Practically every used shortboard I’ve ever seen had cracks or repairs on at least one of the fin bases when the fins were glassed on lightly with only a few strands of rope. On the last several hundred glass-on fins I’ve done, I didn’t use rope on any of them.