Fin Rope..?

Fin Rope. Normally I buy bundles of it from a surf supplier.

But can I just take long strands of scrap fiberglass, bundle them up, and cut them to the same length?

Not sure if this is a valid way to make a rope. 

I learned from the guys here that strips of cloth cut on the bias works just as well. Usually do 3 or 4 strips around the 1" wide laid up at the base of each side and it has proven to be very strong.  Haven’t bought fin rope in years thanks to that tip. 

Just did these using that method on Wednesday actually. 

I’ve never heard the phrase ‘cut on the bias’. Do you mean just cut the glass into 1" strips and use those? Like not actually separating each individual fiber into a bundle. 

Bias just means to cut at a 45 degree angle. Supposedly it adds strength when glass is laid up like this as opposed to just regular 90 degree angles. Ive attached an example. Might be hard to see though.  

 

What’s on the right side of the pic is what I’ll use 3 or 4 of instead of the rope. I always have a ton of glass scraps after my lamination so this is pretty handy. 

Pull apart a piece of 6oz cloth and you have fin rope.

I see now. So 3-4 of those on either side instead of fin rope. Very clever 

This is what I first thought of doing. Do you have an estimate for how many strands of cloth I need to make a rope?

I yard of roving is more fin rope than even a busy board builder will most likely ever use up.  Lot easier to pull strands, count the number of strands needed for each side, tape one end  and saturate.   Lays down next to the fin nicer than cloth and definitely stronger.  Then put your football patches over that.  You fight bubbles and delam using cloth as a substitute.

McDing with the knowledge as always. Definitely going to pull apart my enormous pile of 6oz scrap and save some money. About how thick should the rope be? How many fibers? 30 or so? 

I’ve gone to boat supply stores, (they never cut cloth straight) and asked if I can buy the jagged edge of their 10 oz cloth.  They will often cut the edge straight and give it to you.

Roving comes apart in strands very easily.  If you are not familiar with “roving”, I’ll take a pic for you later today when I get by the shop.  I’m thinking we used to use 5—7 strands per side at the base, with three football patches on each side.  All laminated in one process.  Babysitt the base with your finger.  Keep smoothin and pressing it down until the resin sets.  Fin rope packages that you buy from suppliers are just roving pulled apart.  The strands are bigger than what you would come up with from cloth.   Separating strands of cloth is a pain in the a$$.  Separating strands of roving is easy.  They practically fall apart.  They are bigger, so you need fewer per side.   Lowel

I know I’ve got a bigger scrap around somewhere, but I think you get the idea. Lowel

This looks like the stuff, and seems like I can just go pick it up at this place near me. $42 for 50"x24", which I think is about 33 yards. Way more than I’ll ever realistically use in my life. Hoping they can cut a smaller piece. Glassing on plywood fins on an old MR twin to give it some life 

That’s Bondo, Evercoat and Fiberlay for you.   Home Depot.  Just order a ft or two online.  Foam EZ, Fiberglass Hawaii, Surf Supply, Greenlight, Surf Source etc…  Find somebody who glasses boats. The local dory glasser gave me a foot off his roll.