Keel Strip

Advice
#1

Need to replace a keel strip on a fiberglass boat. Already have a fiberglass strip on there but it’s starting to wear through in the front and back.

Anyone have recommendations for materials that would make a truly bomber keel strip, rather than another fiberglass one that will need replacement in another 5 years?

Thanks

#2

Make a wet putty of epoxy and fumed
Silica and apply to bow and stern where worn. “Keel strips” are a waste of time.

#3

you got 5 years …??
that’s pretty good…I did the resin / silica putty build up on my s&g … i ground thru that in a couple

years a couple times…



I tried this: http://www.clcboats.com/shop/products/boat-building-supplies-epoxy-fiberglass-plywood/marine-epoxy-fiberglass/kayak-rubstrip-kit.html



resin carbon impregnated polyester. Okay… I have had to build that up once too… Kayak is 8 yrs old.

#4

5 years
nothing last forever. Crush diamonds and mix with epoxy.

#5

Dynel
Thickened epoxy will not be as strong resin-impregnated fabric.



Dynel fabric seems to have excellent abrasion resistance. I use plain weave, 5 ounce/square yard Dynel cloth. It cuts easily and does not fray at the edges as readily as fiberglass. If I use fiberglass, I generally use S fiberglass which is stronger and more abrasion resistant than E fiberglass, although significantly more expensive.



Dynel fibers soak up a good deal of resin so one layer of 5 ounce cloth is usually plenty for a keel strip or abrasion plate. Adding graphite powder to your epoxy is said to provide additional abrasion resistance although I have not seen proof of this.



Here are a few photos of a keel strip I applied to a Royalex whitewater canoe:



http://www.flickr.com/photos/42020723@N02/albums/72157671439996460



Whitewater boats are highly rockered and tend to see a lot of wear center amidships from scraping over rocky shelves, etc. This was a Royalex canoe so I used G Flex epoxy. For a composite boat I would use conventional epoxy such as West System 105 resin with 205 or 206 hardener.

#6

Thanks for the replies
I was looking for something like the dynel material. Found carbon tape while hunting around on the internet, but not sure it’s as abrasion resistant and is a bit pricier. https://www.acpsales.com/Carbon-Woven-Tape.html

#7

Kevlar tape

– Last Updated: Aug-18-16 12:05 PM EST –

What about using Kevlar tape?

http://www.jamestowndistributors.com/userportal/show_product.do?pid=1491&familyName=Kevlar+Tape+2+inches+wide

I opt for that factory option on all the P&H composites I stock and it takes a mighty long time to wear that through, and while the mid-Hudson NY area isn't Maine, it's rock all the same. Not the land of sand here. Ok, drifting into Seussian.

Once you gel coat over it, none's the wiser as to its composition.

See you on the water,
Marshall
The River Connection, Inc.
Hyde Park, NY
www.the-river-connection.com
fb.me/theriverconnection

#8

will work, not my choice
Aramid cloths are better used for interior layers and seams. Part of the reason is that aramid fibers “fuzz up” when sanded or otherwise abraded.



You will see this on skin-coated hulls with an external layer of aramid. You simply cannot feather the edges of an aramid strip or patch as well as fiberglass or Dynel.



Keel strips and rub rails are more about abrasion resistance than adding strength. Aramid fibers are stronger than Dynel fibers (in tension anyway) but Dynel is not bad.



If aramid is used for exterior keel strips or patches, I would strongly advise using peel ply in their application so that a decently fine edge can be achieved without sanding.

#9

Always surprised me
How easy it was for heels to wear through a layer of Kevlar inside a hull. I’ve reglassed with glass and polyester cloth and it lasts forever.



The whole reason Kevlar felt works so well on canoes is that it swells up to a very thick ablative layer. My $.02 is that one should just wear the heck out of the bow and stern on kayaks until well into the fabric layers and then with that well defined platform build up a thick ablative layer with thickened epoxy where the wear occurs and don’t bother with layers of cloth that end up wrapping around to areas that get no wear. On one kayak I layed a shoelace like tube of dynel that had a strip of Kevlar tape packed inside. Epoxied on and taped down it was about 1/2" wide and 3/16" thick. On a big tandem I glued down a 16" strip of polyester line outer core soaked in epoxy, about 1/4" thick worth of tough ablative material. More material without having to fair in layers of cloth.

#10

Epoxy and sand.
Thickened epoxy mixed with sand is by far the most durable bow and stern keel protection Iv’e ever used. The more sand in the mix, the better the wear.