C-Forum

Yeah, yeah, yeah, I know. Hence the subject line.

This one is for a good cause. Adaptive paddling program, non-profit = money is tight.

Who'd-a-thunk-it, these bigger recreational kayaks are made of a multi-layer material sorta like Royalex but aren't Royalex. Old Town offers expensive repair kits. I tried to buck that by applying ABS soup based on acetone which peeled off like an onion skin. I experimented with an ABS soup based on MEK -- adhesion doesn't look good.

Does anything cheap stick to this stuff?

Thanks,

Ken Dubel

Did they make some canoes from the same stuff? Is it a polyethylene material? I saw a canoe repaired with their kit and it looked brand new - it had been repaired and painted and you had to have the patch pointed out to see it. Unfortunately I never saw what the kit consisted of, but it sounded like it was fiberglass cloth and resin? The owner said he wasn't comfortable trying the fix so he took it to a boat store (as in motor boats) and paid them to do it.

If you can get some more info about the kit, we might be able to come up with something equivalent and you *mgith* be able to save some money. But, I'd be willing to bet that their kit works pretty well if you went with it - it might be the safer bet.

Here's an Old Town mnaual with info about the different materials and, later in the file, repair methods:

http://www.kayaks-and-kayaking.com/supp ... ldtown.pdf

Polyurethane resin?

BREAKS/CUTS/PUNCTURES: Discovery repair
kit (part #1331.0641). Contains a 2-part
polyurethane resin system, nylon cloth, sand
paper, brush, and instructions. Repairs of this
nature normally require a patch both inside
and outside of the hull. The patch will be applied
very much like fiberglass, however this
resin is superior in that it is very durable as
well as flexible.

FINISHING: Roto spray paint (part
#1331.1880). Use to cover any repairs.
Colors available to match Discovery canoes.
Please keep in mind that your hull’s color may
have faded somewhat over time and may not
match perfectly.

SPECIAL NOTE FOR ALL SUPERLINK
3™ POLYLINK 3™ AND LINEAR
POLYETHYLENE HULLS
POLARIZATION
All polyethylene hulls need to be polarized
prior to any attempted repair or bonding.
No material will permanently bond to
polyethylene as it is before polarizing. You
must first be sure the area is roughened with
sand paper and clean. To polarize you will
need a hand-held propane torch. The torch
will have a flame about 3 inches long. Inside
will be a smaller, brighter blue flame. This
smaller flame must contact the hull in the
area to be bonded. Simply wave the flame
across the hull like you were painting it with
a small brush. This process does not involve
melting, blackening, or even getting the surface
hot. What is important is having the
gases given off in the bright blue part of the
flame oxidize the surface to be repaired. Do
not touch the area with your bare hands
after polarizing as oils from your skin will reverse
the process.

Thanks for the link. How scary does this sound:

"POLARIZATION
All polyethylene hulls need to be polarized
prior to any attempted repair or bonding.
No material will permanently bond to
polyethylene as it is before polarizing. You
must first be sure the area is roughened with
sand paper and clean. To polarize you will
need a hand-held propane torch. The torch
will have a flame about 3 inches long. Inside
will be a smaller, brighter blue flame. This
smaller flame must contact the hull in the
area to be bonded. Simply wave the flame
across the hull like you were painting it with
a small brush. This process does not involve
melting, blackening, or even getting the surface
hot. What is important is having the
gases given off in the bright blue part of the
flame oxidize the surface to be repaired. Do
not touch the area with your bare hands
after polarizing as oils from your skin will reverse
the process."

I have done patches on Discovery canoes using: (1) the torch polarization technique described by Old Town, (2) epoxy resin (System 3 or WEST), and (3) polyester cloth (order this from Sweet). I have done many more of these on ABS boats, but seem to remember it working OK on the Discovery boats. I use the polyester cloth in an effort to keep the patch flexible which stresses the bond to the hull less than if the patch is stiffer (e.g., made of glass or Kevlar cloth). Good luck.

Sounds like we may need to suck it up and buy the repair kit.

Thanks for the tips!

Ken

I wonder how that new West Systems Gflex compares to a urethane resin...

Roy...... polyester cloth is an OK choice. If Kevlar is used, the patch will NOT be stiffer than a glass patch. In fact, it won't be stiffer than your polyester patches. Kevlar has less strength in compression than just about all other cloths used for composite work.

Now, if you had to put a patch INSIDE a poly boat, Kevlar would usually be an excellent choice. Inside, it will usually only be in tension, unless used for patching along chines.