Date: Tue, 7 Apr 1998 11:10:11 -0500
From: PPierquet@us.teltech.com (Patrick Pierquet)
Subject: [baidarka] Re[2]: Re[2]: Hypalon or urethane coating????
To: baidarka@lists.intelenet.net
Many thanks, Bill....good information!
- Patrick
______________________________ Reply Separator _________________________________
Subject: Re: [baidarka] Re[2]: Hypalon or urethane coating????
Author: baidarka@lists.intelenet.net at Internet
Date: 4/7/98 11:23 AM
Yes there is a difference between normal exterior urethane and AU. I have
been using a product by ZAR. The exterior satin. It seems to reduce
yellowing and the satin is less brittle than the gloss. I want as white a
finish as I can get and still have a translucent appearance.
As I said I put two coats of urethane all over the boat. I also add a strip
of polypropylene fabric on the keelson as a rub strip. I use polypropylene
because of my experience with it on paddle edges. It is much more resistant
to abrasion in that application than nylon. It is also easier to apply than
strips of polyester. I pay special attention to stitching to eliminate any
leakage there.
The bond between urethane and the AU is amazing if the AU is applied within
a reasonable time frame. Within a couple of weeks seems optimum. If you
paddle between then you must clean the hull very well. I have done this and
even waited longer than a couple of months. I found that after cleaning and
just before applying the AU I softened the urethane with acetone it helps.
I prefer to apply the AU within one day if possible.
The Aliphatic Urethane is nasty stuff. Read the MSD sheets before buying
it. It is not cheap. It is a 2 part material with a short shelf life unless
steps are taken to preserve it. It and the polyester fabric are available
from George Dyson. The AU is over $100. I split the original gallon for A
and B into quart cans to keep them longer. I have stored AU for over a year
that way. You have to fill right up to the top to keep the O2 and moisture
out. George says some fill the can with N2 before closing but I don't
bother. I get 8 boats per gallon set.
Precautions are very necessary. I have a fresh air breathing system I use.
A complete head and shoulders flexible hood supplied with air from the
outside plus a suit to cover the rest of me and of course gloves. The fumes
can get you in the lungs, through the skin and through your eyes. I take
every precaution possible. I have done it out of doors and then I still
wear a type 3 charcoal respirator and gloves and suit. I don't like to do
it outside because of bugs. You would think it would send every bug out of
the county but it doesn't and you can't dig the bugs out afterward.
A pint of A and a pint of B are mixed just before application. I use a 3"
roller that has been carefully combed to remove any lint. Again you can't
dig out it out later. Two coats one right after the other are possible as
the drying time is fast. I have also tried using a brush for the second
coat. It might be a little smoother but now I don't bother. I clean up with
acetone and get the hell out of there. I like to let the shop air out
overnight before I go back in without a respirator.
You can actually put it in the water within a hour of coating it if you are
very careful not to touch the coating(such as a rock or the bottom). I have
done it and it does not seem to damage it at all. Otherwise it will take
about 2 weeks to really cure. It will be tacky up until that time. Once it
hardens it is very abrasion resistant. I routinely drive my boats up on the
shore even rocks and mussel shells here and in Maine without a problem
The reason I don't coat the top of the boat is that I try to keep that part
off the bottom and I like to paint decorations on some of my boats. I have
found that you can draw what you want on the urethane wait until it dries
overcoat it with one more coat of urethane and you have a well protected,
decorated boat.
It got a little longer than I expected but now you know what I know.
Bill
----------
> From: Patrick Pierquet <PPierquet@us.teltech.com>
> To: baidarka@lists.intelenet.net
> Subject: [baidarka] Re[2]: Hypalon or urethane coating????
> Date: Monday, April 06, 1998 2:26 PM
>
>
> Hey, thanks, Bill! Yes, I AM interested...it sounds like there's a
difference
> between plain ol' urethane, and ALIPHATIC urethane; where do you purchase
these
> materials? (I have a price list from Cal Polymers, that lists about a
dozen
> different formulations of 2-part urethanes, along with their physical
> properties....are you familiar with their product? I'm especially
interested in
> their product because they claim they are "less toxic than other
commercially
> available systems", and can be ordered in quantities as small as
one-quart.)
> I'd like to try the Dyson polyester/urethane on my boat. Any tips would
be
> greatly appreciated! See you....
>
> - Patrick
>
> ______________________________ Reply Separator
_________________________________
> Subject: Re: [baidarka] Hypalon or urethane coating????
> Author: baidarka@lists.intelenet.net at Internet
> Date: 4/6/98 1:48 PM
>
>
> I mentioned in my reply to Charles Hall that I use the two part Aliphatic
> Urethane on my boats. I discovered that using the AU without a precoating
> of exterior urethane does not seal the fabric well. I therefore pre coat
> the entire boat with urethane to make the boat watertight.
>
> The AU is an excellent coating for abrasion resistance. If you apply it
> over the urethane within a week or so there is a bond between the two
that
> is impossible to separate. It also adds a strength to the fabric-coating
> combination that is amazing. I have had people try to put a sharpened
1/2"
> dowel through a sheet of the combination material. I finally found one
very
> big guy who after several attempts did get it through. The hole closed up
> so that very little water would have gone through.
>
> I must warn you that the AU is nasty stuff. I use a fresh air breathing
> apparatus with full suit and gloves when I apply it. The MSD makes for
some
> scary reading.
>
> I have not used hypalon so I can not make a comparison. I have seen it on
> other boats and it seems to work well. AU is clear while I understand
that
> hypalon can't be purchased clear. The AU-urethane-polyester makes a very
> pretty translucent skin. Looks great when the sun is shinning through it.
>
> If you should be interested in using it I could give you some tips that
> might make it easier but I won't bore you with it now.
>
> Bill Low
>
> ----------
> > From: Patrick Pierquet <PPierquet@us.teltech.com>
> > To: baidarka@lists.intelenet.net
> > Subject: [baidarka] Hypalon or urethane coating????
> > Date: Monday, April 06, 1998 12:10 PM
> >
> >
> > Can anyone comment on the advantages/disadvantages of hypalon
> coatings
> > versus urethane elastomers? I've noticed that one of the
> > manufacturers of folding kayaks uses urethane, whereas most of the
> > others use hypalon. I've read that urethanes are generally
lighter,
>
> > and tougher, than hypalon coatings. Any comments? The urethane
is
> a
> > 2-part material, so I suppose it's a bit "fussier" to use than
> > hypalon, but I've read that the hypalon contains very dangerous
> > solvents. Can anyone comment on this? Thanks in advance for any
> > suggestions!
> >
> > - Patrick in Minnesota