How to repair ASA skin damage ?
dubois
made several 1 to 3cm cracks accross the nose at about 10 cm from the
tip of the nose. One of those cracks has soaked up water. So what I have
done, is a small hole at the very tip of the board to drain the water.
From time to time I stick a vaccum cleaner on the hole and I manage to
suck out some more water. Up to know I've managed to remove about one
wine glass full of sea water. The problem is that there is an area
of the ASA skin around the crack which is very slightly soft when I
press hard on it. Also when I knock on the board with my knuckles, it
sounds differently around the crack area ( like if there was a thin gap
between the core of the board and the skin.
What should I do at this point ? I have to do the repair myself as there
are no Mistral agent or repair centers in the country I live. I can get
fiberglass, epoxy, microballons here but no divinycell foam or vaccum
bagging equipment or other fancy stuff. Should I simply wait a few more
days for the core to dry further and simply cover the whole nose area
with 2 or 3 layers of fiberglass ? (It will look ugly but at the end of
the day that is not to important). Should I sand the ASA skin down to
the foam core or fiberglass layers before laying the new fiberglass ?
Any advice is greatly appreciated as I have had this board imported by a
friend only 1 month ago. Thanks in advance.
Francois
E-mail : ge...@hkstar.com
dcro...@us.ibm.com
dubois <dub...@netvigator.com> wrote:
> I've just cracked the nose of my Mistral flow 276 with a catapult. This
> made several 1 to 3cm cracks accross the nose at about 10 cm from the
> tip of the nose. One of those cracks has soaked up water. So what I have
> done, is a small hole at the very tip of the board to drain the water.
> From time to time I stick a vaccum cleaner on the hole and I manage to
> suck out some more water. Up to know I've managed to remove about one
> wine glass full of sea water. The problem is that there is an area
> of the ASA skin around the crack which is very slightly soft when I
> press hard on it. Also when I knock on the board with my knuckles, it
> sounds differently around the crack area ( like if there was a thin gap
> between the core of the board and the skin.
>
You need to perform a little surgery and cut away all of the damaged/wet
material -- epoxy won't stick very well to a wet area. If you don't get down
to sound material you are opening the door for future water intrusion
reslutling in added weight and a no longer fun board. I've had mixed success
with removing water with vacuum, others swear by it. Obviously the less you
suck up the less you have to remove. A normal vacuum cleaner is of minimal
use - they stall out as soon as the pressure differential is applied. You can
mail order the West Epoxy vacuum bagging kit or just order the ventury type
generator - it will pull about 20 in. of HG. (approx 10 psi or 2/3 atm.) and
it runs off of an air compressor. you hcan use 6 mil poly sheeting and duct
tape to secure and 3/8" poly tubing.
None of this may be necessary if you can grind/cut away the damaged area with
a disc sander. Using divinicell would be nice (again you can mail order from
places like Monterey Bay Fiberglass and the like), but you can do what the
surfers do and just mix up cabosil and add microballons and cover with
several layers of cloth. Take the time to tape off the area that you don't
want epoxy getting on - use wax paper as a mask (epoxy resin won't stick to
it). Watch out for the epoxy eating/melting the EPS core -- they say that
slow hardner minimzes this problem. Do a test on a small sample first -
nothing worse than pouring the stuff on and watching it eat a huge crater in
your board. Make sure that you protect the repaired area from UV by painting
the repair when done -- the epoxy will rapidly yellow, get brittle and
eventualy strat to break down, thus letting water back in.
The idea is that the less you tear apart the less you have to put back and
the easier life is. Speculating over the net is tough and you should try and
find some one local who may have experience with this stuff, but it sounds
like you may be in a remote location. It doesn't have to be a windsurfer --
if there are boats or a marina around then there should be one or two people
who've worked with the materials and done some repairs. Having said all this
I once repaired a board by simply drilling a bunch of holes and injecting
epoxy via a syringe into and under the damaged area -- no surgery required,
since this was a "crushing" type of blow and the skin had not yet failed. It
really depends on the exact nature and extent of the damage. One otion is to
just glass over the area and leave whatever water is trapped inside -- not an
ideal repair, but easier.
Dave
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dubois
Thanks a lot for your kind advice and good explanation. I've let the
board drain for about a week now next to a dehumidifier and it has just
stopped dripping. I've also weighted it on a not very accurate personal
scale but the board seems to be at its original weight or very close. I
also sanded the skin of the board down to the fiberglass and I saw that
the fibers had a 2 cm crack. I then grinded through the fiberglass and I
found a black material which also has the same crack. I suppose I'm
going to have to sand through that black material down to the EPS or do
as you suggested with inserting epoxy-microballons putty with seringes.
Thanks again,
Francois