Gel Coat for Dummies

Help.

I want to repair some self-inflicted wounds on the
leading edges of the wings on my LS1-d. The wounds
were created when getting the wings out from and/or
putting them back into the definintely non-Cobra/Komet
trailer. While not a Cobra, it is a 'serpent' type
of trailer, but more of a intestinal 'tape worm'...

I scraped off little bits of gel coat from time to
time and I want to reapply gel coat. Fill the little
divots and sand them off.

But, how do you sand the leading edge? These divots
were probably no more than about 50 mm long for the
largest and no more than about 10 mm high, again for
the largest. Others are smaller. And, they are right
on the nose of the leading edges.

I've begun the work with some gel coat and I've sanded
it down, but wondering what the 'right' way would be.
What size sanding block to use? I'm using a milled
piece of wood that measures about 75mm wide by 15 mm
thick by about 450 mm long and wrapping a sheet of
sanding paper around it.

My sanding movements have been parallel with the leading
edge, trying to keep the sand paper right over the
gel coat which 'stands proud' above the surrounding
areas.

Any help will be appreciated.

Thanks,
Ray Lovinggood
Carrboro, North Carolina, USA

There's a lot more in this article then you need ... you can actually
paint gelcoat with a brush for small LE repairs ... a sanding block/bar
is essential ... a small one is probably OK for small dings ... I use
longer for LE refinishing.

http://sailplane-racing.org/Articles...asw20_wing.htm

KK

Ray Lovinggood wrote:
Help.

I want to repair some self-inflicted wounds on the
leading edges of the wings on my LS1-d. The wounds
were created when getting the wings out from and/or
putting them back into the definintely non-Cobra/Komet

Just to look at this a little more ... small fixes are often the most
difficult. As you sand down the newly applied material, you ultimately
hit the surrounding area and remove gelcoat there ... sometimes to the
point where the underlying darker glass surface starts to show. Except
for small chips, I always use some type of disclosure agent which shows
where I am sanding. I have also used tape to shield areas ... this can
help ... and always use the finest grit paper possible ... slower is
better. Leading edge sanding around the front radius requires feel and
wrist action ... it would be easier to explain on the phone if you want
to discuss.

KK

There is an excellent video series on gel coat repairs for the
fiberglass boat community. These will give you the general knowledge
you need. You can then use the group for the more specific knowledge of
work on sailplanes.

Cosmetic Gelcoat and Fiberglass Repair Volumes I-III
V I: Gelcoat 100 minutes
V II: Stress Cracks, Air Voids, and Fractures 104 minutes
V III: Color Matching 34 minutes
Bennett Marine Video 1989
Marina Del Ray, CA 90292

Nothing new here, but what I do is use a short piece (6 inches) of 1
inch square aluminum bar stock. I put strips of various grades of
wet/dry sandpaper on each side. Say, 200grit, 400 grit, 600 grit, 1000
grit.

I support the wing leading edge down and paint on some matching
gelcoat. The leading edge down assures complete coverage of the
leading edge dings.

When the gelcoat hardens I use the multisided sanding bar to
progressively remove the higher material, using water and finer
sandpaper as I progress down.

Finish with polishing compound and wax.

Bob

On 12 Dec 2004 17:17:38 GMT, Ray Lovinggood
wrote:

Help.

I want to repair some self-inflicted wounds on the
leading edges of the wings on my LS1-d. The wounds
were created when getting the wings out from and/or
putting them back into the definintely non-Cobra/Komet
trailer. While not a Cobra, it is a 'serpent' type
of trailer, but more of a intestinal 'tape worm'...

I scraped off little bits of gel coat from time to
time and I want to reapply gel coat. Fill the little
divots and sand them off.

But, how do you sand the leading edge? These divots
were probably no more than about 50 mm long for the
largest and no more than about 10 mm high, again for
the largest. Others are smaller. And, they are right
on the nose of the leading edges.

I've begun the work with some gel coat and I've sanded
it down, but wondering what the 'right' way would be.
What size sanding block to use? I'm using a milled
piece of wood that measures about 75mm wide by 15 mm
thick by about 450 mm long and wrapping a sheet of
sanding paper around it.

My sanding movements have been parallel with the leading
edge, trying to keep the sand paper right over the
gel coat which 'stands proud' above the surrounding
areas.

Any help will be appreciated.

Thanks,
Ray Lovinggood
Carrboro, North Carolina, USA

What, if anything, do you do about matching the shade of the existing
surface?

Tony V.
http://home.comcast.net/~verhulst/SOARING

Hopefully, basic white without tints.

Gels and Imron may discolor with age and environment. I had an Imron
painted Open Cirrus and tried very hard to match and sought 7 different
opinions before ordering, using the factory color charts. Under overcast
and blue sky and fluorescent lighting there was some divergence between a
light gray tint and a light blue tint. I went with the predominently female
opinions, since color vision deficiency is more generally a male trait.

It was a bit blue once applied, the gray may have worked better. However, I
had to order a minimum amount and when the person I sold my final share to
damaged the glider, the fuselage was re-sprayed with the remainder, so it
finally matched.

Frank Whiteley


"Tony Verhulst" wrote in message
news:ld8vd.227573$HA.7445@attbi_s01...
What, if anything, do you do about matching the shade of the existing
surface?

Tony V.
http://home.comcast.net/~verhulst/SOARING

Tony,

That's the LEAST of my worries. :-)

Ray

At 04:30 13 December 2004, Tony Verhulst wrote:
What, if anything, do you do about matching the shade
of the existing
surface?

Tony V.
http://home.comcast.net/~verhulst/SOARING

OK everyone, take a deep breath before responding how stupid my approach
is... I am fully aware of the potential damage that _could_ occur.

One method that I have used successfully doing similar things to my
wings is to use a _clean_ mill ******* file. I know, I know.... sounds
like heresy to lay a file on your wing but if you lay it flat, parallel
to the leading edge, it is possible to "file" down the proud portion of
the gelcoat without gouging into or scratching the existing gelcoat.
The file rides smoothly over the existing gelcoat but takes off the
excess new gelcoat. It takes a light sensitive touch but makes very
quick work of the job because the teeth of the file only catches on the
raised replacement gel coat.

Try at your own risk!!!

Larry Goddard
"01" USA



Ray Lovinggood wrote:

Help.

I want to repair some self-inflicted wounds on the
leading edges of the wings on my LS1-d. The wounds
were created when getting the wings out from and/or
putting them back into the definintely non-Cobra/Komet
trailer. While not a Cobra, it is a 'serpent' type
of trailer, but more of a intestinal 'tape worm'...

I scraped off little bits of gel coat from time to
time and I want to reapply gel coat. Fill the little
divots and sand them off.

But, how do you sand the leading edge? These divots
were probably no more than about 50 mm long for the
largest and no more than about 10 mm high, again for
the largest. Others are smaller. And, they are right
on the nose of the leading edges.

I've begun the work with some gel coat and I've sanded
it down, but wondering what the 'right' way would be.
What size sanding block to use? I'm using a milled
piece of wood that measures about 75mm wide by 15 mm
thick by about 450 mm long and wrapping a sheet of
sanding paper around it.

My sanding movements have been parallel with the leading
edge, trying to keep the sand paper right over the
gel coat which 'stands proud' above the surrounding
areas.

Any help will be appreciated.

Thanks,
Ray Lovinggood
Carrboro, North Carolina, USA

Actually that's a very good idea, Larry

We did just that when the repair shop was open ('76
to '96)

+ Scrub with acetone to remove wax and crud.

+ Sand edges with 600 to remove oxidized gelcoat (or
a yellow ring will be trapped at the edge of your repair)

+ Mask off and brush on several coats of gelcoat. Use
heat gun to make it dry faster (hair dryer works)

+ Remove high spots with a file, this works best on
straight sections, like leading edges.

+ Wet sand with a block (600 & 800)

+ Buff out with a wool pad and liquid buffing compound.

We called the above, 'Dings & Things' Every annual
came with a request to fix this ding and take a look
at ---------------------
Best if a reasonably clever owner does this on his
own.
Happy, Happy to all on ras,
JJ

At 06:30 22 December 2004, Larry Goddard wrote:
OK everyone, take a deep breath before responding how
stupid my approach
is... I am fully aware of the potential damage that
_could_ occur.

One method that I have used successfully doing similar
things to my
wings is to use a _clean_ mill ******* file. I know,
I know.... sounds
like heresy to lay a file on your wing but if you lay
it flat, parallel
to the leading edge, it is possible to 'file' down
the proud portion of
the gelcoat without gouging into or scratching the
existing gelcoat.
The file rides smoothly over the existing gelcoat
but takes off the
excess new gelcoat. It takes a light sensitive touch
but makes very
quick work of the job because the teeth of the file
only catches on the
raised replacement gel coat.

Try at your own risk!!!

Larry Goddard
'01' USA



Ray Lovinggood wrote:

Help.

I want to repair some self-inflicted wounds on the
leading edges of the wings on my LS1-d. The wounds
were created when getting the wings out from and/or
putting them back into the definintely non-Cobra/Komet
trailer. While not a Cobra, it is a 'serpent' type
of trailer, but more of a intestinal 'tape worm'...

I scraped off little bits of gel coat from time to
time and I want to reapply gel coat. Fill the little
divots and sand them off.

But, how do you sand the leading edge? These divots
were probably no more than about 50 mm long for the
largest and no more than about 10 mm high, again for
the largest. Others are smaller. And, they are right
on the nose of the leading edges.

I've begun the work with some gel coat and I've sanded
it down, but wondering what the 'right' way would
be.
What size sanding block to use? I'm using a milled
piece of wood that measures about 75mm wide by 15
mm
thick by about 450 mm long and wrapping a sheet of
sanding paper around it.

My sanding movements have been parallel with the leading
edge, trying to keep the sand paper right over the
gel coat which 'stands proud' above the surrounding
areas.

Any help will be appreciated.

Thanks,
Ray Lovinggood
Carrboro, North Carolina, USA