Gel coat removal - water sanding vs. straight line sanding

On Feb 8, 7:00*pm, "Morgans" wrote:
"jsbrake" wrote

I'm probably not going to like the answer... I'm very glad that the
gelcoat on my mistress is in great shape.

*I can't imagine a reason to remove all of the gelcoat off of anything. *In
refinishing, you get down as deep as needed in problem areas and then build
it back up, scuff up the rest, and shoot a new thin even coat on the whole
thing, and be done with it. *Thin is the key; don't put on more than you
took off.
--
Jim in NC

I have seen several examples where someone attempted to remove only
the "bad gelcoat" layer. In a year or two it looked terrible!

"mike" wrote

I have seen several examples where someone attempted to remove only
the "bad gelcoat" layer. In a year or two it looked terrible!

Oh, yes, the devil is in the details, isn't it.

There are degrees of bad. If the bad is cosmetic, i.e., scratches and
oxidation, a removal of the surface and reapplication of a compatible (ah,
more details that can be the devil) new layer will look fine.

If there is degradation of the jelcoat to fiberglass/carbon fiber/Kevlar
bonding, then the detail is the devil. Nothing to do but to take it all
off.

This is a case where working with someone that can teach the ins and outs of
fiberglass work can be invaluable, or valuable enough to save many man-hours
and material bucks.
--
Jim in NC

On Feb 8, 10:11*pm, "Morgans" wrote:
"mike" wrote

I have seen several examples where someone attempted to remove only
the "bad gelcoat" layer. In a year or two it looked terrible!

Oh, yes, *the devil is in the details, isn't it.

There are degrees of bad. *If the bad is cosmetic, i.e., scratches and
oxidation, a removal of the surface and reapplication of a compatible (ah,
more details that can be the devil) new layer will look fine.

I can't imagine a reason to remove all of the gelcoat off of anything.

This is a case where working with someone that can teach the ins and outs of
fiberglass work can be invaluable, or valuable enough to save many man-hours
and material bucks.
--
Jim in NC

You mentioned, " I can't imagine a reason to remove all of the gelcoat
off of anything."

and then in a following post,

" If there is degradation of the gelcoat to fiberglass/carbon fiber/
Kevlar
bonding, then the detail is the devil. Nothing to do but to take it
all
off."

I was addressing your first dictum.

Mike

"mike" wrote

You mentioned, " I can't imagine a reason to remove all of the gelcoat
off of anything."

and then in a following post,

" If there is degradation of the gelcoat to fiberglass/carbon fiber/
Kevlar
bonding, then the detail is the devil. Nothing to do but to take it
all
off."

I was addressing your first dictum.

You got me on that one.

OK, how about, I can't imagine removing all of the jelcoat unless it was
already trying to remove itself. g
--
Jim in NC

Hello,
Having refinished only a shk which is primarily wood construction with fiberglass cockpit and leading edges, IMHO if you decide to purchase a pneumatic (air) driven sander, dual action orbital or "air file" there is a world of difference between quality tools and Harbor freight cheap imports.
I recomend Hutchins brand tools, powerful, smooth action, and easy on air demand. also you can use a water flood with air tools.

For heavens sake wear a high quality air mask, that previous comment of not needing one because the particles are too big is B.S. and dangerous!
As an ICU RN I work with pulmonologists every day and ran that one by them, one simply stated "I wouldn't breath that with your lungs"

As far as time required, I removed three complete top coats of paint (about 75 lbs worth) and primers and fillers. brought up the new coatings and used polyurethane top coat, 18 meter wings, 4 foot wing root, big constant taper fuse, about 1100 hours.
B.T.W. prestec products ROCK!
Good luck and best wishes!
Scott W.

As far as time required, I removed three complete top coats of paint
(about 75 lbs worth) and primers and fillers. brought up the new
coatings and used polyurethane top coat, 18 meter wings, 4 foot wing
root, big constant taper fuse, about 1100 hours.
B.T.W. prestec products ROCK!
Good luck and best
wishes!
Scott W.


1100 hrs... divide by 20 hours/week = 55 weeks , just over a year of
working in the shop after the full-time job.

YIKES! I'm really, really glad I've got good ol' Scwabbelack
(spelling?) on my Kestrel... original 1972 gelcoat in great shape.

On Feb 10, 1:27*pm, jsbrake wrote:
As far as time required, I removed three complete top coats of paint
(about 75 lbs worth) and primers and fillers. brought up the new
coatings and used polyurethane top coat, 18 meter wings, 4 foot wing
root, big constant taper fuse, about 1100 hours.
B.T.W. prestec products ROCK!
Good luck and best
wishes!
Scott W.

1100 hrs... divide by 20 hours/week = 55 weeks , just over a year of
working in the shop after the full-time job.

YIKES! *I'm really, really glad I've got good ol' Scwabbelack
(spelling?) on my Kestrel... original 1972 gelcoat in great shape.

650 man hrs for club members to refinish ASK-21. Gelcoat off, fill,
contour, respray in acrylic urethane.
About 1/2 that for ASW-19 in gelcoat.
Good news is no need to go to gym for upper body exercise. My doctor
says that, for a fat guy, I have pretty good arms and shoulders.
LOL
UH

"shkdriver" wrote

Hello,
Having refinished only a shk which is primarily wood construction with
fiberglass cockpit and leading edges, IMHO if you decide to purchase a
pneumatic (air) driven sander, dual action orbital or "air file" there
is a world of difference between quality tools and Harbor freight cheap
imports.
I recomend Hutchins brand tools, powerful, smooth action, and easy on
air demand. also you can use a water flood with air tools.

I can only agree with the comment to buy quality air tools, made by any of a
number of manufacturers. The difference in air consumption between a cheap
one and a better one doing the same amount of work can easily be twice as
much air being consumed by the cheap one. No kidding.
--
Jim in NC

On Feb 9, 7:42*pm, shkdriver
wrote:
Hello,
Having refinished only a shk which is primarily wood construction with
fiberglass cockpit and leading edges, IMHO if you decide to purchase a
pneumatic (air) driven sander, dual action orbital or "air file" there
is a world of difference between quality tools and Harbor freight cheap
imports.
I recomend *Hutchins brand tools, powerful, smooth action, and easy on
air demand. also you can use a water flood with air tools.

For heavens sake wear a high quality air mask, that previous comment of
not needing one because the particles are too big is B.S. and
dangerous!
As an ICU RN I work with pulmonologists every day and ran that one by
them, one simply stated "I wouldn't breath that with your lungs"

As far as time required, I removed three complete top coats of paint
(about 75 lbs worth) and primers and fillers. brought up the new
coatings and used polyurethane top coat, 18 meter wings, 4 foot wing
root, big constant taper fuse, about 1100 hours.
B.T.W. prestec products ROCK!
Good luck and best
wishes!
Scott W.

--
shkdriver

Scott..............Prestec isn't a PU product is it?

I'll be looking at a total paint job of the HP-24 sometime soon. Right
now it is all bare carbon. Can't decide if I want to go with Simtec
products or use a 2-pack PU. a-la PPG concept.

Brad

On Feb 10, 9:55*pm, Brad wrote:
On Feb 9, 7:42*pm, shkdriver
wrote:





Hello,
Having refinished only a shk which is primarily wood construction with
fiberglass cockpit and leading edges, IMHO if you decide to purchase a
pneumatic (air) driven sander, dual action orbital or "air file" there
is a world of difference between quality tools and Harbor freight cheap
imports.
I recomend *Hutchins brand tools, powerful, smooth action, and easy on
air demand. also you can use a water flood with air tools.

For heavens sake wear a high quality air mask, that previous comment of
not needing one because the particles are too big is B.S. and
dangerous!
As an ICU RN I work with pulmonologists every day and ran that one by
them, one simply stated "I wouldn't breath that with your lungs"

As far as time required, I removed three complete top coats of paint
(about 75 lbs worth) and primers and fillers. brought up the new
coatings and used polyurethane top coat, 18 meter wings, 4 foot wing
root, big constant taper fuse, about 1100 hours.
B.T.W. prestec products ROCK!
Good luck and best
wishes!
Scott W.

--
shkdriver

Scott..............Prestec isn't a PU product is it?

I'll be looking at a total paint job of the HP-24 sometime soon. Right
now it is all bare carbon. Can't decide if I want to go with Simtec
products or use a 2-pack PU. a-la PPG concept.

Brad- Hide quoted text -

- Show quoted text -

I recommend PPG Concept (90288 super white) with PCL polyprimer (907
white) for primer. You must be very careful when spraying acrylic
urathane, this stuff can kill you! Get a respirator with hose outside
the spray booth, use plastic gloves, hat and glasses leaving no
exposed skin. You will need about 3 gallons of mixed product which
means 2 gal of paint, 1 gal of catalist and half gal of thinner ($1000
bucks or so). Spray on 4 medium coats or until you get good orange
peal everywhere which is an indication you have enough paint on. Let
it cure out for 24 hours at 70 degrees, then block sand (wet) with 600
followed by 800. I spray on guide coat (spray can) before hitting it
with 600 then use the black powder rubbed on in the area before
hitting it with 800. Then let it cure out for a good 3 more days
before buffing with a wool pad and liquid rubbing compound.
Hope this helps,
JJ