Gel coat

PostPost by: davidallen » Mon Oct 11, 2004 2:21 pm

Hi,

I am in the process taking an angle grinder to my pride and joy to remove
all the gel coat cracks prior to having it painted. Some of them are
obvious, but there are a series of very faint parallel cracks on the boot
lid , right across the letters LOTUS.

I thought at first they were cracks in the paint, and indeed can not find
any cracks in the gel coat under the paint. However, in Mick Millers article
in Lotus News there is a comments that these cracks may also be in the gel
coat.

Has anyone seen similar marks and/or advice would be welcome.

David
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PostPost by: saarhus » Mon Oct 11, 2004 3:37 pm

I hope you haven't started grinding yet. IMHO, the LAST thing you want to do is REMOVE the gel coat. The gel coat should be gently uncovered, preserved and repaired. How you uncover it is critical, and will have a direct effect on how many hours you will need to spend getting ready for paint. There are several ways to remove the old paint, but grinding it off with an angle grinder is not one of them. This is like doing brain surgery with an axe. Some people have had good results with a paint stripper. Others use a low abrasion "bead blaster". Others prefer to hand sand down to the gel. Use whatever suits your circumstances, but be very careful to preserve the gel..

If you use a liquid stripper, you will probably be using water to remove it. If so, there may be areas where the fiberglass is exposed. These areas could allow water to penetrate to the fiberglass. Since it is porous, there will probably be some water penetration. Not good. This needs to be eliminated, either air drying (slow) or with a heat lamp, being careful not to overheat the fiberglass.

These are my personal observations and experiences. Your results may differ.

Cheers!

Stan

I am in the process taking an angle grinder to my pride and joy to remove
all the gel coat cracks prior to having it painted.
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PostPost by: davidallen » Mon Oct 11, 2004 4:14 pm

Sorry. I probably did not make myself clear. I only plan to grind out the
cracks and refill with fibreglass tissue paper/body filler as per Mick
Miller's instructions in the Lotus News Mag.

Mick Miller suggests using a chisel to remove the paint (est. 70 hours,
ouch!) I am looking at using soda blasting.

David (angle grinder at the ready!)

-----Original Message-----
From: Stan Aarhus [mailto:***@***.***
Sent: 11 October 2004 15:25
To: ***@***.***
Subject: Re: [LotusElan.net] Gel coat



I hope you haven't started grinding yet. IMHO, the LAST thing you want to
do is REMOVE the gel coat. The gel coat should be gently uncovered,
preserved and repaired. How you uncover it is critical, and will have a
direct effect on how many hours you will need to spend getting ready for
paint. There are several ways to remove the old paint, but grinding it off
with an angle grinder is not one of them. This is like doing brain surgery
with an axe. Some people have had good results with a paint stripper.
Others use a low abrasion "bead blaster". Others prefer to hand sand down
to the gel. Use whatever suits your circumstances, but be very careful to
preserve the gel..

If you use a liquid stripper, you will probably be using water to remove it.
If so, there may be areas where the fiberglass is exposed. These areas
could allow water to penetrate to the fiberglass. Since it is porous, there
will probably be some water penetration. Not good. This needs to be
eliminated, either air drying (slow) or with a heat lamp, being careful not
to overheat the fiberglass.

These are my personal observations and experiences. Your results may
differ.

Cheers!

Stan

I am in the process taking an angle grinder to my pride and joy to remove
all the gel coat cracks prior to having it painted.














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PostPost by: saarhus » Mon Oct 11, 2004 4:19 pm

Whew! What a relief!

Cheers!

Stan



Sorry. I probably did not make myself clear. I only plan to grind out the
cracks and refill with fibreglass tissue paper/body filler as per Mick
Miller's instructions in the Lotus News Mag.

Mick Miller suggests using a chisel to remove the paint (est. 70 hours,
ouch!) I am looking at using soda blasting.

David (angle grinder at the ready!)
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PostPost by: rodlittle » Mon Oct 11, 2004 4:19 pm

I used a Skarsten scraper to remove my paint, and I still need to grind
off most of the gel coat and re tissue it all
Cheers
Rod
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PostPost by: simon.mitchell » Mon Oct 11, 2004 6:18 pm

David,

I've just finished repairing and spraying the boot lid of my plus 2, which
had cracks of exactly the same type and in the same position as you
describe. I ground them out with an 80 grit disc on a grinder before
re-tissuing, filling, priming and painting.

My feeling is that they're stress cracks, so I'd definately recommend
sorting them while you have the chance!

Cheers,
Simon
'68 Zetec Plus 2
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PostPost by: elansprint71 » Mon Oct 11, 2004 9:42 pm

If in doubt, grind it out.

Pete (little experience with car glass-fibre repairs, but lots with boats... think about it- massive shock loads, salt water...).
----- Original Message -----
From: ALLEN, David
To: ***@***.***
Sent: Monday, October 11, 2004 3:18 PM
Subject: [LotusElan.net] Gel coat


Hi,

I am in the process taking an angle grinder to my pride and joy to remove
all the gel coat cracks prior to having it painted. Some of them are
obvious, but there are a series of very faint parallel cracks on the boot
lid , right across the letters LOTUS.

I thought at first they were cracks in the paint, and indeed can not find
any cracks in the gel coat under the paint. However, in Mick Millers article
in Lotus News there is a comments that these cracks may also be in the gel
coat.

Has anyone seen similar marks and/or advice would be welcome.

David






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PostPost by: lotuselan2 » Tue Oct 12, 2004 12:52 am

David et al

Here is a related lesson I learned the hard way. Lets say you follow most
of the advice on other replies and you take all the paint off down to the
gel coat and do your repairs as if a brain surgeon, not the chain saw
murderer, you will be down to bare gel coat. Unfortunately this gel coat
has tiny pores even before you get down to any glass. Prior to priming one
might wipe clean the surface with water, mineral spirits or other low
volatile liquid. IN TO THE PORES IT GOES! Use a high quality finish coat
and it locks in the low volatility liquid. Slowly over years the liquid
works it way through the primer and finish coat which, if good, is a perfect
barrier to volatiles. The result, a BIG UGLY BLISTER. I have a whole car
full of them.

8 years after painting the car I removed the boot and the bonnet and sanded
back down to the gel coat. In the later stages of sanding I saw little wet
spots in the sanding dust. They were persistent. I set the parts out on a
bright sunny dry day and came back a few hours later to find miniature
volcanoes all over the surface. I am still working on these parts and still
have to use a hair dryer on small spots to get the stuff out. My case may
be extreme because I used mineral spirits to do my final wipe down, but
BEWARE of those tiny pores.

Ken
'69 +2 with BDR

p.s. Find yourself a good DuPont paint dealer and work with him every step
of your restoration. They can be a great asset. Plan on spending a lot of
money on their over-priced but effective products.
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
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PostPost by: Bill » Tue Oct 12, 2004 6:57 am

Rod, What is a "Skarsten" sctaper?

Bill
----- Original Message -----
From: "Rod Little" <***@***.***>

Sent: Monday, October 11, 2004 9:22 AM
Subject: Re: [LotusElan.net] Gel coat



I used a Skarsten scraper to remove my paint, and I still need to grind
off most of the gel coat and re tissue it all
Cheers
Rod












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PostPost by: Gordon Sauer » Tue Oct 12, 2004 8:13 am

I agree--grind it out. Have similar cracks along my trunk lid--looks like
mild impact to lid--just enough to stress the glass and show up as cracks--mine
showed in the paint too with too many layers. Gordon Sauer
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PostPost by: Gordon Sauer » Tue Oct 12, 2004 8:42 am

A little more on this gel coat business--I had my silver flake +2S roof done
at a boat place and I can see they went back with gel coat before shooting the
metalflake clear--it's held up well now some four years later. However,
despite there being spray and brush on versions of gel coat available, my sense is
that you don't have to go back to gelcoat. I am shooting a two-pack primer
much like Featherfill but staying with DuPont system. Then coming back with
urethane color for the remainder of the body. I painted my Elan DHC some twenty
years ago--mind you only the bottom and part way up the sides (these are
interminable projects) and never have had any paint trouble. This was using a
lacquer based primer (20 years ago!) and acrylic enamel after chemical stripping.
Also, I had chemically stripped the roof of my +2S (since the previous owner
had shot the silver roof in car color!) and still have had no wicking or
residual chemical action. Now I take my time when doing all this (duh) so maybe
that's the answer--but paint still drying basically after 8 years is strange.
I doubt if any of us that have stripped a body for painting, however done, had
any gel coat left and has anybody gone to the trouble of replacing the gel
coat prior to priming and painting? Gordon Sauer
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PostPost by: rodlittle » Tue Oct 12, 2004 9:01 am

Hi
Basically it is a blade usually carbide or other hardened material held
rigidly at a steep angle to the handle >90degrees
rather like holding a single edged razor blade in your fingers and
dragging it across the surface.
Usually used for paint removal/ surface finishing in the wood and
buiding/painters industry
Hope this helps
Rod
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PostPost by: type36lotus » Tue Oct 12, 2004 11:30 am

A further warning to go along with what Ken says. Decide everything
in advance before you start filing and priming. I did not the result
was a more limited selection as the primer I used was only compatible
with a select list of top coats. So know what color, what brand, what
type of paint you want, then proceed with fillers and primers.

Mike
66 S3 Coupe'

--- In ***@***.***, "lotus" <lotuselan2@c...> wrote:
Ken
'69 +2 with BDR

p.s. Find yourself a good DuPont paint dealer and work with him every
step
of your restoration. They can be a great asset. Plan on spending a
lot of
money on their over-priced but effective products.
Mike Geiger
66 S3 Coupe', no more :-(
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PostPost by: davidallen » Tue Oct 12, 2004 12:14 pm

I know there is an on going debate whether the use of paint striper is wise
or not. I had previously decided not to use it. However, I recently used
some on household woodwork and discovered it would only strip off single
coats of paint at a time.

Consequently it should be possible to strip just the top coat and leave the
primer.

Anyone had any successes/failures/dissolved their car? Brands?

David

-----Original Message-----
From: Michael Geiger [mailto:***@***.***
Sent: 12 October 2004 11:30
To: ***@***.***
Subject: Re: [LotusElan.net] Gel coat




A further warning to go along with what Ken says. Decide everything
in advance before you start filing and priming. I did not the result
was a more limited selection as the primer I used was only compatible
with a select list of top coats. So know what color, what brand, what
type of paint you want, then proceed with fillers and primers.

Mike
66 S3 Coupe'

--- In ***@***.***, "lotus" <lotuselan2@c...> wrote:
Ken
'69 +2 with BDR

p.s. Find yourself a good DuPont paint dealer and work with him every
step
of your restoration. They can be a great asset. Plan on spending a
lot of
money on their over-priced but effective products.
















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PostPost by: type36lotus » Tue Oct 12, 2004 4:31 pm

I used paint stripper for fiberglass purchased at Home Depot. It has
been 3+ years and so for no problems. The car has sat in the hot
Florida sun many times with no issues. In many places the gel coat
had been completely weathered away with no ill effect from the
stripper. Unfortunately I did not do proper remediation of the
stress cracks and of course they have come back. I was told that if
they were light (they were, as well as expansive) I could use epoxy
primer, which I did, and it would fill the stress cracks and be a
replacement for the gel coat. The bare fiberglass seems okay, but the
filling of the stress cracks is not. I was concerned about my
abilities to fiberglass tissue almost the entire car, so I did not, I
really should have.

Mike Geiger
66 S3 Coupe'

--- In ***@***.***, "ALLEN, David" <david.allen@e...>
wrote:









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