Poly paint

[Miguel Lavalle]

I am considering buying a second hand glider that was recently =
refinished
with poly paint as opposed to gel coat. What is poly paint? What are the
pros and cons of poly paint compared to gel coat?

Regards

Miguel

[BTIZ]

as long as the surface below was properly prepared.. should be ok.. that is
the standard for replacing old gel coats.. sand it down.. re profile the
wing.. and paint it..

BT

"Miguel Lavalle" > wrote in message
...
> I am considering buying a second hand glider that was recently =
> refinished
> with poly paint as opposed to gel coat. What is poly paint? What are the
> pros and cons of poly paint compared to gel coat?
>
> Regards
>
> Miguel
>
>
>
>

[Jose M. Alvarez]

I think that Miguel was asking the difference between gel coat and
poliurethane paint.
Anyway I don't have enough knowledge about the matter to explain it!

"BTIZ" > escribió en el mensaje
news:4ljnb.94824$La.83537@fed1read02...
> as long as the surface below was properly prepared.. should be ok.. that
is
> the standard for replacing old gel coats.. sand it down.. re profile the
> wing.. and paint it..
>
> BT
>
> "Miguel Lavalle" > wrote in
message
> ...
> > I am considering buying a second hand glider that was recently =
> > refinished
> > with poly paint as opposed to gel coat. What is poly paint? What are the
> > pros and cons of poly paint compared to gel coat?
> >
> > Regards
> >
> > Miguel
> >
> >
> >
> >
>
>

[Steve H]

Hi Miguel,
I used to own a Sportvega which was finished in a polyurethane paint. As
I understand the explanations at the time, the polyurethane finish is
softer, more elastic and cheaper to re-do. At around that time the BGA
DG 500 went to some astronomical height above Aboyne, in Scotland. I was
told that the extremes of temperature to which it was exposed and,
possibly, the rapidity of temperature change on ascent and descent,
resulted in extensive gel coat cracking; and that the polyurethane
finish on my rather ancient Sportvega would not have been similarly
affected. Lastly, if you do the prep work, a reasonable garage could
respray the glider for you at much less expense than the usual aviation
prices.
Steve

-----Original Message-----
From: Glider Pilot Network ]
Sent: Tuesday, October 28, 2003 9:46 AM
To: Steve H
Subject: [r.a.s] Re: Poly paint


------------------------------------------------------------
Newsgroup: rec.aviation.soaring
Subject: Re: Poly paint
Author: Jose M. Alvarez <>
Date/Time: 09:40 28 October 2003
------------------------------------------------------------
I think that Miguel was asking the difference between gel coat and
poliurethane paint. Anyway I don't have enough knowledge about the
matter to explain it!

"BTIZ" escribió en el mensaje news:4ljnb.94824$La.83537@fed1read02...
> as long as the surface below was properly prepared.. should be ok..
> that
is
> the standard for replacing old gel coats.. sand it down.. re profile
the
> wing.. and paint it..
>
> BT
>
> "Miguel Lavalle" wrote in
message
> ...
> > I am considering buying a second hand glider that was recently =
> > refinished with poly paint as opposed to gel coat. What is poly
> > paint? What are
the
> > pros and cons of poly paint compared to gel coat?
> >
> > Regards
> >
> > Miguel
> >
> >
> >
> >
>
>



------------------------------------------------------------

[JJ Sinclair]

>What is poly paint? What are the
>pros and cons of poly paint compared to gel coat?
>

Hi Miguel,
There are two "Poly" paints used on sailplanes, Polyeurathane and Acrylic
Urathane. I just repainted my Genesis 2 with Acrylic Urathane and found it very
easy to work with. Preped the non-damaged areas by contouring with 60 grit,
followed by 220 and then paint with 3 medium coats. Wet sandad with 600wet and
800wet, then wool buffer and liquid rubbing compound.
The Genesis 2 and LAK -17 are painted with Acrylic Urathane by the
manufacturer. The only down-side that I am aware of, is the softer paint
(urathane) may blister more quickly, if left too long in a wet trailer
JJ Sinclair

[Marc Ramsey]

JJ Sinclair wrote:
> The Genesis 2 and LAK -17 are painted with Acrylic Urathane by the
> manufacturer. The only down-side that I am aware of, is the softer paint
> (urathane) may blister more quickly, if left too long in a wet trailer
> JJ Sinclair

Actually the choice of paint is an option (at least on the LAK-17).
Ours is painted in painted with polyurethane. For $400 more we could
have had it painted in acrylic urethane, but we couldn't find anyone who
would say flat out it was worth the extra money. They also give you the
option of the ugly (but apparently bulletproof) epoxy paint that was
standard on the earlier LAKs...

Marc

[JJ Sinclair]

> They also give you the
>option of the ugly (but apparently bulletproof) epoxy paint that was

I would stay away from the epoxy paint because it yellows very rapidly and one
ends up with a ship the color of urine.

BTW, I have the color of the Acrylic Urathane used on the Genesis 2. It is;
Toyota 040/HP


JJ Sinclair

[John Galloway]

At 22:12 28 October 2003, Mike Borgelt wrote:

> A few people around here got Ventus 2's unfinished
>and had them
>painted here with polyurethane.
>
>Mike Borgelt

If it were now they would have been able to get them
finished in PU by the factory.

John Galloway

[Mike Borgelt]

On Tue, 28 Oct 2003 16:01:27 +0000, Robert Ehrlich
> wrote:

>Miguel Lavalle wrote:
>>
>> I am considering buying a second hand glider that was recently =
>> refinished
>> with poly paint as opposed to gel coat. What is poly paint? What are the
>> pros and cons of poly paint compared to gel coat?
>>
>> Regards
>>
>> Miguel
>
>All gliders in my club have gel coat, but our tow plane, a Super Dimona,
>has a polyurethane paint. Some of the gliders have been refinished here
>in our workshop, and the quality of this finish is far better than the
>polyurethane of the Super Dimona. But this quality is probably also
>better than the quality of a brand new glider. A few years ago, one of
>our member who had learnt the skills for doing that kind of finish was
>able to convince Schemp-Hirth to sell to him a new Ventus 2c unfinished,
>arguing that he would be able to do the finish better than in the
>factory, and he did it. If I understand it correctly, the main difference
>between paint and geal coat concerning the quality of the finish is that
>with paint it results mainly from work done before the painting and
>with gel coat from work done after spreading the gel coat. Small corrections
>are possible with the gel coat, I remember the owner of the Ventus 2c
>adding some droplets of gel coat here and there during the process
>before sanding again. Small defects become much more obvious when the
>surface comes near to its final state. In a similar way, minor scratches
>are easy to repair on gel coat by puting droplets of gel coat and
>sanding. I don't know for paint. Also I have seen broken tails repaired
>and re-gelcoated around the break with nothing remaining visible from the
>break after that. Again I don't know for paint.


The words "quality" and "gel coat"(as used currently by most of the
German glider manufacturers) should not be used in the same article.

The currently used gel coat will last a few years before cracking and
causing a very expensive refinish.

Polyurethane won't crack. Take a look at an old Pik20 or Std Jantar.

The scandal is that the cracking of the gel coat has been known since
about 1977(only a couple of years after they went to that product) and
the manufacturers flat out refuse to do anything about it.

Yes there are gel coat products that won't crack but as they "weren't
invented here" the manufacturers don't want to know.

A few people around here got Ventus 2's unfinished and had them
painted here with polyurethane.

Mike Borgelt

[Mike Borgelt]

On 28 Oct 2003 22:19:54 GMT, John Galloway
> wrote:

>At 22:12 28 October 2003, Mike Borgelt wrote:
>
>> A few people around here got Ventus 2's unfinished
>>and had them
>>painted here with polyurethane.
>>
>>Mike Borgelt
>
>If it were now they would have been able to get them
>finished in PU by the factory.
>
>John Galloway
>

Schempp's are offering that now???

Mike

[Paul]

Yep!
They finally are.
So are Stemme and DG/LS
Paul


> >If it were now they would have been able to get them
> >finished in PU by the factory.
> >
> >John Galloway
> >
>
> Schempp's are offering that now???
>
> Mike

[ruediger]

Mike Borgelt > wrote in message >...
> On Tue, 28 Oct 2003 16:01:27 +0000, Robert Ehrlich
> > wrote:
>
> >Miguel Lavalle wrote:
> >>
> >> I am considering buying a second hand glider that was recently =
> >> refinished
> >> with poly paint as opposed to gel coat. What is poly paint? What are the
> >> pros and cons of poly paint compared to gel coat?
> >>
> >> Regards
> >>
> >> Miguel
> >
> >All gliders in my club have gel coat, but our tow plane, a Super Dimona,
> >has a polyurethane paint. Some of the gliders have been refinished here
> >in our workshop, and the quality of this finish is far better than the
> >polyurethane of the Super Dimona. But this quality is probably also
> >better than the quality of a brand new glider. A few years ago, one of
> >our member who had learnt the skills for doing that kind of finish was
> >able to convince Schemp-Hirth to sell to him a new Ventus 2c unfinished,
> >arguing that he would be able to do the finish better than in the
> >factory, and he did it. If I understand it correctly, the main difference
> >between paint and geal coat concerning the quality of the finish is that
> >with paint it results mainly from work done before the painting and
> >with gel coat from work done after spreading the gel coat. Small corrections
> >are possible with the gel coat, I remember the owner of the Ventus 2c
> >adding some droplets of gel coat here and there during the process
> >before sanding again. Small defects become much more obvious when the
> >surface comes near to its final state. In a similar way, minor scratches
> >are easy to repair on gel coat by puting droplets of gel coat and
> >sanding. I don't know for paint. Also I have seen broken tails repaired
> >and re-gelcoated around the break with nothing remaining visible from the
> >break after that. Again I don't know for paint.
>
>
> The words "quality" and "gel coat"(as used currently by most of the
> German glider manufacturers) should not be used in the same article.
>
> The currently used gel coat will last a few years before cracking and
> causing a very expensive refinish.
>
> Polyurethane won't crack. Take a look at an old Pik20 or Std Jantar.
>
> The scandal is that the cracking of the gel coat has been known since
> about 1977(only a couple of years after they went to that product) and
> the manufacturers flat out refuse to do anything about it.
>
> Yes there are gel coat products that won't crack but as they "weren't
> invented here" the manufacturers don't want to know.
>
> A few people around here got Ventus 2's unfinished and had them
> painted here with polyurethane.
>
> Mike Borgelt

What gel coat product did GROB use? The finish is poor but all the
Astir's usually have no cracks. There are very few refinished Astirs.
Thank
Ruediger

[F.L. Whiteley]

"ruediger" > wrote in message
om...
> Mike Borgelt > wrote in message
>...
> > On Tue, 28 Oct 2003 16:01:27 +0000, Robert Ehrlich
> > > wrote:
> >
> > >Miguel Lavalle wrote:
> > >>
> > >> I am considering buying a second hand glider that was recently =
> > >> refinished
> > >> with poly paint as opposed to gel coat. What is poly paint? What are
the
> > >> pros and cons of poly paint compared to gel coat?
> > >>
> > >> Regards
> > >>
> > >> Miguel
> > >
> > >All gliders in my club have gel coat, but our tow plane, a Super
Dimona,
> > >has a polyurethane paint. Some of the gliders have been refinished here
> > >in our workshop, and the quality of this finish is far better than the
> > >polyurethane of the Super Dimona. But this quality is probably also
> > >better than the quality of a brand new glider. A few years ago, one of
> > >our member who had learnt the skills for doing that kind of finish was
> > >able to convince Schemp-Hirth to sell to him a new Ventus 2c
unfinished,
> > >arguing that he would be able to do the finish better than in the
> > >factory, and he did it. If I understand it correctly, the main
difference
> > >between paint and geal coat concerning the quality of the finish is
that
> > >with paint it results mainly from work done before the painting and
> > >with gel coat from work done after spreading the gel coat. Small
corrections
> > >are possible with the gel coat, I remember the owner of the Ventus 2c
> > >adding some droplets of gel coat here and there during the process
> > >before sanding again. Small defects become much more obvious when the
> > >surface comes near to its final state. In a similar way, minor
scratches
> > >are easy to repair on gel coat by puting droplets of gel coat and
> > >sanding. I don't know for paint. Also I have seen broken tails repaired
> > >and re-gelcoated around the break with nothing remaining visible from
the
> > >break after that. Again I don't know for paint.
> >
> >
> > The words "quality" and "gel coat"(as used currently by most of the
> > German glider manufacturers) should not be used in the same article.
> >
> > The currently used gel coat will last a few years before cracking and
> > causing a very expensive refinish.
> >
> > Polyurethane won't crack. Take a look at an old Pik20 or Std Jantar.
> >
> > The scandal is that the cracking of the gel coat has been known since
> > about 1977(only a couple of years after they went to that product) and
> > the manufacturers flat out refuse to do anything about it.
> >
> > Yes there are gel coat products that won't crack but as they "weren't
> > invented here" the manufacturers don't want to know.
> >
> > A few people around here got Ventus 2's unfinished and had them
> > painted here with polyurethane.
> >
> > Mike Borgelt
>
> What gel coat product did GROB use? The finish is poor but all the
> Astir's usually have no cracks. There are very few refinished Astirs.
> Thank
> Ruediger

All of the Twins from Grob, Twin Astir's and Twin II's, I've seen have
developed cracking on the leading edge of the wing at some point. This is
due to the gel coat being applied post wing assembly. That from the molds
seems robust.

Frank Whiteley

[Robert Ehrlich]

Mike Borgelt wrote:
> ...
> The words "quality" and "gel coat"(as used currently by most of the
> German glider manufacturers) should not be used in the same article.
>
> The currently used gel coat will last a few years before cracking and
> causing a very expensive refinish.
>
> Polyurethane won't crack. Take a look at an old Pik20 or Std Jantar.
>
> The scandal is that the cracking of the gel coat has been known since
> about 1977(only a couple of years after they went to that product) and
> the manufacturers flat out refuse to do anything about it.
>
> Yes there are gel coat products that won't crack but as they "weren't
> invented here" the manufacturers don't want to know.
>

This is not true of all manufacturers. DG and Centrair use a very
good quality of gel coat, at least on the latest gliders (Pegase
90) for Centrair. My clubs owns 2 Pegases 90, they are 8 and 9 years
old and look like new. We also sold a DG 300 in order to replace
it by a more recent glider, I think it was more than 10 years old
and had no cracks. OTOH the policiy of the club is to buy used
gliders with badly cracked gel coat and so lower price, and to
use the local skill and available time to refinish them. So I
have seen badly cracked LS1f's and LS4's.

> A few people around here got Ventus 2's unfinished and had them
> painted here with polyurethane.
>
> Mike Borgelt

[Mike Borgelt]

On Wed, 29 Oct 2003 10:24:12 +0000, Robert Ehrlich
> wrote:


>
>This is not true of all manufacturers. DG and Centrair use a very
>good quality of gel coat, at least on the latest gliders (Pegase
>90) for Centrair. My clubs owns 2 Pegases 90, they are 8 and 9 years
>old and look like new. We also sold a DG 300 in order to replace
>it by a more recent glider, I think it was more than 10 years old
>and had no cracks. OTOH the policiy of the club is to buy used
>gliders with badly cracked gel coat and so lower price, and to
>use the local skill and available time to refinish them. So I
>have seen badly cracked LS1f's and LS4's.
>

Robert,

That was my point. There are good quality gel coats available but some
manufacturers refuse to use them and this has gone on for 25 years.

Anybody know what product DG are currently using. I've seen that it is
Vorgelat T35 in which case my friends in the glider repair/refinish
business tell me you *will* have a problem.

Mike Borgelt

[Paul]

Our DG 1000s maintenance manual lists Lesonal UP Schwabbellack 0369066
or the MGS T35.
The glider is made with the lesonal.
The T35 can be used for repairs if needed.
Paul


"Mike Borgelt" > wrote in message
...
> On Wed, 29 Oct 2003 10:24:12 +0000, Robert Ehrlich
> > wrote:
>
>
> >
> >This is not true of all manufacturers. DG and Centrair use a very
> >good quality of gel coat, at least on the latest gliders (Pegase
> >90) for Centrair. My clubs owns 2 Pegases 90, they are 8 and 9 years
> >old and look like new. We also sold a DG 300 in order to replace
> >it by a more recent glider, I think it was more than 10 years old
> >and had no cracks. OTOH the policiy of the club is to buy used
> >gliders with badly cracked gel coat and so lower price, and to
> >use the local skill and available time to refinish them. So I
> >have seen badly cracked LS1f's and LS4's.
> >
>
> Robert,
>
> That was my point. There are good quality gel coats available but some
> manufacturers refuse to use them and this has gone on for 25 years.
>
> Anybody know what product DG are currently using. I've seen that it is
> Vorgelat T35 in which case my friends in the glider repair/refinish
> business tell me you *will* have a problem.
>
> Mike Borgelt
>
>

[Liam Finley]

With a PU finished glider, how do you deal with the spar cap shrinkage problem?

[Mike Borgelt]

On 29 Oct 2003 22:47:59 -0800, (Liam Finley) wrote:

>With a PU finished glider, how do you deal with the spar cap shrinkage problem?

You sand it and paint it again.

Around here the glider buyers are getting the wings in gel coat,
flying for a season or so, sanding and painting in PU.

Mike Borgelt

[Mike Borgelt]

On Thu, 30 Oct 2003 16:05:37 +1300, "Paul"
> wrote:

>
>Our DG 1000s maintenance manual lists Lesonal UP Schwabbellack 0369066
>or the MGS T35.
>The glider is made with the lesonal.
>The T35 can be used for repairs if needed.
>Paul


Schwabbellack is the good gel coat. The current formulation does get
brittle at low temperatures and I believe there have been some
mechanical cracking failures after exposure. This is different
cracking from the Vorgelat cracking but sadly the same amount of work
to fix.

Mike Borgelt