Advise wanted for maintaining gelcoat that is already FUBAR

[PBA]

Thanks for taking a look.
Pictures are linked below.
The story goes this poor glider sat in a trailer for some years in Texas and it ate the otherwise bulletproof gelcoat.

Per usual the tops of the wings are the worst. Some of the sanding has gotten down to the gray layer that covers the fiberglass. Deep crazing/cracking in the gelcoat covers most of the upper surfaces of the glider.

I have no interest in a refinish at this time.



Perhaps I should just do nothing, but you can feel the "roughness" of the gelcoat when you run your hand along the wings. I was thinking I could improve this with some fine grit block sanding? What grit and what combination? Perhaps just a rubbing compound with an orbital sander?

I'm looking for advise on the best way to slow the destruction of the gelcoat. I know there is no saving it.

I'm thinking some form of block sanding to level the gelcoast as best I can and then waxing to prevent more moisture ingress?

Some have suggested spray paint to cover the bare spots, others have suggested gel coat patch for that?

Hoping for more discussion than flaming...


LINK TO PHOTOS: http://s35.photobucket.com/user/pba110/slideshow/Glider%20Finish%202015

[JJ Sinclair[_2_]]

FUBAR to the max.................beyond recognition, but not beyond repair. I am finishing up an LS-3a that looked just about that bad (photos available). Figure I could do another next Winter for something like 15K out the door, grind it all off, heavy prime with Polyprime, light prime & fill last pin-holes, contour with long board, paint with Acrylic Urethane, wet sand with 600, buff and wax.
E-mail me at..........johnsinclair75(at)yahoo.com
JJ

[PBA]

Thanks JJ, I'll definitely reach out. So you are saying just leave it alone?

[[email protected]]

On Tuesday, April 7, 2015 at 4:11:18 PM UTC-4, PBA wrote:
> Thanks JJ, I'll definitely reach out. So you are saying just leave it alone?

You would be well advised to book JJ before he sobers up and realizes what he offered.
For temporary you could chip out the very loose stuff,and fill with body filler using white catalyst, and sand smooth. You won't do harm with this temporary measure but I would not suggest doing it on any but the worst spots where peeling is happening.
It all gets sanded off next winter.
Good luck
UH

[PBA]

OK, that sounds reasonable to use a little white catalyst on the real bad areas and leave everything else alone.

Thanks UH

[Dave Springford]

There was a Standard Cirrus a few years ago at my club that was left for so long that the cracks moved through the gelcoat and into the layer of glass below. The proper repair required removing all of the gelcoat, then the first layer of glass, putting on a new layer of glass and then new gel coat.

Don't leave it too long or this could happen to you too.

[Bill T]

What is it about north Texas and gliders in trailers. We picked up a Janus C from north Texas years ago. One season in the desert and the gelcoat was popping off the wings. Owner took all the old gelcoat off, it chipped off very easily, there is a video of it on YouTube. Re profiled the wings, prepped as JJ described, painted with poly and sanded to a glass finish. Looked great when he was done.
BillT

[Jonathan St. Cloud]

JJ does great work and he is "retired" so I would take advantage of his offer, before he decides to spend the winter doing something fun. Plus a complete refinish for 15K, great deal.

[Papa3[_2_]]

On Tuesday, April 7, 2015 at 6:11:43 PM UTC-4, Dave Springford wrote:
> There was a Standard Cirrus a few years ago at my club that was left for so long that the cracks moved through the gelcoat and into the layer of glass below. The proper repair required removing all of the gelcoat, then the first layer of glass, putting on a new layer of glass and then new gel coat.

[Charlie M. (UH & 002 owner/pilot)]

On Tuesday, April 7, 2015 at 4:52:53 PM UTC-4, wrote:
> On Tuesday, April 7, 2015 at 4:11:18 PM UTC-4, PBA wrote:
> > Thanks JJ, I'll definitely reach out. So you are saying just leave it alone?
>
> You would be well advised to book JJ before he sobers up and realizes what he offered.
> For temporary you could chip out the very loose stuff,and fill with body filler using white catalyst, and sand smooth. You won't do harm with this temporary measure but I would not suggest doing it on any but the worst spots where peeling is happening.
> It all gets sanded off next winter.
> Good luck
> UH

Ummmmm..... yeppers.... we just went through similar........ doing a bit now can help forestall the "complete refinish" that's coming up.

[PBA]

One other thing to add, I know there are some people out there flying glass ships with pretty worn out finishes. What are your thoughts?
I've read about the gelcoat cracks continuing into the fiberglass, but I've also read about people saying they've never seen that in a career of refinishing sailplanes.
The appearance and performance degradation (which seems to be minor if not at all from SeeYou analysis) of my my finish doesn't bother me, but the idea that it would impact the safety of the glider does. Nonetheless, I feel if this were really an issue with safety, we would have seen a structural failure of a wing given how many sailplanes are out there with cracking gelcoat. To my knowledge we have not.

One other question, where's the best place to find "white catalyst" previously mentioned, come to think of it I don't even know what that is!

[Eric Munk]

There are a number of publications on gelcoat cracking by respectable
manufacturers (DG, Schempp-Hirth, Schleicher), check their websites.
Various manufacturers have very specific demands of what is tolerable or
not. I would say that common sense alone would dictate this particular
glider be given a strip-back to GRP then refinished. Wouldn't be surprised
if some glassfibre damage turned up.

[Surge]

On Wednesday, 8 April 2015 12:53:22 UTC+2, PBA wrote:
> One other thing to add, I know there are some people out there flying glass ships with pretty worn out finishes. What are your thoughts?
> I've read about the gelcoat cracks continuing into the fiberglass, but I've also read about people saying they've never seen that in a career of refinishing sailplanes.

I recently chatted to a local aircraft repairer regarding gelcoat damage and flying it with the existing damage.
His take is that the damage will progress if you're flying in wet and freezing conditions because moisture gets into the cracks and makes them run as well as extend further down into the first layer of epoxy and finally the glass.

Personally I'd rather fork out the money and get it fixed before it becomes a more expensive repair (replacing first layer of glass).
There's also the pride aspect about flying something that looks like it has been looked after and not dragged out of a rubbish dump.

[[email protected]]

вторник, 7 апрел� 2015 г., 21:55:37 UTC+4 пользователь PBA напи�ал:
> Thanks for taking a look.
> Pictures are linked below.
> The story goes this poor glider sat in a trailer for some years in Texas and it ate the otherwise bulletproof gelcoat.
>
> Per usual the tops of the wings are the worst. Some of the sanding has gotten down to the gray layer that covers the fiberglass. Deep crazing/cracking in the gelcoat covers most of the upper surfaces of the glider.
>
> I have no interest in a refinish at this time.
>
>
>
> Perhaps I should just do nothing, but you can feel the "roughness" of the gelcoat when you run your hand along the wings. I was thinking I could improve this with some fine grit block sanding? What grit and what combination? Perhaps just a rubbing compound with an orbital sander?
>
> I'm looking for advise on the best way to slow the destruction of the gelcoat. I know there is no saving it.
>
> I'm thinking some form of block sanding to level the gelcoast as best I can and then waxing to prevent more moisture ingress?
>
> Some have suggested spray paint to cover the bare spots, others have suggested gel coat patch for that?
>
> Hoping for more discussion than flaming...
>
>
> LINK TO PHOTOS: http://s35.photobucket.com/user/pba110/slideshow/Glider%20Finish%202015

Здрав�твуйте!!
Я из СССÐ* и Ваши беды мне понÑ�тны.
Заходите вот �юда - и мы Вам поможем.
https://groups.google.com/forum/#!forum/1235677

[Charlie M. (UH & 002 owner/pilot)]

On Tuesday, April 7, 2015 at 11:28:53 PM UTC-4, PBA wrote:
> Charlie,
> When you say "doing a bit" now can forestall the "complete refinish" what does that mean?
> Thanks for the responses.
> It seems like everyone is saying don't do anything but refinish it.
> I hear that.
> JJ and I live on opposite coasts, what's the best way to get the glider out there if driving it myself is not an option?

At a minimum, a GOOD coat of wax (after a wash & dry) can help seal the gelcoat surface to slow aging.
A bit better is to wetsand the gelcoat to "smooth" followed by a good hardwax application.
You will regain some of your glider performance (smooth is better than crack ridges) and the wax seals the surface.

At some point, the gelcoat really needs to be removed and replaced. It's not an easy job (dusty, dirty, labor intensive) thus the cost can be high.
Sanding gelcoat (from ~midway through a refinish to final sanding) is sorta like "trying to polish granite with wet toilet paper". It's just time consuming.

We just did a "sand and hardwax polish" on a ship with crazed gelcoat. It looks a lot better, smoother and more uniform in color, and may go another 1-2+ years before ending up where it was. It's also more likely to get regular washes and soft wax (which helps).
In the end, it will need a full refinish since ANYTHING put on top will just crack yet again where there are existing cracks.

If you want the ship trailered across the country, there are people in soaring that do it for a "living". Sometimes they take a ship one way, another one back instead of going empty.

[ND]

On Wednesday, April 8, 2015 at 10:15:47 AM UTC-4, Charlie M. (UH & 002 owner/pilot) wrote:
> On Tuesday, April 7, 2015 at 11:28:53 PM UTC-4, PBA wrote:
> > Charlie,
> > When you say "doing a bit" now can forestall the "complete refinish" what does that mean?
> > Thanks for the responses.
> > It seems like everyone is saying don't do anything but refinish it.
> > I hear that.
> > JJ and I live on opposite coasts, what's the best way to get the glider out there if driving it myself is not an option?
>
> At a minimum, a GOOD coat of wax (after a wash & dry) can help seal the gelcoat surface to slow aging.
> A bit better is to wetsand the gelcoat to "smooth" followed by a good hardwax application.
> You will regain some of your glider performance (smooth is better than crack ridges) and the wax seals the surface.
>
> At some point, the gelcoat really needs to be removed and replaced. It's not an easy job (dusty, dirty, labor intensive) thus the cost can be high.
> Sanding gelcoat (from ~midway through a refinish to final sanding) is sorta like "trying to polish granite with wet toilet paper". It's just time consuming.
>
> We just did a "sand and hardwax polish" on a ship with crazed gelcoat. It looks a lot better, smoother and more uniform in color, and may go another 1-2+ years before ending up where it was. It's also more likely to get regular washes and soft wax (which helps).
> In the end, it will need a full refinish since ANYTHING put on top will just crack yet again where there are existing cracks.
>
> If you want the ship trailered across the country, there are people in soaring that do it for a "living". Sometimes they take a ship one way, another one back instead of going empty.

DO NOT WAX in its current condition. i would strongly advise agaist that. there is too much fiberglass exposed and it could lead to problems during the refinish that could compromise paint adhesion. heavy sand and polish on my glider to hold the wings over for one year while we refinished the fuselage, and did not wax. our crazing was not as advanced as yours, and wasn't peeling but i wasn't taking any chances. that's my only disagreement.

[ND]

On Wednesday, April 8, 2015 at 6:53:22 AM UTC-4, PBA wrote:
> One other thing to add, I know there are some people out there flying glass ships with pretty worn out finishes. What are your thoughts?
> I've read about the gelcoat cracks continuing into the fiberglass, but I've also read about people saying they've never seen that in a career of refinishing sailplanes.
> The appearance and performance degradation (which seems to be minor if not at all from SeeYou analysis) of my my finish doesn't bother me, but the idea that it would impact the safety of the glider does. Nonetheless, I feel if this were really an issue with safety, we would have seen a structural failure of a wing given how many sailplanes are out there with cracking gelcoat. To my knowledge we have not.
>
> One other question, where's the best place to find "white catalyst" previously mentioned, come to think of it I don't even know what that is!

the cracks don't manifest themselves in the same way when they continue into the glass. they simply appear as faint white lines in the glass, running in the same direction as the crazing. it definitely happens, and there is more than one way to deal with it.

[Morgan[_2_]]

Todd at Yankee Composites finished up the wings on my Duo in January.

They weren't as bad as the original poster, but they had serious cracks in the gelcoat. I had bought myself some time by wet sanding the wings annually and filling a few chips, but I knew it was terminal for the gel coat.

As to performance, I don't think it makes enough of a difference to notice.

One year at our contest, the cracks had lifted over winter and I hadn't yet sanded them down. One morning I wet sanded the right wing. Flew 500k with the asymmetric sanding. Could not notice a thing, aside from the right wing looking smoother.

Sanded the other wing the next morning since smooth feels better, but no turning or yaw tendencies were noticeable which I was a little surprised at.

ND is correct, the cracks will propagate down to the glass and will be visible as little lines. Todd sanded down to the finish glass and then applied a very thin veil cloth to present a new crack free surface to spray on the new Polyurethane system on.

The results are gorgeous.

I put a few pictures of the process up include a shot of what the cracks look like when they hit the glass.

https://plus.google.com/u/0/108472988763833362098/posts/5iRDt3Jany6?pid=6135422158884313586&oid=108472988763833362098

Morgan

On Wednesday, April 8, 2015 at 8:31:21 AM UTC-7, ND wrote:
> On Wednesday, April 8, 2015 at 6:53:22 AM UTC-4, PBA wrote:
> > One other thing to add, I know there are some people out there flying glass ships with pretty worn out finishes. What are your thoughts?
> > I've read about the gelcoat cracks continuing into the fiberglass, but I've also read about people saying they've never seen that in a career of refinishing sailplanes.
> > The appearance and performance degradation (which seems to be minor if not at all from SeeYou analysis) of my my finish doesn't bother me, but the idea that it would impact the safety of the glider does. Nonetheless, I feel if this were really an issue with safety, we would have seen a structural failure of a wing given how many sailplanes are out there with cracking gelcoat. To my knowledge we have not.
> >
> > One other question, where's the best place to find "white catalyst" previously mentioned, come to think of it I don't even know what that is!
>
> the cracks don't manifest themselves in the same way when they continue into the glass. they simply appear as faint white lines in the glass, running in the same direction as the crazing. it definitely happens, and there is more than one way to deal with it.

[Eric Munk]

I've done (together with somebody else) replacement of the top glass on a
Cirrus, both wings top surfaces, due to advanced gelcoat cracking going
into the skins. Trust me: you don't want to go there.

At 15:31 08 April 2015, ND wrote:
>On Wednesday, April 8, 2015 at 6:53:22 AM UTC-4, PBA wrote:
>> One other thing to add, I know there are some people out there flying
>gla=
>ss ships with pretty worn out finishes. What are your thoughts?
>> I've read about the gelcoat cracks continuing into the fiberglass, but
>I'=
>ve also read about people saying they've never seen that in a career of
>ref=
>inishing sailplanes.=20
>> The appearance and performance degradation (which seems to be minor if
>no=
>t at all from SeeYou analysis) of my my finish doesn't bother me, but the
>i=
>dea that it would impact the safety of the glider does. Nonetheless, I
>feel=
> if this were really an issue with safety, we would have seen a
structural
>=
>failure of a wing given how many sailplanes are out there with cracking
>gel=
>coat. To my knowledge we have not.=20
>>=20
>> One other question, where's the best place to find "white catalyst"
>previ=
>ously mentioned, come to think of it I don't even know what that is!
>
>the cracks don't manifest themselves in the same way when they continue
>int=
>o the glass. they simply appear as faint white lines in the glass,
running
>=
>in the same direction as the crazing. it definitely happens, and there is
>m=
>ore than one way to deal with it.
>

[Jonathan St. Cloud]

I am sorry, remind me again why PIK gliders and glass sailboat do not have crazing and cracking problems, yet expensive German gliders do?!

[PBA]

Wow, that's some beautiful work on those wings!
I wish I had the time and expertise to do it myself, although others have suggested it's misery...

Thanks for all the comments guys, great information coming out of this thread

[[email protected]]

On Tuesday, April 7, 2015 at 12:55:37 PM UTC-5, PBA wrote:
> Thanks for taking a look.
> Pictures are linked below.
> The story goes this poor glider sat in a trailer for some years in Texas and it ate the otherwise bulletproof gelcoat.
>
> Per usual the tops of the wings are the worst. Some of the sanding has gotten down to the gray layer that covers the fiberglass. Deep crazing/cracking in the gelcoat covers most of the upper surfaces of the glider.
>
> I have no interest in a refinish at this time.

My ship was built in 1973 and has light crazing on the top wing surfaces and control surfaces, I just wet sand and wax. I believe that the crazing is more of a cosmetic issue more than anything but it makes re sale a little more difficult to someone who does not understand this. I have seen some ships with cracks that run 12 or more inches and look deep, the concern is if reaches the glass below. I refinished the fuselage this winter, next winter maybe the tips and maybe when I reach a 100 I may have a completely refinished sailplane.
>
>
>
> Perhaps I should just do nothing, but you can feel the "roughness" of the gelcoat when you run your hand along the wings. I was thinking I could improve this with some fine grit block sanding? What grit and what combination? Perhaps just a rubbing compound with an orbital sander?
>
> I'm looking for advise on the best way to slow the destruction of the gelcoat. I know there is no saving it.
>
> I'm thinking some form of block sanding to level the gelcoast as best I can and then waxing to prevent more moisture ingress?
>
> Some have suggested spray paint to cover the bare spots, others have suggested gel coat patch for that?
>
> Hoping for more discussion than flaming...
>
>
> LINK TO PHOTOS: http://s35.photobucket.com/user/pba110/slideshow/Glider%20Finish%202015

[Morgan[_2_]]

Todd did an amazing job and that shine is just from wet sanding.

It is a massive amount of work though. 400+ hours on big wings like a Duo and it's not fun work. I had fantasies about doing a lot of the work myself, especially the gelcoat removal, but it would have taken me months just to remove the gelcoat since I have a job and would be limited to weekends or evenings, if I could have found a place to work.

So in the end, I spent the money instead of the time. We also broke the project in two. Wings and horizontal this year, fuselage next year.

Jonathan: I believe the PIK was painted in PU, not gelcoat. But yeah, frustrating to refinish a 15 year old glider. While flexing might be an excuse for the wings developing some stress cracks, the fuselage has the worst crazing on my glider.


On Wednesday, April 8, 2015 at 11:43:13 AM UTC-7, PBA wrote:
> Wow, that's some beautiful work on those wings!
> I wish I had the time and expertise to do it myself, although others have suggested it's misery...
>
> Thanks for all the comments guys, great information coming out of this thread

[[email protected]]

On Wednesday, April 8, 2015 at 2:22:01 PM UTC-4, Jonathan St. Cloud wrote:
> I am sorry, remind me again why PIK gliders and glass sailboat do not have crazing and cracking problems, yet expensive German gliders do?!

Polyurethane paint
UH

[Ramy[_2_]]

On Wednesday, April 8, 2015 at 12:31:14 PM UTC-7, wrote:
> On Tuesday, April 7, 2015 at 12:55:37 PM UTC-5, PBA wrote:
> > Thanks for taking a look.
> > Pictures are linked below.
> > The story goes this poor glider sat in a trailer for some years in Texas and it ate the otherwise bulletproof gelcoat.
> >
> > Per usual the tops of the wings are the worst. Some of the sanding has gotten down to the gray layer that covers the fiberglass. Deep crazing/cracking in the gelcoat covers most of the upper surfaces of the glider.
> >
> > I have no interest in a refinish at this time.
>
> My ship was built in 1973 and has light crazing on the top wing surfaces and control surfaces, I just wet sand and wax. I believe that the crazing is more of a cosmetic issue more than anything but it makes re sale a little more difficult to someone who does not understand this. I have seen some ships with cracks that run 12 or more inches and look deep, the concern is if reaches the glass below. I refinished the fuselage this winter, next winter maybe the tips and maybe when I reach a 100 I may have a completely refinished sailplane.
> >
> >
> >
> > Perhaps I should just do nothing, but you can feel the "roughness" of the gelcoat when you run your hand along the wings. I was thinking I could improve this with some fine grit block sanding? What grit and what combination? Perhaps just a rubbing compound with an orbital sander?
> >
> > I'm looking for advise on the best way to slow the destruction of the gelcoat. I know there is no saving it.
> >
> > I'm thinking some form of block sanding to level the gelcoast as best I can and then waxing to prevent more moisture ingress?
> >
> > Some have suggested spray paint to cover the bare spots, others have suggested gel coat patch for that?
> >
> > Hoping for more discussion than flaming...
> >
> >
> > LINK TO PHOTOS: http://s35.photobucket.com/user/pba110/slideshow/Glider%20Finish%202015

I bought my first glider (LS4) when it was already recommended to refinish it. I put 2000 hours on it for almost 10 years, sold it, and since then it had been flying for another 7 years. It had yet to be refinished, only waxed annually and sanded few times. Other than cosmetic and resale value there not seem to be any impact. I think most people refinish their gliders way before it is really necessary.

Ramy