Your Opinion Would Be Appreciated

In 2006, Bob Lacovara gave a presentation at the SSA Convention in Ontario, CA about gel coat and refinishing. He basically said that a good refinishing job will involve removing all the gel coat down to the composite substrate (but not getting into the substrate AT ALL!) if the gel coat exhibits crazing or cracks. Just sanding to a smooth finish and then applying a top coat of filler, new gel coat or paint will allow the cracks to manifest themselves rather quickly. He also said that the wide disparity in the quality of a gel coat finish on older gliders was traced to the glider manufacturers' process of applying gel coat into the mold and the time that lapsed between the application and actually laying in the first composite layer. In the early days of composite manufacturing, it was thought that the gel coat could go as much as a couple of days before the composites had to be laid over the uncured gel coat. After examining records from several manufacturers, it was discovered that a gel coat surface that had no more than an hour of exposure to the air before being sealed by laying in the composite skin and wing structures showed little or no deterioration, cracking or crazing even after a couple of decades, whereas gel coat that was applied and exposed to the air for more than four hours (and sometimes overnight or even longer) exhibited various degrees of crazing and cracking over time. Mr. Lacovara also stated that there have been many different types of gel coat over the years, and some are better than others. He also stated that the boating industry uses far superior coatings today that are pretty much unavailable to the sailplane industry, simply because glider manufacturing is so tiny compared to the boating world. He estimated that ALL the glider manufacturers in the world would total less than ten percent of the capacity of even the smallest boat manufacturer. At the time of his presentation, Bob was the Secretary of the American Composites Manufacturing Association and had access to a great deal of information on composite manufacturing worldwide.

George Moffatt was quoted as saying that, "Glider designers, when plied with enough drinks, will eventually admit that there are good ships and bad ships from the same molds."

On Monday, February 15, 2021 at 7:51:56 PM UTC-5, Mike Carris wrote:

Yes, I have seen two sailplanes from the same factory, same make, same model and same gelcoat. One was taken care of, buffed, Wx' blocked and sealed yearly and was still near perfect after over ten years . The other was not taken care of and had crazed gelcoat and needed a refinish. Having worked in a sailplane repair shop it has been noted that people often do not take care of their sailplanes.

Just to build on this, while there are differences of opinion on the specific products that people use (German hardwax vs. modern polish; old-school carnuba vs. modern formula coatings) the common denominator is that people who regularly maintain the finish miraculously seem to get the "good" gliders and those who don't... well you get the picture.

That's not to say that if you get a "Monday Glider" (gelcoat sprayed Friday and glass not put in until Monday) you'll have perfect gelcoat. But you certainly will get much worse results if you do nothing.

My protocol that has worked very well through two new gliders is an annual polish (I use 3M products but could just as easily use "hardwax") sealed by 3M Marine Wax done in the spring on ALL surfaces. Then, usually late summer I hit the wings top side only with another polish and wax. The full ship takes pretty much a whole day in the shop. The wings topside only maybe 2 hours.

If I fly a lot (e.g. during a contest) I reapply liquid wax on the leading edge after a few days.

When I sold my 13 year old LS8 (finished in original gelcoat), the IA who did the pre-purchase called it "factory new" at least under a 2x loupe. I'm sure if I had my buddy run it through the SEM he would've found the crazing... :-)

P3
ACA Chief Refinishing Officer (CRO)

Bob:
A few additional points to think about:

One of the most desirable options for the ASG-29 pure glider is the fuselage tank (which can be made removable and replaced with the storage shelf). Without that tank a 200 lbs pilot with chute, drinking water & lunch can't get the glider to its 600 kg maximum even with the wing tanks & fin tank chock filled. Even if you want to fly with partial water, the glider handles much better with the weight inboard. I always fill the fuselage tank first and then add water to the wings to get to the wing loading I want.

Buying a glider from an estate has its negatives. There is nobody to show you the rigging tricks, or to explain what that little box on the left side of the fuselage is, find the FR calibration sheet (if any) or tell you when/if the trailer tires were replaced or answer the million other questions an owner would know the answer to. And, the same holds true of having the AI or AP who maintained or repaired the glider do the first annual or pre-purchase inspection. Sometimes fresh eyes are a good thing.

I'd like to know when or if the Mylar has been replaced. Especially if it's been in a trailer without aileron/flap locks ( a bending load on Mylar in a hot trailer for 2 years is not good) . Fresh Mylar matters in the '29 and it's not an easy or cheap job to do yourself.

There is a difference between a gelcoat glider with a carefully documented and demonstrable damage/repair history and one without that. I am aware of 3 instances where people sent gliders to Eastern European refinish facilities who "discovered" improperly done repairs that stopped the re-finish work until corrected. The owners were helpless to argue and just paid 5000 Euros or so more than they planned for the re-repair. So, if there is a plan to refinish the gelcoat at any time in the future, it's important to know exactly what happened in the past.

Additional things I'd like to know: Does it have covers? Is the XPDR mode C or S and when was it last calibrated? Any spare parts? A parachute? Things to budget for: new batteries, XPDR check, CN I upgrade to II (if possible). New radio (search this forum for Dittel FSG2T problems - I've junked 2 of them).

Things I wouldn't care about: clear vs. tinted canopy (you really don't notice it), Cloth vs. leather interior (leather looks great but sticks to your legs if you are wearing shorts), total time ( 400 hours vs 1400 hours on a glider doesn't really matter).

Lastly, I think time of year is important. Gliders sell for more money in the Spring. I would expect as much as a 10% difference in the sale price depending on a sale in mid-winter compared to April, May or June.

ROY (who has #29041 in the US and 1/2 of #29014 in South Africa)

On Tuesday, February 16, 2021 at 4:00:00 PM UTC-5, Roy B. wrote:
Bob:
A few additional points to think about:

One of the most desirable options for the ASG-29 pure glider is the fuselage tank (which can be made removable and replaced with the storage shelf). Without that tank a 200 lbs pilot with chute, drinking water & lunch can't get the glider to its 600 kg maximum even with the wing tanks & fin tank chock filled. Even if you want to fly with partial water, the glider handles much better with the weight inboard. I always fill the fuselage tank first and then add water to the wings to get to the wing loading I want.

Buying a glider from an estate has its negatives. There is nobody to show you the rigging tricks, or to explain what that little box on the left side of the fuselage is, find the FR calibration sheet (if any) or tell you when/if the trailer tires were replaced or answer the million other questions an owner would know the answer to. And, the same holds true of having the AI or AP who maintained or repaired the glider do the first annual or pre-purchase inspection. Sometimes fresh eyes are a good thing.

I'd like to know when or if the Mylar has been replaced. Especially if it's been in a trailer without aileron/flap locks ( a bending load on Mylar in a hot trailer for 2 years is not good) . Fresh Mylar matters in the '29 and it's not an easy or cheap job to do yourself.

There is a difference between a gelcoat glider with a carefully documented and demonstrable damage/repair history and one without that. I am aware of 3 instances where people sent gliders to Eastern European refinish facilities who "discovered" improperly done repairs that stopped the re-finish work until corrected. The owners were helpless to argue and just paid 5000 Euros or so more than they planned for the re-repair. So, if there is a plan to refinish the gelcoat at any time in the future, it's important to know exactly what happened in the past.

Additional things I'd like to know: Does it have covers? Is the XPDR mode C or S and when was it last calibrated? Any spare parts? A parachute? Things to budget for: new batteries, XPDR check, CN I upgrade to II (if possible). New radio (search this forum for Dittel FSG2T problems - I've junked 2 of them).

Things I wouldn't care about: clear vs. tinted canopy (you really don't notice it), Cloth vs. leather interior (leather looks great but sticks to your legs if you are wearing shorts), total time ( 400 hours vs 1400 hours on a glider doesn't really matter).

Lastly, I think time of year is important. Gliders sell for more money in the Spring. I would expect as much as a 10% difference in the sale price depending on a sale in mid-winter compared to April, May or June.

ROY (who has #29041 in the US and 1/2 of #29014 in South Africa)

Thanks Roy, there are a couple more that I will be considering, I am in no hurry, if the Florida weather doesn't get better soon I might as well just keep my 27. Since I am now retired and bored I thought about heading west for the summer months and fly there. The 18 meter wings would be good in that environment, much more than the Florida environment.
Speaking of radios, I am not a Dittel fan, I would change out to Becker immediately.
As you know I am a purist, but it has surprised me how popular the sustainers and self launch models have been. I cannot ever see myself buying one of those, "Motorgliders", but the numbers speak for themselves. Also the arrival of the new AS33 will be very interesting.
Thanks for the information, fly safe. Bob

Bob,
I retrieved Kathy after a land out at a local gravel airport. She did
not know how to remove the wing outer panels and I figured it out while
she was digging for the manual in the trailer. It's just like the '27.

And Fidel was the sole maintainer (to my knowledge) and he cleaned and
waxed the ship annually.

Dan
5J

On 2/16/21 3:04 PM, wrote:
There is nobody to show you the rigging tricks