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#402411
I have been wondering for some time why there isn't a 'white' version of Technora laminate sailcloth.
For example, WW offers a Mylar laminate, UVPXW10 White (Polyester and Technora fibers) which I believe uses Titanium Dioxide in the film to create UV resistance and an overall bright white appearance. However, there doesn't appear to be a white version of the full Technora offered by any HG manufacturer.

White laminates (with black fibers) may not look as cool and groovy as the clear versions ... but they sure are more visible.

Does anyone know why Dimension-Polyant doesn't add the Titanium Oxide to the Technora line?
Does adding Titanium Dioxide as a pigment to the film add much extra weight to the material?
Should those of us who prefer the safety aspect of more visibility vs. coolness start requesting full Technora white laminates from HG manufacturers?
#402413
I don't know if you would see the black Technora through the white Titanium Oxide film.
If you order enough of it, Dimension-Polyant would probably make it. That's why Wills Wing has the limited quantities of purple ODL4.
#402414
It may have something to do with longevity
I have a few otherwise perfect wings where the high tech cloth has de laminated and not by uv exposure.

My all Dacron wings from the mid eighties still work well . Setup , fly ,pack up quick.
That said, manufacturers will make what will sell that year for whoever will buy it ..perhaps ask for it ?

For those who are lucky enough to buy new gliders often ..Dacron keeps its value better for this reason.
#402415
wonderwind_flyer wrote:
Fri Feb 23, 2018 12:46 pm
I have been wondering for some time why there isn't a 'white' version of Technora laminate sailcloth...
I seem to recall asking WW whether I could get a sail made with opaque white ODL06 laminate and the answer was, yes but the sail would be a little bit heavier and stiffer than if it were clear UV-stabilized ODL06. AFAIK - ALL of WW's laminate sail fabrics are now UV stabilized and do not rely on titanium dioxide which, does not prevent degradation of the outer layer of film and subsequent flaking off of the titanium dioxide layer and further degradation of the lower layers. I've watched it happen on enough different sails.

4oz. woven Dacron fabric also breaks down under UV and eventually rips or blows out. I've seen it happen enough times but not on 4.8oz or 5oz. fabric sails. I own a T2C that has over 652 hours on a white, UVPX sail which is mostly in good shape except where the sail gets folded over and rolled up near the tip wands. It's on its last legs however and gave me more than my money's worth during its life. I wish I could say the same for other sails I've owned but it seems like luck of the draw.
#402418
wonderwind_flyer wrote:
Fri Feb 23, 2018 12:46 pm
White laminates (with black fibers) may not look as cool and groovy as the clear versions ...
That's a matter of opinion. I really miss the days of setup areas resplendent with sails of every color of the rainbow. Clear may be trendy, but this is one fad I can't wait to see come to an end, and the visibility issue will hopefully hasten that demise.
#402420
I thought the transparent sail topskins looked really cool and when I bought my U2 thats what I ordered. I have noticed that it gets extremely hot when in the sun even just for a little while. In the middle of the 2nd season I started to get a flutter on the right side between the last two batons. This has just gotten worse. Now, I know there is no way to prove this, but I believe that the heat has something to do with this. I don't know if anyone else has experienced this problem, but I certainly have. I noticed on the sport 3 prototype the transparent sail is on the bottom skin instead of on top. Is there a reason for this? If I had it to do all over again I would get a white topspin and transparent bottom skin. There is a reason you don't see many GA aircraft that are painted black, it just gets too damned hot.

As far as white technora laminate goes, I don't know if it would help keep things from getting as hot if it were on the top skin. Perhaps not burn your fingers hot, but the greenhouse effect would still have it getting pretty hot nonetheless. I know someone is going to reply to this and say that the technora doesn't shrink... I have heard it before. I just don't buy the argument that something getting that hot has no effect.
#402421
DAVE 858 wrote:
Sat Feb 24, 2018 7:13 pm
I thought the transparent sail topskins looked really cool and when I bought my U2 thats what I ordered. I have noticed that it gets extremely hot when in the sun even just for a little while. In the middle of the 2nd season I started to get a flutter on the right side between the last two batons. This has just gotten worse.
Dave,

If you want to fix that flutter, the RC airplane hobby shops can sell you Carbon Fiber rods and planks in various small sizes. Use planks on straight runs, and rods on curving runs. You may need to unstitch a few stitches near one rib to insert the CF sticks. Sometimes you can insert the sticks inside the hem of the trailing edge, or maybe between the sail layers, between the zig-zag stitch holes. Use some fine sandpaper to round off one end of the CF that goes into the sail first. The CF stick should be as long as the stitching between the ribs there. Lock the CF in place with a few new stitches, back into the original needle holes in the sail. This "repair" will be almost invisible. Any ordinary sewing needle and UV-proof upholstery thread (from a fabric shop) can do the job there.

If you let it flutter too long, it will get worse, and may not be fixed by CF sticks.
.
#402422
Ive had that glider for 3 years now I think. Anyway, I think its about to the point where its not fixable. Now Im on the fence of spending the coin on a new sail or just buying a new glider. Being short on funds at the moment I can't really do either one. I have noticed that with full VG, if I fly slower, it doesn't flutter hardly at all. Its when I'm going fast that it happens, which sucks because it sounds like I have a motor when I do aerobatics.
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By red
#402423
DAVE 858 wrote:
Sat Feb 24, 2018 7:46 pm
Ive had that glider for 3 years now I think. Anyway, I think its about to the point where its not fixable. Now Im on the fence of spending the coin on a new sail or just buying a new glider. Being short on funds at the moment I can't really do either one. I have noticed that with full VG, if I fly slower, it doesn't flutter hardly at all. Its when I'm going fast that it happens, which sucks because it sounds like I have a motor when I do aerobatics.
Dave,

Carbon Fiber sticks cost less than a new sail. 8) I believe that sail is fixable, from what you say.

All IMHO, of course.
:mrgreen:
#402442
The UVPXW10 was mentioned in the original posting but it this isn't the same as a white version of WW's UVODL06 or UVODL04. I have a sample of the UVPXW10 and there are Technora fibers in there but not as much as the full Technora material. Does anyone on the .org have a glider made with UVPXW10? I'd be curious to know how the material works for them.

JD mentioned that there may be a slight handling loss (and slight weight penalty) in a glider made with the Titanium Dioxide pigment. I had an older Litespeed with a PX5 main body sail material and this material has the Titanium Dioxide pigment. Sweet flying glider with great handling ... but maybe with a Technora sail it would have been even sweeter.

The 'greenhouse effect' of the clear Technora sounds like another good reason to favor a reflective white laminate sail.
Might be interesting to find out if there has been heat degradation research/testing performed on the clear Technora materials.
#402443
wonderwind_flyer wrote:
Mon Feb 26, 2018 7:05 pm
The UVPXW10 was mentioned in the original posting but it this isn't the same as a white version of WW's UVODL06 or UVODL04. I have a sample of the UVPXW10 and there are Technora fibers in there but not as much as the full Technora material. Does anyone on the .org have a glider made with UVPXW10? I'd be curious to know how the material works for them....
My 2011 T2C 144 sail is made from UVPT which is the predecessor to UVPXW10. The sail has lasted a very long time and flew well.
#402456
DAVE 858 wrote:
Mon Feb 26, 2018 9:35 pm
It gets so hot I can't hold my batons. That can't be good.
Science suggests a 'hot' wing flies better:
https://www.researchgate.net/publicatio ... s_purposes

Conclusions:
"The effects of wings colors of migrating birds with soaring and gliding capabilities on their flight
performance have been investigated and discussed. Taking the Albatross wing as an example, the temperature
of the top surface of the wing was calculated through an energy balance. Then, the Blasius solution for laminar
boundary layer was used to calculate the generated drag forces of the wing. The results showed that, through
using the thermal balance of the wing surface for the different wing colors, the temperature difference between
using black and bright surface colors is approximately equal to 10oC. It was also found that the black top wing
color of the albatross improves its flight performance by reducing its drag, regardless of the weather or the place.
The observed reduction in the drag force over the wing can be one of the main reasons behind the high endurance
and efficiency of these migrating birds. The performed analysis in this study showed the impacts of the surface wing
colors on the effectiveness of migrating birds. This analysis is so beneficial and can be utilized to mimic new generation
of biologically inspired drones with high endurance due to the accurate selection of the wing surface colors."
#402461
Thx for the link KTMpilot. Quite an interesting article.
Before reading the article I thought that many birds had darker upper surfaces only to appear camouflaged to predatory birds flying above them. I believe the same is true for fish too ... even predators like sharks have this color/shade scheme for stealth purposes. Fish probably don't get the higher temperature, lower drag benefit though.

For us though, high visibility is a low-cost safety feature.
#402462
I ran that dark wing color article by my aero engineer brother, and let’s just say that he wasn’t impressed with the study.
I would guess that it is probably an evolution for survival that these birds have dark upper surfaces for the same reason that I dislike them on hang gliders.
The heat issue for the longevity of the carbon structure would give me some concern. Has anyone measured the temps they are getting in the Technora wings?

Please bring on the white Technora.

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