Clean, maintain, fix my windscreen (Sonex A model)

[tom.corso]

I will start by complaining mildly that I don't like looking through the windscreen of my Sonex A model. Flying almost any airplane into the sun is visually challenging and the angle of this windscreen makes it worse. Reaching the geezerly age of 72 has made me less tolerant and more crotchety about such things.

I am hoping that one or more of you knowledgeable and dedicated Sonex drivers and builders has some suggestions that will help me. I did search the general discussion posts and didn't find anything about caring for the windscreen. If someone can point me to a useful post, I will appreciate that.

#1. when I attempt to clean the inside/underside of the windscreen my arm is just barely long enough to reach the front. While in that wiping/washing position I am unable to see if I am helping or making things worse. Does anyone have tools, techniques or products that work.

#2. I have lots of small surface scratches on the outside of the windscreen and for all I know on the inside too. I believe I will have to remove it to really evaluate the underside and work on it. Lots of screws but otherwise not a big deal. I hope to clean both sides to remove whatever is on it down to the surface and to try not to cause more harm doing the cleaning. Are there products / techniques that will work to remove or (fill?) minor surface scratches. The gentleman that I purchased N179ES from last November had replaced the windscreen not too long before the sale. I trailered the plane home from Napa CA. to Milwaukee, WI on an open flat trailer. We removed the wings and prop and I wrapped the fuselage with stretch / shrink wrap from nose to tail. I put "soft" blankets over the windscreen and canopy but I think there was plenty of movement and friction to cause the scratches.

#3. If it just makes more sense to replace the windscreen:
A. recommended source for polycarbonate
B. clear or tinted
C. Do I need a full 4 ft x 8 ft sheet
D. I assume I will use the old windscreen as a pattern
E. How best to mark and cut the material without damaging it.

I do have the plans but I'm not too good at looking at detailed drawings and absorbing all the information and I know that missing a small instruction can lead to ordering new material. I bought an already built Sonex because I don't have the patience and stamina to complete a complicated, long term project.

[daleandee]

You have come across some common concerns that we all share. I'm not near the smartest guy here but I'll toss in my two bits:

What you are looking for is 3mm thick bronze tint polycarbonate sheet. I don't have the plans in front of me but others can verify or vilify that information.

You will need a 4X8 sheet (you could go smaller if available but a 4X4 sheet is not quite large enough).

You could use clear instead of tinted but it wouldn't match the canopy. I know at least one builder that used clear.

If there is a way to clear scratches from Lexan it is unknown to me. Lexan is very soft and durable but it scratches easily. When I clean mine I use Lemon Pledge and a microfiber cloth. You can wash it with mild soap and water but never wipe it when it's dry and always wipe in one direction. Cleaning the inside is tough but usually that part doesn't get too nasty.

Seeing out the windshield while flying into the sun is a large concern. At my home field during the winter the winds were favoring the runway directly into the sun. I lost sight of the runway as I was approaching and had to go around and get a second try at it. Sometimes if I'm looking for something straight ahead I have to tack like a sailor!

Dale
3.0 Cleanex

[GraemeSmith]

Spitballing:

The RC folk polish out small scratches in Lexan with a soft cloth, damped with plain water and a dab of toothpaste.
I have never tried it and would experiment carefully on a scrap before committing to the real windshield.

Similarly - a car headlamp restoration system might work - but again - experiment on scrap first.

[GraemeSmith]

And the result of the experiment is:

Either product worked

Either
the finest white 3M-Finessit (no wax or silicones)
Or
Mother's Power Plastic 4Lights

removed fine scratching from the LEXAN windshield today.

and with a little patience restored a cloudy area caused by canopy cover rub.

Observations:

The Mothers comes with 3 finer and finer grades of wet and dry papers - FORGET THEM. Disaster on the scrap I practices on The plastic overheated and got worse - not better.
Use the Mother's sponge polisher (the blue thing) in a drill chuck.
DO NOT press hard. Lots of very light passes or you will get swirl marks in the Lexan. Just be patient, keep it light and keep it moving.
DO NOT allow the job to get hot. The compounds are pretty liquid as it is - keep lots of plain water on hand to rinse and keep the job cool.
Patience.

--

It's almost impossible to photograph the before and after but I removed:

- "dullness" caused by a canopy cover rubbing in the wind and restored to full shine
- fine scratches caused by a headset headband that had rubbed the plastic
- 4 years of that finer scratching that develop - no matter how careful you are.

In fact it did such a good job on the localized bits I repaired today - I'm now going to have to give the whole windshield a pass to get rid of the rest of the glare making scratches.

[gammaxy]

Graeme,

How is your windscreen maintenance holding up? I've been less successful, but have probably not given it as much effort as you. I also suspect even if I got the outside surface good, I'm going to need to remove the windshield to polish the inside too... but if I do that, I might as well install and new one.

My windscreen is under a plane port so is directly exposed to the sun several hours each day and is showing signs of discoloration. I've always been careful about not scratching it, but the way dirt is statically attracted to it makes it probably impossible. There's also small cracks starting to appear on the outer surface. As a result, glare from the sun makes it difficult to see out the front in a lot of orientations. I'd get a lot more enjoyment out of flying if I had as good a view out the nose as I do out the sides.

Trying to think of what I should replace it with and have learned a little about abrasion resistant polycarbonate that is coated on both sides with a hard coating. I'm thinking that might be the solution, but I understand there is a minimum bend radius otherwise the coating can delaminate. The other difficulty is finding it in bronze color with affordable shipping. I can find it from several places (McMaster, TAP Plastics, and Shape Plastics) in clear for around $400. Doesn't help that it's an awkward size where a standard 48x96 sheet will have a lot left over, but not enough for two. I'll probably experiment with the clear and see if it revolutionizes the forward view, but interested to see if anyone else has already tried abrasion resistant polycarbonate. Making it out of plexiglass is another option I might consider--my canopy is holding up excellent still.

[Skippydiesel]

My "bronze" polycarbonate had blemishes/dark patches in the material - didn't much like it anyhow. Replaced with clear - may not look as "cool" but way better visibility.

I too was attracted by the "abrasion resistant polycarbonate" however the suppliers, I discussed this with, advised against.

Here, in Australia, there is a guy who will supply a pre bent perspex/Acrylic Sonex windscreen - a lot more scratch resistant and only slightly less impact resistant (due to angle)

[DCASonex]

Sounds like what you really need is something to block the sun's UV rays.

David A.