diamondaviators.net

dmloftus wrote: ↑Fri Oct 08, 2021 10:27 pm

rwtucker wrote: ↑Fri Oct 08, 2021 10:15 pm There is a chance that a wax containing silicone was applied to my DA40 maybe 10 years ago. Is there a permanent change in play or does the clock run out eventually? Since I'm hangared when-not in the air, I can't make a case for much UV break down. What are the implications?

I'm not arguing for silicone-based products, but being the third owner of my plane I have no idea what has been used on it in the past. This is a really interesting article about silicone misconceptions with regard to autos. If everything he says is true, I'm really curious how much different the effects are on our airplanes vs autos:

https://www.autogeekonline.net/forum/ho ... ducts.html

That article seems to be focused on paint / cosmetic issues. The Aviation Safety article that David referenced said the avionics problems they attributed to silicone was resolved after a good wash.

Interesting. I dunno. I suspect some rubber ducky antennas have high silicone contest. Some mobile phones are sealed with silicone sheets. Come to think of it, I have an old 80 meter trap long wire with silicone covering. Silicone is a decent insulator but not as good as fiberglass or acrylic. None of this is identical but perhaps there is scientific evidence?

Pledge does appear to contain silicon. I can't remember where I suggested using it, but in the past I have used it on the FIKI panels on the leading edge. Those are metal, so I think it is probably okay.

Colin wrote: ↑Sat Oct 09, 2021 8:09 pm Pledge does appear to contain silicon. I can't remember where I suggested using it, but in the past I have used it on the FIKI panels on the leading edge...

Bad idea. From Chapter 8 of the DA42 AFM Supplement S03 (bold emphasis added by me):

8. AIRPLANE HANDLING, CARE AND MAINTENANCE
The porous panels can be cleaned with soap and water using a clean, lint-free cloth. Isopropyl alcohol, ethyl alcohol or methylated spirit may be used to remove oil or grease. Furthermore approved de-icing fluids, AVGAS and jet fuel are permitted for use on the panels.

CAUTION
Do not apply polish or wax to the panels. Certain solvents, particularly methyl ethyl ketone (MEK), acetone, lacquer thinner and other types of thinners and solvents damage the inner membrane of the panels. Mask active area of panels with a low tack tape when using solvents or painting the airplane in the proximity of the panels or when the airplane is stored in a dusty environment.

Every effort should be made to keep those tiny holes from being clogged. The purpose of a wax is to fill in tiny voids, and the voids on a TKS panel are the holes that the fluid gets pushed through. Any effort to wax TKS panels works against their designed purpose.

Oh, that is excellent to know. (I admit I only did this the first two months I had the plane. I tired of wiping the bugs off and my use of the TKS is incredibly limited.)

Thread drift: What do people do to clean their panels (I see what is allowed, curious what people are actually using)? Certainly bugs filling the holes is just as bad as the wax possibly filling them.

Colin wrote: ↑Sun Oct 10, 2021 3:32 pmThread drift: What do people do to clean their panels (I see what is allowed, curious what people are actually using)? Certainly bugs filling the holes is just as bad as the wax possibly filling them.

To drift even further…

I prefer to clean the panels from the inside out, i.e. run the system. Better to push the bugs out with deice fluid than push them in with anything else. Just flick the big bugs off with a fingernail and wipe any residue with water. I run the system once a month or so, usually in icing conditions (I live at FL180), but will run it just prior to entering rain if it has been a while - the rain cleans the goop off pretty well.

For anyone who is concerned about prior silicone, when I told my (Diamond certified) paint shop guy that I was really careful about no silicone, he said it is not as much of an issue as it was before - that their cleaning solvents remove everything now. So if people are worried about what happened with previous owners, it’s probably fine.

Colin wrote: ↑Sun Oct 10, 2021 3:32 pm Thread drift: What do people do to clean their panels (I see what is allowed, curious what people are actually using)?

Assuming you mean the PFD/MFD, I use iCloth cleaning wipes.

Colin wrote: ↑Sun Oct 10, 2021 3:32 pm Thread drift: What do people do to clean their panels (I see what is allowed, curious what people are actually using)? Certainly bugs filling the holes is just as bad as the wax possibly filling them.

Official Guidance:

I wet down the canopy and leading edges after flights with water to soften the bugs and follow with Wash Wax All and a microfiber cloth. I use the newer cloths on the canopy. In Minnesota we get about 6 months of bug-free flying. My FBO's hangar seems to produce a lot of dust so I use a California Car Brush for that. It works great. Once a year I wash it with Aero Magnolia Fleet Wash and apply Klasse for protection and a shine. The Fleet Wash will remove paint so make sure it's diluted quite a bit. In the spring I clean the belly with Carbon-X diluted 1:2 and paper towels. I keep the oil at 4-6 qts and that helps keep the belly clean. I used a light polishing compound (no silicone) by hand last year and it helped quite a bit with the shine. Most people tell me it looks pretty good for 2003 paint.