The International Cessna^® 170 Association

I just restored the original sun visors in my plane and i'd like to put something on the rubber u-channel edging to protect it from UV and ozone. I'm aware of some of the automotive products like 303, but I thought some of you who work on planes with de-icing boots, for example, might have some other suggestions. Thanks in advance.

Gene,
I found the sun visor pictured below at KRN. It was NOS with a p/n of AK 8055-1, the same as in fig. 101. (That being said, I notice that the mount tube faces the opposite direction from the illustration). Note that there is no rubber u-channel around the edge. I’m still in the market for a matching one — no matter what condition. Age Master #1 is what is used on deice boots. At $377/qt. it’s probably not what you’re looking for. This stuff soaks into the rubber; it’s not just a surface treatment. According to this white paper, it’s ozone rather than UV that causes cracking in neoprene deice boots.

Rather than looking for the elixir to preserve your u-channel it might be cheaper to replace it with u-channel made of something more weather resistant. Search online and you’ll find numerous charts that compare various elastomers in all sorts of categories including ozone resistance. It seems Ethylene Propylene Diene Monomers (EPDM) and silicone do well in this category. This u-channel might be worth considering.

Gene-
I can send you a small 3oz. spray vial of Agemaster if you PM me your mailing address. It should last you a lifetime of sun visor treatments. I used it on 30" tundra tires back when I had Super Cubs. My Airstreaks never had a crack in them in many years of use and I never saw another set without cracks. The stuff really works.

Richard, thank you for your kind offer. As Gary pointed out, that stuff isn't cheap. I've sent you a PM.

Gary, for some reason, I knew you would have an answer. At $377, though, I'm not going to buy a quart anytime soon. (And given Richard's offer, I won't need to - thank you again Richard.) The EPDM U-channel you found is different from the edging on my visors. The edge is too square. Spruce sells a rubber U-channel that is almost identical (if not identical) to the original edging I replaced on my visors. I'll get the part number when I go to my hangar today. I'll also take a photo or two so I can respond to the rest of your post. It's a little bit of thread creep, but you raise an interesting issue about the early sun visors.

You've got to wonder what Age Master is made from. That stuff is crazy expensive!

I did a little searching to find the source of that u-channel. Looks like Modus Advanced has quite a variety of shapes available. SBR (Styrene-butadiene rubber) is not very weather resistant so make sure the style you buy is made from EPDM if it's going to be exposed to the elements.