Black pigment in windshield fibreglass???

[Captain Avgas]

I note that many builders have added black pigment (dye) to the first layer of epoxy resin/filler laid around their windshield. This is obviously to achieve a more aesthetic finish when the finished product is viewed from inside the cabin.

However I would suggest that all black pigments are based on carbon black...and I have been advised that interfacing carbon and aluminium is a no-no because it promotes rapid corrosion. Of course if corrosion were to develop at the interface between the aluminium upper skin and the pigmented epoxy it could result in a loss of the windscreen.

Does anybody have any LONG TERM experience with using black pigment in the windshield fibreglass....any other comments.

[Rivethead]

I wonder if the resin doesn't encapsulate the carbon well enough to be a non issue?

[Captain Avgas]

Originally Posted by Rivethead

I wonder if the resin doesn't encapsulate the carbon well enough to be a non issue?

Quite possibly, but you never know about these sort of things. Does anyone have any long term results using black pigment.

[tinman]

Another option is to paint a border on the inside of the windshield. I did this with a flat black latex paint. It took several coats to get good coverage, but it looks very sharp and should be benign to the plexi and aluminum.
Don

[newtech]

Don't use Sikaflex primer and don't paint your airplane with House of Kolor Kandies.

Steve Eberhart

[Rick of Austin]

I have been using carbon black in my expoy layups for years as both a uv protectant and for improved asthetics.
The fairings on the bare aluminum show no adverse effects.
It likely that the carbon particles are 100% encapulated plus the alodine on the aluminum may help too.
It works great.. actually I got the idea from the West Systems manual.

[Captain Avgas]

Originally Posted by newtech

The Sikaflex primer used by the guys gluing in their canopies is black. It is a little expensive but a small can could be shared by several builders. I will be ordering a can later this week.

Steve Eberhart
RV-7A, working on the canopy and getting ready for all of the House of Kolor Kandy Apple Red that will be applied in a couple of weeks.

Steve, the black Sikaflex 209 Primer that RV builders are using is 25% MEK and 20% Ethyl Acetate. Both of these are solvents that are in the worst category for causing crazing and cracking of acrylic. It might be OK on the flat unformed acrylic used on boat windows etc....but it might be a different story on a highly formed aircraft canopy due to possible internal stresses locked into the acrylic during the forming process. Personally I wouldn't use this product on my canopy.

I note that you are planning on using House of Kolor Kandy Apple. The "real" red Kandy Apple process is applied by laying down a silver or gold metallic base coat and then coming over the top of that with several layers of a transparent coating containing a red dye. That's what give this process it's amazing "depth". It ends up looking like a toffee apple and that's where the name comes from.

However I have been advised that the Kandy Apple process is virtually unmatcheable for touch-ups and is generally only used for show cars etc.

House of Kolor have another product which is simply a base and clear. It's better than standard auto paints but not as striking as Kandy Apple...but at least you can match it. If you have the true Kandy Apple and you scratch your fuselage or have other damage to the paintwork (almost an eventual certainty on a plane) then you might have to repaint the whole fuselage again. I think that's not practical.

So are you really going with "Kandy Apple" or are you going with a base and clear from House of Kolor.