On Sun, 03 Mar 2019 09:45:02 -0800, Senna Van den Bosch wrote:

To be honest, never done it or had it done on a car or glider, I bought
my DG 101 last year and want it to stay in great condition and stumbled
upon that care kit with waxing and polishing products and thought it
might be worth the effort

I, and other pilots at my club, used to use Mer car polish, but
apparently its now a non-starter because recently they've been adding
silicone to the mixture. The polish in blue containers did not use
silicone but the more recent polishes in black containers all include it
in their ingredient lists.

I've been told to never use silicone based polish because it is said to
make repairs to fibreglass or carbon structures very difficult or
impossible to repair.

In fact I remember reading that here, so it must be true!

OTOH I've not seen any publications that mention the effect of silicone
contamination on repairability. The only article on repairing FRP
structures I've seen, in a search I just carried out, that even mentions
contamination in any detail is:

https://compositesuk.co.uk/system/files/documents/
repairoffrpstructures.pdf

It has a short section about contamination (half a page in a 33 page PDF
document) that mentions "fuel, oil, hydraulic fluid, etc" and moisture,
but says nothing about the perils of silicone-based polishes.

The other 2-3 publications my search turned up that didn't turn out to be
pushing supplier's products either did not mention contamination at all,
or gave no details apart from describing how to sand through surface
finish.

So, what's the deal?

Are silicone-containing polishes etc to be shunned?

Can anybody recommend an FRP repair publication that gives any more
details about dealing with contamination than the one I quoted above?


--
Martin | martin at
Gregorie | gregorie dot org