Continued from a previous thread on thickness of wax layers. Note, I don't make any claims about effectiveness, I am only measuring the thickness!
Thanks to *******, I have a large selection of waxes and also sealants to test, so I have started a new thread. Here are a few results from the last three days.
Testing as before, applying coatings to clean 6" silicon wafers.
20 random spots were measured to give some statistical significance to the results.
Below I quote the average thickness and the standard deviation (sd). The standard deviation gives an indication of the spread in the results.
.........................................................................................................................................................................................................................
***** Vintage (4 coats applied at 24 hours intervals)
Wax applied with microfibre, hazed and lightly buffed with clean microfibre cloth.
Thickness after first application = 25.6 nm; sd = 2.5 nm
Thickness after second application = 26.3 nm; sd = 3.2 nm
Thickness after third application = 24.9 nm; sd = 1.9 nm
Fourth layer applied by hand.
Thickness after fourth application = 27.4 nm; sd = 1.7 nm
Because of the spread in the results, as given by the standard deviation, you can't read anything into the small differences in thickness.
This seems to show, once again, that you can't layer wax.
.........................................................................................................................................................................................................................
*****seal
This gave me some problems at first, not having used the product before, because of the difficulty in applying a thin enough initial layer to the relatively small 6" wafer (compared to a car panel).
First attempts were definitely too thick, giving strong interference fringes on the smooth silicon wafer that changed rather dramatically as the product dried (very slowly).
The end results were very patchy. After advice from *****, I then cut down the amount of product to no more than one drop, applied with a 1" square of microfibre cloth.
This easily spread over the whole surface of the wafer and dried to a haze-free finish in a few minutes. Again, 20 random spots were measured.
Coats applied at 24 hours intervals
Thickness after first application = 17.3 nm; sd = 1.2 nm
Thickness after second application = 16.6 nm; sd = 1.1 nm
Again, no evidence of layering being possible.
An even smaller amount applied to a different wafer:-
Thickness after first application = 21.9 nm; sd = 2.3 nm
.........................................................................................................................................................................................................................
***8
This was applied lightly with a 1" square of microfibre cloth but it did not spread evenly over the wafer surface.
Whereas the *****sealobviously wetted the surface, this almost seemed to be like trying to rub water into the surface.
I wasn't too surprised by the results below (as yet, only one layer applied).
Thickness after first application = 4.9 nm; sd = 1.4 nm
.........................................................................................................................................................................................................................
Red*****
This product was much more like *****seal, wetting the surface and spreading easily. Not easy to wipe off, so maybe too much applied.
Thickness after first application = 22.1 nm; sd = 0.7 nm (a very uniform film!)
.........................................................................................................................................................................................................................