Hi,

I am doing surface quality studies an want to seal a cnc milled cavity (surface roughness approx Ra 0.8µm) on a new/unused Sika M960 board (1,2g/cm3 density) with S120 sealer.
The laminates shall be of very high surface quality.

1) For this purpose: How many S120 applications do you reccomend? My plan is 4-5. Enough?
2) Referring to "De-Nibbing" a tool making professional explained to me, that he sands tooling boards after every sealer application with gradually decreasing grits from 400 to 1200: Do you reccomend this as well? How long do I have to wait until i can sand a S120 layer? 20min @RT enough? Or better 20min @60°C - The data sheet is a bit unclear here, unfortunately.

Many Thanks
Holger

As hanaldo says, I don't see the need for all the sanding?  You could elevated temperature cure but it might not help the surface finish initially if you don't allow it to touch dry first.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Hi,

thanks for all the valuable advises. I will then follow your experience and sand only the pre-final coat to de-nib as shown in the video.
Many thanks, Holger