Priming the elevator skin parts4h
June 19, 2022
The task of the day was to prime the elevator skin parts.
Another priming session.
First, I cleaned all the parts with the EkoClean, then etched them with EkoEtch. This time I washed parts immediately after removing the EkoEtch to avoid accidental contamination of outer skin surfaces with EkoEtch (which leaves corrosion marks). I think it worked better than the last time -- the outer parts of the skins look clean.
Then I shot the primer. I need to think about how to optimize my space better. My paint booth is very small, so I had to prime skin outside of it, on a piece of cardboard. I am not sure I need the paint booth since it does not have any fans anyways. The only job it does is it contains overspray somewhat. Maybe, I just need to prime in multiple sessions -- it dries relatively fast, and after 15 minutes I can carefully handle the parts.
I struggled a bit with the finish today, it was powdery like it was drying before reaching the surface. It is expected with the temperatures we are having (it was probably 80-90ºF in the garage at the time I was priming). Adding the flow fixed the issue, but I was getting too much of the primer.
There was advice on VAF to try to reduce the pattern size. I will try it next time, I actually needed a smaller pattern for the stiffeners anyway.
Another issue was that the gun blows small parts away. I will try lifting the chicken net to see if that helps. I think the air is reflected from the floor, blowing the parts around.
Overall it was okay, I missed one spot on the left skin (you can see it on the leading edge on the left). Also, a few stiffeners got bad priming due to handling while I tried to hold them. Luckily, all of them are from the left elevator, so I will leave them for now. When I will be priming the understructure for the right elevator, I will consider stripping the primer from the badly primed ones and re-prime them.
Also, I forgot I wanted to prime the leading edge of the rudder skin. Bummer. I wanted to roll it and finish it, but I guess it will wait until I do the right elevator understructure.