Ivan's RV-7

Priming the elevator skin partsTimer icon4h

June 19, 2022

The task of the day was to prime the elevator skin parts.

Another priming session.

The parts are ready for scuffing.

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.

The stiffeners primed. The left elevator skin.