The Priming Wars

The Priming Wars

This topic was driving me crazy for weeks now. If you’re new to aircraft building you should know that there’s a never-ending war in regards to the proper (and best) way to protect your aircraft against corrosion. I hate this war, it makes so much harder for someone that is just trying to start to decide what to do. You will find thousands of people defending every single possible point of view, from not doing anything at all to the incredible hazardous two-part epoxy process and everything in between.

Honestly I would rather not do any priming but I don’t think that’s a viable option for me. I do not live close to the sea but we do have a LOT of snow for half the year, so the aircraft may be exposed to lots of humidity. But I was decided to not do the epoxy part. That’s just too much work for me and I really don’t want to deal with that nasty stuff. Also, this part of the project is boring as hell and I wanted the easiest possible way so I decided to follow what a lot of other builders have done and use a self-etching primer in rattle can. My initial plan was to use the SEM gray one but I could not find in any local supplier here in Canada and shipping this stuff is really expensive because it’s hazardous material. The one I could find was the green Rust-Oleum

I’m still testing this process while building my second toolbox kit but the steps I’m following as of now are: 

1: Scuff with the maroon scotch-brite pad.
2: Wash with Dawn detergent and warm water
3: Dry with paper towel
4: Wearing disposable gloves I’m cleaning the parts with Acetone. Using paper towels for this too
5: Finally applying the self-etching primer 
6: After 15+ minutes. Applying a second coat if needed

I was really not impressed with the results. I may need to improve this process. (Or change to a different priming method?)
I did apply the primer after dimpling and I felt it was not easy to scuff where the dimples were, this made applying the primer harder as it did not wanted to hold to the surface. I did try to first apply the primer and dimple later but the dimple die did mark the part as you can see in the image below: 

Also, it was really easy to overdo it and end up with too much primer running down the part. But I guess that’s just lack of practice.

All in all I actually liked the color. But I guess the gray would still be better. Not much of a big deal as I’ll apply this to the internal side of the skins that no one will see. I still have to decide what to do with the cockpit skins but I may just apply the primer and then a paint coat on top.

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