Priming Leading Edge Ribs   January 13th, 2008

I have put both fuel tanks away, and I am ready to go back to the leading edges. I spend all day today priming the ribs and skins. I am still using the Stewart Systems water-based primer.

The wing jig was briefly converted into a rib-holder. I draped tarps on both wing skeletons to keep paint from getting on them.

After speaking to an AFS rep at Oshkosh last summer, I am going to wait for about a week until I start putting the leading edges together. Given the relatively cold weather, this should be plenty of time for the primer to harden.

Posted in Leading Edge, Primer | Comments Closed
After finishing with all of the holes, Vans recommends priming the aluminum where the anodizing has been removed. I didn’t think I could hand paint the countersinks without using a lot of pain (and leaving uneven streaks, etc). So, I covered up most of the flange with masking tape, and sprayed GBP-988. Turned out pretty good…

Next, I spent about a day and a half cleaning up all the 200 platenuts with a scotch-brite pad. After these suckers were pretty clean, I also sprayed them with GBP-988
Finally, actually riveting the platenuts to the spars went pretty fast. I did all of them in about two hours.

As I was draining the compressor at the end of the work session, the drain valve didn’t feel right. Sure enough, I couldn’t get it closed again. I removed it and discovered somehow the seal broke. Fortunately, it was pretty easy to order a replacement part from Sears. I should be here in the next few days. Meanwhile, I guess I’ll do whatever doesn’t require air tools…
Posted in Compressor, Platenut, Primer, Wings | Comments Closed

I finally got to prime the horizontal stabilizer. I used the AFS water-based primer.

I started by washing all of the parts with dishwashing soap (everybody says ‘Dawn’, but we actually use ‘Joy’ in our house!). After drying, I brushed on the AFS Aluminum Etch, which basically removes anything that the dishwashing soap missed. The instructions on the Etching solution talk about the water ‘sheathing off’ after rinsing. I wasn’t exactly sure what this meant until I actually tried it. Sure enough, after rinsing the parts, water will ‘sheath off’! i.e., there will be not a single bead of water on the piece.

After drying again, I laid out the parts on some chicken wire between two sawhorses, and started spraying:

Some things I learned…

  • My Harbor Freight HVLP detail gun seems to work pretty good, with the exception that there is no vent hole in the gravity fed tank. After a couple of seconds of spraying, paint stops coming out until I open and then close the cup again. Next time I use it I’m going to drill a very small hole at the top of the cup.
  • The paint looks like crap right after it is applied. However, 1) This is primer, not paint, so don’t expect it to look as glossy as the white powder-coated pieces that come in the kit. 2) It will look much better after it dries.
  • The primer will harden considerably in about two days. It is VERY easy to scratch it off in the first few hours after application, so great care is required. The best thing to do is to spray the parts and just leave them alone for two days.
  • Two coats is enough. After riveting, I will come back and spray the rivet lines and other places where the bucking bar may have scratched the primer off.
  • After the primer is dry, you have these nice white pieces. As you handle them with your dirty hands, black smudges start to appear. Obviously, these are harmless, but make the pieces look dirty. I used rubbing alcohol to clean up.
Posted in Empennage, Primer | Comments Closed