Wings 54,Total 517 Finally priming wing parts

Wow, time flies. And now it's time to catch up on my build progress over the past couple of days. But first a couple of pics to finish up some of the dimpling prep. I decided to drill and dimple the holes on the top flanges of the aileron support brackets. Problem was that when it came time to dimple them, the female dimple die was too wide and was hitting the radius of the bend for the flange on the bracket. This would have resulted in a badly formed dimple had I not resolved this. Options were to grind down my female dimple die for the 3/32 rivet, or I could use the reduced diameter dimple die that I purchased some time ago from Cleaveland Tools. It is at least 1/8 of an inch thinner than the standard dimple die, and this allows you to form dimples on very tight flanges or oddly formed flanges, such as the over-90-degree-bent flanges on each support bracket.

I was able to dimple the flanges with no problems using the thinner female dimple die:

This next pic shows the basic fit of the parts after both the rear spar and aileron support bracket flanges were dimpled. Note the marks from the countersink cage around the countersunk holes on the end of the bracket, and the straight line marks left by the upper edge of the 3 inch yoke as the upper flange dimples were squeezed:

I think this is the first time since I began this build that I actually used a full sized scotch brite pad to scuff up the surface prior to priming. Turned out to be a lot less work than I thought, and went fairly quickly. Scuffed it with the pad, then cleaned with acetone and a microfiber cloth:

And then it was time to prime!

Here is the paint station setup that I am using. Card table same as all other times before, except this time I am also using the larger paint table and the saw horses. this worked out just fine.

Now some words about the new primer - AkzoNobel Epoxy Primer. The only thing I was worried about using this primer was if suffing the surface with a scotch brite pad was enough surface prep for the primer to adhere correctly, since most others are using alumiprep or some other chemical process to etch the metal. Short answer: Scuffing with the pad was all it took - no chemical process needed. This epoxy primer turns into a hard continuous shell when it dries. My only complaint is that it is supposed to be dry to the touch after 15 minutes, and dry to stack in an hour, and that is if it is about 70 degrees outside. Well, it was 90 degrees here today, and this stuff was only starting to get tacky at 15 minutes. It took about another 10 minutes or more before it was dry to the touch and finished flashing out.

The two plastic pour spouts I picked up from HD, and they sure came in handly, because these two gallon cans came filled to the absolute top of the can, which was something I was not expecting. The pour spouts allowed me to pour the contents from the cans into my mixing container without too much mess, and it looks like they are standing up to the chemicals of the two part primer, so I should be able to reuse them.

The material data sheet for this primer says to mix each part 1:1. Then you let it sit for a half hour before it is time to use it. The new spray gun worked great, except it is definitely designed for doing much larger coverages than the touch up gun I ahve used on all the empennage parts in the past. Results from priming once I had the paint flow and air flow settings where I wanted them was that I got a little bit of Orange peel, but not too bad. I think this happened ebcause of the extra hot temperatures today. The paint cup holds 20 ounces, but I only mixed up about 18 for this first run.

I started with the easel paper. Actually I should back up a bit first. The instructions with the spray gun ($14.00 from HF) said to run solvent throught the gun before using it because it was prepped with some anti corrosive agents before it was shipped to the USA. So I loaded up the cup with some acetone and sprayed the paper until the acetone was all gone. That should have cleaned out any residue from any packing grease or oils. The color is actually a pleasant looking greenish tint:

And now for the fun part. I found out that 18 ounces let me do almost all sides of all the small parts, including the rear spar support brackets and doublers, and the tie down bracets and spacers for both wings, and one complete side of a test trim piece that I scuffed and cleaned and painted first. I was also able to run the test passes shown in the paper above, and one side of the left rear spar, before I ran out of primer in the cup. So I only have one side of one of the doublers, one side of the left rear spar, and both sides of the right rear spar to do before it will be time to ound some rivets again.

The center part is the .040 trim piece that I used for creating test dimples and such.

And then came the cleanup. Acetone seemed to work just fine. A few wipes of the gun and inside the cup after running a small amount through the gun seemed to clean it all up just fine.

And lastly for tonight, I pic of my new PVC air line that I purchased from HD to ensure that the lone was clean and free from possible contaminants. I ahve been using the green colored line for so long, and I had it hooked up to an oiler for the paint shaker, and hooked up all winter long without changing the compressor oil or draining the tank. Just thought it would be safer to use a new air line since I have seen what happens to the paint if contaminants are present. Oh, and yeah, yeah, what a mess, I know. I have a retractable air hose reel that I just have not taken the time to install up in the rafters, but if I have time tomorrow I will start that process, so I can get the hoses off of the ground for a change.