Priming the Rear Spar

Another priming day.  I really don’t enjoy priming, its probably the only part of building an airplane that I despise.  It very well could be my process, so I think I will try something different on the ribs.  However, I followed my normal routine for the spar parts:

1. Scuff all the parts with maroon scotchbrite pads.  My goal was to not take off the alclad, but give the primer a good surface to adhere to.  I figure having alclad AND AKZO primer would give me good protection.
2. Clean the parts with acetone.  This gets rid of oils, scuffing dust, and other contaminants that would cause the primer to not stick.  I have found I have to clean each part three times with a fresh paper towel before the paper towel comes up clean.
3. Spray the parts with primer.

Now, this may not seem like a lot of work, but all that scuffing and cleaning is boring and very tiresome (repetitive).  I am seriously considering switching methods to the Alumaprep, Alodine and primer methods as they dont require no where near the scrubbing and scuffing.  I could just dunk the parts in bulk into tubs of the stuff and let it do its magic.

Anyways, I followed my normal procedure for now, and scuffed up all the parts, cleaned them with acetone and then sprayed AKZO.  Here’s the photos of where I had them all scuffed up, cleaned and re-marked ready for priming.

I will admit a mistake:

It’s hard to see but I only mixed up about 3 ounces of AKZO (1.5 of parts A and B). I let it have its 30 minute induction time, while I suited up.  I thought it would be enough but I learned about halfway through my spray session that it was not enough.  I was only able to finish about 90% of the parts, and I needed to go back and touch up some bare spots on the spars.  SO… thats my mistake.  I had to mix up a second batch, this time doing another 2 ounces of mixed primer and let it sit another 30 minutes to induct.  After it was ready, I finished up my priming session, and left the parts in the booth so the offgases would get ventilated outside.  AKZO has a tendency to off-gas as its curing, and its a strong smell, so they can hang out in the booth for a day or two and cure.

Of course, heres the painter selfie for proof that I did the work

Here’s all the photos from tonights work. I’ll add the rest of the photos when the parts cure and I can get them out of the booth and in to good light to snap some photos.

Google Photos link:

Hours Worked: 3.5