For those following along - you'll recall that I last sprayed primer about (or more than) a year ago - it sprayed great, is super durable, and is super toxic (first time around I did Azko)... I love the end result, but I really hated the process, the positive pressure ventilation is necessary and a hassle to work with and setup/clean - and because of that hassle, I would work on part up until the priming step and then set them aside and continue on to the next section. So this weekend, I figured I'd try something else and I figured I'd give a try with Stewart Systems Ekoprime product.
On the pros - it's WAY less toxic, it's water-based, there's no two-part mixing and initial set-up, and did I mention it's way less toxic? On the cons - I expect durability to be a bit lower (though, the durability portion is really only a during-construction issue EXCEPT in the area of potential solvents...looking at you AVGAS - which will easily take the primer up in the future).
So with my baby-sized can of Ekoprime in hand, I set about the business of priming - gathered a bunch of parts (classically, I forgot a bunch of stiffeners, so another priming day is in my very-near future), and started the priming process, summarized below:
1. Clean part with Prekote - spray part, scrub lightly with gray scotchbrite, rinse thoroughly with water, let air dry.
2. Set up spray table, get all the equipment set up and ready for spraying (taking care to avoid touching parts with bare hands)
3. Mix up Ekoprime (so glad I grabbed a paint mixer for the drill on a whim, it's a necessary thing for this)
4. Measure into 3M PPS cup (I did 250ml of primer and about 20ml of water), mix again.
5. Spray parts with Orange (1.4mm) nozzle (instructions want two coats, but I sprayed heavy-enough that it really only needed 1 coat)
6. Let dry
7. Clean up
Couple pertinent notes:
1. This primer is much more prone to drying on the spray nozzle vs. Azko... Easily remedied via paper towel and blotting the tip.
2. I may need a different air source (or buffer mine with a tank) if I ever consider spraying more than primer - my 30gal single stage compressor got a workout during that spray session
3. The primer sprays...ugly...it's probably me and a bad setup, the paint is going down with a certain 'fleck' like appearance (almost like part of it is dry by the time it hits the surface). However, it flows once it's on the part pretty reliably - especially when the whole tip-gunk problem is noticed and cleaned.
Overall - I am quite pleased with the primer so far - too soon to call on the durability - but spray day was about 10x better than with the Azko as I only needed eye/respiratory protection and given the low-VOC and EPA-rating of this product, it's not much more dangerous than standard house paint. The green color is more limey- than the standard Azko, but hey - we're talking about the inside of parts here...
Lessons for next time:
0. Remember that sharpie may not bleed through this primer as easily, parts need to be remarked AFTER PreKote and probably after the tack coat (Or, do smaller batches and relabel as the paint dries)
1. Try to follow the instructions and attempt the light tack-coat first, that might help my crappy spray experience.
2. re-read up on pressure settings for the spray gun (inlet rec. is 20psi), avoid using the long and thin extension hose as the primary air supply to avoid the whole surging issue. I think I was spraying at WAY too high of a pressure.
3. Remember the top knob is the fan control knob to adjust spray pattern.
4. Remember a piece of scrap/cardboard to dial in the darn gun first