AKZO priming method and suggestions

After reading through the primer wars I think I want to go with AKZO over Sherwin Williams. Mostly due to how durable the stuff is, and how it will "stick" to just about anything, being forgiving to newbies like me when it comes to surface prep.

While I am not 100% sold on AKZO, I was wanting to get some opinions on this method. My goal is to provide some corrosion and basic scratch prevention to my internal surfaces. I live in Southeast TN, its pretty moderate climate here. I plan on keeping the plane for a few years, and then selling to build an RV-10 if the wife allows it. heh.

I don't really want to spend a huge great deal of time in priming, since it seems the Alclad surface is so good at corrosion prevention. I'd like to just add another "layer" of protection to the Alclad. Here's what I am hoping will work:

1. Get parts are ready to prime (drilled, deburred, dimpled, etc)
2. Give the the Alclad a roughing with a scotchbrite pad. This won't be enough to remove the Alclad, as thats not what I want to do. I want to leave the Alclad, but rather scuff the surface enough to give the AKZO something to "bite" into.
3. When I am ready to shoot the primer, give the parts a good cleaning with acetone or some other cleaner to remove oils and contaminates.
4. Mix up and measure the AKZO, let it sit 30 minutes to kick off while I hang the parts for painting.
5. Give the parts a decent coating of AKZO.

Does this sound doable? Is there any cons to doing this sort of priming? If anyone has any experience shooting AKZO over a scuffed Alclad, let me know how it turns out.

Thanks!

Method

You'll get mixed responses. My $.02 below.
I think you're method is good but I recommend a process to remove the Aluminum Oxide. Solvents remove oils but not AO.
Scuff with scotchbrite will remove it, but it reforms in hours.
So I would scuff, clean and spray within a two hour window or scrub with something that will remove the AO two hours before spraying. Alumiprep or grey scotchbrite and Bon Ami cleanser.

Thanks Larry.

I was planning on doing the prepping and painting immediately after.

Will removing the Aluminum Oxide that forms on the Alclad also remove the Alclad?

So something like this:

1. Prep parts by drilling, deburring, dimpling, etc.
2. Scuff the Alclad to get a bite and remove Aluminum Oxide and clean the oils and contaminants with a grey scotchbrite and some Bon Ami
3. Wash with water and towel dry off
4. Spray AKZO

Do I still need to add the solvents step in there to get rid of the oils and such, or will Bon Ami do the job?

I had considered alumiprep, but wasnt sure of how toxic the stuff was and wasn't sure if it also stripped off the Alclad.

Solvent

CubedRoot said:

Thanks Larry.

I was planning on doing the prepping and painting immediately after.

Will removing the Aluminum Oxide that forms on the Alclad also remove the Alclad?

So something like this:

1. Prep parts by drilling, deburring, dimpling, etc.
2. Scuff the Alclad to get a bite and remove Aluminum Oxide and clean the oils and contaminants with a grey scotchbrite and some Bon Ami
3. Wash with water and towel dry off
4. Spray AKZO

Do I still need to add the solvents step in there to get rid of the oils and such, or will Bon Ami do the job?

I had considered alumiprep, but wasnt sure of how toxic the stuff was and wasn't sure it also stripped off the Alclad.

Click to expand...

Basically how I do it except I scuff before dimpling then scrub before priming.
No, you only scuff enough to provide some tooth. Basically dull the surface. On flat parts I use a HF random orbital. The scotchbrite sticks to the velcro pad. Very fast.
Yes, Bon Ami does an exceptional job removing oils.
Alumiprep is just an acid. Perfectly good product. Not toxic like solvents but not great for your bare skin or lungs.
FYI, I spray P60G2 so I can't advise on Akzo but it is a great product.
The test of a prepped aluminum surface is how water behaves on the surface. If it beads like it's coated with oil, the surface is hydrophobic and paint will have a hard time sticking. Try it on an untreated sample.
If the water flows over and coats the surface, it's hydrophilic. Paint will stick.

Great. So It looks like this might be a good plan of action for priming then:

1. Drill, deburr, etc.
2. Scuff the surface with an orbital sander using a scotchbrite. Possibly Maroon pad? This is give a good bite on the surface
3. Dimple parts
(I could put the parts up overnight at this stage if need be)

When I am ready to spray:
4. Clean the oils and contaminants using Scotchbrite Grey and Bon Ami. This knocks off the Aluminum Oxide and any other gunk that AKZO won't adhere to.
5. Rinse with clean water and towel dry
6. Spray AKZO

No worrying about removing the Alclad layer from any of these stages. This should leave the Alclad to do the bulk of the corrosion protection, and the AKZO to give the Alclad a good physical barrier.

AKZO Process

I primed my entire plane (inside surfaces) with AKZO. My process:

1. Wet scuff with maroon scotch brite pad (by hand using rubber gloves).

2. Wash with Dawn detergent and rinse thoroughly (still using gloves).

3. Blow off excess water with air and then let dry for an hour or so (yes handle parts with gloves).

4. Wipe down the surfaces with acetone and white paper towels until the paper towels quit coming up with grey residue on them. (rubber gloves for this step too).

5. Shoot the AKZO.

The rubber gloves in steps 1-3 are to protect the parts from you - not the other way around. Don't want any oils from your hands on the parts.

I wouldn't recommend using an orbital sander for any of this - potentially too aggressive.

I had excellent results using this method. In my experience, the AKZO ends up almost bullet proof.

Keep in mind though that I'm pretty anal retentive.

Well, I shot my first batch of Akzo today. I like this stuff! I wound up buying some left-over from a fellow builder just up the road from me, and found some time today to spray.

I am using a Harbor Freight HVLP gun, with PPS cup system. I set the gup for 45 psi when pulling the trigger, and followed the directions in the manual for the base setting for air and paint.

I had a practice kit that I wanted to play around on with this stuff before I spray my tail parts, and this is how I prepped and sprayed.

1. Dimpled and deburred my parts. I think I will wait on dimpling until after painting. The back side of the dimples was a little rough on my scotchbrite pad.

2. Lightly scuffed the surface of my parts with maroon scotchbrite pad. The goal was not to remove the alclad, but to get rid of any aluminum oxide, and to give a good surface for the primer to bite into.

3. Mixed an ounce of each part a and part b of the Akzo, giving me 2 oz in my cup. I wasnt really sure if this was enough, but I didn't want to have left over since I was only going to be learning on a small batch of parts.

4. While the primer was inducting, I wiped all my parts down with some acetone to get rid of oils and contaminants. Used a fresh pair of latex gloves for this.

5. Setup my spray bench just outside my basement, under my upper deck. Right after I mixed my primer, we had a little rain shower move in (of course, perfect timing) so I was worried it would be too humid to spray.

6. After the 30 minutes, I had my parts ready and got my spray gun ready to go and sprayed my parts down. After a little tweaking of the gun, it was flowing perfect and laying on very nicely.

I am using a half-face respirator with organic filters and I had no fumes at all the whole time I was cleaning with acetone or spraying which was really nice. I also kept the respirator on while I was scuffing since aluminum dust is not very nice stuff. I have a beard, but it didn't seem to affect the seal at all, i had my head right over the parts i was cleaning with acetone and all I could smell was clean air.

I will say that my safety glasses were inadequate when I was spraying. I didn't feel that my eyes were covered enough, even though I was outside and spraying with the wind at my back. Im going to get some goggles that seal around my eyes somehow.

Im also going to look into some other cleaning method besides acetone. My basement has a slight acetone odor from where I was cleaning the parts. I opened my back door and the windows to get some fresh air flowing in there. The house is really well sealed, so it didn't make it upstairs or into the garage. I may give Bon Ami a try, or even Alumiprep.

The parts dried really fast even in the humid post-rain shower weather. But, they still emit a bit of an odor. I brought them in for the night and will check the basement in the morning to see if they stunk up the basement overnight.

Some lessons I learned.... Acetone will very quickly eat through a plastic solo cup, and so will Akzo. It don't matter how careful you are, trying to get paint from a 1 gallon bucket is going to be messy.

Here is a photo album of a few shots I took of the practice kit, before and after. I have another practice kit that I finished a while back that I may spray on before spraying my tail parts.

https://goo.gl/photos/ZM94XqfqQpXCGFP46

Does that look like its done well enough to provide some protection, but not oversprayed?

I hit the local restaurant supply company and got some small stainless steel ladles and used these to dose out the primer and activator from the gallon cans. Pour it into a plastic paint mixing cup that has markings on it and you can see that your ratios are correct. I would pour most of the primer after induction into the sprayer and keep a little bit in reserve. This way when you run out you can decide what parts will get the remainder. I always seemed to be a little bit short on the amount of primer per session.

bruceh said:

I hit the local restaurant supply company and got some small stainless steel ladles and used these to dose out the primer and activator from the gallon cans.

Click to expand...

I use the same approach, but buy $1 sets of plastic measuring cups from the local dollar store. The measuring cups make it easy to dip out the paint without making a mess and control your mix rate.

They are cheap enough that I just toss any dirty ones when I'm finished with a paint session.

Syringes

Use syringes. You can buy them in almost any size. Measure directly into the disposable paint cup. No mess and no waste. Easy to clean. Just shake some lacquer thinner inside and squirt it out. Label them to protect againt cross contamination. If you're concerned about silicone contamination, buy rubberless. I've used both and never had a problem.

I used Bruce's stainless ladle method. I bought mine at a cooking store at the mall. I have a pyrex glass mixing cup that I put the two parts into. I mix it up, let it sit for 30 mins and then pour it into my gun through a paint filter. I've been adding a small amount of lacquer thinner to the mix also because someone on this site suggested it. It doesn't seem to hurt and now its part of my process. I'm not sure if its really needed.