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AKZO Prep

PilotRPI

Active Member
For those of you using AKZO:

I'm keeping away from alodine with my build and am considering using AKZO.

For AKZO, do I have to acid etch, or can I just scuff parts with scotchbright, clean, and spray the AKZO?

If I do have to acid etch, what are the options? Can I use something like Stewart EkoEtch, or must I stick with Alumiprep? Any other good options?

Thanks!
 
For those of you using AKZO:

I'm keeping away from alodine with my build and am considering using AKZO.

For AKZO, do I have to acid etch, or can I just scuff parts with scotchbright, clean, and spray the AKZO?

If I do have to acid etch, what are the options? Can I use something like Stewart EkoEtch, or must I stick with Alumiprep? Any other good options?

Thanks!

If you want the primer to stick, then you need to etch. I used alumiprep. I also used alodine.

I can't answer how the other products may or may not work.
 
I started out doing the whole prep. Alumiprep etch and scuff, then alodine, then primer. After a while I skipped the alodine step and I didn't see any difference in the finished product.

I would definitely etch with something to make the primer stick better.

My process at the end of the build was clean the surfaces with acetone (takes off the markings on the aluminum and any grease/skin oils), maroon scotchbrite scuff with 50/50 alumiprep/water solution, rinse, dry, then one more acetone wipe down before shooting on the Akzo epoxy primer.
 
I used Akzo for everything. You do need to etch the surface, but it doesn't have to be a chemical etch.

I just used maroon scotchbrite pads for a mechanical etch. Then a wipe down with acetone to make sure all dirt and oil is removed, then spray on the Akzo. No alumiprep or alodine.

No problem with adhesion. I can scrub this stuff with acetone and a rag after it's cured, and it holds just fine.
 
Same experience as Ed. I used Prekote for all the internal parts, but for the skins, I too just scrubbed w/ scotchbrite and cleaned w/ acetone. I see no difference in adhesion - tough as nails once cured.
 
I do the etching with the maroon scotchbrite to roughen up the surface. Its a very simple process and I'm not sure why you wouldn't do it that way. The etch is just helping you with the roughening process. The acid is doing the work versus you sanding.

I mix up the acid is a HD spray bottle and sprary it on. I use the scotchbrite and rub the surface simple. I usually work on a few parts at once letting them sit for a little while as I'm doing another part. Then you just rinse off the parts with water.

I'm doing alodining too, but as others have said it may not be strictly needed. I submerge the parts in the alodining solution for 90 seconds. Rinse and you are done. Again I think this is very quick and easy once you get a couple of small tanks setup, one for alodine and one for rinse water.
 
Ditto

Ditto what Ed and Jon said. Depending on the part I may or may not use alodine. I too have moved away from chemical etch in favor of the maroon scotch brite pads. I clean everything with Prepsol (use your degreaser/cleaner of choice) after scuffing and shoot the AKZO. Like Jon said, it's tough as nails and I have yet to have any of it scratch off even after some rough handling (like on my roll bar where there is a lot of contact from adjacent parts). I have also had good luck shooting my interior color coat over the finished product, but that's a different topic.
 
Plus 1 more for.....

Scotch Brite pad and acetone - no alodine or chemical etch. I also clean with Dawn dish soap (orginal formula) in between the pad and the acetone. Primed my entire rear wing spars with it and it turned out fine. A little elbow grease and temporarily sore muscles and hands is much better than chemical prep IMHO. :D
 
I learned a neat trick this weekend. Instead of manually using scotchbrite pads, I met someone using an angle die grinder with 3M roloc wheels. He suggested using the very fine blue discs instead of the maroon, as the high speed may be too aggressive with the maroon.

So those discs, acetone, and AKZO spray seems like a much better/quicker process for protection rather than some of the other things I've seen.
 
Prep

The maroon pads stick perfect on my random orbital. It's actually not aggressive. They work great and fast.
 
The maroon pads stick perfect on my random orbital. It's actually not aggressive. They work great and fast.

I was going to say the same thing. A maroon pad on a random orbital makes very quick work of deburring match-drilled holes in wing skins. :) It feels a little like cheating, but I manage to live with myself afterwards.
 
I learned a neat trick this weekend. Instead of manually using scotchbrite pads, I met someone using an angle die grinder with 3M roloc wheels. He suggested using the very fine blue discs instead of the maroon, as the high speed may be too aggressive with the maroon.

So those discs, acetone, and AKZO spray seems like a much better/quicker process for protection rather than some of the other things I've seen.

Blue Roloc disks are about the equivalent "grit" to the maroon 7447 hand ScotchBrite sheets.

They don't use the same color coding system. :)
 
Blue Roloc disks are about the equivalent "grit" to the maroon 7447 hand ScotchBrite sheets.

They don't use the same color coding system. :)

Thanks for clarifying Gil. It was actually me that showed Jesse the blue discs over the weekend, but I was unclear it was the same grit as the maroon.

I know this thread is about AKZO but for the Sherwin Williams primer I am finding that I don't even need to scuff the surface and it has good adhesion. Just a quick clean with Acetone and good to go.
 
Newbie question: when you all talk about AKZO, which Akzo are you referring to, exactly? They seem to have a lot of different products.
 
Interior Primer

The description is "interior" primer. My impression is that this would be fine as a primer under a finish exterior paint, but that it would not handle UV long term on it's own, hence the "interior" Is this correct?
 
The description is "interior" primer. My impression is that this would be fine as a primer under a finish exterior paint, but that it would not handle UV long term on it's own, hence the "interior" Is this correct?

Yes, many airframe manufacturers use this primer, or a similar solvent resistant primer on the outside of the structure. When top coat paint is applied to the exterior the solvent resistant primer is usually scuff sanded and a fresh coat of primer that is compatible with the top coat is applied prior to the top coat paint application.
 
Reviving an old thread here.....

I plan on going the scuff/clean/Akzo route. Those who did this process BEFORE dimpling, did it hold up well?

I hope to prime in larger parts batches before dimpling, then do any small touch ups necessary with a primer pen if needed after a file or minor trim, if it makes sense to do so in some areas.

I may plan on chemically etching with 50/50 Alumiprep/Water or EkoEtch along with the maroon pads if it would help hold to a dimple.
 
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Process

Reviving an old thread here.....

I plan on going the scuff/clean/Azko route. Those who did this process BEFORE dimpling, did it hold up well?

I hope to prime in larger parts batches before dimpling, then do any small touch ups necessary with a primer pen if needed after a file or minor trim, if it makes sense to do so in some areas.

I may plan on chemically etching with 50/50 Alumiprep/Water or EkoEtch along with the maroon pads if it would help hold to a dimple.

Basically how I did it. In my case the primer is P60G2.
One caveot. The real issue with paint prep on aluminum is removal of aluminum oxide before spraying the paint. If you scuff first, there's no way to get paint on before the AO forms again so pick your poison. Personally, I clean with Bon Ami and grey scotchbrite before spraying. Alumiprep would work fine too.
 
Thanks - I intend only on doing this to interior surfaces when they are ready to prime. Not on the exterior surfaces or rivet lines. I'll let a pro painter do that prep (someday, hopefully).
 
Dimple After

I use Akzo primer and I dimple after priming. I've had no problems at all with the dimpling process damaging the primer.
Everyone has their own preference here, but there's a couple of reasons I prefer to dimple after priming. First, it is much easier to prep your parts (especially if scuffing with scotchbrite adds) without all the dimples. Second, and this is my own silly reasoning, is that if you prime after dimpling you may, very slightly, (fill in) the dimple with primer. Dimpling after gives you a nice full dimple.

Btw. My prep process is scuff with maroon scotchbrite pad and prekote.
 
For me its:

  • Maroon Scotchbrite and Bon-ami
  • Rinse thoroughly
  • Wipe down with denatured alcohol (acetone leaves a residue)
  • Primer goes on within 2 hours of scuffing
  • Dimpling after primer dries (using EcoPoxy). I've absolutely no issues dimpling after priming.
 
+1, I've been dimpling after priming and it holds just fine - just respect the cure time (personally I give it 48h after applying primer before doing anything, may be possible with less but I haven't tried). I'm also careful to not apply primer if relative humidity is higher than their specified limit - the one time I did it over the limit, I got bubbles and it didn't hold as well.
 
Started using Akzo on the wing kit, awesome stuff. Much much better than the rattle cans I used on the tail, and in the end will probably be less $$.

My process has been a Prekote scrub with a maroon pad, rinse, dry, shoot primer. No issues. When I run out of Prekote I'll probably switch to Bon Ami.

Last night I did a test. I had some Akzo leftover from a rib session, and I grabbed a scrap piece of T6 and shot it. No prep, no scuff, no solvent wipe, nothing. Just a quick wipe down with a towel and went. It came out tough as nails.

So my question is, why the prep? I'm sure I shot over an oxide layer, so what's going to happen? Did chromates in the Akzo do a conversion when I shot it?

There doesn't seem to be an adhesion problem (I'm doing the duct tape test right now). Will it corrode under the primer? Did I get lucky?
 
Started using Akzo on the wing kit, awesome stuff. Much much better than the rattle cans I used on the tail, and in the end will probably be less $$.

My process has been a Prekote scrub with a maroon pad, rinse, dry, shoot primer. No issues. When I run out of Prekote I'll probably switch to Bon Ami.

Last night I did a test. I had some Akzo leftover from a rib session, and I grabbed a scrap piece of T6 and shot it. No prep, no scuff, no solvent wipe, nothing. Just a quick wipe down with a towel and went. It came out tough as nails.

So my question is, why the prep? I'm sure I shot over an oxide layer, so what's going to happen? Did chromates in the Akzo do a conversion when I shot it?

There doesn't seem to be an adhesion problem (I'm doing the duct tape test right now). Will it corrode under the primer? Did I get lucky?

From what I have read, the Alclad is a really good corrision prevention layer itself, but it can be easily scratched away, which is why a good primer like AKZO works really well with it. The AKZO provides a tough layer to prevent scratches, and it is also a good for corrosion prevention as well.

If you are not doing a conversion coating (Alodine for example), then the reason we scuff and clean the metal is to promote a better adhesion for AKZO. Granted, its a really good epoxy primer, so it will adhere to just about any surface; we just scuff and clean to give it the best possible surface to adhere to.
 
Loctite 7840

Has anyone tried Loctite 7840 for cleaning parts ?

I was at an engineering company a few weeks ago and this was what they used to degrease parts after they had been in the CNC machine (cutting fluid and lots of slippery grime)
 
dcl,

While I haven't tried the product from Loctite, I really don't have much of a problem with oil or grease when it comes to prepping for primer. Yes, sometimes after oiling a drill or my rivet gun it leaves a bit of residue, but it hasn't been a problem with regard to priming.

The reason I clean the skins isn't so much to remove oil or grease, it's to remove oxidation and to give some "tooth" to the surface so that the primer will stick. I wear surgical gloves during the prep to help eliminate any oil from my hands. During this process any oil or grease is removed. When complete, I rub down with denatured alcohol to insure I've gotten everything off the surface.

Not sure if this addresses your question, I just haven't found a need for a degreaser.

Fred
 
Aluminum Oxide

dcl,

While I haven't tried the product from Loctite, I really don't have much of a problem with oil or grease when it comes to prepping for primer. Yes, sometimes after oiling a drill or my rivet gun it leaves a bit of residue, but it hasn't been a problem with regard to priming.

The reason I clean the skins isn't so much to remove oil or grease, it's to remove oxidation and to give some "tooth" to the surface so that the primer will stick. I wear surgical gloves during the prep to help eliminate any oil from my hands. During this process any oil or grease is removed. When complete, I rub down with denatured alcohol to insure I've gotten everything off the surface.

Not sure if this addresses your question, I just haven't found a need for a degreaser.

Fred

What he said. Remove the AO. That's the enemy. Oils will be cleaned in the process.
 
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