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  #21  
Old 06-09-2017, 06:51 AM
Mudfly Mudfly is offline
 
Join Date: Dec 2011
Location: Alpharetta, Ga
Posts: 98
Default 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.
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  #22  
Old 06-09-2017, 07:09 AM
Reflex Reflex is offline
 
Join Date: Jan 2015
Location: Baldwin City, Kansas
Posts: 67
Default

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.
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  #23  
Old 06-25-2017, 02:34 PM
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rdamazio rdamazio is offline
 
Join Date: Dec 2013
Location: Santa Clara, CA
Posts: 160
Default

+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.
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  #24  
Old 07-11-2017, 08:28 AM
cczarnik cczarnik is offline
 
Join Date: Sep 2016
Location: Middle TN
Posts: 89
Default

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?
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  #25  
Old 07-11-2017, 10:35 AM
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CubedRoot CubedRoot is offline
 
Join Date: Sep 2013
Location: Ooltewah, TN.
Posts: 434
Default

Quote:
Originally Posted by cczarnik View Post
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.
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  #26  
Old 07-15-2017, 06:41 PM
dcl dcl is offline
 
Join Date: Mar 2012
Location: UK
Posts: 20
Default 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)
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  #27  
Old 07-16-2017, 06:45 AM
Reflex Reflex is offline
 
Join Date: Jan 2015
Location: Baldwin City, Kansas
Posts: 67
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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
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  #28  
Old 07-16-2017, 01:30 PM
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wirejock wirejock is offline
 
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 2,706
Default Aluminum Oxide

Quote:
Originally Posted by Reflex View Post
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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