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  #1  
Old 03-01-2015, 06:55 PM
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rdamazio rdamazio is offline
 
Join Date: Dec 2013
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Default PreKote + Akzo - what am I doing wrong?

Hi all.

I chose to use PreKote + Akzo for my plane, and today I did my first primer test on some scrap pieces, which I don't think went very well. I used a HVLP gun set at 20psi, but the end result looks like this:





I tried a few different adjustments on the gun (pattern, air flow, etc.) but it didn't seem to improve - is this the way it's supposed to look? Assuming not, any hints on what I may be doing wrong?

(total primer/painting newbie here btw)

Thanks!
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  #2  
Old 03-01-2015, 07:29 PM
60av8tor 60av8tor is offline
 
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Interesting - is that 20psi at the gun? I'm guessing your pressure is too low. A pic for comparison:

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  #3  
Old 03-01-2015, 07:51 PM
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wirejock wirejock is offline
 
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Default Spraying primer

20 psi is about right if it's at the gun. You should have a flow valve with a gauge right at the gun. Maybe a water/oil filter and flow valve if your in a humid environment. The manufacturer recommended psi is a good start. 23 on mine. Also it will recommend a starting point for the needle valve position. 3/4 turn open on mine. You should see the fan of paint when you pull the trigger to the paint position. The trigger has two positions. When you first squeeze, it feeds air. As you pull farther the paint flows. This allows you to keep the air flowing and control the paint. Most guns have the fan control almost wide open.
It looks like very little or nothing came out.
Try spraying something cheap like lacquer thinner or even water to see how the trigger works and what the fan looks like when the liquid flows.
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Last edited by wirejock : 03-01-2015 at 07:54 PM. Reason: add text
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  #4  
Old 03-01-2015, 07:54 PM
CMW CMW is offline
 
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I would say, after watching your time lapse video, that you didn't stir the Akzo enough. Part A ( the green stuff) needs to be stirred really well especially if it has been sitting for a while. All the solids will settle to the bottom and there can be a couple inches of solids on the bottom that are really hard to stir up. I always use a mixing stick to stir so I can feel whats on the bottom of the can.
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  #5  
Old 03-01-2015, 08:06 PM
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wirejock wirejock is offline
 
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Default Time Lapse

Quote:
Originally Posted by CMW View Post
I would say, after watching your time lapse video, that you didn't stir the Akzo enough. Part A ( the green stuff) needs to be stirred really well especially if it has been sitting for a while. All the solids will settle to the bottom and there can be a couple inches of solids on the bottom that are really hard to stir up. I always use a mixing stick to stir so I can feel whats on the bottom of the can.
I missed that. Yep. Looks like a mixing problem.
I would suggest a big tarp to protect the area. Nice patio.
Also, buy some cheap vet syringes to measure. Clean and no waste for tiny jobs.
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Donated 12/27/2018. Plus a little extra.
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HS SB, empennage, tanks, wings, fuse, working finishing kit
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I cannot be, nor will I be, held responsible if you try to do the same things I do and it does not work and/or causes you loss, injury, or even death in the process.
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  #6  
Old 03-01-2015, 08:19 PM
60av8tor 60av8tor is offline
 
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Quote:
Originally Posted by wirejock View Post
I missed that. Yep. Looks like a mixing problem.
+2 if that was a new can and you only used the Mixing Mate, that's your problem - at least part of it. I use a normal paint stir stick, and for a new can it takes quite a while to mix everything that settles on the bottom.
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  #7  
Old 03-01-2015, 08:26 PM
BillL BillL is offline
 
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Quote:
Originally Posted by wirejock View Post
I missed that. Yep. Looks like a mixing problem.
I would suggest a big tarp to protect the area. Nice patio.
Also, buy some cheap vet syringes to measure. Clean and no waste for tiny jobs.
Yep, I fully agree, not mixed. Those mixers will work, but a paint shop might spin it for a while. The color did not show on the cardboard, so definitely not mixed.

Those mixers also have very precise valves and 1/2 oz can be easily dispensed, but to be accurate, use scales - that is what a paint shop does these days. I hate cleaning those syringes all the time.

I would not remove the respirators until the gun is cleaned.
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  #8  
Old 03-01-2015, 11:06 PM
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rdamazio rdamazio is offline
 
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Smile

Quote:
Originally Posted by sprucemoose View Post
Bit hard to tell from the photos, but it looks like the sheet of blue protective covering is still on the parts. That will need to be removed first. Should peel off fairly easily, unless the parts are quite old, then it takes some more effort.
Ah, I think the blue tint is just an effect of the lighting - I definitely did remove it scrubbing the scotchbrite with prekote would probably have made a mess otherwise.

Quote:
Originally Posted by 60av8tor View Post
Interesting - is that 20psi at the gun? I'm guessing your pressure is too low. A pic for comparison:
Yours looks awesome Yes, it's 20psi at the gun, while not spraying - I did notice that the pressure indication goes down significantly when I actually actuate the gun (when air is flowing), I was also assuming that would be normal (static vs dynamic pressure and all that) - should I be adjusting for 20 while spraying instead?

Quote:
Originally Posted by CMW View Post
I would say, after watching your time lapse video, that you didn't stir the Akzo enough. Part A ( the green stuff) needs to be stirred really well especially if it has been sitting for a while. All the solids will settle to the bottom and there can be a couple inches of solids on the bottom that are really hard to stir up. I always use a mixing stick to stir so I can feel whats on the bottom of the can.
Quote:
Originally Posted by wirejock View Post
I missed that. Yep. Looks like a mixing problem.
I would suggest a big tarp to protect the area. Nice patio.
Also, buy some cheap vet syringes to measure. Clean and no waste for tiny jobs.
Quote:
Originally Posted by 60av8tor View Post
+2 if that was a new can and you only used the Mixing Mate, that's your problem - at least part of it. I use a normal paint stir stick, and for a new can it takes quite a while to mix everything that settles on the bottom.
Quote:
Originally Posted by BillL View Post
Yep, I fully agree, not mixed. Those mixers will work, but a paint shop might spin it for a while. The color did not show on the cardboard, so definitely not mixed.

Those mixers also have very precise valves and 1/2 oz can be easily dispensed, but to be accurate, use scales - that is what a paint shop does these days. I hate cleaning those syringes all the time.

I would not remove the respirators until the gun is cleaned.
Aha, thanks!! The contents of the can looked kind of homogeneous, that's why I didn't think stirring that much was needed.
Yes, it was a new can, just removed the hazmat seal a few minutes before - I'll definitely try again and stir it much more this time - I'll report back with new pictures.
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  #9  
Old 03-02-2015, 12:34 AM
Vansconvert Vansconvert is offline
 
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Yes, pull the trigger and then set the psi to 20.
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  #10  
Old 03-02-2015, 04:10 AM
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sprucemoose sprucemoose is offline
 
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Quote:
Originally Posted by rdamazio View Post
Ah, I think the blue tint is just an effect of the lighting - I definitely did remove it scrubbing the scotchbrite with prekote would probably have made a mess otherwise.
Now that I look at it on a full size monitor I see it better. Ironically, I thought the dress was white... No offense meant by the suggestion; you wouldn't be the first new builder to prime over the plastic.
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