DanNiendorff
Well Known Member
Hi All,
Ealy in my 14A build here and looking for ways to improve my process. After looking over all the options, I've decided to prime as follows:
1) Subtructure Parts -
a) Alumiprep Dip then rinse
b) Alodine Dip then rinse
c) Akzo prime
d) dimple
2) Skins (Internal Side only)
a) Scuff
b) Acetone wipe until clean
c) Akzo prime
d) dimple
I needed to answer several questions to make my process the most efficient...
Question #1:
Akzo recommends a single wet coat to a thickness of 1.0-1.3 mils. As a novice painter - what does that look like?
Question #2:
Akzo has an induction time of 30 minutes - recommended (not required). Does the induction time improve the final product for my purposes? Or should I just go ahead and shoot it.
Question #3:
The Akzo tech datasheet says it is 'dry through' at 4 hours, and does not list a cure time. It does list a topcoat window of 1-48 hours. Which makes me think it is fully cured at 48 hours. It looks like common practice is to wait about 12 hours prior to dimpling. What is the minimum time to dimple?
I did an experiment to answer these questions. I set up two groups of aluminum coupons, which were all treated alumiprep dip/rinse then alodine dip/rinse and air dry. Once dry each coupon was marked with an "x" in sharpie. I set out each group of coupons in a line and sprayed a very light (airbrush) coat along the entire line. Then repeated the light coat along the entire line, excluding the first coupon. Then the second, third, etc..... So that the first coupon had a single light coat, and the second had two, the third had three, etc..... I did this with the first group of coupons without the 30 min induction period, and the second group with paint that had undergone the 30 min induction time.
I measured the mil thickness of each coupon (using Carsys meter), in order to establish a visual reference for myself while spraying to achieve the proper thickness.
I also sprayed a strip of aluminum (same prep steps) with each group, and dimpled it at intervals after spraying to see at what point dimpling could be done, and if the 30 min induction changed the interval necessary.
Here are the results:
I think my experiment answered my questions as follows:
#1 - Thickness visual measure achieved. Hopefully, the pic can help someone else with this and save them repeating the experiment.
#2 - It does look like the induction time lead a more consistent spray thickness over the spread of the coupon group (although It could also have been my technique). It also looked like the final dimple kept better coverage in the induction group. I scratch tested the coupons that fell in the proper thickness range for the induction and non-induction group and could not tell any difference. So it looks like 'recommended' improves some things in the final dimple. And I would use it if I were planning to dimple after priming, however.....
#3 - I found that dimpling after priming will lead to splitting of the primer even after the full cure time. It decreases over time. Here it is early after priming...
And then after 24 hours of cure......
So from this, I conclude that if dimpling after priming it would be wise to use the 30 min induction, and wait at least 24 hours (or more) prior to dimpling if the akzo will be the only protection. However I'm considering using an Alodine 871 Touch-Prep treatment to the hole after dimpling to ensure that areas of primer distortion are protected from corrosion. I imagine this is not a surprise to anyone with experience in this. But I thought posting my data points might help someone without the experience, such as myself.
Ealy in my 14A build here and looking for ways to improve my process. After looking over all the options, I've decided to prime as follows:
1) Subtructure Parts -
a) Alumiprep Dip then rinse
b) Alodine Dip then rinse
c) Akzo prime
d) dimple
2) Skins (Internal Side only)
a) Scuff
b) Acetone wipe until clean
c) Akzo prime
d) dimple
I needed to answer several questions to make my process the most efficient...
Question #1:
Akzo recommends a single wet coat to a thickness of 1.0-1.3 mils. As a novice painter - what does that look like?
Question #2:
Akzo has an induction time of 30 minutes - recommended (not required). Does the induction time improve the final product for my purposes? Or should I just go ahead and shoot it.
Question #3:
The Akzo tech datasheet says it is 'dry through' at 4 hours, and does not list a cure time. It does list a topcoat window of 1-48 hours. Which makes me think it is fully cured at 48 hours. It looks like common practice is to wait about 12 hours prior to dimpling. What is the minimum time to dimple?
I did an experiment to answer these questions. I set up two groups of aluminum coupons, which were all treated alumiprep dip/rinse then alodine dip/rinse and air dry. Once dry each coupon was marked with an "x" in sharpie. I set out each group of coupons in a line and sprayed a very light (airbrush) coat along the entire line. Then repeated the light coat along the entire line, excluding the first coupon. Then the second, third, etc..... So that the first coupon had a single light coat, and the second had two, the third had three, etc..... I did this with the first group of coupons without the 30 min induction period, and the second group with paint that had undergone the 30 min induction time.
I measured the mil thickness of each coupon (using Carsys meter), in order to establish a visual reference for myself while spraying to achieve the proper thickness.
I also sprayed a strip of aluminum (same prep steps) with each group, and dimpled it at intervals after spraying to see at what point dimpling could be done, and if the 30 min induction changed the interval necessary.
Here are the results:
I think my experiment answered my questions as follows:
#1 - Thickness visual measure achieved. Hopefully, the pic can help someone else with this and save them repeating the experiment.
#2 - It does look like the induction time lead a more consistent spray thickness over the spread of the coupon group (although It could also have been my technique). It also looked like the final dimple kept better coverage in the induction group. I scratch tested the coupons that fell in the proper thickness range for the induction and non-induction group and could not tell any difference. So it looks like 'recommended' improves some things in the final dimple. And I would use it if I were planning to dimple after priming, however.....
#3 - I found that dimpling after priming will lead to splitting of the primer even after the full cure time. It decreases over time. Here it is early after priming...
And then after 24 hours of cure......
So from this, I conclude that if dimpling after priming it would be wise to use the 30 min induction, and wait at least 24 hours (or more) prior to dimpling if the akzo will be the only protection. However I'm considering using an Alodine 871 Touch-Prep treatment to the hole after dimpling to ensure that areas of primer distortion are protected from corrosion. I imagine this is not a surprise to anyone with experience in this. But I thought posting my data points might help someone without the experience, such as myself.