2K Standard Activator bad

D

dreiher2

Promoted Users
I have a quart of 6520-4 2K primer I purchased late in 2021, along with activator. I opened the activator in Nov. 2021 and used a small amount. I just tried to spray a bumper with the same quart and activator. It is about 85 degrees in my shop. By the time I finished the first coat, the primer was hard in the cup.

I noticed a tiny amount of graininess right after I put in the Activator and started stirring it, but it stirred fine, and there were no lumps or anything.

Does the Activator have to be used up within 2 weeks?

- Don
 
Don asks a good question, there have been some issues with cups.

Bad activator starts to thicken in the can, and will become less effective at activating the primer, not more. So it's not likely to be the activator, although I would say that activators should be used as quickly as practicable after opening, which hasn't been done in your case.

Also the Tech Manual calls for very thorough mixing of the primer and activator before use.
 
Update. My rep suggested I mix up a small amount in a regular plastic mixing cup. I stirred it like crazy for a few minutes. After about 6 minutes it was the consistency of bondo. In another minute or 2, it was like peanut butter. In 10 minutes it was like bondo that needed longer to set.

I am using a 1.8 nozzle on my gun. No way is this a 30 minute pot life. . . right?

I only had 2 minutes to spray before it started shooting out strings.

- Don
 
You have a bad cup.
Get ezmix or USC or majors branded cup like ppg, sikkens, etc.
So activator is fine or primer would still be liquid after 4 hours or overnight.
Sounds like the cup is mixing at leat 2.1 instead of 4.1.
 
I was careful to mix exactly 4:1 each time. The first coat I added about 10% 885 SPI slow reducer. I did it again for the 2nd coat. My test was 1 oz of the 2K in a NAPA mixing cup, and .25 oz. activator, exactly. I think it hardened slower in my small 1oz test without the reducer, by 2 or 3 minutes.

I guess it must be the heat & humidity today. I will try a 1oz test again tonight when it is cooler.
 
At 90 degrees if mixed properly, it will be sprayable for a solid 30 mins.
Reducer added slows more.
Ratios are off or wrong activator.
 
mixing 1oz accurately is extremely difficult. only way can can mix that small of an amount and get it 1/2 way right is to use the little plastic 1oz medicine cups. even then its difficult. you really need to mix 8oz minimum to get it right and the marks on the cup have to be correct as well.
 
Mixing an amount that small doesnt take much for error. It is crazy though that a cup could be far off enough to be 2:1 vs 4:1. You’d think we would notice when mixing but probably not. We just assume the cups are correct. Def not the case! Gonna have to start mixing with chemistry equipment lol.
 
Barry says its not the temp. I trust the guy who makes this. He also says the reducer slows it down. I found that the reducer did not slow it down, but it made it thin enough to get each coat out of the 1.8 tip Concours gun fast enough before it hardened in the cup.

I find it hard to believe there is something wrong with the primer or activator. The labels are correct.

I dug up an old, unopened gallon of SPI 2K primer and 1 qt. Activator and will give them a try.

I will double check my graduations on my mixing cups too to make sure I am getting the ratio correct.

- Don
 
dreiher2 said:
Barry says its not the temp. I trust the guy who makes this. He also says the reducer slows it down. I found that the reducer did not slow it down, but it made it thin enough to get each coat out of the 1.8 tip Concours gun fast enough before it hardened in the cup.

I find it hard to believe there is something wrong with the primer or activator. The labels are correct.

I dug up an old, unopened gallon of SPI 2K primer and 1 qt. Activator and will give them a try.

I will double check my graduations on my mixing cups too to make sure I am getting the ratio correct.

- Don
Click to expand...
The point is that the graduations on certain brands of mixing cups are wrong. The suspicion is that is what is happening here along with trying to mix one ounce of paint…
 
In the tech manual is says to use 2K activator within 30 days of opening. I see where you opened it in Nov 2021. I don't know if this has anything to do with your issue, but it says 30 days. There is an issue with some mixing cups not being accurate and I can agree with that. 16 oz each in a TCP Global cup dumped together in my shop reads 34.5 oz total for 2?
 
FYI for anyone who cares, Crash alluded to it above but I'll repeat it. When urethane activator goes bad it gets thicker, sometimes seedy, (when sprayed it looks like seeds in the primer or clear) and works slower not faster. Faster is indicative of the issue with many of the mixing cups these days. Hi-Teck and 5-Star being the worst of the offenders.
 
unopened gallon of SPI 2K primer and 1 qt. Activator\
Click to expand...
Still be the Same result if your 'measuring device' is wrong. Which will prove the fact of if it is.
Use a Good USA produced Measuring Cup NOT a Paint mixing Cup,and do the mix in Ounces.
34.5 oz total for 2?
Click to expand...
With the World using the Metric System and USA doesn't know 'which' We want, Containers of All types are different volume wise.
Google search 'How many Ounces in a Gallon' and see what you get.
Guess we'll See what happens.
 
I was digging through my SPI boxes, and I discovered this sheet that was included with my order of Activators. I forgot all about it.
I know there is some flexibility with the amount of time the activators are usable. I definitely was planning on replacing the 2K activator for my summer projects. The half pints are pretty cheap and I should have just gotten a couple more.
spi_activators.jpg
 
When mixing small amounts of paint I go to the metric system. It is so much easier working in mili-liters than ounces, the ml is based on 10's and 100's if you get what I mean. I have glass beakers measured in ml that I mix the paint in. The downside is I have to clean out the beaker. I can mix an ounce or less of paint using this system. Naturally this doesn't work for mixing large amounts
 
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