Technical Where did I mess up with priming?!?!

Hey all,
About 2 months ago I primed my car using Kirker Enduro Epoxy Primer on bare metal, the Kirker laid down beautifully, I have absolutely no issues.. Then I went ahead and applied filler as needed, got the body how I wanted it, etc.. Over the past couple of days I hit all the primer with 220 grit and then Red Scotchbrite to scuff it, as I was far outside the window. I was very meticulous about cleaning the car and getting all all the residue off.

Yesterday I went ahead and put another couple coats of Primer on. My local paint store was out of Kirker so I went with U-Tech E250 epoxy primer. I mixed it at the correct 3:1 ratio. I set my compressor PSI to about 95, and then my gun to 30. I am using the Harbor Freight HVLP (purple). With this Primer I have a texture on my car, it looks like I Rhino Lined it or something haha. I am man enough to admit the problem most certainly lies in something I induced. I highly doubt this has anything to do with the Primer choice!

The only thing I can think of is that I used a different gun with the Kirker than the U-Tech. My first HVLP said on it "Max 43 PSI", the one I used yesterday said "50-70 PSI". So I initially had it set at 50 PSI and it seemed to be blasting the panels, so I turned it down to 30, but it didn't make a difference.

This was literally the second time I have painted a car, and it may have been just dumb luck that it worked the first time. So please, you won't insult me, break it down Barney level for me. What am I missing, and what can I do to correct it? Thanks!!!

 

Why were you using an epoxy primer, instead of a high build urethane primer, at this point?

 

Thin the paint more, increase air pressure..it's about proper atomization.
Use a scrap panel to test on, making adjustments until it lays out flat.
I've painted several cars, but am not an expert, but that's been my experience.
Hopefully a true expert will chime in.
Good luck.

 

Are you too far away from your work? Sounds like it's drying before it hits the panel.

 

Thanks for the advice!

 

I was maybe 6 inches from it. I don't think I did anything technique wise, differently.

 

I was told at the paint store to put a few more coats of Epoxy over all of it to seal everything up essentially. Like I said, first timer so I trusted what the "experts" told me. They told me to then go over it with a high build next.

 

Just looks a little too dry, sand it and go again.

 

Sand it a bit, and spray the high build over it. Shouldn't be a problem once it has the high build primer over the surface. Looks like it was a little thick, or wrong temp range for the catalyst.

 

What should I sand it with? I was thinking go 220 and Red Scotch Brite again??? Any suggestions for changes to make to ensure it doesn't happen again?

 

With like 220 and red scotchbrite? Or is that to harsh? I need to do this within the 7 day window correct?

 

I run my HF purple guns at 40psi, with the trigger pulled, regulator on-gun.

Static pressure will be higher at the regulator off-trigger.

 

Probably not the cause of the texturing, but avoid mixing brands. I've seen it react and lift like a balloon in fairly large areas.

 

I would let it age for a couple weeks. Then practice your block sanding technique with 200 or 320. Then use some high build on it.

 

As mentioned, it looks like it was to thick. The paint/primer should run off the mixing stick like water. If it is dripping and slow moving it is to thick. Block it down with some 220 and go again. The more you block it the straighter it will be.

 

What's the reasoning for this? Truthfully just asking so I can learn!

 

So go closer to a 3.5:1 ratio? I'm assuming the more prime and less catalyst the thinner it is? Or add a reducer even though it claims it doesn't need one?

 

I'll do some more test sprays too. I fluctuated from 30-40 trying different things and it made only minimal difference.

 

I have never shot anything that did not need reducer, even though it will tell you it does not. Just keep at it.

 

Thin the primer more for that purple gun. I think it is a 1.4 tip. I use a 1.8 tip for 2k primer and a 2.2 tip for epoxy or polyester primer. I only use that purple gun for paint due to the 1.4 tip size. I think primer should not be thinned so I use a 1.8 or 2.2 tip.

As the others have said increase air pressure and thin the primer until you get a good fan, atomization and it lays flat if you continue to use that gun.

If you are watching you budget, as we all are, Harbor Freight has a two gun set, one small and one standard size in a black case. They are sliver with purple cap ring and trigger. The standard size comes with a 1.4 and a 1.8 tip. I use that 1.8 for spot priming if I am not doing a complete car. I bought one set used it then about a year later bought another set.
I have used these two sets for primer for at least 10 years with good success.

 

Mix your primer and catalyst at the required ratio...3:1? Then add reducer to thin the mixture to the required consistency. I just sprayed my hood with epoxy and the can called for a 1:1 primer to catalyst ratio. Make sure to get the proper temperature reducer for your weather area. I use Summit's epoxy primer (rebranded Kirker product) and have never had an issue.

 

oldolds suggested letting it age to give it a chance to harden up real good and "gas out"... that is, to allow the volatile and reactive solvents to dissipate so that it's less likely to react with other products.

He suggested to block sand it to continue developing a good service. Flatten and smooth it, get rid of the texturing, and leave in its place good "tooth" for the next coat to adhere to.

 

That's a good idea, I will look into that too!

 

Reduce the primer. If you're going regular 2K type surfacer next just sand it flat and shoot it. The "7 day window" thing is full cure time. Somewhere in there is the thermoplastic time where it can be coated without sanding. Any good urethane reducer will help smooth the texture out of it but it will run easy too. I'm surprised its 3:1 mix ratio too. Every epoxy I ever shot was 2:1.

 

Thank you for explaining the why! I appreciate the knowledge.

 

So wait out the 7 days, sand it down, and shoot the high build on it?

 

Perfect, thank you for this!

 

So to all...

Is the consensus to just wait out the 7 days, sand it flat, then spray my high build on it?
OR
knock it down and respray some more epoxy on it in the next day or two?

I am leaning more towards the first option, but my impatience doesn't want to wait that long haha!

 

My perception is that paints and primers seem to gas out (and shrink and harden) even more after being sanded... after the surface is broken. I may be mistaken.
But I would likely sand it first, wait a week, some last-minute prep including some light final sanding, then prime it again and go from there.

 

Rickybob answered the question!
Thanks @Rickybop