Contaminant type?

[swamp rat]

Here's a couple of close ups of the same area, one with flash the other without, looking at it close up i'm starting to wonder if this is moisture or chemical contaminant more than dust? what do you guys think? I sprayed within the no sand window. This is single stage urethane. Thanks.

One more question, when getting ready to spray the color should i be wiping the primer down with wax and grease remover? or anything else?

[Foot Stomper]

It's dirt/debris/dust.

Like I suggested before, your gun needs cleaning too.

[Valarius_Starchaser]

Dirt or dust for sure like Foot Stomper said if it was an oil or water there would be a fish eye in that location instead of a bump

Whats your exact process of paint prep step by step maybe we will see an error

[MARTINSR]

It's hard to tell from those photos but it looks more like a substrate problem more than anything. "Contaminant" is way over used in paint failures, WAY over used.

It is all over, every square inch of the surface, and looks like it's "Lifting?" It looks like the paint was applied over something like a 1k aerosol or something like that and the solvents from the paint went through the 1k and lifted it from the substrate under it.

A 1k product applied over a harder surface like a 2k that wasn't sanded properly can do the same thing. Not exactly the same understand as what I see there is kinda odd, not something seen often. That is if it can be seen well, which I don't think it can in that photo.


Brian

[Foot Stomper]

Paint failures are hard to diagnose.
The biggest reason for this is that the painter either by choice or lack of understanding, doesn't reveal everything they did, used or short cuts taken.

Not saying you fall under any of these categories, but paint failure diagnosis is like playing detective. What may seem as "normal" process may in fact be the problem.

In this light Mike, if you want us to really help (which I believe you do) spill your guts. Tell us everything... everything from air pressure, filtrations system, relative humidity, temperature, equipment used, products used, time taken .... everything and anything you used.

Once we have all this, we will do our best to help you have a successful project.

[MARTINSR]

Originally Posted by Foot Stomper

Paint failures are hard to diagnose.
The biggest reason for this is that the painter either by choice or lack of understanding, doesn't reveal everything they did, used or short cuts taken.

Not saying you fall under any of these categories, but paint failure diagnosis is like playing detective. What may seem as "normal" process may in fact be the problem.

In this light Mike, if you want us to really help (which I believe you do) spill your guts. Tell us everything... everything from air pressure, filtrations system, relative humidity, temperature, equipment used, products used, time taken .... everything and anything you used.

Once we have all this, we will do our best to help you have a successful project.

As a paint rep I use to laugh when some guy showed me a failure and I explained exactly what he did like I was watching him through the window the day before! LOLOL I literally saw a look on a few guys faces like I was some sort of warlock or something! LOLOLOL

I would hear "Bad batch" often, then I would show them exactly what THEY did to cause the problem. I would get a call and without even going knew exactly what they did. But I would go there anyway and after showing them what they did wrong give them some free clear or something anyway. But it was amazing how many times this happened.

Sometimes the guy honestly didn't know what he did, other times they did and were just trying to cover their butt with their boss, or get free stuff out of me. One was microscopic white specs in a black paint job. The second I saw it under a little handheld microscope like tool I had (bought it on my own) I knew were they came from. I walked into the booth to see that the white paint around the filters was pealing off! LOLOL Yep, application was the problem 99.999% of the time.

Now me personally, I WANT to know what I did wrong! I WANT to learn, not all are like that.


Brian

[swamp rat]

Ok guys, give me a chance here to write it all up, i can spill my guts no problem but when I'm away from the computer its kinda hard to do that, my account stays logged on 24/7 at home but dosn't mean i'm there, i'm not hiding i just have a sometimes busy life.

In advance i am a rookie and this is my first paint outside of a rattle can. I have posted here a number of times with my equipment and other questions plus i have been posting in my build thread, but i'll dig up all the info i can asap. Just started work...

[Foot Stomper]

Brian, your stories kill me with laughter!! HAHAHA!!

At the risk of derailing the OP thread....

One of the funniest experiences I had was when a customer had called to complain that the clear was "too runny"... he had just finished spraying a Toyota 4Runner..."too runny?" for a 2:1 Euro Style high solids clear??? Now what on earth could he have done to make it "too runny"... went through the regular Q&A about reducer, temp, time between coats... then had to ask "how much clear did you use?"... "all of it" was the reply!!!!.... He used all 7 liters or 2.5 gallons of clear on a Toyota 4Runner!!!!

So you just never know what's happened sometimes until all the questions are asked!

[swamp rat]

Built a small paint booth, yes its cramped, I started building a push air booth thinking positive pressure was what was needed but I was corrected to now am pulling the air thru, i have 2 20"x20" intake filters and 1 20"X20" box fan and exhaust filter, on high i can feel the draft on the back of my hand standing in the middle of the booth, the part has been pretty consistent temp of 69.5 to 72 degrees ether side taken with my inferred thermometer, i have a couple small heaters outside the booth to channel heated air into the booth as needed.

MY build thread
http://67-72chevytrucks.com/vboard/s...595019&page=39

I primered the whole fender but only sprayed color on the inside of the fender, masked off the outside. I primed 3 coats

I wiped down the walls and floor with a damp cloth before i sprayed color.

The info data sheet for the primer is posted in this thread,
http://www.myrv14.com/buildlog/20160...rimer-9-13.pdf
http://67-72chevytrucks.com/vboard/s...d.php?t=707029

I have PPG DP50LF 2K primer, DP402LF catalyst, the info sheet stated 1 week between coats maximum or you have to sand, i did 3 coats with about 24 hours apart, didn't sand between coats or before the color. This is probably my problem (my uneducated guess)

My paint is PPG DCC that is a Urethane base mixed 4:1:2 using DP402LF and DT870 mid temp.

So my questions and uncertainty are as follows, do you still recommend sanding between primer coats even if under the time frame?? also before color coats? also do you use wax and grease remover after sanding? something else?

My equipment: Quincy 80 Gal air compressor, to a small manifold with water traps and drain valves, to 2 water separator/filters in tandem, to a pressure regulator set at 70Ft lbs, to 100' of hose, to an inline desiccant dryer, to another 50' of hose, to my cheapo harbor freight pressure regulator set at 20lbs to my HPLV (purple spray gun)

[MARTINSR]

I am not sure I understand. You primed the whole fender, then sprayed paint on the inside of the fender, then primed outside three coats?

The only thing so far is did the paint on the inside go past it's recoat window?

Looking at the photos on my home computer with a little better monitor it really looks like unsanded primer, did you level the primer before you sprayed the paint?

Brian

[MARTINSR]

Originally Posted by Foot Stomper

Brian, your stories kill me with laughter!! HAHAHA!!

At the risk of derailing the OP thread....

One of the funniest experiences I had was when a customer had called to complain that the clear was "too runny"... he had just finished spraying a Toyota 4Runner..."too runny?" for a 2:1 Euro Style high solids clear??? Now what on earth could he have done to make it "too runny"... went through the regular Q&A about reducer, temp, time between coats... then had to ask "how much clear did you use?"... "all of it" was the reply!!!!.... He used all 7 liters or 2.5 gallons of clear on a Toyota 4Runner!!!!

So you just never know what's happened sometimes until all the questions are asked!

One of my favorite memories on the subject was at the time a headache and a half, he was my no. 1 "Freelance engineer." He would use accelerator and retarder in the same paint! He drove us nuts. Once he had a complaint of a failure. I went out there and sure enough, the truck he painted came back a few months later with some bird crap eating it big time. So I did a solvent rub test and sure enough, it had no resistance to the thinner rag at all. Hmmmm, I walked over and did the same test right in front of the guy on a tail gate I had painted in the shop about a week before and nothing to it! I could have poured a gallon of thinner on it and rubbed it with a thinner soaked rag and did nothing!

He still gave me crap that it was a "bad batch" or something.

Another time he painted a boat trailer, the clear failed on it, peeled off the base as I remember. He gave me some story about how it was done by the book. While I was there the owner of the trailer came in and I put on my Police badge and questioned him. I asked about the pin striping, "That looks awesome, who did you have do it?" I asked, it was some guy in another city and I asked about when it was done, "cool" I said. The owner told me clearly how he had painted the base, and then over a week later painted the clear over the top of the stripes, yeah, went over the re-coat window.

Damn that guy was a pain!

Brian

[swamp rat]

Originally Posted by MARTINSR

I am not sure I understand. You primed the whole fender, then sprayed paint on the inside of the fender, then primed outside three coats?

The only thing so far is did the paint on the inside go past it's recoat window?

Looking at the photos on my home computer with a little better monitor it really looks like unsanded primer, did you level the primer before you sprayed the paint?

Brian

Sorry.

I primed the fender front and back 3 coats total. 1st coat, wait 24 hours, 2nd coat, wait 24 hours, 3rd coat, wait 24 hours. I did not sand between primer coats. Then i masked off the outside of the fender and did the same with the color, first coat, wait 24 hours, 2nd coat, wait 24 hours, then took pictures...

No i did not sand the primer before the color. i got mentally stuck on the primer pdf telling me i didn't need to sand if the coats are sprayed within a week.

So knowing my products do you recommend sanding between coats?
Use wax and grease remover after sanding? followed with a clean damp cloth after that?

I think i need a process that i can adhere too.

[swamp rat]

Originally Posted by Foot Stomper

It's dirt/debris/dust.

Like I suggested before, your gun needs cleaning too.

Cleaned, re cleaned and cleaned again. All the teflon paste was removed prior to use.

[Jaysonb]

Are you tacking it off before you spray? If your not sanding the primer, why are you putting 3 coats on? Why are you waiting 24 hours between coats? Prime, let flash, paint. No worries about the recoat window.

[Valarius_Starchaser]

Originally Posted by swamp rat

Sorry.

I primed the fender front and back 3 coats total. 1st coat, wait 24 hours, 2nd coat, wait 24 hours, 3rd coat, wait 24 hours. I did not sand between primer coats. Then i masked off the outside of the fender and did the same with the color, first coat, wait 24 hours, 2nd coat, wait 24 hours, then took pictures...

No i did not sand the primer before the color. i got mentally stuck on the primer pdf telling me i didn't need to sand if the coats are sprayed within a week.

So knowing my products do you recommend sanding between coats?
Use wax and grease remover after sanding? followed with a clean damp cloth after that?

I think i need a process that i can adhere too.

Two problems I see is

1. Not sanding the primer before spraying color whats your reason for not doing so? In my process/experience the primer is always sanded to make the paint surface as flat as possible then that is sealed and then the sealer is painted with color. (I know some guys on here don't even use sealer) I'm also wondering why you are doing 3 coats with no sanding my max before I sand would be two good medium wet coats which I spray at the same time not waiting 24 hours

2. Why did you wait so long between coats of color and whats the exact product you are using? In my experience most colors will have a 24 hour critical re-coat time (that I'm afraid to even take to a 12 hour re-coat time personally)

[MARTINSR]

I have the same questions as him ^^^

Not sanding primer before paint! THAT is just the answer to the odd texture you have in your photos. I am not kidding you, I thought that after seeing it here on my home computer where I could see it better, but dismissed it because I never dreamed you would paint it over unsanded primer.

THAT is what would cause that look, but even then, not just unsanded primer but unsanded primer that was shot very dry. That texture is from spraying it very dry.

The only time you would spray paint over unsanded primer is if that primer was something like an epoxy primer, and that would be on a frame or something like that. Spraying a frame that has been sand blasted with an epoxy primer, then within the re-coat window spray the paint over it, that is an awesome way to paint a frame. But that is with a specific primer designed as a "primer/sealer" not a urethane or filling primer.

A filling primer needs to be sanded, no matter who sprays it.

This is my car just prior to rolling it in the booth and painting it. It is sanded urethane filling primer, a tintable primer, that is why it looks so red.



And after paint.



Brian

[swamp rat]

Ok, so big rookie mistake, won't happen again, as i mentioned before i never got past a rattle can.. The PDF mentioned a recoat no sand window so i assumed i didn't need to sand.

Why wait 24 hours? because that is the time window i have available to lay a coat of paint, 1-2 hours before work.

I used 80 grit on a DA for sanding to bare metal, then wiped it down with wax and grease remover, then the first coat of primer.

I could still use a process to follow for part prep:

What grit would you sand with between coats of primer? would you use the same grit between paint color coats?

After sanding do you use more wax and grease remover? After wax and grease remover do you use a damp cloth like the PDF mentioned? Or just a Tack cloth?

[Valarius_Starchaser]

So you're going from bare metal to primer without any sort of an adhesion promoter or is your primer a DTM (direct to metal) product? this could cause later adhesion problems as well as waiting the full 24 hours between coats of color

You should be able to lay all your coats of color on that panel back to back and then be done with it

for sanding on the primer I use 320 grit on a block (400 could be used as well)

After sanding clean with an air blow gun to get dust out of the bolt holes and cracks then use wax and grease remover THEN us a tac cloth to remove any small particles the rag left behind

[MARTINSR]

Please understand that I am not beating you up for spraying that paint over the unsanded primer, it's all a lesson and I don't mean any disrespect.

I can't make it clear enough, home hobbiests do the most amazing work! From my experience the best cars at the car shows are done by home hobbiests! I am talking even the first car they ever did and it's main arena custom car show quality!

I have seen it over and over and over throughout the years, and I love seeing it and chatting with the guy to find out he is an accountant and he built the car in his one car garage!

Check out this one, the second post on this thread. He is a carpet layer! http://www.hotrodders.com/forum/toda...ol-432905.html

It's like I always say, if you break it down into small enough steps you can do anything!

Anyone who does this stuff in their spare time at home has all my respect, I just wanted to make sure you understood that.

Brian

[Valarius_Starchaser]

I agree with MARTINSR we aren't trying to beat anyone up for anything just want to get to the root of the issue and make it right so you and anyone else having a problem like this can fix it and get the best results because

I genuinely believe you are the best person in the world to build your truck for one simple reason it has the most value to you and you care about it the most not some other guy in a shop to whom its just "another job"

[MARTINSR]

I have a minute to just go over a few basics.

"Flash time" is how long you leave a product like primer before the next coat. It's the solvents "flashing" off leaving the primer as it cures (or dries if you are spraying a 1k without hardener).

Applying the next coat, or the next product like paint or clear too fast is VERY VERY bad and without a doubt 99-1 the most common reason for failures and problems, people pushing it too fast and trapping solvents.

So that being said, leaving a good flash time is a very good thing to do. But it can be too long too and the top of the film gets too hard not allowing the next coat or product to adhere. Follow the manufactures recommendations for flash time and you will be ok.

Cleaning with wax and grease remover is a good thing of course, but be sure it's flashed off completely and not trapped in cracks or scratches or it can cause you trouble, just be careful, wipe with a clean dry rag or towel and be sure it's all gone.

Some primers don't like being sprayed over bare metal, just be sure that is in the manufacturers guidelines as a "suitable substrate."

If you were to spray two coats of that primer leaving a flash time of an hour or so, that "should" be plenty depending on the metal temp and how wet you are applying it. You don't want to apply too wet under any circumstances as the top can glaze off and trap solvents. But it looks like what you have done is pretty dry so that's not an issue. But waiting 24 hours for the next coat isn't the end of the world as long as it's ok on the tech sheet (or call the tech line, they really want to hear from you so you use the product right!) and between coats, a red scuff pad is still recommended if you ask me after waiting that long. And the scuff pad is way easier to get into nooks and crannies.

Brian

[swamp rat]

http://www.custom-aerosol.com/pdf/pp...duct-sheet.pdf

My PDF link for the primer was bad....

So according to the PDF

Bare metal sand with 80 grit, painted surfaces sand with 320-400.
Blow down,
Wipe down with wax and grease remover.
Wipe down with a damp cloth.
Wipe down with a tack cloth.
mix primer, spray one coat
wait 10-15 minutes and re coat,
Let sit over night, sand with 400 grit.
Blow off,
Wipe down with wax and grease remover
Wipe with a damp cloth,
Wipe with a tac cloth.
Re-Prime.
Wait 10-15 minutes and re-coat,
Wait 24 hours
Sand with 320-400.
Blow off,
Wipe down DX cleaner
Wipe with damp cloth, soap and water
Wipe again with DX cleaner
Spray color
Wait 10-15 min and re coat.
Wait 24 hours and surface sand
Blow off,
Wipe down DX cleaner
Wipe with damp cloth, soap and water
Wipe again with DX cleaner
Spray color
Wait 10-15 min and re coat.

[Valarius_Starchaser]

My concern here is that you applied the DPLF overtop of bare steel when is states it can be applied to 1.2-1.5 mils of DPLF OR DX1791/1792

I'm an Axalta man but it appears to me as this product is NOT meant to be applied directly to steel just like the products Axalta makes

The problems that could happen are lifting of the primer which didn't happen here (lucky maybe) but it will make the product layed over it and itself very easily scratched/chipped

If you drive around and see plastic front bumpers with hundreds of small rock chips all over them and large pieces peeling off it is 99% of the time attributed to not using the proper adhesion promoting product before applying a primer/surfacer

On another not the amount of times you need to re-coat a primer is dependent on weather you have any imperfections left on the panel some sections may take 3-4 coats other just the one but having a good layer is never a bad thing to a point of course

I hope none of my ramblings are confusing

[Foot Stomper]

Originally Posted by swamp rat

http://www.custom-aerosol.com/pdf/pp...duct-sheet.pdf

My PDF link for the primer was bad....

So according to the PDF

Bare metal sand with 80 grit, painted surfaces sand with 320-400.
Blow down,
Wipe down with wax and grease remover.
Wipe down with a damp cloth.
Wipe down with a tack cloth.
mix primer, spray one coat
wait 10-15 minutes and re coat,
Let sit over night, sand with 400 grit.
Blow off,
Wipe down with wax and grease remover
Wipe with a damp cloth,
Wipe with a tac cloth.
Re-Prime.
Wait 10-15 minutes and re-coat,
Wait 24 hours
Sand with 320-400.
Blow off,
Wipe down DX cleaner
Wipe with damp cloth, soap and water
Wipe again with DX cleaner
Spray color
Wait 10-15 min and re coat.
Wait 24 hours and surface sand
Blow off,
Wipe down DX cleaner
Wipe with damp cloth, soap and water
Wipe again with DX cleaner
Spray color
Wait 10-15 min and re coat.

Soap and water isn't mentioned in the tech sheet when I read it. Normally soap and water is not part of today's painting processes. I believe it reads more like wiping it down with a damp cloth containing wax and grease remover. I'd skip the soap and water for sure.

A tac rag is going to be one of your best friends too.

The other guys posting here have my vote 100% on all points of encouragement and advice given.

Keep trying to perfect it and you'll look back and feel awesome you did it!

Cheers!

[hugger6933]

The DPLF is also known as the epoxy primer. It is the primer to use over bare prepped metal, But I would after the two to three coats scuff it to knock down all of those little boogers that are plaguing you on this fender. I also would not consider applying base coat right over the DPLF I would use a MP282 high build. Two to three coats sprayed with about fifteen mins of flash time in between and add some MR186 reducer [up to 2 parts] to aid in flow from the gun[and it also helps smooth the primer] . After that has dried sand with 400 to 600 grit paper [400 if solid colors 600 if it has metal flake]. Now it also looks to me like the gun may have not been taken apart and cleaned between uses. How can I tell that? well I know what it looks like when the gun isn't cleaned and that is why I take apart my guns EVERY time anything is put in them. No matter if I spray out a spot of primer the size of my hand I take apart the gun and clean it up. It only takes just a min to disassemble and clean.
You will have quite a few imperfections in the surface even after three coats of epoxy. But those same spots will disappear like magic after three coats of high build. Good luck and happy sanding. Jim