Any last minute advice on spraying metallics?

[Greg L.]

Well guys it's almost D-Day for painting my 69...I'm nervious just thinking about it... I drove down to Montana yesterday to pick up my PPG Cortez Silver lacquer, thinners and a Devilbiss Plus gun, my compressor is almost set up and today I'll finish off on the added lighting in the garage.

As you all may or may not know, I've never sprayed a complete before in a metallic color so I'm looking for some last minute tips or techniques that you guys use that I could apply to try to avoid tiger strips and mottling. Gary Nabors has helped me out a lot over the phone(great guy to talk to!) but I thought I'd just throw the question out there one last time before I actually pull the trigger.

I'm pretty sure that I have the basics in mind but it never hurts to ask again just incase I "missed" something.....right?

[Mike G.]

Re: Any last minute advice on spraying metallics?

Greg: do you have the doors and hood installed? From what I've read, that's crucial with metallics.

In the Eckler's video, Al Sowash paints a mid-year coupe in blue metallic and he alternated directions with each pass: lengthwise and then diagonal and then back to lengthwise.

Did you already do all the jambs like Len did on the yellow roadster? I think that's the best overall approach. I like the DART foam tape to seal off the door/hood gaps.

[Greg L.]

Re: Any last minute advice on spraying metallics?

Thanks Mike.

The doors, hood and headlight doors are installed and adjusted as per factory specs.

I've just recently learned that the doors and hood surround could be sprayed first so no I haven't done that but yes I think I will since you mentioned it.

As it sits right now the car is in grey lacquer primer waiting for a final light sand with 400 and then a wipe and spray of the first coat of color. I'll then let this sit for a few weeks before another light sand and then another color coat.

I've heard of that technique of alternating passes with metallics so I guess it must be one of the tricks. I've also tried to get that DVD of Al's but it's very hard to find and when I do I can't seem to be able to find anyone that want's to ship it to Canada.

One thing I forgot to ask about in my first post was psi at the gun...

Devilbiss recommends for their Plus gun, 25-35 psi for base coat but I assume that this a true modern BC/CC finish and 30-40 psi for single stage.....I'm not quite sure which group lacquer would fall under.

PPG recommends 10 psi at the cap for a HVLP but I have no way to measure that and for a conventional gun they say 30-40 psi for their lacquer.

I see that the proper pressure at the gun for this paint is something that I should get nailed down before I start too.

[Alan S.]

Re: Any last minute advice on spraying metallics?

Hi Greg,
Tomorrow is Sunday. Somehow it doesn't seem appropriate to pray for something as insignificant as painting a car. So maybe pray a 'Prayer of Thanksgiving' for the opportunity to do something you enjoy so much. We are blessed with very good lives.
Regards,
Alan

[Greg L.]

Re: Any last minute advice on spraying metallics?

That is so true Alan. What you said has just put a lot of my "problems" into perspective. We are blessed indeed.

[Mike G.]

Plus Gun Pressure

Coincidently, I just used a Plus Gun to lay down white PPG lacquer (DDL) and I got the best atomization with 32 psi at the gun with the trigger pulled.

I use a mini-regulator at the gun with a 0-60 psi gage for better accuracy. Well worth the $30.

Last suggestion: if you haven't read the tutorial on how to set up a gun, located on the Southern Polyurethane (SPI) website --it's pretty good.

Last, last suggestion: don't get impatient and shorten the flash-off time. In fact, I increase the time by 30% to make sure I don't get solvent popping. Those little craters are a pain to fix!

FYI - I did 3 coats, then waited two weeks and shot 3 more coats. Used just short of 2 gallons of DDL. Have about a quart left.

[Gary C.]

Re: Any last minute advice on spraying metallics?

Greg, know you already have the paint but make sure you got the right size metallic flakes. Most I've seen in the recent past are too large. If you have a question check with Tom Ames. Good luck, Gary....

[Bill W.]

Re: Any last minute advice on spraying metallics?

You need to seal it before the color coat or the color will soften the primer as it soaks in .Lacquer penetrates as it is sprayed. Thats what makes it stick and dry flat without a lot of build. When it soaks into the primer it will bring some of the solvents back out with it. When it is exposed to the sun after all the solvents have dried out in about a year the flatners in the primer could cause the paint to dull out.. In the old days this didnt happen but with the new lacquers it can .A good sealer will prevent this ....Bill

[Steven B.]

Re: Any last minute advice on spraying metallics?

Greg, it has been awhile since I shot a Corvette but just remember take your time and you can't do anything to it you can't fix.

Good Luck and Have Fun!

Steve

[Greg L.]

Re: Any last minute advice on spraying metallics?

Mike- Since you just sprayed some DDL with your Plus gun at 32 psi that is the pressure that I will use too and as luck would have it the Plus gun even comes with a mini regulator. Just a quick question for anyone about the flash-off time...PPG says 5-10 minutes between coats but would it hurt anything to wait even longer like say 20-30 minutes?

Gary- It is supposed to have the correct size flake...(fingers crossed). I did ask and they confirmed that it was the fine flake. The 4x6 color sample card that they sent has very fine flak in it. I really can't see them in the shop but you can once in the sunlight and they are smaller than what you'd see in a modern metallic finish.

Bill- Oh boy...I was told that there was very little if any reason to use a lacquer sealer and that a 2k sealer like DPLF wouldn't likely stick to the lacquer primer any better than a 2k paint. The DPLF also has a warning stating that the lacquer topcoats should be applied within 24 hours of the DPLF sealer or lifting may occur. Since the final topcoat has to be applied several weeks after the initial coat I didn't want to chance it. I even talked to a PPG tech guy about this and he said that it may or may not work so I decided not to use it. Now is there some sealer that you would recommend I use? If I did pass on the sealer would this potential dulling down the road be something that would buff out of the clear or would I be stuck with it?

Steven- This WHOLE project has been quite the learning curve but I couldn't have done it without everyones eagerness to help me. I laughed whe you said "just remember take your time and you can't do anything to it you can't fix.".....some days I think I wrote the book on that one!

One thing I just noticed on the tech sheet is that it says "Note: To avoid the risk of crazing it is best to apply all coats of lacquer in the same day." This conflicts with our "spray a few coats today and a few more in a few weeks" so what exactly is meant by the caution on the PPG Tech Sheet?

[Bill M.]

Re: Any last minute advice on spraying metallics?

One more suggestion: I shot all the fender peaks and edges (doors, hood..) with one coat before I did the whole car coat. I did that because these areas tend to be thin due to the sharp edge. I noticed the painter of the red coupe did the same thing.

In 1980 I shot the whole car in one day (lacquer) and I didn't use a sealer. No problems so far...

[Joe M.]

Re: Any last minute advice on spraying metallics?

As this is lacquer and you will be shooting the car more than once you will have plenty of practise at laying down an even coat. You can shoot the hood and doors off on the first pass and reassemble for the final coats.

Horizontal surfaces and vertical surfaces require different timing and gun position and might impact the spray pattern. Just pay close attention to any differences you might notice when spraying the different surfaces and correct. The lighting is soooo important when shooting those vertical surfaces.

I know you are armed with good information from a lot of knowledgable people so relax and go for it.

[Mike G.]

Sealer?

Yep this is quite the subject of debate on Len's site, isn't it? FWIW, on my Ermine White car, I did use DPLF as a sealer since I wanted a white base to topcoat over, and I also thought it would help seal the lacquer primer from the topcoat solvents. No problems. Would I use it again? Yes, I believe I would.

Definitely agree with shooting extra material on the peaks. And of course, don't color sand on them unless absolutely necessary.

Overall, my biggest lesson learned was that I probably put way too much paint on the car, before getting to the final topcoats. Next time it will just be DPLF (one coat as a telltale), polyprime mostly removed in blocking, and then 2K primer again mostly sanded off. Doubt if I'll ever mess with DZ lacquer primer again.

[Chuck S.]

Re: Any last minute advice on spraying metallics?

...I was told that there was very little if any reason to use a lacquer sealer and that a 2k sealer like DPLF wouldn't likely stick to the lacquer primer any better than a 2k paint. The DPLF also has a warning stating that the lacquer topcoats should be applied within 24 hours of the DPLF sealer or lifting may occur. Since the final topcoat has to be applied several weeks after the initial coat I didn't want to chance it. I even talked to a PPG tech guy about this and he said that it may or may not work so I decided not to use it. Now is there some sealer that you would recommend I use? If I did pass on the sealer would this potential dulling down the road be something that would buff out of the clear or would I be stuck with it?...

DPLF is not a sealer...It is an epoxy primer that serves as a sealer when reduced 1:1.

PPG has other products that are sold exclusively as sealers. Work backwards from the DDL product sheet, and select one that is compatible. I'm surprised PPG Tech Services didn't recommend an alternate sealer when you were talking with them...they may have been reluctant to say what would work in applying PPG lacquer over your existing DuPont primer.

As a way of putting your toe in the water, you might consider painting a small panel as a test before you jump into painting the entire car. This would give you a chance to make changes before you waste a lot of product on the entire car. Given the mix of different manufacturer's products, painting the (primed?) exhaust panel using your plan would give you an idea of the short term reaction between the primer and subsequent PPG topcoats. If the paint doesn't curdle up and fall off in a couple of weeks, then you'll only have to worry about dulling, blistering, etc.

As for DPLF not sticking any better than any other 2K paint, there seems to be something missing in the context there. The author of that statement believes that DDL directly on sanding primer is going to "stick" (and work) better than epoxy primer or any other 2K paint would? You may have had other problems with your plan to use DPLF as a sealer, but I highly doubt DPLF "not sticking" would be the origin. As when applying DPLF, or any coating over any substrate, careful preparation is important...make sure every minute nook and cranny is completely sanded; a lick and a promise won't cut it when it comes to sanding prep.

[Bernie M.]

Re: Any last minute advice on spraying metallics?

can you buff metallics