First time spraying Metallic - quick check

[Grrrmachine]

I just want to confirm that I understood the technique for spraying 2k metallic, before I go out and ruin a panel. Test panel is a sunroof, wet-sanded with 600.

1) Spray one coat, not too wet but not too dry, in a single direction with 50% overlap
2) Allow to flash off (15 minutes)
3) Spray second coat exactly the same as the first
4) Allow to flash off (15 minutes)
5) Spray mist coat at angle to original coat
6) DO NOT TOUCH the metallic coat. No sanding, flatting or tack clothes.
7) Apply two light coats of clear. Allow to flash.
8) Apply two more heavier coats of clear.
9) Wait up to a month before doing any polishing, buffing or waxing.

What I'm not sure is, how much time do I have between spraying the base and the clear? Some places I'm told I MUST wait 30 minutes, to let solvents out, other places say no more than 45mins otherwise the flakes settle too much.

 

[steveo3002]

6 ..you can use a tack cloth if theres any dust specs in it...use it with light pressure only

7/8 what kind of clear are you using

 

[Grrrmachine]

The clearcoat is a 2k acrylic. The primer, base and clear all come from a local (to me) manufacturer, Profix.

I'm most worried about the timings between coats; my eagerness will make me want to slap one coat straight on after another, but I know I need to slow down to let the solvents out... but how long?

 

[steveo3002]

as a rough guide 10-15 mins between the first and second coat , its not so much time as when its flashed off

keep touching a bit on the masking paper , when it doesnt come off on your finger its ready for the next coat

can be nearly instant on a warm day or 25mins in winter

 

[Grrrmachine]

That's a wicked tip, thanks very much.

Having only one gun, I'll have to take it apart and clean it between the base and clear, so that'll give me some time anyway.

 

[steveo3002]

yeah , also just observe the way it looks , when its fresh from the gun it will look darker and wet , maybe patchy if you went heavy in certain areas ....as it dries out the patches will fade and the surface will look dull all over , if theres any wet patches wait longer

infact waiting a few mins longer wont cause any problems

 

[Raf]

waiting longer is better. get the tech sheets for the paints and it will advise flash times (depending on temps and remember they assume you have a booth so its safe to add to that time if you dont have one). these sheets are a must.

i would wait longer before clearing as you can cause more issues not waiting long enough. not sure about the flakes settling too much after 45 mins? not heard that before; you could disturb them if you tack heavy but even a light tacking wont move them so im not too sure if that advise is correct? tech sheets explain all as some paint systems are different.

hth

 

[steveo3002]

flakes wont settle too much , the only reason you need to consider the timing is that if its left forever the clear might not stick so well

30 mins - 1 hr will be no probs

 

[Ducati]

waiting longer is better. get the tech sheets for the paints and it will advise flash times (depending on temps and remember they assume you have a booth so its safe to add to that time if you dont have one). these sheets are a must.

i would wait longer before clearing as you can cause more issues not waiting long enough. not sure about the flakes settling too much after 45 mins? not heard that before; you could disturb them if you tack heavy but even a light tacking wont move them so im not too sure if that advise is correct? tech sheets explain all as some paint systems are different.

hth

One thing that may happen with metallic when being a bit impatient for the base to dry, more so on vertical panels, especially when new to spraying with 2K, is that the thinners in the 2K lacquer can soften the base slightly allowing the flakes to drift slightly down the panel and at a different angle to the rest ot the flakes especially on edges, sometimes not noticeable till the lacquer is on and the panel is viewed from different angles

 

[Grrrmachine]

Well, I sprayed three panels in the end, and they all came out with a good finish and well distributed flakes. I was a bit overeager and got a big run in the clearcoat on one panel, but overall I'm satisfied. Data sheet said 15 mins, I gave it 30, and it all came out good.

 

[langy]

You should be sanding with 800 for COB, 600 for straight paint.
If you get the spec sheet it will tell you how long you can leave before clear coating, It will depend on make but some allow you a 36 hour wndow.

 

[Grrrmachine]

I did ask about the sanding grade on another forum (click here for details) and they said 800 was overkill. I used 800 for the bonnet, taking no chances, but used 600 on the wing I did the same day, so we'll see how it comes out.

I now have to flat out the nibs and use a polishing compound to shine it all up, so that'll be the final stage.

 

[langy]

It all depends on what standard of finish you want mate, my standards are probably higher than others as i look for as perfect a finish as i can get as the cars i work on are not cheap.
With straight colour it will fill in any tiny scratches as it has more body to it whereas basecoat is thin and will show tiny scratches and has no body to it, Pretty obvious if you think about it.

I did ask about the sanding grade on another forum (click here for details) and they said 800 was overkill. I used 800 for the bonnet, taking no chances, but used 600 on the wing I did the same day, so we'll see how it comes out.

I now have to flat out the nibs and use a polishing compound to shine it all up, so that'll be the final stage.

 

[Grrrmachine]

Yeah, I've read the pros and cons on both methods, and certainly I appreciate the level of detail and hard work you pro's put into it. For now, I'm on a pretty steep learning curve already, it seems (spraying a black metallic), so I'm learning how to correct all my flaws as I go.

Fools rush in and all that, it seems.

 

[langy]

Yes for black your panels need to be gun barrel straight.

Yeah, I've read the pros and cons on both methods, and certainly I appreciate the level of detail and hard work you pro's put into it. For now, I'm on a pretty steep learning curve already, it seems (spraying a black metallic), so I'm learning how to correct all my flaws as I go.

Fools rush in and all that, it seems.

 

[Grrrmachine]

So what should I be using to bring back the gloss, after rubbing down with 1000 wet? Just finer papers and lots of elbow grease?