The Spray Painting Thread

[o_man_ra23]

Cuzzo, the iso-free 2k paint on my front spoiler and BMX looks a million bucks. They haven't been subjected to any real UV yet, so can't comment on longevity. Perhaps a good coating of quality wax afterwards will help maintain the gloss level without having to polish (polish removes paint, wax adds a protective coating)

[trd_st184]

Is there any direct risks to sanding 2 pac paint thats been previously painted?

["Z" UTE]

Hi,

Car turned out great that advice worked very well am surprised of the result with just cans, just some annoying overspray dust but hope that should come off with some 3m... Q... Should I use 3m compound to get rid of this overspray on areas that I didn't want it to get on, like it's overspray that got on my GOOD factory clearcoat so im thinking if i use sandpaper I might dig into the clear in attempt to remove the overspray dust, I recon 2000 wouldn't really dig into it but better safe than sorry since I'm getting some 3m stuff as yes my kitten is like wet beach sand.

Just use the 3M to remove the overspray.

More painting done today, I was painting the black frames on my tail lights which had faded. I only had Matt black the Australian Export cans which were Enamel, and I had my U-POL Acrylic clear, so that is why I had to use acrillic over Enamel today in order to get a gloss. When i sprayed the clear coat on i noticed it went pinholy but then pinholes slowly went away maybe one or two stayed, Q...is this a sign of frying or incompatible paints etc or not?

Q... Now that the Acrillic clearcoat has dried ok over the Enamel paint, does this mean all is well or will I just have to wait and let time tell if the paints are incompatible? Months, years?


The Upol laquer probably does not have bitey thinners in it, so sounds like you did OK.

Bit of talk about pearls Micas back there, I'm getting the notion that you cant use pearls/micas/metallics in a 2k system, but only one colour paints? Q... So do you have to use Enamel or Acrillic if you want metal specs in your basecoat or can it be done with 2k aswell?

You can use pearls in a 2K system, they can be in a 2K basecoat, but are more commonly mixed with the 2K clear. Metalized paint will have to be 2k basecoat, as the usual 2K colours are solid colours, and will simply swallow/encapsulate those types of additives, you would never see them again.

Next project is a Celsior with some small chips on the front bumper where somebody has tried to use a paintbrush to touch it up, I hope to get rid of that and try do a blend in here. Q... Can i use normal automotive bog on the plastic bumper or is there special plastic auto bog and whats so different about the plastic bog that differs from normal one.

Q... Some repair guides state hitting the chip lightly with a screwdriver to get any lose bits around it to chip off until i cant get anymore to chip off before doing repair, should I do this?

Q... Do i need to spray prime over the bog i place over the chip or just sand with 800 and spray over?

You need to remove any loose particles and any cracked paint. Chip it out, grind it out, sand it out. I use PPG microfine filler, it works on steel, on paint, and on plastic. You must prime over any bog, you must also plastic prime over any plastic. The plastic primer will work on the PPG filler, and the other colour on the bumper, as a primer.

cheers Chuck.

ps. Just typed all this without the glasses, apologies for any mis spelling

[o_man_ra23]

Is there any direct risks to sanding 2 pac paint thats been previously painted?

That's a good question. Although I don't have a direct answer, I do have some more detailed questions/hypotheses which would help the thought process.

Do the Isocyanates evaporate or chemically bond during the paint curing process? This would make the cured paint more than likely safe.

When selecting a mask for painting, it is the particle size which makes the Isocyanates near impossible to filter out. Once part of a cured paint, the dust from sanding will be a much larger particle size. So a quality respirator (about $60 should get something worth having for this purpose) should filter these particles out safely. If this is correct, then there are no longer free organic molecules floating around to harm you.

[Z2TT]

Chuck but if the pearls are put in the clearcoat, then wouldn't subsequent polishing over the years wear the micas down and make the finish look uneven in the place of polishing?

I remember having a chat with the paint store and they said with metallics pearls micas you have to have them in the basecoat and have a clear topcoat so when your polishing you dont rub any of the pearls/micas away.



So I take it from your comments about the plastic bumper, you cannot use normal bog but have to use plastic bog, is this for flexibility?

["Z" UTE]

Basecoats can contain pearls metallics, and mica's, when this is done, the clearcoat is left alone. An example of these types of paint would be colours like the current Holden blue, and green. The pearls mica's and mettalic are used to refract the light in different ways, effectively altering the visible colour of the paint.

A great majority of pearls are in a clear coat, followed up by a top coat of clear without any additives. You would spray a minimum 2 coats of clear, so putting the pearls in the first clear coat is the way to do it.

A white basecoat would not show a pearl effect if blue pearl was added, but when the blue pearl is added to the first coat of clear the effect is blue pearl over white.

The Stitt's Crown for example has a basecoat of white, a white pearl coat, and a clearcoat over the top, effectively making it a 3 layer paint job. If the pearl was added to the white basecoat, it would not be visible.

Some paint suppliers will try to tell you to use a flip controller as the carrier for pearls or candy, bzzzt, do not use them, these flip controllers do not adhere to a base coat as well as a clearcoat would.

All 2 part body fillers are plastic, so you can use the 2 part fillers (bog) on a bumper. The spot filler, or blade fillers that do not come with a hardener are not plastic, and should not be used for this type of repair. These types of putty's are effectivel paint solids, with a very small amount of thinners to make them pliable. I have not used them in over 10 years, as I have found the microfine fillers do a far superior job, without the shrinkage hassles.

To clear up a point of confusion 2pak paints are supplied in either a 2 part colour, where a hardener is mixed to activate the paint, or a 2 part clear, again a hardener is used to activate the "paint". 2pak primer is also supplied with the primer and the hardener. However, a basecoat for a 2pak paint job will not come with a hardener, it does not use a hardener, it is called 2pak basecoat because it goes under a 2pak clear.

cheers Chuck.

[kremsra28]

chuck, you are a wealth of knowledge, same to you o man ra23, and a few other on this thread, its great to read!!

i painted my s1 rx7 quite a few yrs ago with a 3layer pearl job in acrylic, it was pure red tinter with a lilac pearl over the top which was mixed partly with clear, then clear coat over the top, i did a test panel with the pearl mixed in the red and as chuck said, it dont come thru, i put heaps of pealr in and the results were pretty poor, when it was applied over the red, it was great, like applying candy, i could choose on wat the effect i was looking for which is below, this was the 3rd car i had ever painted and learned just by reading books and asking friends in the trade, that s why i love this thread, i have learned so much more by reading this, keep up the great advice guys,



sorry bout the big pic guys, i couldnt figure out how to resize it in photobucket, if some 1 could tell me that would be great

krem

[pac]

there are plastic fillers specific for plastic bumpers, which have more flex but normal filler is fine as long as you first use plastic primer and on the more ridged part of the bar cover

[Z2TT]

Have just been going through the House of Color products, and they sell Acrylic Urethane, what is Acrylic Urethane? Am stuck again with the terminology, I thought Urethane was like a synthetic paint, so how could it be Acrylic and Urethane?


Also about the Window Time before putting clear on :

http://www.hichem.com.au/hicheminfo/...%20LACQUER.pdf

It says on that document when applying 2pac iso free clear on your job - Wait at least 24 hours before applying clear.

But for Acrillic says 15 Minutes.

Am wondering why isn't there any window time for putting 2pac clear on as in there is no 24 hour window time that it must be done within for 2pac clear like there is with acrillic.
and why do you have to let your paint job dry for at least 24 hours before putting 2pac clear on, something to do with the hardeners?



Am also wondering about Satin/Matt finishes. For the people who want that Flat matt finish, but also want to have a coat over it to protect it, how can they achieve that?
Because if you put clearcoat over a Matt finish, it will become gloss. And if you leave it like it is, you have no clearcoat to protect it.
how you go about protecting matt finishes without making it look gloss? Or is there just no way around this one?


Plastic bumpers, Pac you mentioned so long as you use plastic primer its ok. So Fill up chips with normal bog 2 part or plastic bog... then sand even, and then plastic prime the area your repairing with plastic primer before paint?

["Z" UTE]

Acrylic and basecoats use thinners to carry the paint to the job, the thinners then evaoprates off, and you are left with a solid film of cured paint, which can be recoated in "15minutes".

2pak/2K/2pac all use a catalyst/hardener to cure the paint, it will take 24 hours for the chemical reaction to cease.

You can remove the gloss from clearcoat, by using flatting base instead of thinners. I use Shellite lighter fluid. This is necessary when painting around an instrument cluster on the older cars that did not have plastic all over the place, but had slabs of painted metal. The ADR of the day specified that the paint should not be reflective but matt.

For the bumper repair, if you have not exposed the plastic with you sanding, simply prime over the repair area and then paint. IF you have exposed the bumper plastic, you should use a plastic primer then coat with colour.

cheers Chuck.

[Z2TT]

Thanks chuck.

Only primer I have at the moment is plastic primer, is it ok if I just use that even if I haven't taken it down to the plastic (Just to avoid going to the shop and buying normal primer), or is plastic primer made to be only used over plastic.

And my Soarer is going well, given the clear about a week to dry off now I'm going to use a compound. I have megauirs deep crystal which gives a very very fine shine but i think i need something more abrasive. Is there any chain stores that sell 3M Perfect it (was that the name?), just thinking i might get some 3m stuff, go over it, then finish with the finer meguiars deep crystal polish stuff. Looks like the 3m stuff is what most of the trade use from what i've read as it gets mentioned a lot. Supercheap, Repco any of them have it or would i have to goto some hardware shops or paint places. Does it also come with the pad if not where can i get a pad to suit.

I have also noticed the area where i had originally gotten it down to the primer accidentally on the 1/4 panel, on the finished job that area looks a bit "grey" or is what i'm seeing just light reflections because that surface is much lower than the rest of the paint so i'm seeing the crater even after all these coats?

Might get a picture if the camera can pick it up.

I'd like to know for next time how should I go to try avoid this "Crater", Should I have sanded the surrounding paint more to make the groove more progressive, or should I have bogged up the place where i got it down to the primer, then level it down.

If use bog (unless you have something else in mind), when sanding the bog down, is there anyway to "know" when it's level with the surrounding surface, or is it a hit and miss thing or use your hand to run it across the panel.

Thanks.

["Z" UTE]

The plastic primer will be fine, no need to buy more.

The 3M would normally be available only at paint supplier and panel beating supply shops.

Maybe the colour was not a perfect match, or is primer showing through? If so the coats of paint are too thin.

After applying the "bog" and roughly shaping the area, spray a mist coat of a contrasting paint colour, ie. white over black, or black over most anything, best bet is matt acrylic. (The gloss stuff will clog your sandpaper quite quickly.) When the mist coat is dry, sand using a block, the high area's will be cleaned of the matt paint really quickly, and the low areas will show up. Either re bog or sand again depending on the results of your "guide coat" sanding. You can continue putting addiotional gude coats on. In the end you should have a perfectly flat area with no highs or lows and all the guide coat should have sanded off.

cheers Chuck

cheers Chuck.

[Z2TT]

Hi,

Today I went to the paint shop to get some supplies. Asked them if they had any 3m Perfect it, but they only had K&H Buff N Shine, which for some reason had a 3M Logo at the bottom, but they told me to first sand the clearcoat to get all the fisheye out and to get it even first, so I did with 1500.

Then I rubbed the area with the buff n shine. I finished with some Meguiars Deep Crystal Polish and it turned out pretty good, the crater on the original damage is harder to see now, but other than that....

1. Where the new clearcoat is, and where it meets the old clearcoat I can see a type of "cloud" or snail trail, it was less noticable once i used the polish but when looking closely you can see it, and under light you can see it sort of from a distance. I'm wondering is there anyway to fix this or is this just what you get when you do blend ins. Would spraying thinners across the panel help melt it in? Or would that just create problems. Next time when i do this sort of repair should I spray thinners over the whole panel once i have applied the final coat of clear? You mentioned doing this with the paint but with clear too?

Am wondering just is there anyway to avoid this cloud outline when doing blend ins without having to respray the whole car. Would attemping to buff it out help or will I be forever wearing away my new clear coat and still be seeing the cloud until I totally wear away the new clear that i applied?

2. When i was finished, when i get close you can notice some pin holes, cant be seen from distance but close up I see subtle pinholes on the final finish. Could this be pinholes on the base coat from applying it too rough still being visible through the clear? As when i run a finger across the panel i cant feel the pinholes, so not sure if there on the clear or base.

["Z" UTE]

Unfortunately with spray cans, you sometimes get a good finish, most often not. It really takes a lot of practice to get this type of spraying right. I think you will probably just have to live with what you have there, or have another go at it. Sounds like the pinholes are in the colour, you could scuff the clear, apply more colour and clear again.

The "halo" you are getting at the edge is not removable. To prevent this in future, you must spray a light coat of thinners over the painted area, to blend the new paint/clear to the old, but it must be done during the painting process, not anytime later. Buffing will never eliminate the halo, but it may hide it for 6 months. Buff and wax it again when it reappears.

cheers Chuck.

[trd_st184]

If i used a slide hammer to take a dent out, whats the best way to fill that hole again? I saw people use quiksteel before. I want it to be as similar to the original metal as possible.