The Spray Painting Thread

[GT4_adelaide]

So far i've nearly read through the entire thread, information overload. I have just bought a boot-lip spoiler for my Lexus which is fiberglass and has come already primed. I have my uncle helping me who used to be a panel beater and while I'm sure he knows what he is doing he has been out of the business for many years and i'm sure technology has moved forward a bit from his days. I decided i might have a crack at painting my self

My questions are:
Should I be priming it again as I am unsure what sort of primer it is on there and am I right in saying it could react if I use an incompatible paint and is a form of plastic primer the best bet?

My car is white with a pearl finish - would you recommend 2k or acrylic for this type of finish?

Is a clear coat necessary for acrylic? My uncle said it wasn't, just wet dry working up from 800 then using a buffing tool and polish to bring out the shine but from what I've read in here you can do either

Finally i know it isn't to do with painting but what would be the best type of silicone or sealant to use that won't react with the paint when sealing around the spoiler

thanks in advance

["Z" UTE]

Last question first, never use silicon sealant anywhere near your car, what you need is Urethane Sealant. Sikaflex will do. Silicons react badly with paint, and the Acetic cure silicons will eat the metal of the car.

The white pearl paint job on your car is a 3 layer job, so that is what you will have to do on the spoiler. Basecoat colour, white pearl, then clearcoat.

Buy your three paints/clear as above, and buy some primer from the same supplier/manufacturer. This primer will act as a sealer/barrier between whatever the spoiler makers used and your new paint.

Prime the spoiler, guide coat, wet rub with 320, then with 800 wet, apply basecoat colour, apply pearl coat, then apply clearcoat. If using acrylic or 2pak the process is the same. Acrylic will require 2-4 coats of clear in varying mixes to achieve a great gloss finish. With 2pak, 2 coats of clear and if the finish is good, you can fit it straight up to the car without colour sanding and buffing.

In the 2pak system you use what is called COB or clear over base. First step is the base colour, then the pearl coat, the pearl will be mixed with a flip controller or carrier. Then you clearcoat with the 2pak clear.

In the Acrylic system you apply a white acrylic base coat, then mix your powder pearl into an intercoat clear and spray on. Final step is a couple of good double header coats of clear immediately followed by a clear coat with a high 75-90% thinner content.

Ensure your paint supplier has the exact paint code and colour formulation for your car. The slightest mistint will cause huge problems when the pearlcoat is laid down, as the pearl coat is designed to refract and reflect light at different angles. A touch too much black in the white basecoat paint will show up as a grey basecoat under your pearl.

cheers Chuck.

[oldcorollas]

found a local paint shop near work and they sell "Spartan" brand paint.
for the blue colour i'm looking for, they said around $210 for 4 litres...

VG said around $140 for a similar colour in "concept" brand paint.

any comments on quality of either brand? (for acrylics)

[oldcorollas]

The absolute best bet with surface rust, is to mechanically remove the rust, with sand paper or a graffiti removal disc. (These things are about $12.00 from bunnings, work on your small angle grinder.) The graffiti removal disc is like a plastic birds nest, removes paint and rust, with lttle removal of metal. Mind you, you can generate some heat with these, to avoid panel warpage, best to limit work on bootlids, bonnets and turrets to a square foot, then move to the other panel, just switch between the panels allowing cool down time.

Bought a graffiti remover yesterday after work. Should have done that a year ago. Anyone who is stripping paint and doesn't have a graffiti remover is waisting time and money. It even ripped through the old 2k paint that has been clogging the sander and making the wire brush useless. Best of all, it leaves the metal shiny, so surface rust doesn't start after 2 seconds, and it doesn't remove any zinc coatings.

just echoing....goddamn those graffiti removers are awesome!!!
only used it for 5 seconds and easily the best $18 i ever spent (127mm size)...
will post funny pictures somewhere later

["Z" UTE]

Well after 6 years of faithful service, the Snap On gravity gun starting misbehaving, the spray pattern was a bit wierd.

Stripped it down for cleaning soaked the parts overnight, got to it with the brushes and I could still see paint in places that it should not be. Rememberd I had an ultrasonic cleaner, that I use for injector cleaning, so filled that with thinners and ran the thing for a couple of cycles over the next couple of hours. Well swallow my knob, all the shit got nice and soft, and was easy to clean out with the bottle brush, WIN.

The ultrasonic cleaner is a full metal thing, no plastic so the thinners were never going to be a problem. Bought it off egay a couple of years ago for something like $30.00 delivered.

cheers Chuck.

[MR22ZZ]

Aldi have ultrasonic cleaners on sale this week for $24

[oldcorollas]

they have much/enough power?

[MR22ZZ]

I just bought one... actually $25. will take some pics and post up the info.

I figured I'd take teh chance and if it's no good for my needs the Mrs can use it for her earrings...

[MR22ZZ]

here you go... if you need any more info, let me know

What you get...






Specifications


a few uses...

[o_man_ra23]

Wow, the only item in the world to have it's current measured in Watts!!

Applications section doesn't say spray guns... I dare say it is no good for your application

[MR22ZZ]

lol,

it does say machine nossels though

The one thing that would be interesting to know that isn't listed is the frequency

[oldcorollas]

shits n giggles time

turns out the mudcracks were in the 0.5-1mm thick yellow layer.. and may have been caused by the rubbery silver that had been sprayed on top, cos the primer and blue on top of that were in the cracks.
i think the layers go
primer - nikki - primer - thick yellow shit - silver - thin primer - spray putty(?) - primer - blue basecoat - then final primer layer as if they were going to spray over again

hard to see, but wire wheeling made nice little paint islands

and finally... "fixed" with graffiti removing disc

[o_man_ra23]

The one thing that would be interesting to know that isn't listed is the frequency

Input or output frequency?? Input frequency given is 50Hz, but I would say it is the output frequency you are after.

["Z" UTE]

oldcorolla's, at least one of those layers was applied too wet, maybe even force dried, with lamps or air. This caused the different layers to dry a different rates. These strata's then pulled on each other causing the cracking. The pink blue and beige stuff is all hi fill/spray putty, way too many different products used there. Graffiti disc was definately the answer. Would have used 10 sheets of 80 grit paper otherwise. Trying to fix that without removing the paint, would only have ever led to heartaches, as the cracks would certainly have eventually showed through.

cheers Chuck.

[MR22ZZ]

Input or output frequency?? Input frequency given is 50Hz, but I would say it is the output frequency you are after.

lol, frequency of the ultrasonics