The Spray Painting Thread

["Z" UTE]

Yeah you can get away with 240 dry sanding, as long as you are going to be putting a few decent layers of primer filler on. Remember the harsher the paper the more scratches will be there, and can show through to the top of the primer. The VG Paints guide is pretty well spot on, I like it lots.

The most important thing with a rough as guts poor paint rejuventaion, is to remove as much of the cruddy stuff that you can. Trying to cover cracks and chips will never work out well. Paint does not like filling holes for some reason.

cheers Chuck.

[oldcorollas]

thanks as always Chuck. i have to spread more rep first
unfortunately the VG guide doesn't spread too much light on the "supershitpaint" prep

all good, i'm opening up cracks and filling, and going to try to get reasonable surface with 240 before primer and spray putty.. then probably sand back most of the spray putty so it's mostly just filling scratches..

i guess my plan was:
-try to make cover up most crap/defects, and sand down past the previous 2 colour layers to at least the first primer on top of bog, and leave with a 240 finish
- 2 or 3 coats 1K etch primer (they (VG) reckoned it is fine for on top of other paint as well)
- after flashing off, put on 3-4 coats spray putty, depending on how it builds up.
- guide coat
- allow to dry for a day or two,
- sand down with 400 to get rid of high spots (LOL.. it's all high spots ) and finish with 600 for smoothness

then not sure...
ai) spray 2(?) coats 1K etch primer
aii) spray 4-6 coats colour, wet on wet stylez..

or

bi) spray 3-4 coats 1K etch, then guide coat and let dry for a day
bii) sand back smooth with 600-800
biii) spray 4-6 coats colour

the etch primer is http://wwwvgautopaints-px.rtrk.com.a...h%20Primer.pdf
sprya putty is http://wwwvgautopaints-px.rtrk.com.a...ay%20Putty.pdf

starting to think i should have gotten the 2in1 primer-surfacer instead of the spray putty but .. see how it goes...


this is just airing my thoughts (letting them flash off? ) rather than a call for help... not just yet


the aim for today is to get plastic on the spray tent.. and roll compresssor aroudn the back of th ehouse and actually mix and spray some primer and putty... on "something"
is getting cool now.. probably less than 20 from now on...

[Cuzzo]

Didnt want to bare metal it stew? its fun!

["Z" UTE]

oldcorolla's, spray your etch primer one or two coats, yes it will go over most everything, as it is quite neutral in its reactivity with other paint layers. Apply a couple of coats of the pink putty, a gun with at least a 2mmm tip is required. If you have to thin it big time to spray, then ayou will probably need the 4 coats of putty. Spray a guide coat, and let it all dry, attack with 240 on long board. The low spots will show as they will still have guide coat in them. The high spots will be ver east to see as the underlying paint or bog will show through. Fill your low spots and work your high spots down to come up level with the surrounding areas. Reapply guide coat if you are not sure. Whewn happy with that, spray your 2 coats of primer and a guide coat. Sanding after this stage, you should be pretty right as most low spots should be gone away, but this is the step when you find all the little imperfections, bog em putty em and reprime.

I have found that 3 to 4 coats of colour is all that is required except when using translucent colours, wet on wet will be fine, then a couple of coats of clear straight on top of that wet on wet again. A third and final coat of clear made up of 10-20 clear the rest thinners will level off the entire surface and promote a good gloss level. Be carefull here as this is where you can get runs. Just increase your gun travel speed and gun distance from job, drop your air pressure by 5psi, and trim your fluid feed down a little.

cheers Chuck.

[oldcorollas]

cuzzo, i did in some spots.. but after excavating down 5mm or so in some places.. i thought the better(?) of it

Chuck, using the shit workquip gun for now, 1.8mm for primer, 2.5mm for putty. i removed flash and crap from the holes, so it might work ok..
they say the putty is ready for use, or up to 20% thinner.. i'll practice with both and see how it goes. also need to dial in settings for the gun.. fun fun! going to make notes if i can remember..

I will read and re-read your comments a few trimes so they can soak in.

ok, so better to do it in steps with sanding in between, so it breaks it up into "making it flat" (with putty and bog), "prepping final surface for topcoat" (primer and guide) and then "topcoat"

if i need to use any bog or putty at any stage, then it will need primer on top to help the colour stick and keep colour even?

i'm not after a show job, just a passable rego job, and i hadn't planned on using clear (VG guy said clear was not needed, but i relaise it will be more shiny with it..)
i might see how the flattenin gprocess goes, and if it looks like it might be even half decent, i'll splash out for some clear... and maybe a better topcoat gun

["Z" UTE]

[QUOTE=oldcorollas;1322840


if i need to use any bog or putty at any stage, then it will need primer on top to help the colour stick and keep colour even?

I am not after a show job, just a passable rego job, and i hadn't planned on using clear (VG guy said clear was not needed, but i relaise it will be more shiny with it..)

i might see how the flattenin gprocess goes, and if it looks like it might be even half decent, i'll splash out for some clear... and maybe a better topcoat gun [/QUOTE]

VG guy is correct any topcoat colour will not require clear coat, as the paint will contain the gloss. Try the last coat of colour with 10-20% paint, the rest thinners, this will aid flow out, and give you a smoother glossier finish.

Yep any bog or putty should be sealed over with a coat of primer. Yes it will also aid in keeping the colour uniform. Good thinking on your part

A topcoat gun should be 1.2mm to 1.4mm, any bigger and you will get runs, any smaller and you will be there all day getting the colour/topcoat on.

cheers Chuck.

[oldcorollas]

oh ok.. i thought 1.4mm for 2-pack and 1.8mm for acrylic? will thin out top colour coat as you said (when i finally get aroudn to doing colour...)

luckily the shitgun came with 3 sizes
so..
1.4mm = topcoat
1.8mm = primer
2.5mm = spray putty?

so here's one selection of paint on the car... it varies with position and repair


1= base undercoat, looks like original type, zinc containing passivating paint or siomilar?
2= mixture of two colours of bog
3= topcoat blue
4= primer
5= primer filler?
6= topcoat blue (darker)
7= primer
8= spray putty of various thickness
9= primer
10= topcoat blue
..
11= half the car has a thick layer of primer-filler on top of the last coat of colour

some areas only have one or two topcoat colours, depending on when repairs were done.. a couple of spots only have primer....

also, some of the topcoat colour seems rather brittle, and some clogs up the paper really quickly..

anyway, enough of my whinging
this is going to be the spray tent.... 100um clear plastic over the top and sides.. 2 sides will roll up to get car in and give access to end of car for paint...
probably need to get some old lino or carpet for the base to cover the dirt... or at worst, more plastic film...

["Z" UTE]

Man that is some paintwork.

The blocking of the paper indicates that the paint is really soft, the other brittle paint chips off real easy, it is not adhered properly to the underlying strata. That soft paint is just old and shite from the time it was applied, it WILL move again under your new paint, with resulting crows feet, this will potentially expose bare metal to the elements. Rust city here we come. I honestly suggest you get some grafitti removal discs and rip all that old paint off. About 5-6 discs and 3 hours on the angle grinder and it will be all gone.

2.5mm for spray putty is about right, but if you take all the old crap off, you wont need to apply so much putty.

cheers Chuck.

[oldcorollas]

indeed![/COLOR]

2.5mm for spray putty is about right, but if you take all the old crap off, you wont need to apply so much putty.

no, not so much putty, but probably 5kg of bog

["Z" UTE]

This is the painting thread, not the bog thread. Does someone want to start a thread on panel beating? More metal work than bogwork!

cheers Chuck.

[ian]

another old trick worth considering if using a plastic spray booth
is to earth the car, as you may get static around the plastic attracting
unwanted dust being drawn to the car

[o_man_ra23]

Well, despite my best efforts, the repairs to my paint seem to be coming up a dismal failure I think I have resigned to rubbing all the clear back off, down to the bottom layers of colour, possibly through to primer, get some more colour and clear, and have another crack.

Because of the paint colour used, if I try and repair, I will end up with dark spots (which is what is currently happening). Now all the issues are pretty much in the orange, the black is fairly good, however due to the joining I will probably have to rub the black off the bonnet as well. I'll go with leaving the less visible areas alone (ie where the bumper/tail lights etc sit) and blending the clear over them to reduce the workload.

As I want to go and get the sandpaper tonight for this, what grade should I be using?? I was thinking start with a 400 wet to rub the bulk of the clear off, then 800 wet to get it flat so that scratches don't come through.

Following that, put down some more white (going to get as high an opacity as possible - probably use 2 litres to get the coverage), then drop on the orange (again, I'll need another 2 litres to give me enough paint).

Are there any pitfalls to this method I should watch out for??

["Z" UTE]

Owen, can you minimise the work, by only doing the panels that are affected, or is there no joint line ie. rear qtrs and roof of a Celica.

320 wet will knock everthing back faily quickly, and then a quick once over with 800 wet should do the trick.

If you only rub the clear back, but not off, beware the dreaded breakthrough on the 2pak clear, those feathered edges will react with new paint. You could try a white primer, as primer has less of a tendancy to fry, just seems to have less bite to it. Too much thinners will also cause eruptions on the feathered edges.


Seeing as you have a decent coat of everything on the car, I would suggest you lay down a guide coat before you start sanding the clear off, it will show up any low spots that you may have missed the first time round.

Un tinted white base paint will give the best coverage with the highest opacity.

cheers Chuck.

[o_man_ra23]

Thanks Chuck. The intention is to remove all clear, and have joins where trim etc go - so in non-visible areas.

Items affected are: whole body (ie rear qtrs are bad, but no joins to get an edge on), both front guards, bonnet. I should be able to get away with the doors and hatch just needing re-clearing. I won't re-clear them until the rest has been coloured so I can do all that in one hit and give maximum hardening time for the original clear.

[oldcorollas]

ok, more stupid questions time.

how do you know if you have enough thinner? if the paint doesn't dry before it hits the panel, and has enough time to flow?

when painting in colder temps (like say, 17-18deg) should you reduce thinner, or make all efforts to warm things up?
is it the air temp, or the temp of the paint and the substrate you are painting?
ie, keep paint inside until needs to be sprayed, and use heater to warm up the panels first?
if it is air temp.. not sure what i could do..

edit: i'm compiling a "hot tips" doc from this thread too.... might take a while, but there are a lot of gems hidden in here