The Spray Painting Thread

[o_man_ra23]

Forget the 80 grit, it will clog in the soft layers. I got 60 grit to clog like a mofo. Just buy a heap of graffiti remover pads and save yourself 2 weeks. Better still, just pay to have it sand blasted.

[ta22fan]

I gave up on using straight paper to remove paint very early on. Chemical stripper is not a bad option - tho this'll take you right back to metal. I did most of my car with a random-orbital sander and 60 or 80 grit pads.

Re point 6 - my own recent experience is that you'll need to do this wet - dry just clogs the paper in seconds. Trick on that final blocking is to give it enough to give you a really smooth surface for the colour without going through to the etch or metal. Takes a bit of trail and error and some swearing when it goes wrong.

Gathering you are talking about a complete respray - you need to put 3-5 coats of clear on immediately after the colour. Otherwise sounds about right.

[oldcorollas]

actually i'm finding the 80grit to work pretty well so far. sure it clogs, but a quick wire brush and it clears.. there is just so much paint on there, it makesa lot of dust

i used the brumby graffiti remover before, and while it was good on the boot, it really ripped the metal too... then again, it was a lot faster, but it clogged pretty much instantly on the colour layers, so it was just paint ripping off paint by friction ...
other concern is that it is a bare bare metal approach..

yeah, i should have got an RO whizzer before....
if i can7t get through the roof and the other side in a couple of hours, i'll go get something stronger

["Z" UTE]

oldcorolla's the sugar soap is used to get rid of greae oil and wax before you start any body repairs or sanding. You can also use the sugar soap on the intermediate layers for wet sanding and cleaning down.
Final sand is with 800 wet.
Final clean before colour coat I would use prepsol/wax and grease remover, then tack rag the little bits off crap off. You would not use a tack cloth to wipe an entire car.

ta22fan, clearcoating is only necessary if you are using a basecoat colour. Topcoat colours contain gloss.

cheers Chuck.

[oldcorollas]

woohoo!
did my first hack at painting today... played with settings and put just 1 coat of etch primer on rear 1.4 before it got dark... seemed thickish tho.. will rub it back tomorrow and see how it went.
roughed it, then 240, blew dust off, wax n grease remover, let sit for a bit, then sprayed

Settings for primer (so i don't forget)
shitty Workquip gun
1.8mm
fan control= 3.5 turns
fluid control = 3.5 turns
Air control = 1turn (after 1 or so is maxed anyway)

used about 210mls primer and added GP thinner up to about 280mls (33%)... actually i only meant to put it to 250 (~20%) but even at 33% it seems a bit thick still?

was around 20deg, and when i was test spraying on a sheet of paper, 40 and 50psi would only get a small fan, about 10cm ro less (at handspan distance) dropping it to 30-35psi gave the "handspan at handspan" but was a bit.. "bitty"..
I think it could do with a bit mroe thinning... can says up to 40%, but datasheet on their site said up to 40%.. will try 40% next time.

overall pretty happy with the coverage, and I really need to get organised so i am not tripping over myself
Attachment 13028
and pretty much no overspray, which was nice.

the Josco plastic wire wheel was a bit shit tho.. not so impressed so far...
anyway, time to rip the shit out of more paint

["Z" UTE]

oldcorolla's you can have 60% or even more thinners in an etch coat. Etch should really be a translucent coat. If the stuff is combination etch and primer 50% thinners is good, you just have to get it to a good spraying consistency, add more thinners if required. The recommended 40% thinners is for the controlled environment of a spray booth.

Good to see you have made a start.

cheers Chuck.

[oldcorollas]

thanks Chuck yup, combination etch/primer
the can said "up to" 20% "if required"... but my brain got the maths wrong in the heat of the moment and put closer to 40% even at the 33%ish, is was not such a great consistency, didn7t "flow" on the surface, but was ok to lay down a thick layer.

ok, will try at 50% next time.
had to stir the can for abotu 10-15mins.. was quite chunky with i first started stirring

yeah, am feeling much better about the shitbox now that the primer went on easily
so much so that i attacked the drivers shti side and ripped off down to metal in places.. going to bash some bits in and rip off the filler too.. try adn make it look more normal shape

thanks for everyones advice and encouragement so far!

[o_man_ra23]

What pressure was your compressor set at?? Too high a pressure and it won't flow real good either.

[oldcorollas]

the regulator was set to be about 32-35psi dynamic.
I tried 40 and 50psi dynamic, but with the higher pressure, i couldn't get the fan wide enough...
seems liek there is not enough air getting to the aircap at the higher pessures, to fan out the paint? so was not oval enough...

i'll mix up some 50% and try the higher pressures again

[o_man_ra23]

With the gun you have, you should set it closer to 20psi. I find anything above 25 and I get a dry spray with my workquip gun.
EDIT - those are dynamic pressures. My other gun works great with a 15psi dynamic pressure.

[oldcorollas]

i was setting it with you in mind
the paint data sheet said 300-400kpa = much higher pressures!
so i tried 40, was shit, tried 50, was worse, tried 35, was good, paint was still wet on the panel and coverage was good.
I could try lower pressure next time too...
it will change with primer/putty/topcoat as well i imagine..

err.... is the workquip actually a HVLP gun? or a gravity fed high pressure gun?
in the end, it doesn7t matter, just whatever settings make it work.

thinking abotu it, thinner primer, lower pressure and lower fluid control should give wider pattern and more even coat...

[ToyTA22]

When testing spray pattern, with any gun, I use a scrap of sheet metal and hold gun about 12 to 15cm away and give a very short squirt to see pattern. At that distance should give oval pattern about 20 to 25cm high. Keep adjusting gun and pressure till this pattern is achieved.
I've had good success in using this method.
If you can't get wide enough fan with gun adjustment, try more more pressure.
Out of curiosity what type of paint are you using?
I used Dulux Autosolv acrylic laquer on my TA22 2 weeks ago and the Etch/Primer was to be used straight with 400kpa conventional gun or 200kpa HVLP gun.

Keep going what you have done so far looks fine from the photo.

[oldcorollas]

paint is "Concept 1K etch/primer"
I'll put fan control to max, and try different pressures, but yesterday higher pressure seemed just make fan thinner.
this is a "not particularly good" Workquip P102G, so the adjustments level out pretty quickly (fan control has 4.25 turns max, and probably does nothing after 3.5, air control does nothing after about 1 or 1.25 turns but has 2.25turns max)
oh.. and the atomising holes in the aircap are not straight or even ya get what ya pay for

[o_man_ra23]

It is a HVLP gravity feed gun. From memory, it should be about 25psi max for that gun. I was running about 35-40psi doing the acrylic on the ute, which was coming out shit, no coverage, no fan. Dropped the pressure to 20psi, same thinning ratio, same gun settings, and the flow was great (too much product on caused a run on the first hit, so dropped the product off), the fan was huge, and the coverage was outstanding (used half the amount of paint to get double the coverage)

[oldcorollas]

wish me luck! gonna try and whack on primer now..

also going to do some test spray patterns for different pressures with max fan and see what happens

fingers, toes and intestines crossed!!



edit: dammit! all ready to go and NOW neighbours decide to sit in the backyard drinkign beer... farken...... go inside ya bogans...
light fading.. losing chance... wtf am i gonna do...