The Spray Painting Thread

[V-Na]

I'll be fixing these two problems shortly:





My plan is to flood the exposed areas with rust converter, then apply primer and finally touch up paint.

I'm not worried about the dents or filler for this vehicle. I just want to protect it from rust and have it in a decent state of repair.

Is my plan OK? Or do I really need to take the surface rust and surrounding paint back to bare metal?

Any tips?

[oldcorollas]

removing rust is a good thing.

[V-Na]

removing rust is a good thing.

I didn't let this occur. I received the vehicle in this condition.

[oldcorollas]

?? i mean, removing rust before painting over it is better than using lots of rust convertor

[V-Na]

I see, should I go over it with some coarse sand paper or steel wool? I don't have a grinder.

["Z" UTE]

I see, should I go over it with some coarse sand paper or steel wool? I don't have a grinder.

120 grade dry sandpaper, will do the trick. Make sure you remove the paint that has lifted or has gaps under it, sure as eggs there will be rust under there. After sanding, clean it all off with some warm water and a little sugar soap. Dry the area with clean cloth, apply a thin film of rust converter, prime and paint, Cans will do at stage, as you just want to prevent any further rust. Just follow the directions on the spray cans and do not try to put too much on at one time.

cheers Chuck.

[V-Na]

Something that's been confusing me:

I have Ferropro Rust Converter and Ferropro Meta Kleen Rust and Grease Remover.

I've used the 120 paper and the rust was very light and only on the surface. The rust converter bottle says "For clean and lightly rusted metal use Meta Kleen intead of Rust Converter". It also says in the directions "Leave a thin layer of firm rust - Do not remove this layer." But I've pretty much taken it back to bare metal with the 120 paper.

The Meta Kleen directions make out that it's supposed to be wiped off after it's cured.

The Rust Converter is 290 g/L Phosphoric Acid and a milky liquid.

The Meta Kleen doesn't say what's in it but is a dark green translucent liquid.

At this stage I'm thinking I should apply the Rust Converter.

["Z" UTE]

You have done the right thing. Use the rust converter (Phosphoric Acid). This acid replaces the steels long gone protective coat. It is called phosphating. If it leaves a thick skin, lightly sand that with 800 before applying any primer.

cheers Chuck.

[DrNick]

can a suction gun be ok for acrylic tops coats, clear, primers with the correct tip, settings? as I used it and it sprayed better then my gravity fed gun maybe my compressor cannot supply enough air? its a 2.5HP jobbie

For sure man, I used a Star suction feed for my acrylic for ages. Also many years ago at tafe we also used Iwata suction feed guns. The one I have has a 2.0mm tip which might be a bit on the large side but like with any gun you get the hang of it eventually.

I used this gun for everything to respray this car in 05 :



Although the sheer amount of prep work for the respray completely put me off painting anything again for a few years and I'm only just getting back into it again lol. Now I use HVLP stuff which I find a lot flatter finish off the gun and also cleaner to use without the clouds of overspray that the suction gun seemed to produce.

[Z2TT]

I checked with the seller, and the manufacturer of the gun does not sell any other tips, so I'm stuck with 1.7mm, guess this is going to be a problem

Should have bought a gun that has different available tips

["Z" UTE]

I checked with the seller, and the manufacturer of the gun does not sell any other tips, so I'm stuck with 1.7mm, guess this is going to be a problem

Should have bought a gun that has different available tips

Trot into your local paint and panel supply shop, with the new gun, and see if they have any suitable replacement nozzles. 1.7mm is a sort of nowhere size, you need 2.0mm for primer and hifill, and you need a 1.2mm-1.4mm for colour and clear.

That being said the 1.7mm will lay on primer, it will just take longer thats all.

cheers Chuck.

[Z2TT]

Oh ok, so just with 1.7mm I will have to lay it on a bit more heavily or put more coats on?

And as for 1.7mm being too big for spraying 2pak colour, what drawbacks might that cause and how to get around with it? Will it lay on too much paint and increase chances of peel and runs?

["Z" UTE]

Oh ok, so just with 1.7mm I will have to lay it on a bit more heavily or put more coats on?

And as for 1.7mm being too big for spraying 2pak colour, what drawbacks might that cause and how to get around with it? Will it lay on too much paint and increase chances of peel and runs?

You will have to travel slower with the 1.7mm nozzle to get the same coverage using primer.

The 1.7mm will not provide the degree of atomization required for a colour coat or clear coat. The paint film will be extremely prone to orange peel. ie. one coat will peel up, but you will still have to lay another coat, further increasing the "peel".

cheers Chuck.

[DrNick]

Why dont gravity feed guns atomize the paint as well? 1.7mm on a suction feed gun would work out nicely but not on gravity feed. Is it just the increased paint flow?

[oldcorollas]

think of how carbies work...