White substance on paint?

[laneychief]

Please help, I sprayed my minor bright blue and after waiting some weeks for the paint to go off I used a compound and a finishing glaze, on recommendation, it's now left a white almost powdery substance on most of the car, which goes away when wet but returns as soon as it dries!


Any product I can use to rid me of this permenantly??


Cheers

[katy]

Sounds like your compound was too coarse.

[laneychief]

So what does that mean?

The residue goes away with water, I was worried it was the primer showing through but it's not

I'm hoping a miracle substance exists for just such circumstances and someone in this fountain of knowledge will know?!

[kennatt]

if the compound was too course then you have in effect flatted the surface down as though ready for top coating,try to polish it out with t cut,followed by a polish with blue colour back Available at halfords

[MarkyB]

A picture would help a lot, it's been very cold recently, not ideal weather for spraying <understatement>!

[laneychief]

I've had this problem for a while, sprayed june last year, just hoped it would of washed away or something

I'll put a picture in the morning. Thanks again all!

[Neil MG]

At a guess I would think a machine polish with light cutting compound (like G6) would sort it out. If that doesn't seem to be working or there are any marks in the surface you might need to try a heavier cut (G3). If you haven't done any machine polishing before use good quality compounding heads, keep the speed right down, don't let the panel get hot and avoid edges. Ideally get someone to show you. It will take several hours, but if the preparation and painting was done to a very good standard the results will be amazing.

You can use any polish you like when it's done. It will look like it doesn't need it, but you will want to protect that shine.

[bmcecosse]

What type of paint did you use?

[ASL642]

Sometimes if you use cellulose paint and the weather temperature is too cold/damp you can get a "cloudy" look. If G3 doesn't work the only way to resolve it is to flat it down and respray when the weather improves.

[laneychief]

I used cellulose yes, I've got some g3, what's the proper procedure for applying it by machine? Like, g3 on body, or mop head and do I need to dampen anything down, should the car be dry etc...


Cheers

[Neil MG]

You need to keep the polisher speed down and make sure you have a good quality head suitable for G3. Use a small amount smeared on the head and work in small areas. Make sure that the compound is allowed to break down (spread it across the area being worked before doing several repeat passes) Be sure the panel does not get hot, by touching regularly.

Take your time in the beginning and try not to get over confident as the surface starts to shine! Be very careful around edges and be certain never to let the side of the compounding head touch when working on angled surfaces. It will rub through before you can blink!

No need for any water.

You will need to go over with a lighter cut to remove the swirl marks, but that can wait 'til summer.

The very best is if you can arrange for a professional valeter to give you a demo, or at least watch them at work.

Be warned it will take a long time to do properly. Even the professionals can spend over 8 hours machine polishing a car. You might need to plan for double that, but just do one panel at a time.

[lambrettalad]

sounds to me as if the paint has probably "bloomed" could have been a combo of temp (too cold and or humidity too high) when applying the paint,some colours show it more than others.

[MarkyB]

Can we not see a picture?
It would really help to see the problem.

[laneychief]

You can see it there, its hard to take a picture of![frame][/frame]

[bmcecosse]

I think you are seeing through to the primer.......

[laneychief]

Nah it's definitely not because it rubs off and when it's wet it's perfect!

[kennatt]

what do you mean that it rubs off,can you see it on a cloth not sure what you mean and then is the paint ok.

[laneychief]

No it kind of like buffs off, if I put polish on it and rub it really really really hard it goes, but sometimes it comes back after a while after the polish wears off!

[tysonn]

Sounds like blooming.Mainly caused by moisture trapped in the atomised paint as its being sprayed.As advised earlier a good compounding session should get rid of it.G3 followed by G10.

[kennatt]

well without seeing it in the flesh can't say what it is.but blooming 99% of the time is seen a few minutes after topcoating,caused by too low a temperature,or a cold wind blowing onto the wet paint,the celly thinners drops the temp of the panel as it flashes off causing in effect slight freezing,hence the need for antibloom thinners which have a slower evaporation rate to keep the temp up,it is simple to get rid of by cutting back,and only effects the top of the paint,it just sort or glazes over and rarely effects the paint or primer underneath. I have never seen it reappear after the cutting back,so sorry but don't know what it is.