Re: Which Aerosol paint?

I only want to sort a couple of spots on my car. If I had the cash to buy a compressor and gun I'd take it to a bodyshop.

"Doki" wrote in news: snipped-for-privacy@doris.uk.clara.net:

Your best bet is to find a local trade shop that will sell to members of the public. I should think most trade shops will. I'm in North Kent and my local trade paint shop is 'BSB Strood' 01634 720322. I understand that they have other branches in the UK. They do sell custom filled aerosols.

The advantage of using a trade place is that when you go in and ask for a particular colour eg Ford Cayman Blue, they usually give you a set swatches of Cayman Blue. You can go out to the car, wipe off the dust on an adjacent panel and pick the swatch that best matches the colour you have on the car. I practice this means you get near identical paint colours - you just won't get that from a Halford's aerosol. The other advantage of a trade place is price. A 5 litre tin of standard cellulose thinners is a trade outlet is £5 or so - you will pay that for half a litre in Halfords. A litre of white paint for my van was £15 and that was diluted 1:1 - so its 2 lites for £20 or so. Two litres would easily do one side of a van. I should look in your Yellow Pages under "Paint, Varnish and Lacquer' or try Yell.co.uk for "Automotive Paints".

Just as a bye-the-bye... don't buy two pack paint from a trade shop. It contains an isocyanate catylst to harden, it is toxic (causes skin and respiritatory problems and sensitization) and requires forced air breathing equipment to protect the sprayer plus a full environment suit. It is the standard paint system used these days and many trade outlets just assume their customers want the paint as a 2 pack. Don't buy it, just stick to cellulose or acrylic based paints - they are much safer to use but slightly slower to dry (recoat in 15 to 30 mins).

Despite what you said to the other guy, if you are serious about spraying, you are going to have to get yourself a compressor. The difference between using an aerosol and a spray gun is the difference between a push bike and a Porsche. From an aerosol you get a dusting of paint, from a spray gun you get a rich thick plume of paint. It is just so much easier to get decent results with a spray gun. I picked up a second hand compressor for £50 a few years ago plus an old DeVilbiss gun for £30. Spend another £50 on air lines and an oil/water filter (necessary) and you are all set up for less than £150. Why not look in

Regards, DaveW

DaveW mumbled:

I have to get someone else to do that bit...my colour vision is apalling.

I'll try the paint place I got rubbing compound from. They do aerosols of primer etc, so I assume they'll do paint too.

Righto. How good is cellulose / acrylic paint once it's dry? Have I got to worry about getting petrol on it etc?

I could probably get the bits I need doing sprayed by someone who knows what they're doing. I've only got a massive shed to work in, so it would be pretty difficult to keep dust down to make a really good job. Can you hire compressors, guns and all the other bits needed?

No, cellulose is ready to respray in about 15 to 30 minutes. I sometimes play a hot air gun, on a low setting, over a panel after it has gone off a bit to speed the process up. The only paint that needs to go into an oven is thermoplatic acrylic paint. As I understand it, this has minute platic ganules in it. They heat it to about 80 deg C and this melts the plastic and give a smoother glossier finish. They can do this to the metal shell of a car with no problems but if you do it to a finished car, you are going to melt all the other plastic trim on the car. So that kind of baking technique is only for original maufacturing. I know some body shops advertise 'low bake' ovens - I assume thay are not using thermoplastic paint, they are just using the oven to speed up the evaporation of solvents or the setting process in 2 pack paints. For DIY work you do not have to worry about baking new paintwork.

I usually do small bonnet chips with a fine paintbrush. I try and get a 'bead' of wet paint in the chip and then when the solvent has evaporated it in more or less flush with the rest of the paintwork. I don't think it is worth taking any more trouble than that as you get a rash of fresh chips every week.

Sanding with fine grit paper eg 1000 or more, between coats. In professional body shops they have things like 'water walls'. Stainless steel walls with water running down them. The operator sprays in the direction of the water wall. This takes the overspray (and dust) out of the air. In a DIY set up you are not going to have filtered air and water walls, which means you are going to have dust and overspray settling onto the new film of paint. The only way to get rid of it is by de-nibbing the initial coats and then compounding the final coat.

I've seen good work come out of bodyshops. A friend had a dent taken out of the bonnet of his AstraMax and the two wings were compounded as part of the work. The bonnet and the wings looked like new afterwards. The guys that did had done a really good job. The only problem was that the rest of the paintwork on the van was 10 year old faded Vauxhall red. It looked a bit funny until he spend a Sunday compounding and waxing the rest of the van.

IMHO, that's crap. Cellulose is a super paint for DIY, but no way is it harder than two-pack. And is much easier to compound.

Correct, Cellulose is much softer than acrylic, Acryic is very brittle even when comparing it with twin pack paints.

IMO far less polishing is involved on two pack because of it's already ultimate shine requires less effort, Cellulose on the other hand does need working to obtain it's full shine potential.

Steve.

Not true, All paint has to go through an oven to make the paint impervious to petrol or cellulose thinners spillage. Factory baked paint finishes for example are impervious from spillage only because the paint is baked on.

The do it yourself people though have no choice regards to oven baked finishes which is why the finish always stays soft for a considerable amount of time after a respray.

Not true, I know one vehicle company who drive their cars with complete trim into the spray ovens, It does not damage plastic or electrical components.

Low bake ovens do exactly the same as the original vehicle manufacturers fast bake ovens, The only difference is on the lower oven settings means the car is baked for a longer period but the result is just the same because you still end up with an oven hard baked solvent impervious paint finish.

True, But the finish always remains soft especially Cellulose.

Steve.

Stephen Hull mumbled:

A friend of mine once designed a tracking pod which attached to Metro chassis as they passed through the production line. They had a habit of dying in the hot bake oven...which was odd 'cos he'd been careful to ensure they could survive the maximum bake time. Turned out that the production line was often stopped and the shells stayed in the oven a /lot/ longer than they should have done and the heat soak did in the electronics.

Didn't do the paint finish any good either.