Thread: painting metal

2/3 of the contents of the spray cans you mention is propellant. The reamainder is paint thinned by approx 1/3. That equates to around 72ml of unthinned paint in each can, which means that it is costing you $97.22/l as aginst the $20.00/l you quote. When you spray the enamel, you will probably thin by around 33% with thinners which costs around $4.00 per litre.

Originally Posted by BobL

- so where's the saving??

For me .Its avoiding the waste factor of the unused portions of the can not wanting to spray cos the spray nozzle or the valve thingy built into the can is all blocked up.

Invariably mine block up and do not want to work after initial use.
Yes !, I clean them up by inverting a spraying for a few seconds.
HVLP guns,in my humble opinion, are the way to go as more product hits what it is aimed at.Given that I am not spraying cars or the like,it works for me.

Grahame

Bob

If you're only painting small items, then get an airbrush rather than a spray gun. You will use much less paint to cover the same area because of the smaller overspray.

Cheers

Jeremy

Originally Posted by Fossil

2/3 of the contents of the spray cans you mention is propellant. The reamainder is paint thinned by approx 1/3. That equates to around 72ml of unthinned paint in each can, which means that it is costing you $97.22/l as aginst the $20.00/l you quote. When you spray the enamel, you will probably thin by around 33% with thinners which costs around $4.00 per litre.

Ah - Ha! now that makes a lot of sense because I can only seem to cover about 1/4 as much with three spray cans as I can with a litre of paint and a brush! I thought it might be because the spray can nozzle has such poor directional characteristics and I was just overspraying.

Graeme, when I finish spraying with a can I wipe away any paint around the nozzle with a rag soaked in thinners - this seems to leave them pretty clear and haven't had one fail on me yet (even the really cheap [$2.98] cans) since doing that.

JMK - Thanks for the tip on the air brush. I think my son has one, I'll see if I can get one and give it a go.

Cheers

Gday Bob, you should look into using automotive acrylic lacquers. They are tough enough to be used on cars and they also dry very quick.

Go into a specialist auto paints supplies and check out the prices and do some sums.

Originally Posted by martrix

Gday Bob, you should look into using automotive acrylic lacquers. They are tough enough to be used on cars and they also dry very quick.

Go into a specialist auto paints supplies and check out the prices and do some sums.

I agree here except the health aspect, ventilation booth etc

Thanks Martrix, those acrylics do sound like a good idea.

RE: Paint booth: I'm fortunate to have after hours access to a big booth at work but the stickybeaks and others are a PITA and also move your stuff around and never leave the spray gun clean enough for my liking. Anyway, now that I have my own gun I think I could always make up an air line adapter and bring it into work.

Cheers

Someone can cheerfully correct me as I don't know the finer details, but I don't think single-pack acrylic lacquer fumes are any worse to your health than enamel fumes.

A good quality respirator with the right cartridges and a well ventilated workspace (outside under cover is best), and its perfectly safe to use acrylics. Its only when you use them day in day out without the right gear on is when it is detrimental to your health.....

Wheres the Master, "Hey Durwood!"

Originally Posted by martrix

Someone can cheerfully correct me as I don't know the finer details, but I don't think single-pack acrylic lacquer fumes are any worse to your health than enamel fumes.

A good quality respirator with the right cartridges and a well ventilated workspace (outside under cover is best), and its perfectly safe to use acrylics. Its only when you use them day in day out without the right gear on is when it is detrimental to your health.....

Wheres the Master, "Hey Durwood!"

You are generally correct Matrix the difference is drying time and how it effects your system as it can be absorbed through the skin more readily than Enamel. Fumes are worse.

The difference is to get a better finish you have to play around with mixtures of clear (not always needed) and more and more percetils of thinners.

Found this http://users.chariot.net.au/~stmezz/paint.htm

do a google for spraying acrylic

this is an excelent site for how too http://www.goldenpaints.com/technicaldata/airtip2.php

Thanks Wheelin,

Where are Perth folks getting their automotive acrylics from?

Cheers

Originally Posted by BobL

Thanks Wheelin,

Where are Perth folks getting their automotive acrylics from?

Cheers

Perth I guess

Originally Posted by wheelinround

Perth I guess

could be - but internet shops could be competitive?

The fumes from any of the paints mentioned are harmful if you get a good dose of them.

So always spray in a well ventilated area.

Lacquers evaporate fast and there is a lot of solvent in the mixture so you have to be in a really confined area to get into trouble. If you painted a car in the open you could safely do it without any mask ( it's what was the norm in shops before the advent of 2 packs.) and noone had a mask.

2 packs had the hardener problem making the paint far more dangerous so the fumes needed to be avoided. so wearing a mask (air fed preferably) and a booth to get dust free results became the way to go.

Acrylic lacquer can be sprayed easily without the mask/booth as the drying is so fast you have to do something stupid like get inside the boot of the car and spray like mad and getting a high build up of vapor that can't escape.

A tin of normal acrylic lacquer has to be thinned at least 50/50 so you get twice as much as you would if you buy a pressure pack can.

Most panel beaters especially the big ones only use 2 pack now but all Holdens up until about 10 years ago were finished with acrylic lacquer from the factory and they were repaired with it so its still widely available.

Depending where you are will determine how easy it is to get hold of some but ask the local smash shops. They will have a supplier who is probably fairly close ( they need supplies sometimes fast) or have deliveries several times a week. In my area the local Holden dealer is the local supplier.

You could ask also if they have any scrap lacquer. Usually the colours are mixed up in the workshop. they usually mix their own colours -the supplier only supplies the basic tinters, this allows then to colour match the colours as they have access to all the tinters.

Once mixed and the car leaves they always have some left over, over a period of time the tins mount up and with the current eviromental laws they have to pay to have it destroyed. You might be able to get a lot of colours for very little cost. Avoid the metallics unless you really need them they need clear over the top of them. The normal colours don't need clear.

An air brush is probably a bit small a touch up gun ( small spray gun ( holds about 250ml) would be good for small objects.

The finish will depend on the surface being sprayed, If its smooth the paint will come out the same if its rough it will be very difficult to get it to omprove no matter how much you apply.

As you havn't used AL you may want to ask further if you get a supply.