Age Old Topic Paint- Enamel V Acrilic V Two Pack

[Mark Sierant]

Hello Forum, I would like to gain some insight into differnt peoples experience with different paint types. To date my experiance in restoring vehicles has always seen the application of Gloss Coats. In which I have always applied Acrilic paint for the following reasons-
1) I t can be applied in a shed with an exhaust fan and respirator on a warm day
2) The flash of time of the paint at the right temp is under a minute therfore only a small chance of bugs and flys dropping in to a sticky situation.
3) Small blemishes can be sanded and polished out.
4) sanding between coats is easy.
4) Repairs can be easily blended in.

Enamel paint is cheaper to buy but has some negatives for me
1) The paint takes up to 1 hour to flash off so bugs can leave their tracks and bodies embeded in the paint.
2) The paint is thicker out of the gun and needs a lot of attention to avoid runs.
3) sanding between coats if you get a run can take days before the paint is hard enough.

I have never applied two pack as the warning on the cans about arsnic in the hardner has just been too scary for me.

Now to some questions based on comments I have heard from people about problems that occur when a flattening base chalk is applied to Olive paint to remove the gloss.

1) The paint becomes porous and allows water to reach the base metal causing rust and paint flake. Does applying a gloss coat over the primer followed by flat coats solve this problem or is the problem a furphy.
2) Acrilic paints that are applied in up to 6 seperate coats do not adhere properly to each other because of the addition of flattening base chalk. This leads to paint layers flaking away when washed especially under preasure. Is this true?
3) Enamel paint performs better with flattening base chalk as only two coats are applied. The paint holds on better under the preasure washer. What are people experiance in this area?

In general how have restored military vehicles stood up to the test of time with the different paints, any comments welcome.

[Mike Kelly]

Mark

You really know how to open that can dont you !

This topic is very timely as last Sunday I was a attendee at the annual commercial vehicle rally in Melbourne . Many varied makes of old trucks were on display . The paint finish on some of them was perfect , too perfect I think . Two pack finish was evident on quite a few . I think Two pack finish is OK for hot rods and moderns , but on a older vehicle is looks too fake and plastic . Also , the vehicle painted in 2 pack can end up looking better than it was at the factory or showroom .

As for WW2 Military vehicles - to give you an idea of how slack the factory finish was on CMP's . I had two NOS Ford cab 12 doors once , no hinges fitted . These doors were finished in a medium green applied straight over the bare metal , no primer at all was used . Same thing on some NOS cab 11 windscreens I have , these were found wrapped in their original paper cover , paint on them is a green enamel straight onto bare metal .

Wattyl here in OZ make a industrial enamel called olive drab , its flattened with a talcum powder base in Liquid form . I have used this paint , but it is too flat , the finish is like chalk and the slightest touch will leave a mark .

Auto Enamel is easy to flatten and you can do it yourself using talcum powder . Just slowly mix it in a small amount at a time until the finish is what you want . To get auto enamel to a semi flat or matt finish , a large amount of talc is required . I have a detailed article from ARMY MOTORS mag from the early 1980's , where a US restorer describes using silica powder as the flatening base in his enamel paint .

Modern one pack epoxy etch primers are light years ahead of what was around years ago . If you use a good quality etch prime , there will be no problems with corrosion for many years . If your vehicles are shedded then this will have a huge effect on the paint lasting longer . Cheap industrial enamels are a waste of time , but good auto enamel is fine .

Acrilic paint and military vehicles - acrilics are difficult to flatten , the ideal finish on a MV is a low sheen something like the heritage house paints have . BTW those water based exterior house paints in low sheen make a ideal disruptive camo paint for camo schemes , hand applied with a brush , just like they did it in WW2 .

Well we could rave on and on , the golden rule for MV's is , don't be too fussy , these things were never finished like a RR Silver Ghost . How long did a paint job last in the tropical heat of New Guinea ? about 6 months at the most before it faded .

Mike .

[Tony Smith]

Mike Kelly siad " BTW those water based exterior house paints in low sheen make a ideal disruptive camo paint for camo schemes , hand applied with a brush , just like they did it in WW2 ."

Race down to your local hardware store. In the Dulux exterior house colours chart, they list under the heritage colours a favourite colour of ours, Portland Stone (Bsc 64). Unfortunately, because it is a standard colour, they don't provide a colour chip for you to use to colour match auto enamel.
Also, Mike Cecil at the AWM let slip that they use INTERIOR water based paint on their display restorations because they will remain inside on display, and as conservators of historic artefacts, water based acrylic is an easily removed topcoat that allows preservation of the original finish underneath for future generations.

[Tony Smith]

I've scanned the colour chart below, but the colour hasn't come out the same as the chart.