Tim, acrylics are a thermo plastic based paint, and are waterproof in nature once applied. When an acrylic job is cut and buffed the paint reflows, as the heat from the buff and cutting compound makes the paint soften and smooths out giving the shine.SunnyTim wrote:Paul, I love the way you have the natural blend lines going with the overspray from the first application of Cameo under the Snowcrest which is just how they were painted originally.
Back to the pourous aspect of acrylic, I have always been taught that acrylic is porous until it is buffed and sealed with polish - but interested in your views on types of polish - although its a nightmare if you applied it the week before you want to paint, I have always used polishes with silicone in them over some of the others, even the old repo liquid polishes seem to sustain a good sealant in my opinion.
Tim
Modern paints are totally different, as you treat them in the same manner as a stone mason cuts and polishes any hard stone by reducing the grade of abrasive till the surface is almost scratch free and them polishing and polishing to further smooth and fill any tiny abrasive marks.
When I was an apprentice, after the first coats of paint gave coverage and some thickness we reduced the amount of paint and increased the thinners to help flow out the surface applications. On more expensive or restorations the paint surface was bloced back after a few days or weeks of allowing the solvents to evaporate and flow coated again. It was allowed to dry out for what ever time was decided before being rubbed down again and machine buffed, all door jams and inner surfaces were hand compounded.
if the car was a resto or a more expensive paint job several extra steps were added to the process
The car would then be washed and inspected, before being buffed with Braso. Washed again and then dry buffed with corn flour. Washed again and then the polishing process began. A paste wax in a large tin, similar to old floor wax was applied. Starting with the roof, and doing one panel at at time. Allowing the wax to breath for about half an hour before removing the excess and using several clean rags to hand finish the surface to a high shine. Door jams and inner panels were treated the same way. Once the first complete coat had been polished out the car was allowed to sit and breath for at least a day before the complete process was reapeated again for a further two or three times. On a smash repair paintjob Repo liquid polish was used to quicken the process.
No silicone polish was ever used, as I suffered a painfull lesson at the hands of thepainter tradesman when i bought in a bottle of this "New" fast and long lasting silicone polish. After I got up off the ground I had to prepsol all the cars in the paint shop several times on my time and expence before they could be painted.
The trade was very different back then.