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Last October painted my truck w/ Brightside and have noticed that I have adhesion problems. I think that I didn't sand the old paint sufficiently well prior to repainting. Also, I lightly coated with Duplicolor spay primer (primarily to hide the old darker color). I can see I didn't use sufficeient primer and this stuff might not be chemically compatible w/ the Brightside.

I'm testing an old fender with Brightside's roll on primer after making certain that I sanded properly w/ 120 grit. Ater the paint has had a couple weeks to dry I will test. Should primer be thinned like paint for a smoother coat?





What I found is that the Brightside primer works great when rolled on straight from the can. One rolling of Brightside primer is equal to about 3 to 5 layers of sprayed on aerosol type primers. So the big advantage with the Brightside primer is :
a ) rolls on thicker
b ) has a higher color and solid content then aerosol spray bombs.

And so you are able to do a very light sanding of the primer with a 400 to 600 grit sand paper on the primer and increase the overall smoothness of the primed surface. If you tried that on a sprayed on primer surface you would not have enough primered coating on the panel to properly sand ( cuz there isn't much on the panel to begin with ). The other advantage of using the Brightside primer is that you can cut it with 20% to 30% Brightside PAINT to assist the primer and give it a head start towards reaching the color you are going to actually be painting it with.

I did a little rant about spray on primer's within the last ten pages of this thread... and if Brightside primer rolled on is a 10, then a Duplicolor spray primer is a 2 in my books. I also ranted about how most primer in aerosol sprays goes into the air or builds loosely on itself with loss of adhesion ( due to flying through the air )

I don't think there is a compatibility problem with Duplicolor primer and Brightside. I think the problem is that the Duplicolor spray bomb primer is an inferior product.

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Also, before the failing paint job I wiped down the truck w/ mineral spirits changing rags frequently. Maybe I didn't let it evaporate fully and I contaminated the surface (I see it take 333 a good 10 mins to evaporate on the test piece at room temp.).





A bigger problem usually occurs when people use a little too much soap in the water when they are wet sanding every second coat of paint OR they are not effectively rinsing off with water to remove any sanding sludge that is loosened up by the wet sanding.

One thought that did strike me about the 'rinsing off' stage following the wetsanding, is the very water itself. One variable between different locations in North America and around the world is the mineral content of the water, additives added to water by the local water distribution companies and whether it is a 'hard water' or a 'soft water'. I do know that in some locations the body shops have to invest money in water softeners or water treatment devices to eliminate the quality of their local water as a variable in how their work turns out.

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Note this reccomendation from Rustoleum:
http://www.rustoleum.com/CBGResourceCenter.asp?sn=sur

"Surface Preparation Guide
Incomplete or insufficient preparation is the single greatest cause of paint failures. All surfaces should be sound, clean and dry before painting. Use the guidelines below to prepare your surfaces for painting.
STEP 1
Remove dirt, grease, oil and chemicals
Dirt, grease, oil or chemicals may interfere with the adhesion of paint. Clean your surface with soap and water, household cleaner or trisodium phosphate (TSP) solution.

Do not use solvents to clean surfaces. Solvents tend to smear grease and oil and levae residue on your surface. Strong solvents can also soften a previous finish and make your new paint application susceptible to wrinkling.

Do you think they are saaying that MS can be a problem?





It's like what we were saying previous about 'dampening' the cloth with mineral spirits rather than saturating the wiping cloth. I believe I tried to describe it as soaking the cloth and then wringing it out to remove almost all of the mineral spirit from the cloth. A soaking wet cloth would leave excess mineral spirits on the surface being wiped and this excess might be all it takes to soften the paint onthe wiped surface. As well, a soaked cloth would just swish and move around any foreign matter on the body panel... where as a slightly dampened cloth will tend to pick up the foreign matter and attach it to the wiping cloth.

Last edited by Marq; 02/25/08 06:29 AM.