Hoping for input

Thank you all for the replies. It had to be a flaw in the plastic. I wound up having to put more primer and paint than I would have liked but it eventually covered. Needs a little more paint work but it will be good enough for a quick build I'm not too concerned with.

The alchohol will not give you that issue. I use it always and never an issue. I have used, however, a tach cloth from time to time and I found that if I wiped an area too firmly with it that it would leave behind a residue that the paint would not adhere too, it would fisheye and pull away. I stopped using those and have not had that issue since. If you are unsure if the area is clean enough, wash it with soap and water and dry it. Then give it a quick blow off with some air and spray it again. Good luck.

BK

Chris -

Just a thought, since you tried different cans with the same results, there seems to be less chance of bad cans. Some sort of contamination somewhere seems likely.

Could be within the plastic, or something might have contaminated the container of denatured alcohol. When using cloths or pads for cleaning, it's important to not hold the pad at the mouth of the container, and then pour into the pad. Repeated wetting of the pad that way, can allow contaminates from the pad to enter the liguid container.

I'd suggest a thorough wipe down of the hull with iso alcohol, then try a test spray. If that works, then you can isolate the denatured alcohol as the culprit, maybe from contamination.

Hope you get it all sorted.

Patrick

ChrisSC

Thanks Harold. The areas that are having the issues are varied. Some are on the bottom of the hull which is very smooth. It all looked perfectly fine before I sprayed it, no noticeable issues with the plastic. I don’t know if it’s something that occurs but I believe there must be some kind of contaminant within the plastic. I resprayed it again a few minutes ago and these some spots continue to just stand out.

 

I posted thinking maybe Denatured Alcohol might leave behind some kind of residue but I don’t think so as I have been using it for years to degrease stuff that I paint and have never had an issue. I can see even when I flooded it with primer as an experiment it sort of puddled which covered some of it but I could see that it still didn’t want to take in some of the areas. It must be the plastic.

 

Harold

Chris, I agree with Don Stauffer. I use isopropyl rubbing alcohol 50% and 70% on styrene, resin, brass and copper and never have a problem with Tamiya Surface Primer, or Vallejo Surface Primer. The Tamiya primer is lacquer based and Vallejo is acrylic.

However, three years I did have trouble with Tamiya can primer on a submarine hull. At the rear of the hull were four fins and from the first coat to the last that area around the fins looked different. I tried sanding and repainting and sanding repainting and got the same results.

Then I purchased an airbrush thinking it would correct the problem, but it was the same results. Fast forward to December 2019 and I finally realized that during the first application of paint certain features on the surface of the plastic can create 'overspray' in other words paint that dries in the air and just sits on wet paint. Overspray can look fuzzy or rough and adding more coat, or heavier coats just makes it worse.

I never completely got away from overspray issues until I purchased a miniature spray gun, but they are expensive I have different problem like to much paint and paint runs. These days I use my airbrush for fine detail and tight corners with very light coats. Sometimes three or four light coats and it works most of the time.

Harold

Don Stauffer

For decades I have used isopropyl for cleaning before painting, and even between coats with enamels and lacquers.  Never had a problem.  If you had problems putting it on that is not blushing (water vapor condensation), because that happens during drying.  How far was the can nozzle while spraying ( I use a distance of three to four inches with those cans- Tamiya's stuff does require being a little closer than those big cans of auto primer.  Could it be a bad can?  Maybe so.

If the can is brand new, you need to shake it at least a minute.  That fine primer does seem to take more shake.  These days I do not wash (soap and water) for anything except resin models or parts.  Very little mold release is used these days on styrene, and a wipe with alcohol always takes what remains off for me.  What brand is the kit?

 

 

For decades I have used isopropyl for cleaning before painting, and even between coats with enamels and lacquers.  Never had a problem.  If you had problems putting it on that is not blushing (water vapor condensation), because that happens during drying.  How far was the can nozzle while spraying ( I use a distance of three to four inches with those cans- Tamiya's stuff does require being a little closer than those big cans of auto primer.  Could it be a bad can?  Maybe so.

If the can is brand new, you need to shake it at least a minute.  That fine primer does seem to take more shake.  These days I do not wash (soap and water) for anything except resin models or parts.  Very little mold release is used these days on styrene, and a wipe with alcohol always takes what remains off for me.  What brand is the kit?