What Am I Doing Wrong?

[jlucky]

Greetings,

Looking for any advice or suggestions regarding the paint issues on this build. I've never experienced this before.

The body is a resin cast from Competition Resins and I've worked with much of their product in the past with great results. I washed the body with soap, let dry over 48 hours. Then put two coats of Tamiya primer...let sit overnight and then applied 2 coats of Tamiya White...let sit overnight...then today applied 2 coats of Tamiya Mica Blue and it produced this result!

In addition in a couple spots when I slowly removed the Tamiya masking tape, some of the white lifted off! Again, that's never happened before. 

What did I do wrong? The room was cool...was it too cool? Did not do a good job washing? Any help would be appreciated.

Jerry

 

[johnyrotten]

What soap did you use, there may have been some mold release left on the surface. That's my thought. Also, how heavy/ light were the coats,  it may not have had enough time in-between coats, that leads to problems as well. Did you scuff or sand the surface before primer. I've learned 90% of a good paint job is what's under it. The preparation. 

Edited February 1 by johnyrotten
Spelling

[mr moto]

I find that soap leaves its own film behind. To be safe, always use a good dishwashing detergent (or something like Super Clean) but never a soap.

[stavanzer]

I'd have waited a lot longer between coats, Myself, but you've done this more often with this resin than I have.

[Ace-Garageguy]

The white spots are what's known as "fisheyes" and are invariably caused by some kind of surface contamination, usually wax or silicone or mold-release agents (probably left in the seams around the hood and decklid).

Since I started carefully and thoroughly final-wiping everything with clean white paper towels and 70% isopropyl alcohol years ago, I've had zero fisheyes.

Contamination can come from anywhere at any time...furniture polish sprayed in another room, additives in whatever soap you used...I've even seen pollen cause fisheyes.

If your primered model sits around for a while, it's a good idea to wipe it with iso just before color too.

Ask me how I know.

Edited February 1 by Ace-Garageguy

[Dave G.]

Yep, fish eyes for sure. My final wash is with odorless mineral spirits, same as Ace with IPA, wiped down with white paper towels. Don't forget to blow off the surface as well.  In 1-1 painting my final wipe down was Dupont 3812 enamel reducer, much like OMS. I'm just following old habits.

Watch out for kitchen cooking spray being air borne . Animal dander has oil in it. Your own spray when speaking can land on the surface. We emit more than one might think. This isn't to make anyone paranoid, just do that final wipe/wash. Also watch out for some IPA, be sure to get the 91 or greater, less than that can or might have soothing agents in it. Don't buy Rubbing Alcohol for this purpose.

[johnyrotten]

41 minutes ago, Dave G. said:

Yep, fish eyes for sure. My final wash is with odorless mineral spirits, same as Ace with IPA, wiped down with white paper towels. Don't forget to blow off the surface as well.  In 1-1 painting my final wipe down was Dupont 3812 enamel reducer, much like OMS. I'm just following old habits.

Watch out for kitchen cooking spray being air borne . Animal dander has oil in it. Your own spray when speaking can land on the surface. We emit more than one might think. This isn't to make anyone paranoid, just do that final wipe/wash. Also watch out for some IPA, be sure to get the 91 or greater, less than that can or might have soothing agents in it. Don't buy Rubbing Alcohol for this purpose.

Everyone I've ever known who is a painter does the same with reducer. Being observant,  you pick up tons of little tricks of the trade. Good tip on the rubbing alcohol, I use isopropyl only. I never thought of additives in it.

[LennyB]

Another vote for fisheyes. I always wipe things down with Prep-Sol, it’s a degreaser used on 1:1 vehicles before painting. I use it because I happen to have it on hand. But as mentioned above using thinner or alcohol will do the trick as well. There is also a product called fisheye eliminator that can be mixed with the paint to help eliminate the issue.   I’ve never used that on a model as I think it unnecessary, just enamel jobs on real cars years ago.   

[peteski]

2 hours ago, johnyrotten said:

Everyone I've ever known who is a painter does the same with reducer. Being observant,  you pick up tons of little tricks of the trade. Good tip on the rubbing alcohol, I use isopropyl only. I never thought of additives in it.

That might be ok for metal-bodied vehicles, but reducers (thinners) for 1:1 automotive paints can be hot enough to start dissolving the previous layer of paint or plastic (if bare plastic is being cleaned with them before painting)l

Milder solvents such as isopropyl or denatured alcohol (I use 99%), naphtha or mineral spirits will do the job and still be safe on plastic. Do not use rubbing alcohol which is isopropyl alcohol, but usually with some other ingredients added. Using a cheap diswashing detergent (one with no added skin softener) and warm water also works well for prepping plastic for painting.

[johnyrotten]

26 minutes ago, peteski said:

That might be ok for metal-bodied vehicles, but reducers (thinners) for 1:1 automotive paints can be hot enough to start dissolving the previous layer of paint or plastic (if bare plastic is being cleaned with them before painting)l

Milder solvents such as isopropyl or denatured alcohol (I use 99%), naphtha or mineral spirits will do the job and still be safe on plastic. Do not use rubbing alcohol which is isopropyl alcohol, but usually with some other ingredients added. Using a cheap diswashing detergent (one with no added skin softener) and warm water also works well for prepping plastic for painting.

I was referring to 1:1  projects with the reducer,  I see how my wording could lead to confusion. Absolutely some plastics wouldn't tolerate "hot" chemicals. Just pointing out things I've seen, as I have no formal training or professional experience as a painter or bodyman, just a lot of trial and error, self education and questions asked. I always pay attention to threads like this,as there are many tips and tricks passed along. 

[Mike 1017]

I spray my bodies with 409 or Fantastic to remove those stubborn stains. Then I wash it with hot water and Dawn and into the dehydrator it goes. I use a brand-new micro cloth to get it out and never touch the body with my bare hands. 

[Spooker]

I've had good luck using lacquer thinner to degrease resin bodies and parts.  Most resins can tolerate at least a short exposure to thinner.  Of course, always test first!  A quick rinse in thinner, then a thorough wash with a dish detergent with lemon and a warm water rinse.

[jlucky]

Hey thanks for the great info guys. I guess my first mistake was using hand-soap rather than dish detergent...even though I washed it thoroughly...it still clearly left some contaminant there. Here's the BIG follow-up question...Can I fix this with spot paint...or will I have to strip all the paint off and start again?

[johnyrotten]

14 minutes ago, jlucky said:

Hey thanks for the great info guys. I guess my first mistake was using hand-soap rather than dish detergent...even though I washed it thoroughly...it still clearly left some contaminant there. Here's the BIG follow-up question...Can I fix this with spot paint...or will I have to strip all the paint off and start again?

Strip it and start over. That's your best chance for success,  spot repair you can't guarantee you got all the contamination off, and you have to try and make everything match. More work in the long run, if even possible. 

[Rick L]

Strip it.

[Dave G.]

4 hours ago, LennyB said:

Another vote for fisheyes. I always wipe things down with Prep-Sol, it’s a degreaser used on 1:1 vehicles before painting. I use it because I happen to have it on hand. But as mentioned above using thinner or alcohol will do the trick as well. There is also a product called fisheye eliminator that can be mixed with the paint to help eliminate the issue.   I’ve never used that on a model as I think it unnecessary, just enamel jobs on real cars years ago.   

22 minutes ago, jlucky said:

Hey thanks for the great info guys. I guess my first mistake was using hand-soap rather than dish detergent...even though I washed it thoroughly...it still clearly left some contaminant there. Here's the BIG follow-up question...Can I fix this with spot paint...or will I have to strip all the paint off and start again?

You base substrate ( plastic) is contaminated.. Send it for a swim in Super Clean. Or depending on the paint 91 IPA could strip it. But full submersion at any rate.

[OldNYJim]

Before you strip it, I would check what Competition Resins suggest for removing paint from their products.

Some resin will be ruined by paint stripping methods that are just fine for styrene…

Edited February 1 by CabDriver

[espo]

A lot of good information and suggestions. The only thing that I think might be of additional help would be consider using an automotive type etching primer to seal the resin body before going any further with your painting process. This suggestion is based on my own personal experiences and there is always the possibility that your results may be different.  

[Ace-Garageguy]

59 minutes ago, CabDriver said:

Before you strip it, I would check what Competition Resins suggest for removing paint from their products.

Some resin will be ruined by paint stripping methods that are just fine for styrene…

EXCELLENT ADVICE. Some strippers will turn some resin parts to goo.

[Dave G.]

4 hours ago, CabDriver said:

Before you strip it, I would check what Competition Resins suggest for removing paint from their products.

Some resin will be ruined by paint stripping methods that are just fine for styrene…

Good point, I forget we had resin here, was thinking styrene.

[bill-e-boy]

Yup - fish eyes for sure form some sort of contaminant.

Strip, thoroughly clean down as above and repaint

At tip for Tamiya metallics and pearls - us a flat as a base of same or similar colour to the top coat and you will find you will get a deeper colour with better coverage. Less creeping away at high points and better cover in the low points. Obviously the flat will not be metallic but a solid colour.

[Rick L]

Another contaminant not mentioned that all modelers should know is a steam boiler. I would imagine that most modelers paint in their basement and a steam valve can spew off oil and whatever before closing. Creating a bad painting environment.

[OldSkool81]

Having worked in the auto body industry in the past, it is indeed fish eye. A lot of incredibly knowledgeable answers where posted here, and many things can cause contamination, silicone being a main one, which is why most auto body shop stay clear of silicone-based detailing products like tire shine or interior products. Funny (or not-so-funny?) story: the body shop I used to work at was attached to my boss's house. One summer day, he was working overtime painting a car. His paint shop's fresh air intake was on the back of the building near where their back yard and deck was. His girlfriend lit a couple of lemongrass mosquito repellant candles on the deck, and the fumes got sucked by the intake. My boss used a full-face fresh air induction mask, and told us that he started smelling lemon in his mask, and at that moment he could see the paint instantly beginning to fisheye right before him!!!😅

Edited February 1 by OldSkool81

[yh70]

if its fresh paint you can soak it in 99% isopropyl alcohol to start with 10 minuets. remove and with a old tooth brush start scrubbing, rinse under warm water. you may not see much different at this time. rinse,dry and re-pete for 5-10 minuets..keep doing this if the paint is fresh it will come off less than a hr...(want work on older paint jobs and do not leave in alcohol over 10 minuets at a time)...it will feel a little sticky but no worries once it air dries all will be good..i have did this on resin builds before with no problem..or break out the EZ Off Yellow Can spray it down wait 4 hrs scrub off under warm water re-pet if needed..

[espo]

Ace-Garage mentioned something very important about striping any resin body or part. I once turned a very nice resin body into mush stripping it with the purple power method. Other than sanding by hand, the best approach might be to contact the original caster of the resin part for suggestions as to how to strip the part without damaging the part.