Bubbles formed on model after spraying krylon gloss coat

Hi :

    I have to ask you an important question first .

    What brand of paint did you use for your color and prime coats ? If you sprayed KRYLON over TESTORS you will get that reaction . KRYLON is a " hotter " paint than others . In doing models for clients I have learned to keep the brands the same .Otherwise you have problems .

I use , on large models RUST - OLEUM primer exclusively and then TESTORS as well as any Acrylic Over that..For clear I use either the aforementioned brand or Craft clear gloss from Hobby Lobby .

   Always use a primer and Never use any brand of paint over enamel or Acrylic that is a " Hotter " Paint .The brand of paint can react with the undercoats . Also , did you paint it with model paints all the way ?

 That's one of the reasons I never mention KRYLON  .Because it's formulated to dry faster it will chemically react with anything NOT their brand . Don't get me wrong . It's a great paint . I just don't use it on models !                 Tanker - Builder

I've had mixed results with Krylon.  It's all I had, so I used it.  It worked fine over Model Master Acrylics and Humbrol enamels.  It really dulled Model Master enamel chrome silver (but I wanted that effect anyway), but completely destroyed the Tamiya acrylic I just used it on.

Great advice, Tankerbuilder, I just wanted to pass on my experiences for others.

There is a forum about Airbrushing and Painting, down near the bottom of the list of forums. You might try there.  Compatibilities of paints are a frequent topic there.

At a guess, I'd say you sprayed too close to the model.

Paint inside a spray can is a mixture of paint and liquefied propellant.

When you spray, it's unavoidable that an amount of propellant is discharged from the can with the paint. When the paint/propellant mix hits the atmosphere outside of the confines of the paint can, the propellant boils off and "gases out".

As long as the can is a sufficient distance from the subject (typically 10-12 inches) when you spray, the majority of the gas will be released by the time the pain hits the surface.

Too short a distance and the paint will reach the surface still containing unexpended propellant. If the paint starts to skin before all the propellant gases out, bubbles will be trapped below the paint's surface.

It'll also happen if the paint is laid on too heavily and especially under hot, dry conditions which cause the paint to skin over very quickly.

Note also that it's not peculiar to any particular paint brand. Any and all spray paints will do this, but it's more apparent with clears for the simple reason that you can see through them.

Hi :

    I have to ask you an important question first .

    What brand of paint did you use for your color and prime coats ? If you sprayed KRYLON over TESTORS you will get that reaction . KRYLON is a " hotter " paint than others . In doing models for clients I have learned to keep the brands the same .Otherwise you have problems .

I use , on large models RUST - OLEUM primer exclusively and then TESTORS as well as any Acrylic Over that..For clear I use either the aforementioned brand or Craft clear gloss from Hobby Lobby .

   Always use a primer and Never use any brand of paint over enamel or Acrylic that is a " Hotter " Paint .The brand of paint can react with the undercoats . Also , did you paint it with model paints all the way ?

 That's one of the reasons I never mention KRYLON  .Because it's formulated to dry faster it will chemically react with anything NOT their brand . Don't get me wrong . It's a great paint . I just don't use it on models !                 Tanker - Builder

I use krylon primer and krylon paint. Since it's 2 tone, I sprayed gloss blue on the top roof and decided to use my black primer as the main color on the body. The bubbles formed on my black primer. Also does it mean I have to stripped the paint and star over again?

AHA !

The plot thickens .I will ask you now .How long before you sprayed , did you shake the can and how Clean was the model's surface .These are very important factors here . I found out , quite by accident I might add.

.I bought some Paint in a spray can .( brand is unimportant ) I sprayed a client's model  .Had to strip the whole darned thing . Maybe there was a bearing on this , that when I checked the can to see if I did a no - no I found out the can was over five years old Before I had purchased it .

      In dealing with paint from a body shop ownership stand point - paint formulations change every year ( slightly ) .Now with the shift to non-cfc's in the propellant this affects the end results in that , it can ( I asked a Chemist ) change the very nature of the product .

  So you could have two cans , different batches , that are sensitive to this . And this could be different from the primer to the surface the paint is going on too .

   Years ago , I loved my paint jobs that were perfect because I used a tack-rag ( or cloth ) to prep them for paint . Bought some different brand ones and the paint already on the subject got tacky and wouldn't set after I used these rags .Turns out , that company used a cleaner enhancer that should not come in contact with model level or house - hold paints .

    I hope this explains some of what may be wrong here .Also , did you wash the model well and RINSE it well and let it air dry Before you sprayed it ? ( another point to consider ) .Bye .      Tanker - Builder

What I did was after everything was finished  I let the paint dry for a few days then shake the gloss spray can and started spraying the model and it seems ok so far. Did it twice(shaking the can every once in a while) and no bubbles.  The next day I did a more intensive spray (moving slower since I saw this tutorial on how to spray using paint can in youtube) since I noticed the gloss were uneven and I wanted to have all the body part glossy, that's when i noticed the bubbles forming on one side of the body. Now when you asked if I had washed the body did you mean before spraying the gloss? And thanks to everyone who contributed.

Yes .

No I didn't. Yet like I mentioned on the first 2 coat everything was ok except for the uneven gloss. Do you just wash it with water and let it air dry before applying the 3rd coat of gloss?

I would say YES to that question .Then let it air dry under some kind of dust free cover ! You can take a paper towel ( not a KLEENEX ) and siphon off the excess water before covering it .