Jump to content

Roden plastic and paint-lift?


Gazzas

Recommended Posts

HI Everyone,

   I've only been back in modelling for 3-4 years now.  I generally use tube acrylic paint over either bare plastic or Alclad Primer.

 

For the past three days I have been fighting the same paint-lift problem despite stripping and re-priming the wings twice.  And it's always down to the plastic.  The acrylic paint sticks to the Alclad no problem.

 

The Alclad Primer just doesn't stick to the wings that well.  Usually Alclad never comes off without sandpaper.  But I can take it off the Roden plastic with either a fingernail or a nylon bristled brush.

 

I've run out of ideas. 

 

Anyone got any?

 

Thanks,

 

Gaz

Link to comment
Share on other sites

Try a hot primer, like Tamiya spray can type. Or automotive type, finally, the nuclear option is to decant some automotive adhesion promoter and spray that.

Thanks for the reply.  I figured that Alclad primer would be 'hot'.  Maybe not.

 

Gaz

Link to comment
Share on other sites

Before you try that, try cleaning it with a caustic chem. Not sure what you have there, but here we have Bleech White, Purple Power, Simple Green, etc. soak at the parts for 15 minutes, then scrub with a toothbrush. That will get rid of any mold release agent.

 

However, if you cleaned, sanded, and your paint flaked, then I suspect it's the plastic formula. You probably need to use adhesion promoter.

Edited by 1to1scale
Link to comment
Share on other sites

Thanks for the tip!  I've got simple green and that worked great on the acrylic paint.  Because it's a WWI plane, I can't sand very much because of the wavy structure caused by wood and canvas.  I think what I'm going to do is sand the damaged areas as smooth as possible then paint with enamels and brush since the A/C were doped by brush at the factory.  I have the base color enamels, so should be able to mix easily.

Link to comment
Share on other sites

The biggest problem with paint adhesion is grease/oil. I always degrease models before painting. Handling models will leave natural skin oil residue all over the model. I use a degreser spray made by a brand called Tec7, available from my local hardware store. Look for "Tec7 Cleaner". It does not attack paint or plastic. I spray it on, spread it with a brush and then wipe all over with paper towel or cotton buds in the smaller places. Wiping is important. I read on forums about people soaking parts in really aggresaive substances with "no good results". If the part is only soaked, then the oil/grease is just diluted and possibly spread over even more area. Wiping actually removes that oil/grease from the surface.
Hth,
Radu

Edited by Radub
Link to comment
Share on other sites

The biggest problem with paint adhesion is grease/oil. I always degrease models before painting. Handling models will leave natural skin oil residue all over the model. I use a degreser spray made by a brand called Tec7, available from my local hardware store. Look for "Tec7 Cleaner". It does not attack paint or plastic. I spray it on, spread it with a brush and then wipe all over with paper towel or cotton buds in the smaller places. Wiping is important. I read on forums about people soaking parts in really aggresaive substances with "no good results". If the part is only soaked, then the oil/grease is just diluted and possibly spread over even more area. Wiping actually removes that oil/grease from the surface.

Hth,

Radu

 

Indeed, simply soaking is not enough.

I usually wet the parts with warm water, then  scrub with soap and a toothbrush, and then  rinse them with warm water and still the toothbrush.

If my model is greasy after so much handling, before painting i rub it with a kitchen towel and some mineral spirit, as alcohol would attack some puttied areas.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...