Newbie Modelling Questions

[markoid]

Hi all, 

 

I’ve created a crash test dummy to practice weathering.

 

I cleaned the model. 
Brush painted 3 coats of acrylic colour, blue on top, off-white on the bottom.

Then used a MIG panel line enamel paint.

 

Issues:

 

I noticed some blistering, which equated to removed paint once I removed the enamel weathering with a cotton bud. What would cause this? 
 

On one section of the model, the weathering enamel would not rub off with cotton buds. Why would this happen? I have yet to try thinners, but imagine it will remove it. Just wondering why it comes off in some areas with cotton buds and not in others (smoothness of paint?)…?

 

Generally it worked well though.

 

A separate test saw me spraying Matt varnish on the model. This pooled in a few areas (white gloopy mess). It took lots of sanding to rectify and even then there was  some evidence of the issue. What would cause this? 
 

Thanks for any guidance/advice/experience.

[scotthldr]

Hi, I’ll try to explain the acrylic/enamel thing.

 Acrylic paints can be referred to as a cold paint while enamels are referred to as a hot paint due to the chemical make up within each type. Therefore both types don’t generally go well together. However with care and some basic knowledge both can be used in partnership.

 

Enamels over acrylic: due to the hot chemicals(thinners), within the enamel it tends to dissolve the acrylic underneath, add in the abrasive nature of the brushing action and it will more than likely disturb the acrylic. By using an airbrush and misting on thin coats of enamel over the acrylic, gradually building it up, good results can be had.

 

Acrylics over enamel, this is easier although it’s vitally important to ensure that the enamel is not only dry but fully cured which can take over a week, this allows the gases produced by the enamel thinners to escape from the paint. If not the gases will cause the acrylic to blister and separate.

 

Regards the Matt varnish, was this out of a spray can? It’s sounds like there wasn’t enough control of the pressure which has resulted in more varnish being sprayed in certain areas. As with the above, lightly misted coats gradually built up will get rid of that issue.

Edited November 27, 2022 by scotthldr

[Mike]

aboard Mark - I've moved this to the paint area of the Tools & Tips section

[markoid]

1 hour ago, scotthldr said:

Hi, I’ll try to explain the acrylic/enamel thing.

 Acrylic paints can be referred to as a cold paint while enamels are referred to as a hot paint due to the chemical make up within each type. Therefore both types don’t generally go well together. However with care and some basic knowledge both can be used in partnership.

 

Enamels over acrylic: due to the hot chemicals(thinners), within the enamel it tends to dissolve the acrylic underneath, add in the abrasive nature of the brushing action and it will more than likely disturb the acrylic. By using an airbrush and misting on thin coats of enamel over the acrylic, gradually building it up, good results can be had.

 

Regards the Matt varnish, was this out of a spray can? It’s sounds like there wasn’t enough control of the pressure which has resulted in more varnish being sprayed in certain areas. As with the above, lightly misted coats gradually built up will get rid of that issue.

Thank you, it was a spray can - that sounds and looked like you describe. 👍