What about Gesso Primer?

[CY343491]

Hi,
I've seen some miniature painters using Gesso primers to prime their miniatures by brushing, i mostly work on 1/35 vehicles i have a big bottle of gesso and i want to airbrush it, have anyone tried it before? Will brushing give me good results if i can't airbrush it?

 

[urumomo]

What type of gesso and why on polystyrene ?

 

[blakeh1]

Yeah I never quite got the use of gesso as a primer for plastic minis/models. I would be worried it pulls up.

Personally I think you get better results sticking with a primer made for plastics but I can see how gesso might sound appealing and it is much cheaper (although not necessarily less toxic than spray primer depending on which gesso brand you use as some have carcinogen or toxicity warnings)

If you want to try gesso just beware of some potential issues...

it goes on thick, you can thin it with water but you have to be very careful of tiny air bubbles that pop up during stirring or application

you have to apply it with a brush, airbrushing it one would be very hard as the mix would be constantly clogging the airbrush even at it thinnest, nand if thinned to much it will lose it's cohesion

also it shrinks, a lot. So much that sometimes it can often crack or leave pinholes of bare plastic as it shrinks and you have to go back and do touchups, especially on hard edged corners

You may also encounter it pulling up from smooth plastic surfaces if you do any kind of masking. Thinned gesso is more susceptible to this

gesso is very similar, to if not a form of acrylic paint. So anything that you would be wary of priming with a water based acrylic, you would no want not use gesso on either as a primer

Honestly if you are looking to save costs on primer when painting commercial styrene kits, with most paints you could just skip primer all together rather than using gesso

the only reason I prime these days is to have a dark base to provide some natural shading as I paint the base colors, or if I have had to do a lot of seam filling

On the other hand, for metal miniatures, or resin kits, they must be primed

 

[CY343491]

What type of gesso and why on polystyrene ?

I've found a st.petersburg sonnet black gesso primer with a big bottle in my workshop and don't know where it came from, also don't want to waste it.

 

[CY343491]

Yeah I never quite got the use of gesso as a primer for plastic minis/models. I would be worried it pulls up.

Personally I think you get better results sticking with a primer made for plastics but I can see how gesso might sound appealing and it is much cheaper (although not necessarily less toxic than spray primer depending on which gesso brand you use as some have carcinogen or toxicity warnings)

If you want to try gesso just beware of some potential issues...

it goes on thick, you can thin it with water but you have to be very careful of tiny air bubbles that pop up during stirring or application

you have to apply it with a brush, airbrushing it one would be very hard as the mix would be constantly clogging the airbrush even at it thinnest, nand if thinned to much it will lose it's cohesion

also it shrinks, a lot. So much that sometimes it can often crack or leave pinholes of bare plastic as it shrinks and you have to go back and do touchups, especially on hard edged corners

You may also encounter it pulling up from smooth plastic surfaces if you do any kind of masking. Thinned gesso is more susceptible to this

gesso is very similar, to if not a form of acrylic paint. So anything that you would be wary of priming with a water based acrylic, you would no want not use gesso on either as a primer

Honestly if you are looking to save costs on primer when painting commercial styrene kits, with most paints you could just skip primer all together rather than using gesso

the only reason I prime these days is to have a dark base to provide some natural shading as I paint the base colors, or if I have had to do a lot of seam filling

On the other hand, for metal miniatures, or resin kits, they must be primed

Do you suggest applying it with brush on big models with proper consistency? I also use dark basing on my models like you, i've mostly used tamiya xf-69 to to this day as an undercoat it looks cheaper but it's really more expensive.

 

[blakeh1]

Do you suggest applying it with brush on big models with proper consistency? I also use dark basing on my models like you, i've mostly used tamiya xf-69 to to this day as an undercoat it looks cheaper but it's really more expensive.

The idea is it goes on thick, so thick it actually looks like you obscured details, but then it will shrink

you actually want to kind of glob it on rather than doing thin coats

around the 3 minute mark here is a sample of priming with it

it is pretty counterintuitive to the normal practice of doing very thin layers and kind of shocking how thick it looks




or this one around the 7 minute mark

 

[the Baron]

I wonder if people painting soft plastic figures, like Airfix' figures, used it as a primer, because it might be more resistant to cracking or flaking off. It reminds of the trick some used of using white glue to prime them, because it helped prevent that.
Personally, I would not use it to prime any model, but for making ground work or texturing on diorama pieces.

 

[CY343491]

I wonder if people painting soft plastic figures, like Airfix' figures, used it as a primer, because it might be more resistant to cracking or flaking off. It reminds of the trick some used of using white glue to prime them, because it helped prevent that.
Personally, I would not use it to prime any model, but for making ground work or texturing on diorama pieces.

Have you ever used it to make black wash for dioramas?

 

[the Baron]

Have you ever used it to make black wash for dioramas?

No, wouldn't even think of it. It's far simpler to take some acrylic paint and water, or oil and mineral spirits, to make a wash.