Do all parts of a plastic model kit have to be undercoated please?

[Guest]

And if so, are any better than others, or as I suspect, is this a lot more complex a question than it appears?
Max

[Mr Bowcat]

Max, I'm not stalking you, honest.

Personally I undercoat everything. It gives (imo) a better finish to the top coat, highlights any defects and helps the other layers stick better.

Personally I like the Stynylrez/Badger primers.

[Guest]

Max, I'm not stalking you, honest. :smiling3:

Personally I undercoat everything. It gives (imo) a better finish to the top coat, highlights any defects and helps the other layers stick better.

Personally I like the Stynylrez/Badger primers.

Cheers Bob!

[Jim R]

Hi Max
Agree with everything Bob said.
Jim

[Guest]

Hi Max
Agree with everything Bob said.
Jim

Thanks Jim,
And I’ve just remembered that there are undercoats and primers. Are they used interchangeably?

[PaulTRose]

same thing really

i use everything from mig or vallejo to cheapo automotive primer in a rattle can (which funny enough keeps proving itself to be the best!)

[Guest]

same thing really

i use everything from mig or vallejo to cheapo automotive primer in a rattle can (which funny enough keeps proving itself to be the best!)

Really! Thanks Paul.

[Guest]

And how important is it to match top and bottom coat?

[BarryW]

The use of primer is advisable for the reasons mentioned. To me it is part of creating the canvas onto which you apply your base coats. It can also be used as part of your shading/colour modulation process.

I use an airbrush and for that would recommend either Stynylrez or MRP primer both being excellent.

The first primer coat is to help highlight any build flaws. When assembling you will get filler, glue marks, sanding marks and overspray which makes it difficult to identify problems like unfilled hairline seams or sanding scrapes, knife cuts or even a part slightly misaligned or perhaps a glue ‘blob’. A good primer coat can help highlight these enabling you to take corrective action. You might find yourself going over the model a few times with this until you see the nice even primer over a perfectly prepared model.

By using a coloured primer it can help shade for the base coat. I will ‘black base’ a model with black primer which helps modulate a base coat colour, perfect for lighter colours for instance. Also if you use water based acrylics the primer can give you a surface for the paint to grip that otherwise might peel away from bare plastic. It also blends together different materials into a single colour for painting such as plastic, resin, p.e. white metal and so on.

[Jim R]

Hi Max
I do not think of the first coat of paint being undercoat. It is primer. Some kits have resin and metal parts and the primer provides a nice uniform surface for the next processes. I only use 3 primer colours - white, black and grey. Most often grey. I will use black on shadow areas. Under wheel arches or behind track runs. White sometimes for flat, horizontal surfaces like a truck bonnet or the top of a tank turret. Then when the top coat is sprayed you get a realistic shading.
Jim

[Guest]

Coming late to this discussion. ..
I use the base colour for each area as "undercoat".
Except on figures, as undercoating with enamels risks obscuring moulded details. So, no undercoat on 1/35 or 54/65mm figs.

[Guest]

Many thanks to all, especially Barry for all that detail. It’s looking like a big learning curve ahead!
Cheers
Max