Halfords paint primer question

[wombat]

hello all. I wonder if I could check back a couple of half remembered facts from previous threads elsewhere:

(1). Halfords plastic primer spray can is acrylic 

(2). You can put enamel on top of (well cured) acrylic but not the other way around.

 

thanks all

[Space Ranger]

(1). Don't know about Halford's; I don't think it's sold here in the US.

 

(2). This gets complicated. The general rule that I have followed since so-called "acrylics" were introduced is: "acrylic" over enamel over lacquer, but not the other way 'round. However, this depends on what kind of "acrylic" we are talking about, and this is where chemistry enters the picture. Most people use the term "acrylic" to refer to water-miscible paints such as Tamiya's. But not all "acrylics" are equal. A paint is composed of a pigment (color), a vehicle (the carrier liquid), and a binder (the film-forming component of the vehicle that holds the pigment in place after the paint dries. "Acrylic" may refer to the pigment (synthetic as opposed to organic), or the binder (synthetic as opposed to organic, such as linseed oil or a petroleum-based oil solvent). Most hobby "acrylics" are, I believe are those with synthetic pigments and/or binders, usually in a water-miscible (mixable) vehicle. But some "acrylics" are acrylic lacquers (acrylic pigments in a quick dry solvent that contains nitrocellulose resin, another organic substance), and some are acrylic enamels (acrylic pigments in a petroleum-based solvent).

 

Enamel paints use a process that allows polymers in the paint to set and bond together so when the paint hardens, it will not soften again. This is why you can brush additional coats over the original coats once they have cured. In contrast, lacquer paint dries when the solvent has evaporated and can soften over time or dissolved with the application of additional coats. Tamiya "acrylics" are technically enamels, using acrylic pigments which polymerize in an organic solvent — alcohol — which just happens to mix with water.

 

The point of all this is that you should be aware of the chemistry of the "acrylics" you are using. But for most hobby acrylics. the general rule that I set out in the beginning applies.

 

 

 

[wombat]

“Acrylics” that are really enamels!?!? My head hurts.

 

having looked at the can it refers to cellulose so it’s that kind of acrylic

[Space Ranger]

10 minutes ago, wombat said:

“Acrylics” that are really enamels!?!? My head hurts.

There will be a quiz tomorrow. :-)

[Davva]

I use the Halfords plastic primer with Humbrol enamels. Works fine, just wish there was a wider range of colours other than Grey & White

[cmatthewbacon]

I’ve never had any issues with the brick  red and yellow/beige Halfords regular primers over plastic either...

 

They all dry a bit rougher than Tamiya fine surface primer, though.

 

best,

M.

[Dave Swindell]

The ordinary halfords primers work fine on plastic.

The "plastic" primer is a description of the paint, not the substrate it is sprayed on (though this is usualy plastic as well).

The paint is formulated to remain flexible (plastic) without cracking when used car bumpers etc.

This feature isn't really relevant to plastic models, so you can get the 500ml can of ordinary primer for £1 more than a 300ml can of plastic primer.

[wombat]

So basically, it shouldn’t work but it does ?

[bentwaters81tfw]

12 hours ago, wombat said:

So basically, it shouldn’t work but it does ?

Correct. I use it all the time. Just make sure the primer has gassed out and dried thoroughly. Sometimes you get a reaction. I have had it craze. Try a test piece, or even coat the primer with Klear before the colour coat.

[Davva]

On 18/04/2019 at 09:39, Dave Swindell said:

The ordinary halfords primers work fine on plastic.

The "plastic" primer is a description of the paint, not the substrate it is sprayed on (though this is usualy plastic as well).

The paint is formulated to remain flexible (plastic) without cracking when used car bumpers etc.

This feature isn't really relevant to plastic models, so you can get the 500ml can of ordinary primer for £1 more than a 300ml can of plastic primer.

Now that I did not know... thanks👍

[wombat]

On 5/9/2019 at 9:03 AM, bentwaters81tfw said:

Correct. I use it all the time. Just make sure the primer has gassed out and dried thoroughly. Sometimes you get a reaction. I have had it craze. Try a test piece, or even coat the primer with Klear before the colour coat.

Unlikely to be a problem...I get so little time for modelling you can count the rings between coats of paint...

[Skodadriver]

On 4/13/2019 at 11:37 AM, wombat said:

hello all. I wonder if I could check back a couple of half remembered facts from previous threads elsewhere:

(1). Halfords plastic primer spray can is acrylic 

(2). You can put enamel on top of (well cured) acrylic but not the other way around.

 

thanks all

 

Sorry I didn't reply sooner but I've only just noticed this thread.

 

I have used Halfords primer for a couple of decades, sprayed on to bare plastic and overpainted with every conceivable type of paint - enamel, acrylic in all its varieties, automotive, polyurethane, metallisers. You name it I've applied it over Halfords and I've never, ever had an adverse reaction either between the primer and the plastic or the paint and the primer.

 

Spray it on, let it dry, rub it down lightly (I recommend 1200 grade wet and dry followed with 0000 grade steel wool) and you're ready for the top coat. While it's a bit rougher than Tamiya primer, Halfords is a LOT cheaper and more readily available in my part of the world.

 

It's always a good idea to try an unfamiliar product (or combinations of products) on a scrap model or a cheap kit quickly knocked together before tackling your masterpiece.

 

Dave G