Priming?

[seadude]

Is priming always necessary when building a model kit? Or do some people like to skip priming and just grab a brush and spray can and just paint right away?
As I've mentioned in this thread here:
http://www.whatifmodelers.com/index.php/topic,40345.0.html
.........I plan to build two P1000 Ratte tank kits. One will be in a desert tan/sand paint color, the other will be in a German grey color. I was originally going to go with a olive drab green color for one of the tanks, but changed my mind. The plastic parts for the tank are molded in a tan type color that you can see in Post # 46 here:
http://www.whatifmodelers.com/index.php/topic,40345.45.html
Should I use a white primer or a gray primer on both tanks? And I should also mention that I'll be painting one tank with Tamiya TS-46 Light Sand, and the other tank painted with Tamiya TS-4 German Grey. For the TS-46 tank, smaller parts will be brush painted with Testor MM Acryl # 4813 British Gulf Armor Light which is a very close match to the TS-46 Light Sand spray.

[Rick Lowe]

I've done both, but priming gives a nice, neutral surface/colour to start from. Especially useful for something that's had a bit of hacking about (not the case here, but still).
It can help find flaws you couldn't see before, also. Helps with paint adhesion to PE or resin (or when you've forgotten to wash the thing).
If you use a black, then it can help hide bare plastic if you miss (or can't reach) some of the inner nooks and crannies...

On the whole, my 0.02 says a nice spray primer would be better than not.

HTH

Cheers

Rick

[scooter]

I usually prime with the base color.  For example, my updated Ferdinand, I primed it with Krylon's ultra-flat sand, and then used it as that as the base coat.  And almost a year and a half on, still looks great-

[Hobbes]

For Humbrol and Revell enamels, priming doesn't seem to be necessary. For other paints, YMMV.

[kerick]

it can be useful to prime with a color other than your finish color so you can tell when you have even coverage and when you may have missed a spot. If you have different colors of plastic and putty to cover priming can help get an even finish. Some putties absorb paint more than others which can affect the finish. Priming will help build a sealed layer on the putty.

[pyro-manic]

I would say always, always prime.

[seadude]

For lighter colored parts sprues like light gray, tan, white, etc. Is it better to use a dark colored primer? And vice versa for dark colored parts sprues: Using a lighter colored primer like light grey or white?
What would work best on the tan colored parts sprues I have? Also, would it be ok not to prime the small parts like the anti-aircraft turrets or other tiny/small parts? I'm mainly concerned about priming the bigger parts like hull, turret, etc.

[kerick]

The color of the sprue doesn't really matter as much as the color of the finish paint. White or light grey primer under a sand finish coat would be fine. You just don't want something really dark and then try to use a light color finish coat or vice versa. That would take several coats of finish color which would waste paint and hide detail. If you are painting bright red or yellow on a car or civilian aircraft use white primer. Just don't use primer that is very close to the finish color or you won't be able to judge coverage. I would say for your projects use white or light grey for either tank as long as the primer is a few shades lighter than the German grey you mentioned.

[zenrat]

Priming is one of these topics where everyone swears their way is the only way but in the end I think it comes down to personal choice.

I prime with light grey primer (unless it's red and then I may use Tamiya pink primer or red oxide and I may use matt black enamel as a primer for black paint).  If I am doing a light colour I will then undercoat with white undercoat.  I have tried white primer but it doesn't have the colour density and takes more coats that doing grey primer and then white undercoat.
I would prime the grey tank with grey and then colour over that.  The sand one i'd put on white undercoat before the colour.
I do out this way because it's the way i've got used to doing it on 1/25 cars to get shiny paint.  On aircraft and military stuff, if brush painting (which I tend to do as I hate masking) having primer or undercoat to paint onto makes for a better finish and needs less coats.  With small parts I will attach them to toothpicks or cotton buds and give them a light squirt of primer from a rattle can.  And sometimes I won't.  If parts sit next to each other and different shades will show (and it matters) then paint all the parts together giving everything the same number of coats.  Yellow seems to be particularly prone to this.

As far as sprue colour goes it has no bearing on primer colour.  Although Red and yellow plastic can be a real PitA if using a light colour as they can bleed through making a white paint job pink or primrose.

[NARSES2]

As Zenrat says  it really is a matter of personal choice.

I always prime resin. For plastic if the kit required more then just a touch of psr then I always prime as it helps me spot any problems left. If it's been a nice clean build then you can get away without priming.

I tend to use grey primer for most things but white if I need to paint the kit white or red/yellow/green, although the latter colours can be difficult whatever the primer colour.

Also to echo Zenrat pink primer works well for red and perhaps surprisingly for yellow as well

[Rick Lowe]

I usually use whichever rattle can primer I have at the time, but it's a valid point as to what has been said about thinking about the top colour.

I have noticed that Tamiya will brush paint ok for me ONLY when there is a primer coat - and sometimes not even then... it hates me. 

Cheers

[zenrat]

Green undercoat is also good for red.  It's an old car painters trick to make the red look deeper.

I'll be trying pink under yellow on the next car I paint that colour.

[Army of One]

My tupence worth......I prime.....using Halfords rattle cans  of white or grey...but then I do mostly aircraft models and they suit the colours I us.......I have read the previous comments re primer colours and paint over it......I prime as I was told yonks ago it helps paint adhesion and can show of colours better.....

[Rick Lowe]

Green undercoat is also good for red.  It's an old car painters trick to make the red look deeper.

I'll be trying pink under yellow on the next car I paint that colour.

Now THAT is interesting... you'd have thought it was counter-productive. Have to try that.

Can you keep us updated as to how well the Pink/Yellow works, please?

Cheers

[scooter]

I know yellow under blue can be tricky. But since I need to get rid of the school bus yellow anyway on said school bus...