Why grey primer?

[Milo]

Why does everyone start with a grey primer and then a white primer after that?

[MeatMan]

I do it because its hard to see imperfections with white primer. I use grey primer to find and fix imperfections then if I need white primer I'll spray a thin coat of it.

[Dpate]

Besides for base coats. Its good practice to use grey primer to see any imperfections on the model that you may of missed. Only need light coat or two of grey primer to see what u missed. Happens all the time though! You think u cleaned all the mold lines etc and it looks good, and you go to primer and BOOOOOOOM…..Small piece of flash or mold line or dent or something laughing at you. 

Edited July 25, 2023 by Dpate

[Milo]

How do I even clean seamlines and flash? I'm not really ever successful 

[afx]

I would recommend you do a search for model car body preparation videos to help get you started.

 

Edited July 25, 2023 by afx

[redscampi]

5 hours ago, Milo said:

How do I even clean seamlines and flash? I'm not really ever successful 

In my experience, it takes patience, practice and repetition. You may have to work the same area multiple times. A variety of tools may be required in some spots. If you can, practice on some junk bodies and parts to get a feel for it. Treat every part of the kit as a model by itself. When you are happy with that piece, go on to the next.  Rushing through any section will give you less than desirable results.  Mostly, have fun! 

[atomicholiday]

I agree with all that's been said above.   Body prepping requires scraping, filling, and sanding mainly.   Which technique depends on the flaw you're trying to fix.  It might even require all three techniques to fix one problem. 

The way the process works is, you work on all the  problem areas you can see,  shoot a coat or two of primer,  and look for spots that need more attention.   The primer will make them easier to see.   Then you repeat the whole process again until all the flaws are fixed.   You might get lucky and fix everything first try,  but most likely you will repeat the process a few times.   

Patience is key here.   If you miss something, it will become even more obvious when you start painting color or clear coat. 

Give a shot. 

[Horrorshow]

I use grey primer because I can see it better on the white styrene 

[R. Thorne]

Grey primer is easier to see imperfections.  White primer gives the color coat  more “brightness” as the base coat (primer) affects the color coat.

[Dpate]

18 hours ago, Milo said:

How do I even clean seamlines and flash? I'm not really ever successful 

You can use the back side on a xacto blade at an angle to clean up flash etc. I use a ceramic blade though as it’s safer, and can’t damage the plastic by accidentally gouging it. Seamlines and moldlines is different though. The SMS tool is pricey as is the blades, but one blade will outlast 100 pack of xacto blades far as sharpness goes. 
 

Edited July 25, 2023 by Dpate

[OldNYJim]

23 hours ago, Milo said:

How do I even clean seamlines and flash? I'm not really ever successful 

This video might be helpful:

In fact, the whole series is really good - definitely worth watching IMO

[Dpate]

Mold line cleaning

[ColonelKrypton]

On 7/24/2023 at 9:38 PM, Dpate said:

Its good practice to use grey primer to see any imperfections on the model that you may of missed.

Grey primer works well but before you even get to the primer stage you could also use a very light spray of silver over the area you are working on.

Silver shows imperfections even better than gray primer and only a very light coat localized to the area you are working is all that is needed. And, by the time you are done working on that are you will have sanded off or otherwise removed most or all of the silver you had used.

cheers, Graham 

 

[Ulf]

I'm probably not the only one who was surprised when the primer dried, I take à lot of pictures with my smartphone and watch in peace and quiet. Teamsmeetings are becoming a little more productive in fact.

[Ulf]

A follow-up question, I have had some bad luck with ordinary (cheap) universal primer flaking on a Car.
What do you think, should I have used Tamiya's primer, have I neglected to sand or have I applied the color wrong?
I have washed with detergent and toothbrush.
I read about someone who scrubbed with some abrasive paste in corners that are difficult to access.

[stitchdup]

primer works best when it has something to bits into. i usually use some fine grey scotch pads then follow with cheap abrasive household cleaners and a toothbrush. I had a lot of problems doing foil before i started doing this as the paint was just laid over the plastic but had nothing to hold onto due to smoothness of the plastics. I use duplicolour acrylic primers. they will work with tamiya paints.

[Ulf]

Thanks for the response, I will try gray Scotch-Brite but above all be really careful and prep in all corners.