Do you really need to use a primer on the Tamiya kits prior to painting?

you should on the metal, the plastic if cleaned is not necessary.

Priming is always a good idea to even out the overall finish of the final project. If you paint the final coat without it you can have parts with weird finishes from the metal to the plastic. Primer is essential to protect the metal parts from corrosion and adds tooth for the paint scheme later. Plus you can sand, putty, fill holes, add more parts and then prime again to check your finish before the final coat. I included my M4A1 in progress as an example. I just added the metal schumo bits and am about to add putty for the welds. once complete I add more primer and finish up. This is just my opinion of course.

Yes, some type of first layer of primer should be used, especially metal and resins. Plastic CAN soak up the paint (like acrylics) and lose the overall color.

Be careful chosing the primer though. Some really cheap ones must have several coats of paint or need to be sealed.

Plus, clean or wash the item before the primer/paint process to remove any mold release agents and even the oils from your hands.

HTH

I primed the metal but not the plastic road wheels and the hull.

I guess I should have posted this question before I cracked open the paint.