Primer question

Like I always say, Google is your friend,here check this out

https://www.google.com/search?q=what+does+primer+paint+do+on+plastic+models&sca_esv=559959589&sxsrf=AB5stBi1_QnpnuemQH9tARiFc-wy2tZ3Qg%3A1692965429252&ei=NZroZNGDD96optQP-e6TyAo&oq=what+does+primer+paint+do+on+plastic+&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIiV3aGF0IGRvZXMgcHJpbWVyIHBhaW50IGRvIG9uIHBsYXN0aWMgKgIIADIFECEYoAEyBRAhGKABMgUQIRigATIFECEYoAEyBRAhGKsCSOY5UJMLWKcvcAF4AZABAJgBrQGgAYENqgEEMC4xMrgBAcgBAPgBAcICChAAGEcY1gQYsAPCAgoQABiKBRiwAxhDwgIIEAAYigUYkQLCAgcQABiABBgKwgIGEAAYFhgewgIIEAAYigUYhgPCAggQIRgWGB4YHeIDBBgAIEGIBgGQBgo&sclient=mobile-gws-wiz-serp

It's interesting what happens when you conduct some tests for yourself. And on different materials and with different top coats. In my tests over several years, especially on styrene plastic models, the primered ones have always won, this is with Mr Primer Surfacer and with Stynylrez primers. I haven't yet tested Mr Surfacer but intend to. The tests are for resisting scratches and also masking tape adhesive, both natural and detacked. The tape is a pull test, to which in some cases detacked on non primed paint pulled right off with the tape but with primer even natural tape did not pull the paint in some instances. In some cases with blue painters tape even.

And you can forget acrylic paints with no primer, it may fall off all by itself just from flex and such. Yet with primer the bond is strong. Some of the worst paints I tested without primer became the best with prime. Model Master Acryl being one of those.

Then you have tonal control to consider. Read Tojo's link.

Great answers thanks 

Your welcome,I get into researching stuff

I do lots of research but just got tired and decided to ask

John3M

I do lots of research but just got tired and decided to ask

 

Well now you know a bit more than you did when you asked your question, so it's been fruitful. You should also know though, not all primers are created equal. So there is something for you to determine for yourself. Primers really are quite the topic. And the topic of much controversy. The ones I mentioned work for me and the relatively mild paints I use, the harshest perhaps enamel top coat. But guys who like hot lacquers may not agree with my choice. And those folks are out there using paints like MCW automotive lacquers, or Splash lacquers, Ditzler lacquers and hotter products from the 1/1 auto industry or Duplicolor. Even some commercial enamels ( non model) have acetone in them, an arche enemy to mild primers and sometimes even to styrene.

oldermodelguy

You should also know though, not all primers are created equal. So there is something for you to determine for yourself. Primers really are quite the topic. And the topic of much controversy.

That's what it comes down to.  Research is a good starting point for getting ideas, but experimentation with those ideas is going to lead you to your own, personalized solution that works best for your situation.  At one point, I was even using the nasty, real Zinc Chromate primer from rattle cans that I would buy from the aviation supply place near where I work (the stuff you can't buy anymore).  Also tried several of the automotive primers.  Tried the Testors Model Master rattle can primers.  All of them worked great, but it was really easy to screw up with a rattle can or come across an occasional rattle can that had nozzle issues that made it impossible not to screw up.  At one point, after using primers for a while, I wanted to answer the question of "Are primers even necessary?"  For me, I found that they were absolutely necessary for the paints I was using at the time.  Without primer, I found that the paint would go on, but I could tell right away that it wasn't really sticking to the plastic.  The airbrush was kind of just pushing the paint around, instead of building opacity.  I read about Mr. Surfacer, which I had always thought of as a choice for filling seams, but never thought of it as a primer until I saw people doing that with it.  Tried that and loved the results.  Being able to airbrush it looked so much better than anything from a rattle can, just because so much of the fine detail was still sharply defined.  Then it was on to experimenting with different thinners, and figuring out how much time it required to get to the optimal point of being ready for paint.  I ended up using an extra Tamiya F-14A upper fuselage as my test bed, and my test for adhesion was to put a piece of Dymo label tape on it, burnish it down, and then RIP it away.  When that no longer pulled primer, that ended up being the method I settled on.  These days I use decanted Tamiya Surface Primer.  Its essentially the same stuff as Mr. Surfacer, but my storage solution is a lot less frustrating than those little bottles with plastic lids that tended to get tiny cracks in them.  I store it in a 4 ounce mason jar, and a single can of Tamiya primer goes a LONG way when thinned with MEK for airbrushing.  Also made it easy to decant the entire can, by using an extra mason jar lid with a 1/4" grommet installed in it.  I just epoxy a party straw to the Tamiya nozzle, let it cure overnight, and then blast that whole can through the straw into the mason jar, with the grommet keeping the gases and splashback from going everywhere.

Eaglecash867

 

  These days I use decanted Tamiya Surface Primer.  Its essentially the same stuff as Mr. Surfacer, splashback from going everywhere.

 

I shot decanted Mr Surfacer just this morning. I didn't thin it, normally would a little bit.  It could have used a little thinner but it went ok for what I was doing, a bench seat and fire wall. Two coats and done, the second coat just to catch spots I missed on the first pass at a different angle. And with about 1/4 of a thimble amount of primer and still dumped some back in the Jar ( you don't get to dump anything back in from a spray can lol). I used my Paasche VL with side cup, about 18psi of air. Huge difference from what would have been wasted shooting from the spray can. Came out fine.

I don't use MEK, I don't even have MEK. I use hardware store lacquer thinner. Now my Mr Primer Surfacer I buy in a jar, I thin that with Mr Leveling thinner. I only thin it about 30% because for jarred primer it's fairly thin.

Then I have my Stynylrez, I use that more than the other two combined but it's a whole other story. I won't go down that road right now.

Thanks fellas I appreciate the information by the way re Mr Surfacer i see at least 3 versions of this product? Eaglecash could you add a photo of your epoxy straw setup?

now if you could tell me how to eliminate the popup video that allways contaminates my screen

John3M

Eaglecash could you add a photo of your epoxy straw setup?

I searched around a little bit in the archives and found something better.  This thread has more detail on my decanting method, along with lots of pics.

https://cs.finescale.com/fsm/tools_techniques_and_reference_materials/f/18/t/189063.aspx

John3M

now if you could tell me how to eliminate the popup video that allways contaminates my screen

I'm always on a Windows laptop, using Chrome, and I just use an ad blocker.  The one I use is called AdBlock.  No pop-ups with that installed.

John3M

Thanks fellas I appreciate the information by the way re Mr Surfacer i see at least 3 versions of this product? Eaglecash could you add a photo of your epoxy straw setup?

now if you could tell me how to eliminate the popup video that allways contaminates my screen

 

Mr Surfacer can be bought in 500, 1000, 1200 and 1500 . The numbers correspond with it's surfacing capability in filling imperfections. 500 fills most but is coarsest too, 1500 fills least but it's film is smoothest. Now with that said, I mostly use 1000 which works fine and levels plenty smooth for my needs. It retains details well. 1000 and 1200 are middle ground obviously. But even Mr Primer Surfacer 1000 comes out quite smooth indeed, as well as it's older cousin Mr Surfacer 1000. A lot of folks like the 1200 or 1500.

Then there are jars that have to be thinned for air brushing. Or spray cans in a couple of sizes.

Finally, various colors according to your needs..

Pop Ups: I have a pop up blocker on my computer, I don't see pop ups. I also have Privacy Badger that blocks back door intrusions, presently that's blocking 3. Not bad, I see 5-15 at some other sites.

I can't help you with the O ring picture, I don't decant that way.

Edit: Privacy Badger is now blocking 33 trackers ! So I'll go out of here for a while.