Can I use a flat white or flat grey as a primer instead of buying primer?
uh, what are you painting, scale models or miniatures? if it is the first one, I would have to say get the primer. if the later, sure go for it.
Shhh! [XX]That is a well guarded secret. I do just that on most of my builds where priming is a requirement.[#toast]
Absolutely. Tamiya flat sky gray (acrylic, no less) is my primer of choice.
This is an interesting question. Especially since I use Tamiya paints and they don’t make an acrylic primer. Just the other day I purchased Testors Model Master Gray and White Acrylic Primer to fill in for the lack of Tamiya primer. I’m wondering though, do you think the MM acrylic primer is just flat gray paint? Or do you think it is a special forumula that makes it a primer? I would like to just use Tamiya sky gray like you mention Triarius if the MM primer is just regular paint. Does anybody know about this?
Thanks
Burt
Primers are sometimes—not always—formulated for certain characteristics, and those vary. For example, many automotive primers are made to form thick coatings that, once cured, can be sanded. Primers are also usually formulated to dry and cure relatively quickly so that they can be sanded and overcoated in a short time. Some primers are intended to help hide the color of the substrate, others only to improve adhesion of the overlying paint.
In scale modeling, there are only three reasons to prime: to help find surface defects, to improve the color and hide of colors like white, yellow, and orange, and to prepare the surface for a specialized coating such as Alclad. Since my primary use of primer is for the first of these, and since I tend to wait quite awhile after priming or force cure the paint, the Tamiya flat gray works quite well for my purposes.
Whether the MM primer is specially formulated for any of the specific characteristics of a primer—especially adhesion and rapid drying—I do not know. I do know I’ve had more adhesion problems (and heard of more adhesion problems) with MM acrylics than any other brand. Tamiya acrylics, once fully cured, have the second best adhesion of any acrylic I’ve tried (Polly Scale has the best). I use Tamiya because it is more economical than Polly Scale to use as a primer.
The critical thing with any paint, but especially an acrylic primer, is that it must be fully cured—and acrylics are generally slow to achieve full cure.
Thanks for all that information Triarius. So do you think if I primed with Tamiya gray, but had to use let’s say, Polly Scale Navy Blue over the top, would the two brands work well together? Have you had success with mixing these two over each other?
Tamiya and Polly Scale are my brands of choice—I hardly use anything else except Talon metallic acrylics.
Tamiya and PS work well together because they use different solvent systems. Tamiya is primarily alcohol, PS primarily aqueous.
I use some automotive primer called “Zink Galvanizing Compound” and I use it for paint to stick better, and that primer I use works perfectly!! [:)]
Are you talking about this?
It’s high in Toulene and MEK…be careful applying it to bare plastic. It could cause it to craze. Definitely DO NOT use near open flame…the propellent in the can is Butane and Propane…the only inert thing is the zinc it contains as the primer medium.
That’s not the one, HawkeyeHobbies… Mine is made by arrow and has instructions written all over it. Texting applied over bare metal. Also it has a blue cap, and produced by Arrow…
It works beautifully [:)]
Sheesh! Huxy! At first glance at your pics, I thought you got too close to flames that HH wrote about![:O]
Ross and Gerald: Does this thread bring up the old buggaboo about enamel paint over acrylic…and vice-versa? Or is curing time of the primer the key?
Curing time is the key. I painted layer over layer of mixed match paints. The only time I’ve ever had problems is when using a lacquer based paint over something else before it had fully cured. The paint reacted with the previous layer and crazed it. That’s what I get for being in a hurry. Lesson learned.
I used a spray can of some kind of paint from work once…being the right color I decide to give it a try. It covered the model beautifully! After a short while I was able to remove the masking. The next day I was going to start applying the decals…when I returned to my workshop I had a mess of molten plastic resembling an aircraft on my bench. The paint had a slow but lethal reaction with the plastic. Then I read the label…FOR USE ON METAL SURFACES ONLY! Duh![V]
See why those re-re-released old school kits are still appealing…gives newbies the chance to make the same mistakes we did at an economic price point. Of course now many of those paints we used are long gone for environmental reasons. Once a neighbor lady painted her car with a case of spray paint. You know what…it really turned out nice too. Not body shop quality but still acceptable for a family beater mobile. Everyone laughed when she started…but in the end she had the last laugh.
Nam,
Curing time and surface cleanliness are the keys to the Kingdom of Adhesion and Smoothness.
I felt pretty sure of yours and Geralds ideas on this…I needed the re-enforcement and thought further clarification would be helpful in this thread for others’ sake.
No hijack intended…but thanks guys!
Hey Guys,
I just got done priming a few days ago and noticed some areas that I needed to go back in and work on. After working out some of the problems with some sand paper, I sprayed my priming layer on for a second time over those problem areas, but have now noticed that the priming paint has dried at two different shades of gray. I will note that I am using Tamiya Sky Gray as my primer.
Now I’m not sure if I just didn’t spray enough paint on so that the plastic wouldn’t show through or if there was something on the model after sanding that is causing those areas to dry a different color. Any thoughts on this?
Thanks
In all likelihood, it’s not a problem as long as adhesion is good. There are several things that could cause this. The most likely are the change in surface texture from sanding, difference in application, and contamination of the surface with sanding residue. Only the last is necessarily bad. Whenever you sand, the model has to be cleaned thoroughly.
It is also possible that you did not get the same degree of dispersion of the pigment each time. Grays tend to have that problem, especially in a reduced state, because of the widely different specific gravities of the pigments in them. Since this is a primer coat, it makes no difference.
There is a modeling subject where a special primer is a must. I’ve learned from my wargame forums that many guys use Rustoleum Plastic Primer when painting soft plastic figurines (like the 1/72 ones from Revell, Airfix, Zvezda etc.
Dave
Hey Ross,
Thanks for that bit of information. So do you think when I lay down my blue and white colors I will be able to see those different primer colors in some sort of way, or will these colors cover up those uneven primer areas?
If the primer has a different surface texture (look at it in raking light so as to produce a glare on the surface) you will see the difference in the finish coat. Dark blue will hide pretty well, but white should be undercoated with silver.