Opinion on primer painting please

I don't know that it matters what type, AB or rattle can. It's just, in my opinion, important to make sure you do prime.

If you use acrylics, then look at Mr. Surfacer or Vallejo's Primers. 

Bob

Agree with that. Wouldn't air brush primer be thinner?

Lt. Smash

If you use acrylics, then look at Mr. Surfacer or Vallejo's Primers. 

Bob

Air brush or rattle can?

I only prime on some builds of mine. But in cases where I do prime. I prefer to airbrush the primer due to better control.

Hokey

Lt. Smash:

If you use acrylics, then look at Mr. Surfacer or Vallejo's Primers. 

Bob

 

Air brush or rattle can?

Vallejo is airbrush only (I think).  Mr. Surfacer can be either.  I prefer airbrush because I get more control. 

Bob

Actually, Vellejo offers both the spray and AB type primers. I'm debating which to get. The spray type is easier to use for sure. However, Vallejo AB primers come in Dark Yellow & Russian Green among many colors. Since I build mostly WWII German & Russian AFVs, those primers would also serve as base coats. Any thgouths?

Thanks all for the input!

I don't prime as I see no need for it.

Chris

I have always used a primer, even in my enamel days

and I also always pick a primer based on being able to use it as one of the colors on my model

I use a white on the bulk of my aircraft, because if I get a good primer coat that I am happy with, all I have left to paint on the model is the topside, and the trim colors

The importance of a primer when using Acrylic paints is simple, once you know how Acrylics dry,,,,,I am only talking true Acrylics, in the western sense of the term, not the Acrylic Lacquers marketed as Acrylic paints, because they can get away with it

Acrylics that are water clean up need a primer coat,,,,,,because they dry into a membrane over the plastic model, shrinking as they do,,,,they don't have that "bite" to grab the plastic that Enamels and Lacquers have

so, they need a buildup of coats, to cover the plastic as a "seal",,,,,,,that "seal" after it has done all of its shrinking, gives the paint something to "bite" into that it wouldn't have on the bare plastic,,,,,and the best bite is onto paint of the same manufacturer

 I use LifeColor white primer under LifeColor paints, Vallejo has a gray that matches one of the Jet colors, and Testors Model Master has an Acrylic Primer in Gray

I would think your idea would work just great  to eliminate a coat of paint on a model,,,,,and that would also save some time along the way

Rex

I use Tamiya grey primer in the rattle can. Wonderfully forgiving and gives their paint excellent adhesion.

TarnShip

Acrylics that are water clean up need a primer coat,,,,,,

I have yet to see any paint that is "water clean up" for modeling.

I use Tamiya acrylics and have never needed a primer even with extensive masking like this P-47D of Gabby Gabreski's.

GreenThumb

There are at least 5 paint lines that are truly "water clean up for modeling",,,,Tamiya and Gunze are not in that list

they are the two that claim to be Acrylics because they can get away with it,,,,,based solely on the fact that their pigments are made of ground up colored plastic particles

LifeColor, Vallejo (all the many lines), PolyScale (and the related Floquil), Model Master Acryl (current formula), and Italeri (same formula as Vallejo),,,,,can all be cleaned right out of the paintbrush with running water, I think I heard that XtraCrlyix and Revell Aqua can also

those paint lines all adhere by the "evaporating membrane" method,,,,,and need a primer to keep them from creeping away from corners as they shrink (I have actually used 5 of the 7 paints I have named above)

the Tamiya and Gunze paints get their adhesion the same way as Enamels and Lacquers do, they bite into the plastic a bit, and as the hot solvents evaporate, the pigment is imbedded in the plastic, and on top of it

the confusion is based on applying a term to one type of paint, to another type, when they should have completely different names "Acrylic Enamel" vs "Water clean up Acrylic"

TarnShip

they are the two that claim to be Acrylics because they can get away with it,,,,,based solely on the fact that their pigments are made of ground up colored plastic particles

Rex, this may be hearsay.

I'll concede that the bottles I'm looking at are "vintage", but the contents are listed as follows:

Tamiya Acrylic:

• Water Soluble acrylic resin 40.3%
• Pigment 14.1%
• alcohol 19.9%
• Water 25.7%

Gunze Aqueous:

• acrylic resin 23%
• pigment 14%
• alcohol 27%
• glycol 10%
• water 26%

The current formulations of these paints may have changed a little over time, but I don't think they would be too different.

The term "acrylic" does not simply refer to the paint being water soluble (which both Tamiya and Gunze Aqueous are, when wet) - it refers to a particular chemical formulation which, when it cures, forms acrylic polymers. The type of reducer/carrier medium used is irrelevant.

Acrylic paints don't just dry, they also cure. This curing process causes the binder in the paint to form a film of acrylic polymer on the surface of the model.

okay, I said membrane, you say film

completely different

and that itself means I am lying when I say that I can clean those 5 kinds of paint from the brushes with running water

and that a primer is needed with those 5 kinds of paint to give the paint something to adhere to as the film/membrane is formed

I will just quietly keep on using the 3 out of 5 Acrylics that don't make SWMBO weeze and go to the ER, and I will continue to avoid the 2 that act like Floquil Lacquer, right down to the use of Lacquer thinner to make them "hot spray and fast dry"

I would suggest a primer regardless of the paint. A primer is not only meant to help the paint stick better, but it's designed to give you a solid base color and identify any seams or gaps you missed along the way. The Vallejo primers (acrylic) are great, just be sure to clean the model well beforehand. Tamiya primers (lacquer) are my preferred primers for their ease or painting and durability.

When using ANY type of acrylics, a primer is a must. As Phil said, ALL acrylics form a layer over the plastic, which really doesn't "bite" down onto anything. Acrylics stick better to themselves than anything, but a good primer will help. As already stated, acrylics may set or dry in a matter of minutes, but they take hours to fully cure. Even with a primer, let the acrylics fully cure for several hours before masking.

Tamiya, Mr. Hobby, and Gunze acrylics have stronger thinners, but are still acrylics, and they can lift off the plastic just like other acrylics. The only reason they have stronger thinners is to make them airbrush better, since you don't get the surface tension/cohesion in alcohol that you do in water. Even if you use lacquer thinners with the above, the paint still won't bite onto the plastic (it will just airbrush better). High-tack masking tape or your finger nail can lift them off an un-primed model.

I honestly don't understand why this wouldn't make any member of a forum angry

one guy says something "stuff don't stick to stuff, it forms membrane, needs it's own stuff to stick to goodly"

another member says (in rebuttal, lol) that "stuff forms film, because if don't stick to other stuff as well as it sticks to itself"

and the first is "internet wrong", but, the second is "high internet genius"??

Acrylics need a primer, because they need something to stick to besides the plastic that they won't adhere to,,,,,,,because they don't bite into the plastic for their adhesion

Acrylics that are true water clean up, actually do clean up with just water, and then the brushes can be "washed with soapy water and shaped with your fingers, and stored upright to dry" just like the final stage of cleaning a brush used for enamels,,,,,,in your airbrush it is a good idea to run an airbrush cleaner through to make sure there is no paint drying in there between this paint session and the next,,,,,dried Enamel can be cleaned out of your airbrush fairly easily,,,,dried Acrylics take a soaking in Airbrush Cleaner, at least overnight, to loosen up the dried paints

the two "Acrylics" that won't clean up with soap and water, I have no idea about,,,,,they would try to kill my Lady if I use them in the house, same as Lacquer would

I have no idea what substitutes work for thinners or cleaners,,,,,,I use Medea Airbrush Cleaner, and LifeColor, Vallejo, Testors Universal Acrylic thinners for my LifeColor, Vallejo, Color of Eagles, Model Master, and PolyScale paints,,,,,and will use Italeri for those paints, and try the Vallejo thinner on the Italeri paints,,,,,,I ruined 2 paint brushes "back in the day" by trying to follow "home brew concoction" thinner advice,,,,at $4 to 6 each, I don't risk brushes on those ideas anymore,,,,,,,,,oh, and I wash models before painting,,,,had the oil caused fish eye thing once,,,,no sense repeating that lesson, either

but, each person should do it his own way, of course,,,,,,,as long as there is no spark and stoicometric mix combined

Dude, I have no idea what you're talking about. Everyone here seems to be in agreement that acrylics don't bite onto plastic and thus need a primer. I don't see anyone here making accusations of "internet wrong" or whatever it is you are referring to. We're all just trying to help. Nobody is trying to tell you what "acrylics" to use for whatever you want to use them for.

And as you said, everyone does things their own way. For instance, I usually warn people about letting acrylics sit too long in an airbrush, cause I ruined a nozzle once when the acrylics hardened overnight. But it sound like you had better luck cleaning out dried acrylics. Neither of us are wrong, we just had different experiences.

I don't know why you are getting angry over a forum post. None of this is set in stone, and there's enough frustration already trying to build a model. I don't know if you're trying to pick a fight with me or what, but best of luck to ya. I don't really care either way. I'm just here to help out where I can with what I know and/or have had success with.

Cheers

naw, not trying to pick a fight

I just don't get where I say something, and then that gets skipped over, so that the person that repeats what I said is the one that is quoted

it is not as big a deal as I made it, sorry for that

I do not do many things in this hobby the "way it is done now",,,,I go ahead and use the name brand stuff for everything, sort of a snowball effect of kit price, I think,,,,,once I pay so much for a Nine inch long jet, I can't make myself use cheap choices from then on, or skip steps ingrained from 40+ years of doing this

hate the thought of a nickle brush, a half price paint, or using water instead of real thinner, causing me to ruin a $40 kit, painted with 8 different colors of $4 bottles of paint, with a $20 decal sheet

and just in case you ever need it,,,,,,,,there is a "soak-em" product for each kind of paint that will work to clear out an airbrush, as long as you dissemble it and remove certain things, like Badger's Teflon washer, before soaking it,,,,,,some will only soften the hardened paint into a goo, but, then you can get it out of there