We are having a discussion about this on another thread. I thought I might ask some specifics here instead of hijacking the other thread. Know what I mean? What is the difference in the "base" of paints? I think I know what "water based" means. What are the differences in lacquer, enamel, acrylic, others? How do these apply to automotive paint types or other paint types? I like to use the water based paints because I think it is safer. It seems to work well now. At least better than 10-15 years ago. Pretty open ended question, I know. Maybe there is a website about this?
Flash, I allways thought the 'base' referred to what the paint started with like 'latex house paint' has a 'latex' base. But I don't think that holds true for model paints as I think that the term 'base' for model paints refers to what you use to thin or clean up the paint with. Floquil used to be a 'solvent' base but the new formula is 'water' based. However I do recall the when Badger made their 'water' based paint we quickly learned that thinning with 'water' would have some pretty funky effects. I haven't used Badger for so long that I've forgotten what worked as far as thinning, it was either alcohaul or windshield washer fluid. Accupaint is alcohaul based paint too. My 2 cents. 2slim
Actually Floquil is still a solvent base, meaning it is an enamel. It used to be a laqcuer base, virtually an automotive lacquer, but government regulations forced us to change it into a more user friendly enamel formula much like Model Master and Testor. That said, even though both Floquil and Model Master enamels are made in the same plant, they are not the same. In the craft and model industry, Acrylic base is any type of paint that is water soluable. It is made up of a vehicle or binder, solvents, pigments and additives. Polly Scale uses a water soluble resin as a vehicle. These resins can be diluted or reduced with water, water cosolvent mixtures and sometimes with alkali. This type of resin is produced in water soluble form by incoperating acidic groups, e.g, carboxyl, in the molecular structure. These groups are then neutralized by bases such as ammonia or amines to form products soluble in water. So in this case, because of the vehicle the solvent is and can be water. If you have had trouble with tap water, it is because of the chemicals in the water, not the water itself. I always use Polly Scale thinner, but in more humid weather you can use bottled water. The few times I have used city water were bad:angry: Any paint that uses a chemical as a solvent is usally, at least in our industry, a solvent base. Enamels use a solvent base thinner basically anything that is not a water or alcohol base. Both Lacquer and enamels are considered solvent base, so if we look at what is out there for us train modelers we have: Floquil: Enamel, solvent base Polly Scale: Acrylic, water base Model Flex: Acrylic, water base Scale Coat: Lacquer, solvent base (and requires a barrier) Accu-Paint: Enamel, solvent base Is this a help or am I boring you? Paint can be a dry subject, pun intended:teeth:
Now when you are thinning solvent based paints you generally have two types of paint or bases, Enamel and Lacquer. Although both are a solvent base, they require different thinners. Enamels: In general the best thinners for enamels are those which contain petroleum distillates. These thinners are primarily blends of aliphatic hydrocarbon solvents such as mineral spirits, naphtha, or stoddard solvents. Occasionally these thinners also may contain small amounts of aromatic hydrocarbons (such as toluol or xylol) to enhance certain application and performance properties of the paint. Lacquers: on the other hand, usally contain little, if any, hydrocarbon solvents. Instead, they usally contain what is often referred to as "active" or oxygenated solvents. These include ketones (such as acetone, MEK and MIBK), esters (isopropyl acetate, butyl acetate) and sometimes alcohols (isopropyl alcohol, butyl alcohol), and occasionally small amounts of aromatic hydrocarbons. Now lest you think I actually remember all of this, no it is from our Model Master Technical Guide. I wish I could remember all of this but I'm no lab tech guy. Is this helping?
Concise Information Not boring me...:thumbs_up: Exactly what I wanted to know. Your last summary of the types is best. I looked up some internet information and found that most technical writing is about automobile or structure paint. I found some basic dictionary definitions that were good, too, but they are generic. I was surprised to learn that lacquer is a natural product, originally from Japan, of course, and the transfer medium never completely dries. Here is the dictionary definition: "Any of various clear or colored synthetic organic coatings that typically dry to form a film by evaporation of the solvent; especially : a solution of a cellulose derivative (as nitrocellulose). Also, a durable natural varnish." It states that it was originally derived from the sumac tree. As I understand it now, the "solvent" and the "water" is the carrier type. The "acrylic," "enamel," and the "lacquer" is the pigment. It explains why you can't mix these. Thanks for the information. :happy19pb:
Not boring me either! A lot of my paints are 15-20 years old, still usable. Paints are one area of the hobby, I think, that a lot of modelers just don't follow. So the more information the better.
Glad you guys are enjoying it! Color theory and paint has become my passion ever since I started working here at Testor six years ago. Some other interesting things about paint that may be of help to you. The two most comon paint bases, acrylic and enamel have different charecteristics. Acrylics: As said above they are water based and dry a bit different. Acrylics generally use an alcohol base as a thinner so you can airbrush them, as you know alcohol tends to dry faster than water. That is why Polly Scale thinner which is primarily made up of alcohol has a reducer in it. The reducer does two things, one supends the drying time of the paint paint and two helps with the flow of paint. Acrylics dry from the inside out. Dry heat is the best way to spead up drying acrylic. Also of note, try to use the minimum of thinner with acrylics as the thinner will break down the paint and adhesion. Unlike solvent base paints, the thinner becomes part of the paint even after it is dried. That is why I recomend 25% thinner to 75% paint to most Polly Scale colors. A 50/50 mix will make masking and lifting problems later. Enamels: Enamels are maid up of alykds and as such enamels actually heat up as they dry. That is why a lot of the old timers used to put their metal models in an oven at a low heat seating. The aylkds heat up and cause the paint to develop a skin and dry from the outside in. This chemical process is much like the oxidation in steel. Unlike acrylics, thinner and other solvents eveporat as the paint cures and one is left basically with the pigments and resin. Thinning enamels as much as 50/50 or more is fine and is not uncommon. Another misconception is confusing "Dry" time with "Cure" time. Dry essentially means, that one can touch it without the paint surface becoming marred or getting paint on your fingers. Dry time for acrylics can be as soon as 15-20 minutes and enamels can be anywhere between 2o-60 minutes depending on the sheen. Flat enamels generally dry faster than gloss. Cure time means that the paint is fully set up and is ready for decal solvent, additional coats etc. Acrylics cure much faster, I have succsessfully painted a BNSF engine with orange, then green, then clearcoated, decaled and then added a flat clear to finish it in about 24 hours. That said, with customer locomotives, I generally wait 24 hours between coats to play it safe. Enamels need at the minimum 24 hours before they are resistant to decal solvents and additional coats. Maybe what we should do is start a thread on how I paint an engine completely from Polly Scale acrylics. If there is intrest, I have a project on the table I have been taking pictures of.
That would be great, Jim. With Floquil essentially unavailable here in Oz, PollyScale, amongst other water-based acrylics, are what is generally available. I'm doing more and more painting of late and have bought PollyScale lately. I'd would appreciate getting some inside info before laying down test paint.
I second! A how-to thread about acrylic painting would be great. I have several freight cars I'd like to paint with acrylics. My experience has been with solvent based paints. I just don't want to deal with the odor, clean up, and disposal of enamel paint even though I like the end results on the model.
Well then if the mods approve, I will finish up the Galesburg Tribute locomotive and post a how to on how I detailed, painted and decaled the locomotive. As many of you know I have been talking up the Galesburg RR Days show. Every year Testors has a large hand in it and this year will not be any different. Each year Harry (Littlegiant) allows me a display at the Carl Sandburg College model train show. As a tribute to to the home road, CB&Q, I backdated my painting a bit from BNSF to CB&Q. This years locomotive, er make that "motor" as the Q called them is a chinese red and gray GP30. I choose this model because it was the same locomotive that was used in the 100 year anniversary of the road in 1964 and at the time it was the pinicle of modern horsepower. I'll start a thread either here or on the N scale forum on a step by step on how it was done. Sound cool?
Jim, I think the mods would love it! At least this mod would. So much has happened in the paint world in the past few decades that few modelers have kept up. I go into my LHS and there are racks and racks of paint, and then more racks--so I have no idea of what I'm buying. I think there are only a few members out there who have followed paint technology. I think there are many more--myself included--who would do much more painting if they understood what was what. For example, I've got a lot of undecs that I need to paint for the PRR. This is not a difficult paint scheme--DGL (Brunswick Green). But I managed to ruin a bottle of paint by putting the wrong thinner into it--I thought the brands and types matched. I think the manufacturer changed formulations between the date I bought the thinner and the date I bought the paint! Please, go ahead!
Ok guys, will do. I just got most of the decals done on the CB&Q GP30 so maybe I'll post on Friday the begining and post and answer questions as we go. I should be finished with it next week at this time. For this locomotive I'll talk about my favorite choice, Polly Scale acrylic. So come Friday with an airbrush!
Safer in that it does not cause brain damage. But inhaled fumes can coat bronchial tubes and lungs, and the coat builds up with repeated exposure, eventually causing breathing problems. Avoid the fumes by wearing a respirator! Ben
I'm at the point where, if I don't know exactly what the thinner is, I just chuck the bottle. I still have a lot of the old Floquil paints, and a gallon of the thinner, so they will stay, as they are easily reconstituted. I have a lot of new paints, so they stay too. But I've chucked a lot of paints from the "intermediate" period, due to disasters mixing the same brand thinnner with the same brand paint, only of different generations. I'm painting some pretty big items--ships and bridges up to 40 inches long, entailing a lot of effort. No way I'm going to risk those due to incompatibilities!
