- Member since
November 2005
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FAQ: Painting and Airbrush
Posted by Anonymous
on Saturday, July 12, 2003 1:46 PM
Welcome to the PAINT & AIRBRUSHING FAQ!
The intent of this FAQ is to summarize, especially to newcomers, the thoughts and experiences of the posters to this specific forum, and such should be kept in mind.
This is a work-in-progress, and will be updated and revised continually. If you see anything that needs revision, please e-mail me.
Read and heed!
edit: Safety section added 5/1/04. I regret not adding this section at the onset.
SAFETY
One of the critical points new modellers overlook is safety. Regardless of how small a project may seem, or how minor the fumes, safety should be a priority.
The key element to a good modelling session is safety. Let's run through the elements necessary to prolong your experience:
1. Ventilation
It cannot be stressed enough that ventilation is the most important safety precaution one can take. The preferred situation would be a steady airflow away from the modeller, towards the project, exhausted from the room to the outside environment (filtered, of course. I wouldn't do to kill off your friendly neighborhood tree-climber with your hobby). Most of us, however, do not have this luxury. As such, there are steps that can be taken to help.
A simple solution would be the use of an inexpensive box fan, found at Wal-Mart/Target/etc, placed in front of an open window. This would permit the flow of noxious cheicals to be exhuasted to the outside environment. To be further environmentally-conscious, a simple, inexpensive (and I mean CHEAP) filter furnace can be placed in front of the fan to filter the vapors. Note, your project needs to be between you and the fan to be effective.
Another possibility would be the use of small fans to force the fumes away from the modeller towards an exhaust source.
A couple of further safety tips to keep in mind with ventilation:
a. You are working with noxious, highly combustible chemicals.
b. Be aware where those fumes are being exhuasted. Saving yourself and killing your roomate/family with the fumes will be counterproductive.
c. Airflow needs to be continuous.
2. Respirator
Some consider this an optional item when modelling (including gluing).
UPNORTH would remind us otherwise:
QUOTE: I use a dual cartridge respirator myself.
Enamels are bad if inhaled, but so are acrylics. Acrylics are essentially plastic suspended in a liquid form, the liquid part evaporates out in the curing proccess leaving a think plastic coating.
Heard about a guy once having to have emergency surgery to remove good sized chunks of both of his lungs because they'd become so clogged and coated with plastic. Guess where it came from. Yep, acrylic spray paint without a respirator.
"Non toxic" on a label doesn't mean fool proof. I want to be around a long time to tell everyone about my plastic airforce, so the respirator is a sound investment that pays for itself easily.
Note: for some hobby applications, the cheap dustmasks don't always help, lots of things can get through them (resin fumes for example) and do you a world of hurt. Respirators, safety goggles and occaisionally latex surgical gloves can be you best friends. |
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Further, Styrene has an excellent 'tutorial' for beginning respirator users:
QUOTE: 1. Inspect the respirator. Make sure the inhalation and exhalation valves seat well against their mounts, and ensure there is no dirt between the valve and seat.
2. Put the neckstrap on first, then the head strap. (BTW, you should not be wearing a respirator if you have a beard or other facial hair that interferes with the facepiece seal).
3. With the respirator adjusted to your face, cover both the respirator cartridge inlets with your hands. If your hands are too small, try a small plastic bag in each hand that will cover the inlet. Breathe in. The respirator should collpase slightly on your face. If there are any leaks around the facepiece, readjust the respirator, and try again. When you can take a breath and hold it for about 10 seconds without a leak, you have a good seal. This is called a negative pressure fit test.
4. Next, cover the exhalation valve and breathe out slightly. The facepiece should expand on your face, but air should not escape from around the seal. This is a positive pressure fit test.
5. Breathe normally. If you can't breathe, or if you encounter difficulty getting air through the respirator moreso than normal, the prefilter side of the cartidge is full and should be replaced prior to your next job.
6. Get a q-tip and wet it in some fingernail polish remover. Standing in front of a mirror, or with a friend, pass the q-tip around the respirator seal and your face. Breathe through your nose. If you can't smell the polish remover, you have a good seal, and the cartridges have not reached the end of their service life. On the other hand, if you can smell the remover, readjust the respirator, do a positive and negative fit test and try again. If the fit is good (no leaks), and you can smell the remover, it's time to change the chemical cartridges.
A couple final thoughts:
Keep in mind that facial deformities, sudden gains or losses of weight, and new dental or oral surgery work may cause problems with getting a good face-to-facepiece seal with the respirator.
Do you have asthma or are you claustrophobic? Difficulty breathing may be due to a previous medical condition, or to anxiety associated with being claustrophobic. If you have pre-existing lung problems, you might want to see your doctor before getting a respirator.
If you have any questions, please don't hesitate to e-mail me |
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For further details on respirators, read this thread
PAINT
First off, how about a nice discussion about paints in general? Murray Kish has this to say: QUOTE: Basically, paints are primarily defined by two major things:
1. How they dry (evaporation, or chemical reaction/curing)
2. What type of 'carrier' is used with the pigment (water based or petroleum based)
When you get into automotive type paints it gets quite a bit more complicated, so I'll ignore that...
I'll tell you a bit more, but firstly you need to know that we (ie. everyone in this hobby) has adopted some terms and definitions of paints that aren't 100% correct. For instance, we often refer to any paint that is 'water-based' as an 'acrylic', however you can get acrylic paints that are petroleum based as well. The definition is complicated and not worth going into, other than to just let you know that the term is used differently in this hobby than it would be by paint 'professionals'. The term 'enamels' is often used to describe paints that are 'petroleum based' when the reality is that many water-based paints are actually enamels in a technical sense. We all know what we mean when we say 'acrylic' or 'enamel', but understanding this is a little bit important if you really want to know about paints.
Back to my definition:
1. How they dry:
a. Some paints are just a pigment suspended in a liquid. When the liquid evaporates, the paint pigment is left on the surface. Not many 'hobby' paints are like this but examples would be like children's water paints, etc where you just add some sort of liquid (water in this case) and the pigment is transfered with the liquid. The liquid could be water based, or petroleum based.
b. Most hobby paints we use go through a chemical reaction when they are drying that is called 'curing' (essentially the paints chemicals are reacting with the air that initiates the 'reaction'). These types of paints are called 'enamels'. It really doesn't matter if they are water based or petroleum based. If they 'cure', then they are and enamel. The most common type you'd be familiar with are Testors or Model Master paints which are essentially petroleum based enamels. However, the Tamiya and Gunze type paints also go through a 'curing' process and essentially then are also enamels, but in their case they are 'water' based. The unique thing about an 'enamel' paint is that once it is fully cured, the process cannot be reversed (the type of paints in 1.a. can be re-dissolved in their thinners and reapplied in the same manner). Enamel paints can be dissolved, but they will not go through the same 'curing' process a second time.
2. The second item that defines a type of paint (and probably the most important to the hobby user) is the type of carrier. (you've probaly heard that oil and water don't mix... well you can likely guess what the two main carrier types are:)
a. water based paints are essentially made up of a carrier that is either water or soluble in water. You'll often hear that people use alcohol with these types of paints and that's because alcohol is generally soluble in water. The actual carrier is usually some exotic mix of alcohol and other mysterious ingredients, but they are designed this way so that younger modellers can just use water to mix their paints (ie. ease of use). However, the closer you can get to the actual chemical used, the better the paint will mix and dilute. That is why many people use alcohol. You will also hear of people using things like Windex, windshield washer fluid and other bizarre things. They all do basically the same thing, but some just seem to do the job better and/or cheaper. Tamiya, Gunze, and ModelMaster Acryl paints are all in this category. You'll notice that they all sell 'thinners' that chemically match their paints. 'Cheapskates' like me prefer to use an alternative that does 95%+ the same job, but is much cheaper and easier to get (ie. alcohol or water).
b. oil based paints have a petroleum based carrier. The same rationale applies here. Any 'petroleum' based item (ie. Turpentine, Varsol, Mineral Spirits, etc, etc) will essentially work to thin the paint, but the closer it is to the actual chemical used by the manufacturer, the better. Some paints work better with Turpentine, and others work better with Lacquer Thinner. Personally, I use Lacquer Thinner for EVERY oil based paint I use. It does the job for me and I don't have a single complaint about using it. Some of these thinners/carriers are very exotic and hazardous to your health. Chemicals like Xylene and Toluene are usually the main ingredients used, but these things are very BAD for your health. That's why we often recommend using a respirator when using these types of paints. The fumes can cause your brayn ot ddo crasy thinks and nnot evn no bout itttttttttt!!!! NO I don't want a sandwich!!
So, now that I've confused you, here's my recommendation:
- when you're using "acrylic" paints (ie. water based), try alcohol as a thinner. It seems to be the most common and gives good results. You can use just plain water as well, but I think that most people prefer to use alcohol.
- when you're using "enamel" paints (ie. oil based), use whatever petroleum-based thinner you choose. Turpentine, Varsol and Lac.thinner will all work reasonably well
- if you're not sure which category it is in, try mixing a little bit on a palette with each thinner and you'll be able to tell pretty quickly. They'll either mix, or not. This is also a good way to determine which thinner works 'best'. ie. try mixing some Tamiya paint with water. Then try alcohol. Then try their thinner. They should all mix, but I expect you will see that the alcohol will blend more 'smoothly' than the water will.
The magic of all this is that you just need to know that these two 'types' of paints don't mix. So, if you're going to do a 'wash' or something like that, make sure that the base coat is one type, and the wash is another type. This way they won't dissolve into each other and make a mess. |
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Acrylic or Enamel?
This is an ongoing debate, which will doubtfully be settled. The choice of which to use appears to depend upon the media being painted (plastic, resin, etc.) and the the tools to be used (brush, airbrush, etc.).
Enamel
Positive:
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- Model Master Enamels (billc3207):
| QUOTE: I use a very simple approach to thin Model Master enamel. I use glass eye droppers to removed the stirred paint from the paint bottle to the air brush spray bottle. I fill the eye droppers to the same level four times then I add thinner with a clean eye dropper (easy to clean up if you keep the paint out of the bulb) that I fill to the same level as the paint droppers. I stir the thinned paint with an old coat hanger wire ( I removed the varnish on the coat hanger wire with steel wool) that has a loop on the end. If I get three or four drops of paint when I lift my stirrer from the paint, I begin brushing. If I get more drops I add a few drops of paint. If I get less drops I add more thinner. I always test the paint on a piece of styrene before I start painting on the model. |
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Negative:
Acrylic
Positive:
- Easy to thin (water)
- Easy clean-up (water)
- [Airbrush]Can be used straight from the jar
- In some cases, thinning is only desirable to control drying time. This is crucial in the when using a brush to prevent brush marks on the model
Negative:
- Tamiya & Gunze Sangyo require their brand of thinner
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Pastels
- paackerson:
QUOTE: Pastels need to be sanded down into a fine powder on sand paper then brushed on to the model. After that use a coat of matte varnish to seal them to the model.
For the washes I use artist oils thinned with mineral spirits. I go over the whole model with a wash then after that has dried I'll go back and add washes to specific areas that need more of a wash. After they have dried for a few days apply a coat of matte varnish because the wash may have a glossy look to it. After this has all dried you can start your dry brushing. |
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- upnorth:
QUOTE: As for the pastels, stay away from oil based pastels, they are practicaly useless for any endeavor in the modeling hobby. They're messy, greasy, they don't ever dry to the touch and they react very unfavourably to any sealand coat you may try to put over them. All this on top of the fact that, because they never really dry, they are dust magnet areas on your model and once the dust is on them its on them for good, its not going anywhere, in the space of less than a year, you'll want to strip all the paint off your model and do it again differently just because it looks so bad from the dust.
On the matter of simulating dust on your models when you really want it there, chalk pastels are your best friend. You do have to grind them up very finely, but they do dry brush on to a model very nicely. |
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How to apply yellow or white paint
"Yellow is one of the hardest colors to get good coverage with along with white. The first thing to do would be to lay down a primer coat of white or light gray. This will lighten the background and reduce the number of coats that you will need to apply to get a nice, even color. As far as it pooling along the edges and raised detail, try and lightly sand the edges to try and knock down that little 'lip' that always occurs along the edges. Lightly scuff the rest of the parts as well with some 400 or 600 grit sandpaper, being very careful around any raised detail. Roughing up the surface, along with the primer coat, will help the paint to adhere better and level out which will help with the build-up along panel lines, details, etc. The only other thing is to put the paint on in light coats and slowly build up the layers gradually until you get the coverage you need. Wet sanding in between coats can help as well. Hope that helps you out." (heylonghair)
Tamiya Acrylics
"My Tamiya acrylics were hard to use also till i figured out that when your using them you should have minimal air flow in the room and they take a while longer to dry. also have a cup of water handy so when the paint gets to thick on the brush and starts leaving that rough brush look, you can just dip it and clean it and then start again." (Airbrush)
"I found the Tamiya acrylics are better for airbrushing, I would try enamels they are far better for hand brushing." (Colin)
FUTURE Floor Polish
Yep, you're seeing that correctly: FUTURE floor polish. Think of it as cheap clear-coat.
Washing
(leemitcheltree)QUOTE: To do a "wash" to weather something, take a little amount of paint on a pallette or in a small container and add a whole bunch of thinner to it, then apply to the corners and engraved bits on your model using a fine brush. Some wipe off the excess, some leave it on. It makes the corners and recesses darken up and gives depth to the model.
VERY IMPORTANT - make sure you use a gentle type of wash over your paintwork because some types of paints will EAT others!!!! If you paint your model with enamels, and then use an enamel wash, the thinners will just eat away the original paint color, making a mess and breaking your heart.
I have painted models with enamels and done a wash with enamels, but I spray the model first with Future floor was, protecting the original paintwork - the Future provides a protective "barrier" between the paint and the wash. |
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AIRBRUSHES
Generally speaking, airbrushes, like any other aspect of modelling, are personal preference. Some use only one brand/type of airbrush. Others use a plethora of brushes, each for a specific job. No one airbrush is THE airbrush to use.
First, a quick listing of places to purchase airbrushes:
Great Models
-Excellent source for airbrushes and accessories, very good pricing
Squadron
Excellent source for airbrushes and accessories, very good pricing
Bear-Air
Excellent source for airbrushes and accessories, very good pricing
Hobby Lobby
Excellent stock, watch for sales of 50% airbrushes and paint
Michael's
OK stock, a good source using one of their 50% off coupons (single item), usually found in the Sunday paper
Looking for a store near you? Try www.hobbyretailer.com
Next, to make any kind of informed decision about an airbrush, you need to have an idea what an airbrush can do for you, how it functions, and the maintenance (mainly clean-up) involved.
I recommend highly to seek out books on airbrushing at your local library, scan through articles in AIRBRUSH magazine and similar titles, do a search online, and finally, check out this FAQ: http://www.io.com/~fazia/arbrshfq.html.
Don't forget to look at the resources on is this website.
Below are listed the different manufacturers as used by Forum members, and either statements or summaries of their experiences.
AZTEK
There is a wide spectrum of opinions concerning this series of airbrushes, ranging from "Oh-Lord-save-me-from-this-airbrush-from-hell!" to "have an Aztek and it works like a champ!" (RonUSMC).
Positive aspects:
-Ease of use (single or double action)
-Easy to change spraying style through screw-on tips
-Easy to clean (only need to clean the tip)
-Lightweight
Negative:
-Requires exact air pressure and thinned paint
-Inconsistent
-Sputters, leakage behind needle/nozzle
-Paints do not perform well
-Feels cheap
Model 430
Negative:
Spraying and sputtering, leakage behind the nozzle. Metallic/Pearl paints tend to run around spray edges.
Model 470
Notes:
-Make sure the tip is set right, and tightened properly
Positive:
Ease of use, easy cleanup.
-"have used it successfully for about 6 years now for a multitude of applications" (renarts)
-Success with acrylic paints, enamels, laquer paints, clear coats, and Future
BADGER/Thayer&Chandler
General:
-Smooth, right out of the box. Excellent results with a standard hobby compressor.
-Easy to maintain
-Watch for the weekly Michael's ad, and the 50% one item (regular price) coupon. I purchased a 350 for $35.
Positive:
-Widely used, easy to buy parts. Virtually every hobby/craft store sells Badger airbrushes and supplies
150
200
Positive:
-"....had it for 15 years and no complaints yet" (sven3839)
-I own a 200-1-IL, and find it a joy to work with
IWATA
HP-C
Negative:
-Expensive parts
Revolution
Positive:
-Atomizes well
-Consistent spray
-Very easy clean-up
PAASCHE
H
Positive:
-"Works good" (Texgunner)
-".... all the airbrush I need" (shermanfreak)
-"Paasche H for over 20 years now. Have 2 of them, one for acrylics and the other for enamels." (uscsn)
Compressor vs. "Canned air"
For an airbrush to function, a source of steady air is required. There are many ways to supply air, ranging from old car tires to high-end professional air compressors. For the average modeller, who is usually limited in space in their 'work area' or 'workshop', space and noise levels are not desired. Therefore, two options are readily available: an air compressor or canister propellant.
First, let's talk about canister propellant. Canister propellant, found at just about any store ranging from Wal-Mart to Art Supply shops, is fairly inexpensive and quiet. The canister, resembling a large spray-paint can, is connected via hose to the airbrush. Simply using the airbrush draws air from the canister.
Postive:
- Inexpensive (about $5-10 per can)
- Quiet
- Does not require a regulator or moisture trap
Negative:
- Long-term cost exceeds the cost of an air compressor
- Canister loses efficiency as it emptys
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