Kitebuilder.com

[stevef]

I just stumble on this article while surfing. The article was part of "WindWriter's" (South Jersey Kiteflyers Newsletter) It can be found here:
http://www.geocities.com/Colosseum/Sideline/8309/wwarc/ww14.htm#d

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Painting on Ripstop - by Mike Eason

Ed. Note: Back in Issue 10 of WindWriters, I mentioned an article exchange program several newsletter editors were involved in. As part of that program, we published Mike Eason’s first article about painting on tyvek. I’m happy to now give you Part 2, dealing with the problems of painting on Ripstop. Be forewarned, though: Mike gets a little technical, but its valuable information for anyone considering using his technique. Enjoy! - dcj2

Another kite painting technique that I first started testing and experimenting with in July of 1993 involves airbrush painting on white or colored nylon (Carrington) or polyester (Icarex) Ripstop with clear, solvent acrylic lacquers, the type used for automotive finishes, colored with transparent dyes.

It all started when I was helping a neighbor repaint his truck using these finishes. He was doing one of those metal flake and clearcoat finishes; you know, the kind where the finish looks like a two foot deep pool of colored glass. Usually an opaque base coat of a shade of grey or even white is applied first, then one or several layers of clear lacquer filled with reflective metal flakes, followed by several coats of clear lacquer colored with solvent based transparent dyes. Knowing that many Ripstop fabrics were originally coated with acrylics to give them their finish and reduce porosity, the proverbial light came on. "Hey, this stuff will stick to Ripstop, and, it's transparent!" Ripstop coatings now may be acrylic, polyester, polyurethane, polypropylene, or combinations of other modern polymers but all are compatible with solvent acrylics.

At that same time a few kitemakers were first using florist's spay colors on kites. The florist's sprays are used to color dried flowers and weeds in floral arrangements and can even be used to color fresh flora. But their drawback is that the colors used in the florist's sprays, while quite permanent on Ripstop, are opaque pigments rather than transparent dyes. Opaque pigments create color by how they reflect different wavelengths of light falling on them but, mostly, block any light passing through from behind. These early attempts looked great on the ground by reflected light, but the saturation of their colors was dulled in the sky when sunlight, coming from behind, was partially blocked by the opaque pigments. This will be apparent when using artist's acrylics on Tyvek also, since these are also colored mostly with opaque pigments. Transparent dyes, however, modify light passing through them by filtering out some wavelengths of light and almost totally passing other colors (wavelengths). As in pre-colord Ripstop, the filtering takes place once for transmitted light, the light that comes from behind the kite, and twice for reflected light, the light reflected back off the surface. That's why a kite looks darker, with more saturated colors, in your sewing room than it does back lighted in the sky.

Before I get too far we should talk a little about airbrushing. An airbrush is nothing more than a miniature air powered spray gun. Some airbrushes can produce anywhere from a 2mm line to a broad fog effect. They are available in single and double action models with various interchangeable tips for different spread patterns and come in internal mix and external mix versions. Some brushes use siphon or pressure material feed, or both. They typically only need a small volume of air at low pressures so a large compressor is not necessary, although a good quality regulator with moisture and particle filters is very beneficial. You can even run an airbrush from a really pumped up spare tire and regulator, with a homemade hose adapter made from a used "Fix-A-Flat" can, for quite a while without even owning a compressor. If you've never used an airbrush before, start with a simple single action brush, available at a local hobby shop or art supply. Badger (brand name) has one, a single action, siphon feed type withan air hose and material bottle that sells for less than $80.00 (US). You can pay much more, of course. You should also be able to find a similar model at any Sears, Roebuck, and Co. store.

I won't go into airbrush technique in detail here, but would suggest some practice first if you've never used one before. Practice with some inexpensive airbrush paints and paper, using the guides that always come with a new brush. An art supply or hobby shop will also be a good source of how-to books on airbrushing. Basically, all paint application effects are controlled with varying air pressure, dilution of the paint, volume of paint flow, distance from the surface, and speed of your brushing stroke. Hard and soft edges can be controlled using "friskets" or cutout masks on or at varying distances from the painted surface. Frisket films are available with a removable sticky back. And there are even special frisket knives with swiveling blades for cutting intricate patterns and curves in frisket film. But engineering drafting mylar, masking tape, paper, cardboard, and an exacto-knife are all good substitutes.

The clear lacquer that I've used is PPG Industries, #DCA 468, "Duracryl" Hi-Performance Clear Acrylic Lacquer. A notice on the can stipulates that the product is intended for use by professional car refinishers only and is not intended for sale to the general public, but I had no problem purchasing a quart can for $18.56 ($24.13 List) at a local auto paint, body, and detail supply shop. The associated PPG dye pigments come in pint (16 oz.) or quart (32 oz.) bottles in a variety of primary colors. They are very expensive so it's best to talk your supplier into, like I did, selling you small, four ounce quantities in your own containers. The dyes are so concentrated that four ounces of each primary will be sufficient to paint at least ten big kites. Normally they would custom mix your colors into the clear acrylic right in the store just like custom house paint mixes at a hardware store. I found that I could mix almost any color from the three additive color primaries; red, green, and blue. I last obtained four ounces each of PPG red #212 for $19.05, green #217 for $15.40, and blue #216 for $14.48. That red would be about $152.00 per quart, but you'll be measuring it by eye-dropper drops, so four ounces will go a long way. Find containers for your dyes that just hold the quantity you buy and have very tight fitting, screw-on lids. Store the containers upside down to minimize evaporation.

Later on, you may want to obtain some other dye colors that approximate the subtractive primaries; cyan, magenta, and yellow. I'm trying to keep this article as short as possible so I won't go into color theory here. But, if your interested, find one of the Eastman Kodak Co. publications that deal with color theory in a local photo supply or camera shop. Most encyclopedias that you can find at your library should also give enough understanding to get started also. Look up "color", "chromogenic", and "tricolor".

The instructions on the can of clear acrylic call for a dilution of 150-200%, with PPG solvents, for painting your family Lamborghini. That would be 1.5-2 parts thinner to 1 part DCA468 lacquer. The solvents are sold in different evaporation ratings for different shop temperatures in the auto painting industry and are very expensive. I've had perfectly fine results using plain old lacquer thinner from the hardware store. An airbrush, however, requires a much thinner mix to perform well. I have found that, using a Pasche' VL-B external mix double action airbrush, that dilutions of 300-400% of the out-of-the-can lacquer work well for air pressures from 5 to 15 psi (pounds per square inch). That would be 3-4 parts thinner to 1 part DCA468 lacquer.

Normally, the lacquer is pigmented with dyes at a ratio of 1-3% of total volume. For soft shading on Ripstop, where we are using fewer layers of lacquer, I found that a dye concentration of 5-10% was more suitable. More saturated colors can be achieved with dye concentrations, in the already thinned lacquer, of as much as 18% of the total volume of lacquer. Anything from the lightest of fogging effects to color more saturated and brilliant than the brightest commercial Ripstop colors can be achieved with smooth gradations.

I first make up a thinned mix of clear acrylic and solvent that spays nicely in a two to 4 ounce glass airbrush jar with a tight fitting lid. If you don't use all of this in one session store it, tightly capped, upside down to prevent evaporation. Color mixes may be stored for a limited time this way also. If you don't store it upside down the very volatile solvents will escape through almost any lid seal very quickly making the mix unusable even a couple of weeks later.

Then I will use an eyedropper to make the final color mix. Count how many drops are contained in a full "eyedropper-full". A 10% pigmentation of a mix would then be one eyedropper-full of dye to nine eyedroppers of diluted acrylic lacquer, or one drop to nine drops mixed right into a material cup. A Material cup is a small, usually less than one ounce, open topped cup that plugs into the siphon feed opening on the airbrush. Some airbrushes can also use a two to four ounce bottle with siphon tube that fits into the same opening on the body of the brush. An 18% mix could be 18 drops of dye to 82 drops of lacquer. Or, if I know that a full eyedropper-full of lacquer is 20 drops, I could use 18 drops of color and four full eyedroppers plus 2 drops of lacquer. Divide all of these examples by two, three, or whatever for proportionately smaller total quantities. I would recommend testing your mix for the airbrush with several progressive dye concentrations on scrap white Ripstop. Keep a record of the mix proportion written right on the test piece of Ripstop with a waterproof felt marker. This will be very handy later as a reference for future color mixes.

This testing stage would also be an excellent time to experiment with different airbrush effects. A very low air pressure, say 3-7 psi, and a fairly heavy flow of material will produce a spattering effect. The material flow is usually controlled by unscrewing a knob at the rear of a single action brush or pulling the finger control further backward on a double action brush. The pressure is controlled at your regulator or compressor. Try spraying along the edge of a cardboard or heavy paper mask, held right on the white Ripstop, with a light stoke to produce a hard edge. Then vary the distance from the brush to the surface to decrease the amount of lacquer reaching the surface and gradually decrease the intensity of color away from your edge. Also try producing a soft edge by holding your mask or frisket slightly away from the surface, letting some of the pigment fog under the edge. To build up more intense, saturated, color it is usually better to apply multiple light coats rather than one heavy application that would be more prone to running.

I have found that it is far easier to obtain smooth, even fields or graduations of color on Ripstop that is flat and unwrinkled, prior to sewing into, say, an appliqué' kite although I think that some method of stretching an already assembled kite skin could be used to flatten wrinkles and facilitate smooth airbrushing.

I would caution anyone experimenting with these materials to thoroughly read the instructions and warnings on the containers. Make sure you use plenty of forced ventilation. The vapors are extremely flammable and volatile, and you should judiciously use protective vapor masks and gloves. The lacquer and solvents contain various toxic additives, plasticizers, resins, ketones, toluenes, acetone, and esters. Some of these are known to cause cancer and neurological damage as well as birth defects in situations of prolonged occupational exposure. Hey, we don't want any pickled, mutant kitefliers out there so be careful!

I must admit here that I have not, as yet, actually built and colored a whole kite with this technique, except for airbrushed shading of flesh and hair colors in an "Uncle Sam" (pointing) appliqué design on an eighty square foot parafoil built by Terry Lee for Pierre' Langlois. It's that new! Although, I have tested the permanence by washing several of my test pieces and a couple of smaller paintings several times in a machine with my regular laundry. Also, a piece left in the sun on my roof for almost a year, held down and partially covered by some thick plates of aluminum for comparison, have shown almost no deterioration of the original colors. The exposed Ripstop itself started to become deteriorated and brittle, though, from the extended ultraviolet exposure.

I do have a kite designed, a ten foot Edo using a combination of acrylic lacquers on both white and colored fabrics and appliqué, but have yet to complete it. It will be a rendition of Sukaroku (S'-ker-ro-ku), a very well known Kabuki theater character, done in a traditional (except for the technique) pose and style. Some of you may even get a finished airbrushed kite in the air before I do! -me
_________________
Steve Ferrel
Measure once, buy twice!

[KiteSquid]

I read this article quite a while ago....

I bought some of the pigments from a auto parts shop...

I never tried it....

Does anbody want to give it a go?????


Especaly anbody who has airbrushing skills??????????????
_________________
VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA


P.S. Yet another post by the Squid..... Doesent he ever shut up???

P.P.S. The wind is like the air, only pushier.

[Stan]

I actually took airbrush classes in college (yeah, I'm old) when studying illustration. I used Paasche, Badger and other fine tools and got fairly good with them so I could work on cars and motorcycles, as well as re-touching photos for publications.

My point (and I have one) is that the cheap-o Chinese airbrush from Harbor Freight is pretty darn good. Mine cost $9 and has done a lot of detail work on bicycles, boomerangs and stuff like that. Fancy ones are nicer, but skill is a big part of the result.

[KiteSquid]

Yup...$9 airbrush


$???????????????? worth of experance using one....

I have an Aztek airbursh that I have not even taken out of the box....

A friend of mine was susposed to teach me how to use it but we both got busy....
_________________
VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA


P.S. Yet another post by the Squid..... Doesent he ever shut up???

P.P.S. The wind is like the air, only pushier.

[Stan]

I wrote a primer on airbrushing for a tech writing class about 30 years ago. Wish I'd kept it.