Just thought I pass along some inf. to those thinking of using the above material on the next project.
I put three different candy trim colors on the long over due Sig Magnum build/re-finish project currently taking place. (13 year build duration.) Anyone who's used the candy apple colors as a kid building model cars and the like should have very little trouble using this material. That said, it could very well present the same pitfalls of the model car candy paints. The big one might appropriately be called "candy striping". As these colors (Brodak) currently don't come in rattle cans (spray bombs) the lack luster performance of the classic Testor spray can will not be inflicted on your model airplane, as was the case with your old AMT Big Daddy Roth Roadster.
Candy Striping: This is caused by a repeated build up of material heavier in one spot then another. Due to the fact that the candy colors are transparent to the extreme they need to be applied in such a fashion so as to get an even coat over the area in question. This is of paramount importance.
Should your spray guns /stroke/ speed/ pattern/ change over the course of application you could end up with the dreaded "Stripe". Once the Stripe is there, the application of more material will typically only enhance the striped effect. If you can be very selective with the aim of the paint stream you can do some damage control,( but it's best not to go there in the first place). This is based on the need to apply more material to the "lighter" covered areas, in an attempt to bring them up to the "darkness/depth/intensity of the "striped" area.
Avoid the "Stripe" how to's: (What worked for me, and what I think are good general spray practices).
1) Try to maintain a constant distance from the target surface to the tip of the spray gun. Moving the spray head up and down along the stroke will change paint pattern and material density and area of coverage at the painted surface. Try and maintain 90 degree angle to the surface also, for the same reasons.
2) Maintain consistent stroke rate with your passes. This will help keep the material lay down constant, and consistent with all passes over a given area.
3) Apply light fog coats for the first few passes to build a bit of a base. Better to go light then heavy, ..you don't need to be behind the eight ball right out of the gate. This will also help you to develop a "feel" for the way the material covers. Lighter application will give more control over the finished product.
4) Change the direction of the passes with each pass made. Start perhaps with length wise strokes for pass #1. For pass #2 angle the stroke 45 degree's right or left. For passes #3 go 45 degrees opposite to pass #2 with the stroke. Pass #4 could go cross wise. Then repeat as required. I've found that the shorter the stroke path picked, the easier it is to maintain control of the coverage. Some may find it hard to put a consistent pass down the length of a 30 inch wing panel. Angled passes, leading edge to trailing may be better for some, ..then reverse the pass 45 degrees from trailing to leading.
5) Mask and spray the complete area that you intend to cover with the "candy" in one sitting. To do spot painting of a single assembly and then expect that it will match preceding painted assemblies may be courting disaster. Take the time to prep everything and mask everything that will be candied, all at once. Assemble parts (temporarily if possible) so that every part is shot at the same sitting for a given color. Flaps, elevators, rudders, and cowls and the like if tacked in place, will allow for the natural continuation of the paint flow from one piece to the next. Pattern and density will be consistent if this done.
6) Dial in the spray equipment for the widest pattern that will give you the least number of passes over/for a given area. If a wing panel is the largest target for the candy, dial in the gun pattern to give best coverage for this panel. The wider the pattern (within reason) will help to reduce the possibility of stripes. I've not found it necessary to change the pattern for different areas, ..just dial it in for best overall effect, and then use this set-up to do the whole shoot.
7) Pick a starting point, then move around the model in the same direction coat after coat, for the different target areas of coverage. This will help to do a couple of things: a) Will help you keep track of where you are in the process, ie: how many coats have been applied. And b) where they have been applied, and where they have not. Don't jump from nose to tail and all points in between, ..it's to easy to lose track of where / what / and how many / coats have been applied. I found a clock wise rotation around the model worked best for me.
8) Take your time!!!!! The coats build slowly if your equipment is set to give light coverage.
Regarding surface prep:
Any thing that is visible as a flaw will be visible in the candy color, and maybe enhanced somewhat. Think of this stuff as clear (which of course it is for the most part) and tend to any flaws with this in mind.
Base color prep typically includes laying down a silver, or gold metallic under coat which will give the finished product that sparkle. I used Brodak silver for my base under coat, to which candy blue, green, and orange (of a sort) was applied. The silver was applied over an over-all aircraft color of Insignia White. The silver tends to build thickness rather quickly I found, or perhaps I was a little heavy handed, ..most likely the later, us care in any case.
{The "sort of orange" candy color was hand mixed, ..I forgot to order the orange. I mixed yellow with candy red to give me an orange color that leans more to the red end of the spectrum. ratio was 4/1 yellow to red. I think 4/.5 (yellow to red, ...half as much red as I used) would have done an even better job and pushed the color more into the orange band.}
Regarding Silver: Depending on the amount of silver/gold applied different effects will be achievable. The deeper the silver/gold application, the darker the resulting candy color will be.
I tried an interesting effect where by I masked off an area 1/4 inch larger then the area that the base silver was applied to. This resulted in a silver area outlined with a 1/4 inch wide stripe of Insignia White. I then shot the candy as stated above. The result was a candy coated area that was outlined in a rather glowing translucent trim stripe of a slightly different color temper due to the Insignia White base color, ..I really like the effect. A word to the wise here is needed, ..don't get caught up in spraying the base white area, ...keep your eye on the base silver coverage, .. as it's getting darker with every pass you make over the white area that your eye is drawn to.
Tech stuff:
I shot with a gravity fed HVLP gun (full size automotive unit) sourced from the local UAP outlet for about 129.00can. Pres. was around 25psi, from a small Craftsman compressor. It ran a lot given the volume of air required by the gun. Over spray was kept to a min. that I've never seen before, ..I like this HVLP thingy. Material waste will surely be kept down with the use of HVLP systems (High Volume/Low Pressure)
Paint Mix: Mixed 50/50 color to thinners. Thinner make-up consisted of 75/25 thinners/retarder, all Brodak products.
In the very high humidity conditions I was shooting in I had little if any trouble with "Blush" using this mixture. It was shot outside in 33C temps (at the top of the scale) down to a comfy 23C yesterday. I never did get the official humidity number, but the humidex warnings were in full effect during these spray sessions,....I was soaked by the time the job was done.
Inclosing: "Candy Colors, ..they play with your mind man!"
Just when you think your ready to put the last coat on , stop, don't do it. You've probablely (maybe) got all you'll need as is. It seemed to me that I always went one coat to many, ..the color got just a bit darker then I had envisioned. So before you put that last one on take time out to check your work, and look for the desired effect that you where after, ..do you have it already, ..or do you really need that one last coat? Walk away from the thing and rest your eyes.
What seemed to play into this mix was the masking job. By that I mean, ..all that paper and stuff you put on to protect everything else hides the base aircraft color and any other previously applied colors. I used automotive body shop masking paper on this project, you know that light blue stuff, and smaller widths that were pinky-orange in color. This masking material helped to fool my eye somewhat. So be aware of this psycho eyeball effect. The finish is somewhat darker then design, but it sure do look perty anyway , ...ya know wha'ta mean Vern?
Tony