MAD as HELL!!

IT comes down to a simple problem...Last weeek I finished my cougar. Painted all with BRODAK DOPE. The main color is (or was Royal Purple)with Lemon Yellow and Miss Ashly Red. Every thing was going PERFECT! untill I sprayed the top coat of clear. All of the colors EXCEPT the Purple came out SOOOOO GOOOOD, the PURPLE turned BROWN. Some FOUR letter words were following quite heavely here in Portland. So what went wrong? why would one color turn shi&%$ and the others came out perfect. ABOUT ten mins ago I recived a phione call from a top 10 flyer who ALSO had the same thing happen (color) to him. What's the deal! I'M MAD...
Has this Happen to anyone else? how do you corect this problem?
Scott (high blood pressure)Riese

Just out of curiosity, did you happen to spray the purple over the yellow? I once painted a plane white, then sprayed red accents over that, with no problem, then sprayed clear with quite a bit of retarder and it basically melted through the layers just enough to turn the red into a pale pink. I don't recall what dope I used but it wasn't Brodak. Kind of interesting that there have been a couple of Brodak dope problems showing up on the boards the past few days, makes you wonder if there was a bad batch or if Brodak dopes don't deal well with cold weater shipping, (or storage for that matter).
Kiiski

Hey Scott After I told you about problems I had with lemon yellow, you still used it!!! Sadly, there are some problems with the new dope. At least the early packaged material. John Brodak will do everything possible to get this stuff correct. I have returned some samples for examination to see what went wrong. There are some real good features with the Brodak dope, but it isn't the second coming of Christ as lots of people lead me to believe.

The Lemon yellow came out Prefect so did the Miss Ashley Red. I sprayed over primer. Before I srayed the clear it was the most beautiful purple that you have ever seen. How can clear change the finish for your plane in less then 10 mins. ONLY the purple changed color. Scott

>The Lemon yellow came out Prefect
>so did the Miss Ashley
>Red. I sprayed over primer.
>Before I srayed the clear
>it was the most beautiful
>purple that you have ever
>seen. How can clear change
>the finish for your plane
>in less then 10 mins.
>ONLY the purple changed color.
>Scott

I'm probably the least expert dope finisher around, but a guess ould be that the clear melted the color, the base, and maybe the primer together. Maybe the clear was too much of a wet coat, or you used too much retarder.

Do whatever Roy says, he knows a billion times more about it than I do.

Scott If in using the primer, you ended up with a white base, then the lemon yellow probably worked for you. I apply all colors over silver because silver is the basis for my finishes. If you had sprayed lemon yellow over silver, you would have been "mad as hell" much sooner is the process! I have been advised to spray the colors over white, but I disagree with this unless white is to be the main color of the model. Spraying an additional pigmented coat or two just adds unecessary weight and I have trouble enough keep the weight down! Besides, diana cream is my favorite color, not white!

Scott:

My belief is that the Brodak purple is a candy color, designed to interact with both the base and the top colors?

I know that the candy carries a higher percentage of clear in it. Windy suggests putting silver into it if you want a "metalic" looking purple.\

See Ya

I painted my Testors Senior 29 with Brodaks all the way. Two thin coats of clear to set the wood grain, then covered the entire wood parts with medium silkspan followed with two coats of medium thinned clear lightly sanded after the second coat. Then a fairly heavy coat of sanding sealer well sanded after . Then a SILVER coat sprayed on. BAD DECISION. Then the Cub Yellow. The silver under coat gave the yellow a putrid green cast. Two more coats of yellow buried it SOME but not much and ADDED a ton of weight. The red trim covered nicely.
My second Senior was finished the same except WHITE was substituted for the silver. A dream, and only one coat of yellow covered. Silver is not ALWAYS good for under coat.
Bigiron
PS take a look in the March issue of Flying Models mag. All the planes shown under construction and the one flying inverted are mine. The other one belongs to Mr Bill Schmidt. (it has yet to be flown).
Bigiron

IT seams that alot of people are haveing alot of problem with BRODAK dope. I'm going back to areo gloss, sig, luster coat, mono coat, on the next plane, I'VE never had a problem with THEM.....lol. SO... as I see it Bret Buck has the best stuff out there...missile paint. Can't cure a cold, but IT can go to the MOON. Scott

Marvin, I disagree with your comment that applying color dope over silver is a bad idea. I have put sig color over silver for years and I learned this technique from the master himself. Windy has used this method for many many concours winners. Besides, as a retired A&P mechanic I know that dope and fabric work on full scale aircraft requires a good coat of silver to protect the fabric from untraviolet light damage. Silver paste is sold at aircraft supply stores to be added to clear just for this purpose. We did not have to paint the airplane white to get the colors to work. If the dope will not cover silver, then it simply does not have a solid pigment or enough pigment. This isn't rocket science. Right Brett???

I think we have to watch the distinction between full size planes and our models. Those who paint our full size planes are not concerned about the thickness and weight of the paint coat. On our models, however we would never load it on as thick as they do on the full size planes.

Yellow and white are the two hardest colors to cover. Windy has for years sold extra pigment to add to SIG dope because it is notorious for not covering in either white or yellow. Add too much pigment, however, and it gets chalky. Too little and it won't cover. And then, if we add extra thinner and try to cover with a thin coat of yellow dope over a substrate that the added thinner will eat into, the result can sometimes lead to meltdown.

I feel the Brodak dope is much easier to use in this respect, and covers much better than the equivilent SIG dope. But, it is dope, and we have to treat it with the respect that it requires.

The problem with the purple above may have been identified if it was, indeed, a candy color that already contains clear and should not be clear coated over. In that case, however, we need to have warning lables applied.

On the yellow over silver, we prefer to use Polar Grey, but the white base will make the yellow brighter. In both cases, we are still attempting to apply a much thinner coat than applied on a full-scale plane, so the light color (white or yellow) will be affected by what lies underneath. Polar Grey will cover with a very light coat, and is still light enough in color to provide an effective base for a light top coat of yellow or white to be applied over it. Or an imperfect white base could be used for yellow top coat providing a brighter yellow with less total dope than if the yellow were to be applied alone.

We have done a number of planes using White SIG dope (which always needed more pigment) and now Matt has used Brodak white on the winter scheme of his latest Stuka. Although it gave him a front row plane at the Nats, his comment to using white as the base was "never again". The darker colors simply cover better using less dope.

Just think of it this way: four or five extra pounds on a Piper Cub are tolerated to get adequate coverage with yellow over silver. But we don't want to tolerate an extra ounce on our models and that's where our problems come in.

THANK YOU..MR. STUKA You answered my question. NOW we need to fix the problem. I will send a letter to Mr. Brodak and ask him that a disclamer needs to be added.
AS for the cougar It's going to be sanded (the purple) and re-shot of Purple. The plane is finished and came out at 35oz with all of the hardwear so I do have some room as weight goes. Thank you all who hepled IN my days of MADNESS. Scott Riese

Leonard, you completely miss the point I was trying to make. The silver does not add appreciable weight as it is used in coats that would still be applied if only clear was used. Silver makes all the boo-boos much easier to see and sands much easier than polar grey. Unless you care to wet sand which I do not. Most of the silver is sanded off anyhow. The principle between full scale and models still apply. The colors should cover. They did in the "old days" and there is no valid reason why they should not do so now. You talk about extra wight and then you add white just to get a brighter color??? Brodak silver sands like a dream, like the sanding sealer of the good ol' days. To hamper this process with thin pigments is really sad.

A couple of comments have me confused. Leonard says that the purple, if a candy color, is dyed clear and cannot be clear coated. WhoooooH! If you DON'T clear over it, the dye will leach out and run all over the paint, your hands, your clothes, won't it? That's my experience with dyed clear over colored tissue which looks like candyapple with a hint of grain showing. Also, I read in SN that white pigment is titanium oxide, and is thus very heavy as pigments go, one of the heaviest. Note to self...use white dope for trim only. "Big Planes don't worry about weight of
a couple coats of paint"? I seem to recall that a 747 can take something like 700 lbs of paint, and you betcha they are not likin' that. A lot of 'em use trim only...clear dope and colored tissue, more or less. I worked at Boeing on the 747 weight reduction program. We whittled everyplace to get the weight down, and it came to something like 6,000 pounds saved!
Maybe the cure is to butt-join the colors, i.e, not overlapping them? Wouldn't it be best to apply a coat or two of clear before applying the trim colors anyway, to seal the base color and to also seal the masking? Too much retarder sounds like a possible cause or aggrivator? Clear dope and colored tissue sounds better and better. Steve

I cannot speak to the characteristics of Brodak's paint, Steve, and the dye I used is an extremely hazardous poison that you must have serious respect for if you use it. I built several planes with transparent finishes based on colored silk, but enhanced by using dyed clear dope as the finish.

There was a top coat over some trim color, but I misted the edges and blended it in, so there were large areas with no clear top coat over the dyed clear (Randolph Butyrate). The dyes were the analine type used for crafts when coloring various resins used for castings, blue, and red, and in one case, a purple blended from the two dyes.

There definitely was no leaching of the dyes. One of the planes lasted 8-10 years and over time did receive enough exposure to sunlight to fade just enough to be barely noticeable. I had some planes covered in Jap Tissue and colored silkspans that faded to a far greater extent, much more rapidly.

Steve, for both you and Roy, yes, weight is a concern for big planes as well as small ones. But I was talking about a Piper Cub and with particular reference to an ultralight that is being built at the field where we fly (yes, our "flying field" is an airport half a mile from home.) The builder of this ultralight wanted to paint this plane in Cug Yellow and took it over to an automobile paint shop to have the color coats applied. The builder had hand painted a fungacide on the fabric, and the painters at the body shop then shot it with clear, with silver (as a blocking coat) and followed this up with three heavy coats of yellow. And it is still blotchy, streaky, not what I call "good". And, remember, this was sprayed on by "professionals" at an automotive paint shop.

Now, they may not have been as familiar with the covering qualities of our dope, but it was yellow, and yellow dope, I don't care what yellow or who makes it, is horrible to paint with. And it went over silver. I suspect some of the silver leached up through the yellow and that may have been part of the problem--not so much that three coats of yellow was insufficient to cover, but that the top coats and undercoats may have mixed. Anyway, this was thick paint (dope) applied by professionals, and the results were not something that I would be willing to accept, even on an ultralight.

White and Yellow are both hard colors to cover with. Using a thin silver base or something similar to Polar Grey helps to allow the white or yellow to cover easier, using less dope. Silver, as a base, gives a brighter yellow, but my experience is that the silver can float up through the top coats if the base coat isn't dry enough (and silver usually takes longer to dry), which is why I like the Polar Grey. But the problems mentioned here are NOT solved by going back to SIG. Unless there was a bad batch of Brodak, or the paint was not stirred properly before application, the covering qualities of both the Brodak white and Brodak yellow are far superior to the covering qualities of the same colors in SIG. I know. We have a gallon of SIG white gathering rust in the basement.

On the Purple, I was just wondering if the dope was not intended to be clear coated on top. I don't know. But, again, the top clear coat either ate down into the base coat which caused the color change--and, maybe it isn't intended to be top coated (I don't know) or the substrate under the color took a while longer to work its way up which caused the problem. This could still have been aggrivated by the thinner in the top clear coat causing a "melt down" into the base coats underneath.

One thing that I have found is that thinners have a temprature range that they are supposed to be applied in, it sort of relates to the set up speeds - hot, cold, medium ect. I find that if you spray a heavy coat thinned heavily like i'm sure that Brodak colors need to be, out of that temprature range on the low side you are inviting a meltdown disaster. A little over doesn't seem to be any problem until it get too hot then the paint sets up too fast and it doesn't get enough bit and will pull up fairly easily. When painting with dope anyway, you are really walking a tightrope of acceptable tempratures for the speed of the thinner.

Why don't you write Windy and see what he thinks happened?