For the paint gurus out there

I'm preparing to shoot a yellow base coat on my new ship. Would like to avoid using white as an undercoat to the yellow if possible. Seems like this would be a heavy way to go. Any suggestions on a good way to prepare for the yellow along with any other ideas on coverage, keeping it light, etc? I will be using Sig or Brodack dope.

Hi PM,

I don't like the white primer either so I've taken to using Duplicolor gray sandable primer. I don't know about Sig, tne Brodak's works just fine over it.

I,m sure no paint guru, and I don't no how your paint scheme is. Only paint the yellow in the place where you want to show yellow. Leave the other areas as much as possible with no paint. Mask off the yellow and go for the next coat of color. This way you will save a few ounces.

Not a paint guru but I have had excellent results putting yellow over aluminum. I use dope so it isn't one of the new hizoot finishes but it works great. Perhaps you could try it on a scrap piece to check it out. I mix aluminum powder with clear dope. I can hardly tell the difference in weight of the aluminum and the clear. Any of the lighter colors are much heavier.

I spoke to Windy himself about this. As I remember, he said that the base color one uses for yellow affects the final outcome. Yellow over silver will look different than yellow over white.

A few years ago I went Sig Yellow over Silver on my Southwick Lark ,while the final outcome was pretty the amount of Yellow coats was unacceptable. I would try White or ,light Grey as an under coat .(on a scrap piece that is)

Sure it will, thats why you test on a piece of scrap first. Then you can adjust the yellow shade by mixing 'til you get what you want. My point being that white is about the heaviest paint you can use as is yellow.

>I spoke to Windy himself about this. As I remember, he said
>that the base color one uses for yellow affects the final
>outcome. Yellow over silver will look different than yellow
>over white.

Howard, you and Windy are right on about yellow being highly influenced by the base color. Yellow is fairly translucent and its final color will very much be influenced by what it is sprayed over.

If yellow is sprayed over silver the final yellow will be yellow to the green...it will have a greenish tint to it. The best color to put yellow over is still white; all it takes is a thin, single base coat of white sprayed lightly (it need only have a light, unevenly white "blotchy" appearance) to give the yellow its true color. The yellow will appear much brighter and only an insignificant amount of weight will have been added.

The painter can, of course, put yellow over gray or any other color that he likes, but it will be influenced by the base color. This is true not only of butyrate dopes but also of automotive paints, which is why automotive primers are being tinted to color in most shops nowadays...it saves paint which is significant at a cost of nearly $300.00 per gallon.

Even on full-scale airplanes I put white under all of the translucent colors (yellow, red, some blues, etc.) Metallics are another story and would be off the subject of this thread.

Hi, Bill. I've learned from Don Hutchinson to listen when you speak. We've got a J3, Ol' Four Deuces, that was rebuilt twice and both times didn't get the white undercoat. Sit it next to all those pretty Cubs and it does, in fact, look green, just like you said. Silver under yellow= green. Next time we'll get it right. Best regards and your pushrod turnbuckle is stil working fine in my SV.

I has finded this out a LONG time ago- yellow is a BLEEP. You almost have to put it over white or it will take a thousand coats. The yellow pigment has very little "body" to it. All you need is a fairly decent white blocking coat- doesn't need to be heavy.

>Hi, Bill. I've learned from Don Hutchinson to listen when
>you speak. We've got a J3, Ol' Four Deuces, that was rebuilt
>twice and both times didn't get the white undercoat. Sit it
>next to all those pretty Cubs and it does, in fact, look
>green, just like you said. Silver under yellow= green. Next
>time we'll get it right. Best regards and your pushrod
>turnbuckle is stil working fine in my SV.

Hi Dale,

Good to hear from you. The first J3 that I restored I also put the yellow over the silver and sure enough, it had a green cast to it. So I went ahead and put one very thin coat of white over the yellow and two thin coats of yellow over the white and it looked much better. Glad to hear the pushrod adjuster is working OK for you. See you at VSC!

Bill

LA_Flyer

My condolences on your choice of yellow! As C/L's newest beginner, I picked yellow for my third airplane because yellow's a pretty cool color. Bad choice! Yellow seems to have less pigment than any other color, with the possible exception of clear. Note that I said possible exception! You absolutely need all the help you can get to cover up variations in the underlying structure, so I would REALLY recommend a white undercoat. And resign yourself to applying a lot of coats. I used the hobby shop stuff. (Pactra or whatever brand that is now.) The Brodak paint has got to be better. The other thing that the experts always tell beginners -- "Don't mix different products!" Well, I heard that after I finished plane number two. It is fortunate since it gives 'em all a lot of room to say "I told you so...." They generally gather around my plane whenever they can to find tactful new ways to provide guidance. (Newbies learn too. I generally keep a tape recorder in my pocket so I don't miss any important advice....) The consensus seems to be that the color coat didn't really like the filler material I used on the bare balsa. (This is a Pukey Profile we're talkin' about here. You know, the kind with a O.S. 25 that should make anyone with two feet, at least one elbow and a gyro holding his ears apart post +400's. Yaaaah Right!) Anyway, the combination of these two materials caused a crackled finish or crazing of the underlying filler somehow. After that bad experience, I'm trying to figure out how to buy balsa that is made out of the same chemicals as the paint! Or maybe some balsa logs that come from the forest all prepainted that I can hollow out for a real fuselage. If you locate some, give me a call....

Dave
Newbie and "Pukey Profile Person"
from somewhere near Manhattan Beach

I'm no guru either but my vote goes for a base coat of white. If the finishing of the wood is the best you can do, sand,sand,sand,etc then you shouldn't need too much white. Just be carefull.I used all Brodak dope and this is the way I will do em' all. No mixing of different brands whatsoever for me. The yellow is fairly opaque too.

Duck,

Man, that's awefully pretty.

PM,

Trying to cover anything with yellow dope is going to be problematic. You can get additional pigment to put in it that helps. I think Windy sells this for Brodak paint. Used to anyway. I use auto color urethanes and it's not much of a problem. They have such high solids that a couple of coats of yellow does the job. Over just about anything. But as has been noted; yellow, like red, is pretty transparent. The color underneath will make a difference in the tone of the final color. I painted yellow over a metallic gold undercoat on my classic Shoestring last year had it gave it a cool sort of dark shimmer. White underneath will make it very bright.

On the pic attached: That's one coat of Ford School Bus Yellow over mottled CF veil. No undercoat. It's one of the reason I like auto paint.

I use Brodak's Polar Gray as a base coat on all of my planes. Be carefull when you put other colors over yello though, I have had problems with it bleeding through and changing my second colors. The bleeding becomes a problem if you lay the finish clear on to heavy.

Weight. If you are going with yellow as the base color for the whole plane and you dont put down a base color gray or white first you will dump so much yellow on it to get even coverage it will actually be heavier. Like everyone else has said yellow needs a white base to get the proper coverage. Not to mention a dope finish in a year if yellow will want to fade. White under the yellow wont show the fade. Gray under yellow and it will be green in 6 months.

If yellow is only your trim then you only need to get it really white where you are going to have the yellow. In the other areas you can just dust it on.

Some colors are very transparent and others aren't. Yellow is one of them. Red is very transparent as well. Metalic colors dont seem to be as bad. Reds, Yellows, light greens, some blues, are really transparent. Do some testing. You will be glad you did.

When using dope, never ever spray yellow or red over any color other than white (unless that is the color you want). These colors are translucent and the base will show through. Here is a nifty little trick that I use. Mix up 1 quart of Sig sanding sealer and 4 ounces of Sig White. Thin as needed and brush onto the model. The white paint we added to the sanding sealer gives you a whiter base and also allows you to see the low spots when you candle the model during the sanding procedure. This works like a champ! If you are like me it takes about three coats of sanding sealer to get all the grain filled and by this time the base color is almost completely white. Now you can shoot a very thin coat of white to make the paint base very opaque if you are going to use red or yellow.

I my opinion dope paints are still the best paints out there. I have tried all the different paints and still find that dopes are easiest and most forgiving paints around. Good to great results can be had by a rookie the first time. In addition, they are the lightest paints out there with only 15% solids in clear. How many of you have seen a highly rubbed dope finish? The finish looks like it is a foot deep with nothing prettier

I mix Polar Grey (Brodak) with Brodak white primer 50/50 then thin it 1:2 one part paint two parts thinner. This color is light enough that yellow covers well and it covers in one heavy coat. Its also perfect for finding flaws to be worked out before final paint. Larry NorCal Circle Jerks.