can't afford three and a half ounces

[bill rutherford]

    Just put the white on my new bird and it picked up 3.5 ounces with the white and the coverage is pretty good but needs another coat. It's all certified dope. Would auto basecoat be lighter??? Man I can't that afford that much weight.. Help.   Bill

[John Leidle]

  Hi Bill, what I found in my finishing is that after going to auto paints I didn't gain weight  maybe its lighter because it covers better,  I had many problems with dope & finally dropped Dope products.     John

[Joe Gilbert]

Give it s chance to gas off for couple days then weigh again.

[Mark Scarborough]

Bill,, did you use some form of ground, or base coat, or are you trying to cover the "splotchy" sanded base with the white,, I know you would have better luck if you sprayed at least a grey intercoat before the white so you dont have to hide all the color variations with the white,, I do this even with auto base colors,,
actually I use a white catalized sealer to prevent the solvents from the color from swelling the laquer,, but thats me

[Allan Perret]

actually I use a white catalized sealer to prevent the solvents from the color from swelling the laquer,, but thats me

Can you give a specific brand/product number ?
You ever gonna pick up the Finishing section in SN ?

[bill rutherford]

     I wanted to have an all dope finnish just for grins. Well I decided to sand it all off and go with base coat . At least it's faster and I have a ton of base coat stuff here. Oh yea Joe I let it gas off for a week. I will report when I/am done.   Bill

[Brett Buck]

     I wanted to have an all dope finnish just for grins. Well I decided to sand it all off and go with base coat . At least it's faster and I have a ton of base coat stuff here. Oh yea Joe I let it gas off for a week. I will report when I/am done.   Bill

   On a regular type of finish, 3 1/2 ounces it a lot but not prohibitive. Most good dope finishes come out in the 9-10 ounce range, and everything else you put on will be lighter. People who know tell me a blocking coat of gray followed by less white is lighter than trying to cover everything with white, but I haven't done it.

    Yes, I think epoxy is probably lighter since it covers better, but I think that the white on mine was around 2 1/2 ounces. It's in some post somewhere. Almost all the weight in my finish was the primer and the white. Everything else was in the noise.

     Brett

[FLOYD CARTER]

I avoid all types of primer, because they're just too heavy.  I get by with some extra clear coats with zinc stearate mixed in for filling the wood grain.  It's more work, but the result is a lighter finish.

Floyd

[Avaiojet]

Bill,

Quality auto paints are very opaque, including the primers. They cover nicly.

Put the primer on than board it out and just dust the areas if you go to thin. Might not have to depending on color.

You would be surprised how auto paint Brands differ in quality. Some Brands we used to call weasel p-i-s-s

Can't help you with dope, I have absolutely no interest in it. Said that years ago and I still feel the same way.

BTW. I've been using auto paints since the 80's. Well, actually way before that, but on model airplanes only since the 80's.

Interesting the trade off in weight that's excepted and dealt with to have a great looking model.

This primer, one coat and it's done. Couple of areas need dusting.

My first real stunt ship, The Tank Buster.

29.7 ounces as you see it.

Not actually a bad beginning for a 55" model with enough scale detail to go to prison for.  

[Brett Buck]

I avoid all types of primer, because they're just too heavy.  I get by with some extra clear coats with zinc stearate mixed in for filling the wood grain.  It's more work, but the result is a lighter finish

  Primer is not exactly required, but highly recommended, for epoxy finishes over dope subtrate. Otherwise the adhesion is less-than-ideal. In any case, the primer is epoxy clear mixed with - wait for it - zinc stearate -  and a different catalyst. And I think the same is true of Brodak dope primer.

   The difference is that the epoxy primer (just like the colors) can have a vastly higher ratio of pigment to carrier without adhesion issues than can dope. That's why Windy's method of concentrating the pigment (letting it settle out, then skimming of some of the clear) works or why adding pigment works, but is moderately risky with dope. You can either get adhesion issues or the underlying colors will bleed through. That's also why epoxy covers so much better. The volume of pigment per unit volume of liquid is much, much higher. I would guess that a quart of KlassKote or K&B primer contains about 5x as much filler as a quart of dope. Same with the colors. Pick up a can of Klass-kote White or primer and you would swear it was poured full of lead instead of paint. And it has the consistency of very heavy cream, honey, bordering on pudding.

  The key is that you just don't need to put very much on. I did a lot of pretty careful tests on it, and I think to get a similar level of opacity,  you need something like 2/3 the mass  dope. And that's roughly what you get on completed airplanes - maybe 8-10 oz. of dope and 6-7 ounces of epoxy/car paint to get the same quality of finish, assuming nothing goes wrong.

  All the big weight issues I have seen with it have been the result of treating like dope and applying FAR too much. I knew one notable whose name will be omitted (unless he wants to own up to it) that ended up with something like 12 ounces - of CLEAR alone!

   Car base coat (which I haven't used, but I know most of the pioneers) seems to be much more like epoxy than dope in the covering power VS mass.

   Brett

[Dan McEntee]

   Do a search on here for a thread my son Sean did about "doping dope" with a splash of your base color and you do your normal dope build ups on a dope finish. It's a technique that a local guys does, especially with white airplanes, and comes out witha pretty good coverage and none of teh weight. Sean used it for his Don Hutchinson T-6 Texan that he's building in Aeroshell team colors. Looks really good in the pictures, and he said the only place he had to shoot white was a light coat on the bottom of the airplane. I plane on trying it as soon as I get a worthy project for the process.
  Type at you later,
  Dan McEntee

[bill rutherford]

Well I started sanding the white off tonight. Only took off 10 grams sanding the top of the inbo wing. It was hard sanding the cured dope.  Bill

[Brett Buck]

Well I started sanding the white off tonight. Only took off 10 grams sanding the top of the inbo wing. It was hard sanding the cured dope.  Bill

  Heh! Try sanding cured epoxy!

    Brett

[Larry Fernandez]

[quote author=Brett Buck link=topic=39115

  

  All the big weight issues I have seen with it have been the result of treating like dope and applying FAR too much. I knew one notable whose name will be omitted (unless he wants to own up to it) that ended up with something like 12 ounces - of CLEAR alone!

  
 Brett
[/quote]

Your not making fun of my first Checkmate, are you?

Larry, Buttafucco Stunt Team

[Brett Buck]

All the big weight issues I have seen with it have been the result of treating like dope and applying FAR too much. I knew one notable whose name will be omitted (unless he wants to own up to it) that ended up with something like 12 ounces - of CLEAR alone!

Your not making fun of my first Checkmate, are you?

Larry, Buttafucco Stunt Team

  No, I am not. If it was you, wouldn't you think I would name names? So this one time (and this time only) you are innocent. This was about 20 years ago.

  I told people about the Checkmate, but everybody thinks I am making it up, so I stopped. On the other hand, it flew pretty well!

    Brett

[Richard Imhoff]

I was involved with Ford SVO back in the late 60's and early 70's  we took 8 oz by volume of different colors of the same brand of paint  'I remember it was duPont" we took a bunch of colors that were non metallic and weighed them and White was the heaviest and Red was the lightest. It's just food for thought. I can't remember what the other colors were for weight it was a long time ago.


Just for Grins some stupid info.

We were switching from a funny car "Stampede Mustang with Dick Loere at the wheel" to pro stock and while at Ford one day working in the wind tunnel testing different bodies to find the slickest one, and a 4 door Maverick was the best, a Mustang was decent but we were trying to get the slickest body, for your info a 74 Pinto in the wind tunnel backwards had the lowest drag coefficient

[billbyles]

   On a regular type of finish, 3 1/2 ounces it a lot but not prohibitive. Most good dope finishes come out in the 9-10 ounce range, and everything else you put on will be lighter. People who know tell me a blocking coat of gray followed by less white is lighter than trying to cover everything with white, but I haven't done it.

    Yes, I think epoxy is probably lighter since it covers better, but I think that the white on mine was around 2 1/2 ounces. It's in some post somewhere. Almost all the weight in my finish was the primer and the white. Everything else was in the noise.

     Brett

I put on a light coat of Polar Gray Randolph butyrate to give a uniform  base color under the white.  Then it takes just two medium coats of Randolph Insignia White to get thorough coverage.  On my Impact (700 in^2) the entire dope finish came out at 7 ounces total including the top coats of Sig Light Coat clear butyrate.  I don't try to back mask, just spray the entire airplane white and then apply the two or three color trim scheme plus graphics followed by three coats of Sig Light Coat clear butyrate.  The white background brightens up the reds, yellows, translucent blues, etc.

In my full-scale airplane restoration business I have sprayed many gallons of the base coat/catalyzed polyurethane clear coat systems, epoxy systems, and single-stage catalyzed polyurethane paints so I do recognize the advantages of these systems.  However, I still like to finish my models with the old butyrate dope system...smells like my childhood! 

[FLOYD CARTER]

If you like the epoxy or single-component finishes, consider the repair problem (that is, if you tend to crash a bit).  My experience with K&B epoxy (loong time ago) was, it is difficult to do a repair and "blend" the repaired areas once they have been hosed with epoxy.

Butyrate, on the other hand, makes invisible (?) repairs much easier.

F.C.

[Brett Buck]

If you like the epoxy or single-component finishes, consider the repair problem (that is, if you tend to crash a bit).  My experience with K&B epoxy (loong time ago) was, it is difficult to do a repair and "blend" the repaired areas once they have been hosed with epoxy.

Butyrate, on the other hand, makes invisible (?) repairs much easier.

  Mine has had quite a few repairs, and I haven't had much problem, aside from matching the colors. Sand it down, fix whatever, build it back up. The one place it is obvious is a spot-repair where I really should have done the entire area, and that's a color issue.

   I have had a lot of trouble matching the whites because they tend to yellow over time. I now mix fresh catalyst with catalyst from old rusty cans that has turned brown, adjust until it's right!

   Brett

[Ted Fancher]

I always just added clear until it was heavy enough to fly well.

[bill rutherford]

     I have been sitting here trying to think up some smart ass reply but nothing is coming out. Good one Ted. It really hurt all us weight challenged stunt fliers.

[Allan Perret]

I always just added clear until it was heavy enough to fly well.