Airplane finishing

[Sheldon Hartwell]

Hi again C/L'ers,
      A few days ago, I posted a question about weight on my Sig P-51 Mustang . I got some great responses including Bill Little's about the final paint scheme on the model. Actually, the comment about the finish on the model was an afterthought. Then, after I read the response, it got the gears in the head turning.
     Just how do all of you get the fantastic final finishes on your planes ? I realize that some of you either have or have access to spraying/spray booth facilities. I unfortunately don't have that option. My shop is very small and I put my finish coats on my models using a paint brush and lots of retarder ( so the dope will flow ).
     I don't use any of the current coverings like Monocote, Ultracote, etc.  .   I'm sorry, but I was taught by my dad who was " old school ". He built and flew these models in the 40's and 50's, and like father like son, I followed his footsteps and been hooked since.
     If I have to continue brushing, I will. But, if you people have some alternate ideas, that would be awsome.
                                                                                   Thanks,
                                                                                       Sheldon
     

[PJ Rowland]

Rattle cans like Holts give good results.

Then again the Mona lisa was brush painted, and im sure thats a 20 pointer.

[Paul Taylor]

From what I understand sandpaper plays a big roll in a good finish.

But what do I know, I am a rattle can, monokote untrakote kind of guy.

[Randy Ryan]

Not just tooting my own horn, there's allot of good info here.

http://stunthanger.com/smf/index.php?topic=6622.msg54453#msg54453

[Clint Ormosen]

Not just tooting my own horn, there's allot of good info here.

http://stunthanger.com/smf/index.php?topic=6622.msg54453#msg54453

It's ok to toot a little there, Randy. That post is great for the first time finisher!

Sheldon, read and re-read Randys finishing post. Follow it to the letter and you won't be dissapointed. As for spraying paint, you don't have to have a booth (I don't). If you can get your hands on a gun and a compressor, it's the way to go. I hang my models from the open garage door and spray them. Works good, but once and a while a bug flies into the paint.

BTW, since weight is big concern with your Mustang, I'd try to stay away from the rattle can stuff. Dope is lighter.

Here is my Mustang finished using Randy's posted method.

[Sheldon Hartwell]

Hey guys,
     As usual, your responses have been great. As far as building and structual work, I can generally work my way through it. When it comes to " the Finish ", I usually end up at a wall. Thanks to all of your input, I have a pretty good starting point.
    The next query is addressed to Ty. You stated in your response that you use cornstarch in your mix for filling. I could be doing it wrong, but I had disasterous results. I mixed it up with the clear, put it on, sanded in the usual manner, and thought I was good to go. WRONG. The first color went on fine. Masking and the second color, fine.
When I pulled off the masking tape, the base color under the tape came off like a zipper. I ended up having to sand off everything right down to the bare balsa. Am I doing something wrong ?
                                                                                              Thanks,
                                                                                                   Sheldon

[Howard Rush]

Clint's Mustang is one of the best-finished airplanes I've ever seen. 

[Randy Ryan]

Hey guys,
     As usual, your responses have been great. As far as building and structual work, I can generally work my way through it. When it comes to " the Finish ", I usually end up at a wall. Thanks to all of your input, I have a pretty good starting point.
    The next query is addressed to Ty. You stated in your response that you use cornstarch in your mix for filling. I could be doing it wrong, but I had disasterous results. I mixed it up with the clear, put it on, sanded in the usual manner, and thought I was good to go. WRONG. The first color went on fine. Masking and the second color, fine.
When I pulled off the masking tape, the base color under the tape came off like a zipper. I ended up having to sand off everything right down to the bare balsa. Am I doing something wrong ?
                                                                                              Thanks,
                                                                                                   Sheldon

Sheldon, If you have a Monokote heat gun, or even a hair dryer, use a little heat when you remove masking tapes, you'll be amazed at how nicely it comes off and you won't get lifting and tare out.

[Clint Ormosen]

Sheldon, I've had the same trouble with cornstarch and talc in dope. That's why I use just plane ol' nitrate dope for all the undercoats until the first coat of butyrate color. I haven't had a lifting problem since. Some guys have been putting filler in their clear dope for years without a problem, but it must be some technique I can't figure out.


....and Howard, THANK YOU.

[Balsa Butcher]

Just a technique regarding mixing any filler with dope. I believe I read it in one of Windy's columns. Mix the powder -talc, zinc sterate, cornstarch...whatever with the dope, usually thinned 50/50 at least w/thinner. Let the mixture set for a few hours. You will find that much of the powder has settled to the bottom. Leave it there!

Pour out the liquid (decant) into a separate jar. This is what you will apply to the model. I think one of the reasons you had adhesion problems was that your solution was too thick...had to much filler, not enough dope. That is not to say that cornstarch may not have been part of the problem however I have used it without any issues.

[billbyles]

Hey guys,
     As usual, your responses have been great. As far as building and structual work, I can generally work my way through it. When it comes to " the Finish ", I usually end up at a wall. Thanks to all of your input, I have a pretty good starting point.
    The next query is addressed to Ty. You stated in your response that you use cornstarch in your mix for filling. I could be doing it wrong, but I had disasterous results. I mixed it up with the clear, put it on, sanded in the usual manner, and thought I was good to go. WRONG. The first color went on fine. Masking and the second color, fine.
When I pulled off the masking tape, the base color under the tape came off like a zipper. I ended up having to sand off everything right down to the bare balsa. Am I doing something wrong ?
                                                                                              Thanks,
                                                                                                   Sheldon

Hi Sheldon, usually when that happens it is because the dope is overloaded with filler or if you have used silver for the undercoat then the dope has been overloaded with aluminum paste.  The greater percentage of filler in the dope the less adhesion the topcoats will have.  Also, butyrate dope works just as well as nitrate dope for adhesion; nitrate dope is a holdover from full-scale covering processes such as Grade A cotton or linen and the Ceconite covering process which require that the first coats of dope on the bare material be nitrate.  Nitrate dope was developed back in the late teens/early twenties just before the somewhat less flammable butyrate dopes were developed.

[Bill Little]

HI Sheldon,

Not having a spray unit just means a bit more sanding and rubbing out to get a great finish.  Wet sanding with 800-2000 will remove brush marks, and then do the same with your final clear (after it has cured a few weeks!) to get the "ultra smooth" finish!  Randy Ryan's "article" is great to go by.  

I have seen brush painted models that really look great. It's just is a matter of how much time you want to spend, and how good you want it to look. A great looking dope finish is really a matter of "spending the time".

Big Bear

[Randy Ryan]

The first and last time I ever used talc, I was 14. The Nobler was all brushed and rubbed out, it took me WEEKS!

[Jim Kraft]

Hey Sheldon; You are a man after my own heart. I finish all my planes with a brush. I have an air compressor, three air brushes, and a spray gun, but I like brushing. I don't use any filler, and just use clear dope up until the color. Brushing dope is great therapy. The nice part is when you get to masking for trim. You only have to mask the edge you are going to paint, and not the whole section. (I am lazy)  I started brushing everything about 18 years ago when I was ready to finish a new plane in the dead of winter. My garage was to cold, and the basement was just right. Been doing it ever since.

[jim ivey]

well  shel, Im old  too and use silk, paper n dope. But i can use plastic as well, It hides a multitude of sins and comes out very pretty. the only problem I've had with it is fuel hunts untill it finds a place to get under it, then it gets loose there.When I built the sky tigers I put epoxy around and in the engine and tank  compartments and put a few coats of clear on the rest of the plane to protect the wood. I didnt do that to my 1/2 stunter and iwas sorry. Its pretty but a lot of trouble. Its also just a tad heavier.  jim

[Bill Little]

Opppsss!!!!    

I made a "typo" and didn't catch it until this morning!  I should have written "800-2000" when I was speaking of "grit" used when color sanding, or sanding out for rubbing.  I put "200" which you would DEFINITELY "NOT" want to use once you are at that stage.  Sorry.  And use the paper "wet" once you are in the finishing stages.

An out standing brush painted model, equal to a spray painted one, can be done.  It just takes more time and patience.

Big Bear