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Sig King Kobra - Paint?

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Sig King Kobra - Paint?

Old 02-27-2015, 04:53 PM
  #26  
acdii
 
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Originally Posted by Gray Beard
My glass jobs come out as light as my covering jobs but I won't go into that because I discovered a small problem with my method with glow planes. The only added weight is the 1/16 sheeting that is added to the wing and other surfaces. I wouldn't do anything but glass and paint on a gas powered plane though.
This was the deft issue? EZE Kote can solve that, if you want to spend $20 for less than a quart of it, but I believe I covered a good application technique on another thread.
Old 03-02-2015, 06:43 AM
  #27  
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Originally Posted by TomCrump
If you are not going to glass the fuselage, I would suggest seeking other option than paint.

This debate appears often on RCU, but I have never seen a painted, but not glassed, wood airframe look good.

It may not be immediate, but the wood grain eventually shows through.

.Why not cover the whole airframe ?
I've seen a few planes that were painted over balsa. They don't come out pretty and you can have a whole bunch of paint soak into the wood making it pretty heavy. The grain does show through, too. I saw one crash on takeoff, a red box Topflight P-40. It was so badly damaged there was no way it was going to be repaired. The wood splintered all over the place into matchsticks. I've seen tons of crashed planes but never one that was splintered into a million pieces.

I covered a Sig Kougar with finishing resin and no fiberglass cloth once years ago. After many years of flying, the paint (Hobbypoxy) has cracked badly all over it. I've never done one like that since. Cloth adds much strength and provides a very stable base for the paint.


carl
Old 03-02-2015, 02:17 PM
  #28  
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Wow,
Great comments guys. Thank you for the feedback. A lot to consider...
RP
Old 03-02-2015, 04:56 PM
  #29  
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I just finished covering my Biper Cub, both sets of wings, and fuse, minus the ailerons, rudder, and door in under 2 days. Using Koverall and dope, and it is looking good. Just about done with the first coat on it all, second coat should seal it good, so 2 coats of Butyrate Dope followed by color and it will be done. You could do the same with the Kougar too.
Old 03-11-2015, 04:05 PM
  #30  
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hello

Both these birds is covered with silkspan and clear dope, And quite franlky i don't know if either is still available. But solid wood covered with silkspan and clear dope will not show the wood grain and weight is a non issue. the first pic. is of a replacement fuse for my (at time) 25+ year old Kaos it's over thirty now, the other pic's you should know. the fuse has the silkspan finish.

Silkspan is very much similar to the paper type cover you will find in the stick build kits but a bit stronger, I happened to get a bunch at a swapmeet and always keep a look out for more...Good stuff!
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Old 03-11-2015, 05:20 PM
  #31  
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Well they no longer carry silkspan, but SIG carries Silk and clear dope, so those options are still available for covering. If you are going to go that route though Koverall is a better option as its stronger, but would require colored dope instead of the colored silk using clear dope.
Old 03-11-2015, 07:39 PM
  #32  
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Just checked - Brodak still carries light & medium silkspan. Here's the link for medium: http://brodak.com/finishing-products...-2-sheets.html
Old 03-11-2015, 11:22 PM
  #33  
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I've painted a few planes over the years, and I have used glass and I have also elected not to use glass. I think the main part of the surface prep is to seal the wood with a clear dope, or clear polyurethane. I use clear coat (clear polyurethane) to seal my wood. If you are going to glass the wood, you can also use the clear coat paint to lay down your glass.

By applying just a couple of coats, it seals the surface of the balsa so that you can apply a filling primer. I like to use grey auto lacquer primer. It can be brushed on or sprayed. Once it is dry, less than an hour, you can sand 90 percent of it off and you will see the grey primer in the balsa pores. Dry sanding with 400 grit paper works fine. I would then spray on two more coats of lacquer primer and let dry for a couple of hours, then wet sand lightly with 400 grit paper. After that, it's time to start applying the color coats.

I used to use Super Poxy until it was discontinued. Now I use the Automotive base coat/clear coat system.

The base coats go on flat, and are easy to spray and it doesn't take a lot of paint for good coverage. The clear coats goes on wet. And if you get a run, you can sand out with 800, then 1000, and then 1500 wet, and then buff it out for a wet look shine. If you are good enough not to get a run, you can leave it as is for a nice shiny finish.

Now I don't have an unlimited budget like some people do, so I have to make the most of what paint I buy. I usually only purchase Red, White, Blue, yellow and Black base coat paint. With those colors, I mix them to obtain the colors I want to use.

For instance, I like Cub Yellow so I mix a little red in yellow to get the cub yellow I need. A little black with blue will give me the royal blue I need. You get the picture.

However, That's just my way. Everyone has their way of doing things and they should continue using what works best for them.

A word of warning: If you decide to use auto paint, don't rely on the sales clerk at the paint supply store for information on how to use the paint. He only sells it. Ask a painter at a Auto Body shop.

Frank
Old 03-12-2015, 03:19 AM
  #34  
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+1 on the base coat/clear coat.

Bob
Old 03-12-2015, 04:41 AM
  #35  
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Originally Posted by countilaw
I've painted a few planes over the years, and I have used glass and I have also elected not to use glass. I think the main part of the surface prep is to seal the wood with a clear dope, or clear polyurethane. I use clear coat (clear polyurethane) to seal my wood. If you are going to glass the wood, you can also use the clear coat paint to lay down your glass.

By applying just a couple of coats, it seals the surface of the balsa so that you can apply a filling primer. I like to use grey auto lacquer primer. It can be brushed on or sprayed. Once it is dry, less than an hour, you can sand 90 percent of it off and you will see the grey primer in the balsa pores. Dry sanding with 400 grit paper works fine. I would then spray on two more coats of lacquer primer and let dry for a couple of hours, then wet sand lightly with 400 grit paper. After that, it's time to start applying the color coats.

I used to use Super Poxy until it was discontinued. Now I use the Automotive base coat/clear coat system.

The base coats go on flat, and are easy to spray and it doesn't take a lot of paint for good coverage. The clear coats goes on wet. And if you get a run, you can sand out with 800, then 1000, and then 1500 wet, and then buff it out for a wet look shine. If you are good enough not to get a run, you can leave it as is for a nice shiny finish.

Now I don't have an unlimited budget like some people do, so I have to make the most of what paint I buy. I usually only purchase Red, White, Blue, yellow and Black base coat paint. With those colors, I mix them to obtain the colors I want to use.

For instance, I like Cub Yellow so I mix a little red in yellow to get the cub yellow I need. A little black with blue will give me the royal blue I need. You get the picture.

However, That's just my way. Everyone has their way of doing things and they should continue using what works best for them.

A word of warning: If you decide to use auto paint, don't rely on the sales clerk at the paint supply store for information on how to use the paint. He only sells it. Ask a painter at a Auto Body shop.

Frank
I concur, but being tight fisted I found one coat of clear covered with a layer of wet silkspan applied with clear dope lightly sanded and one more coat (or not) of clear then colored dope works fine. for the average paint job. for high dollar finishes more dope is used. the use of silkspan deletes the use of primer. be careful not to sand thu it. a filler can also be used but thats more money.
Old 03-12-2015, 06:21 AM
  #36  
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Thats all fine and dandy to not use cloth, glass, or silkspan, however, if you just coat one side of the wood, the interior is still exposed to moisture and lack of it and will still cause the wood to shrink or swell, so all your work on the outside could be ruined if you dont apply a sealer to the inside of everything.
Old 03-13-2015, 01:46 PM
  #37  
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Originally Posted by acdii
Thats all fine and dandy to not use cloth, glass, or silkspan, however, if you just coat one side of the wood, the interior is still exposed to moisture and lack of it and will still cause the wood to shrink or swell, so all your work on the outside could be ruined if you dont apply a sealer to the inside of everything.
What you say .... coat the interior is true BUT I must have thirty or so planes, none are coated internally except the tank and engine bay and several are over twenty years old with no ill effect!
Old 03-13-2015, 07:08 PM
  #38  
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If in a humid environment during the summer, then stored where it gets really dry in the winter, it will show cracks if not sealed on both sides. I actually had some iron on plastic film split where it was applied to slab sided fuse made of balsa. It had help of course, my finger. I saw a blemish, touched it and pop, it split. I have since stripped and koveralled it. No more splits.
Old 03-16-2015, 09:27 AM
  #39  
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Guys,
This is great information and thank you for the comments. I don't know if I really accept the notion that since the back is not painted it will crack. My table top is painted and the back is not, It has never cracked. Of course the airplane is not a table and is subjected to flight loads. This might have more to do with it. I still feel however, the glass cloth only adds to surface toughness. But I may be wrong... In this particular application I don't think I need it and I will omit it to save weight.

I have decided that I am going to / have already poly coated the fuse twice sanding between coats. Used an automotive filler primer and am now sanding that smooth. The results are very good so far. I want to use the automotive base coat / clear coat method, but I suspect when I see the cost that may change. I am guessing materials will be in the $200 range. I may be willing to go this route just to learn the application to model aircraft.

I'll keep you posted. I'll get some pictures up soon.
Kind regards,
Rick
Old 03-16-2015, 09:37 AM
  #40  
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I find it interesting that you are worried about weight, and yet you applied two coats of polycrylic to seal the balsa. For a few ounces more you could have had a glassed surface, that accepts paint well, and with no worries about wood grain showing through.
Old 03-16-2015, 09:39 AM
  #41  
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Well a tabletop is at LEAST 3/4" thick and most likely made either of plywood with veneer or particle board with veneer, where the balsa sheeting on the planes are usually 3/32 to an 1/8" thick, and while cracking is rare, it does happen over time. Even solid wood tabletops are known to crack and split over time. It is just the nature of the beast. The glass or cloth helps prevent splitting and cracking, the wood underneath cant move once the glass or cloth has been bonded to it properly. It isnt there to add strength, only as a protective cover over the wood. If you ding a bare wood surface, you could dent or crack it, but if it has a layer of glass and resin, or cloth and dope, it is far less likely to ding or crack. thats the protection it adds.

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