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Building Tips and technical articles. => 1/2 A building. => Topic started by: Bill Little on April 20, 2012, 09:10:52 PM

Title: Cox Foam wings
Post by: Bill Little on April 20, 2012, 09:10:52 PM
I am guessing that most of you remember the foam wings that were given out for free with buying a Black Widow .049.

I have a couple and will build the FW-190 on the plans that come with them and draw up something else for the other set. My problem is what to use for paint.  I tried the Perfect paint years ago and it came off the wing where exhaust hit it.  I am guessing Rustoleum would hold up better?

Any suggestions for what to draw for a companion model to the FW-190?  Maybe a P-47 bubble canopy?

I have some assembled Killer Bee .049s for them.  Good or too much?

Thanks!

BIG Bear
RNMM/AMM
Title: Re: Cox Foam wings
Post by: Larry Renger on April 21, 2012, 01:00:36 AM
Water based Urethanes and Latex house paints ( all thinned appropriatly)  will work well, and are remarkably fuelproof. Lightly sand the areas to be painted, 600 or 800 grit should do. Then clean with rubbing alcohol. I haven't checked, but am pretty sure the volitales in Rust-O-Leum will eat foam! It is an Oil based paint system, almost as bad as a Toluene/Acetone/MEK one like lacquer.

On the FW 190, it had a scale tail, and a longer tail moment and tail area would greatly improve the smoothness of maneuvers.  Copy those areas and moments and style the model to your heart's content.
Title: Re: Cox Foam wings
Post by: Bill Adair on April 21, 2012, 01:34:36 AM
Hi Bill,

I'm curious about your assembled Killer Bee engines.  ???

I'm still looking for an original Killer Bee, but could only find an Estes version. It has the proper cylinder, with different exhaust slits (larger bottom slit), and the backplate is the correct ID of .082", so I bought some lightened and balanced cranks from Bernie, and hope to match one of his lightened pistons to fit my cylinder.

I have no intention of ever foisting this off as an original KB engine, but wanted mine as close to original as I could make it. Of course the cylinder is probably not tapered, and the box insert does not have the Cox date stamp, but I'll know that it at least has a chance to run like the real thing.  ;D

Is that what your referring to as assembled Killer Bees?

Bill
Title: Re: Cox Foam wings
Post by: Bill Little on April 21, 2012, 05:13:33 PM
Thanks, Larry!  I guess I could test the Rustoleum on a scrap of foam.  I didn't think the water based urethane was fuel proof......... ???

John,  I bought some anodized red crank cases, crank shafts, .051 Killer Bee back plates, lightened piston/cylinders, etc., and "assembled" them.  They are as close to the old Killer Bees, parts wise, as I could get.  Obviously not passing them off as "original".  Also using the Galbreath heads/plugs.  I have about 7 of them now.  Been a slow process....... ;D

Thanks, guys!
Bill
Title: Re: Cox Foam wings
Post by: dankar on April 23, 2012, 09:36:11 AM
Just an idea but cover foam wings with tissue or lite silkspan with 50/50 white glue/water. Then you can rattle can paint on it and just sample paint. I use med. silkspand on foam Joe Just Carrier F-4-F and this worked dandy.
Title: Re: Cox Foam wings
Post by: Phillip Kenney on April 23, 2012, 01:36:49 PM
Not familiar with the Cox foam wings. How do they compare with the old Ace foam wings.? They came in straight and tapered style and were about 7.5" long per section and 5.5" at the root.
Title: Re: Cox Foam wings
Post by: RDJeff on April 23, 2012, 02:13:22 PM
Regarding Rustoleum, I just carved out a hunk of foam for the nose on a seaplane, and painted it with Rustoleum, and had no issues at all.  It took three brush coats to get a good gloss, but it looks pretty good. YMMV
Title: Re: Cox Foam wings
Post by: dankar on April 23, 2012, 11:04:11 PM
Not familiar with the Cox foam wings. How do they compare with the old Ace foam wings.? They came in straight and tapered style and were about 7.5" long per section and 5.5" at the root.

These wings are hollow as used for ME-109 Stunter early version. Later Cox went to Ace type foam wings.
Title: Re: Cox Foam wings
Post by: Guy B Jr on April 23, 2012, 11:33:40 PM
Bill, the plans came with the plans and an instruction sheet, called a "Guide". The following is listed under "What to use".

Epoxy glues
"White" glues, Titebond, etc.
Urethane glue, Dow CorningHot melt glue
Water base contact cement, must say "safe for use on Styrofoam"
Single & double surface tapes
Urethane paints, Varethane Plastic
Latex house paints
Topcote, Kwik Kote, Solarfilm plastic coverings

Hope this helps.

Title: Re: Cox Foam wings
Post by: dankar on April 24, 2012, 12:54:16 AM
Wow, good long list.
Title: Re: Cox Foam wings
Post by: Bill Little on April 24, 2012, 02:58:52 PM
Bill, the plans came with the plans and an instruction sheet, called a "Guide". The following is listed under "What to use".

Epoxy glues
"White" glues, Titebond, etc.
Urethane glue, Dow CorningHot melt glue
Water base contact cement, must say "safe for use on Styrofoam"
Single & double surface tapes
Urethane paints, Varethane Plastic
Latex house paints
Topcote, Kwik Kote, Solarfilm plastic coverings

Hope this helps.

Thanks, Guy!  I appreciate it.  On the first pair X number of years ago, I used the Perfect camo paints, supposed to be urethane I believe.  It didn't hold up at all on the wings.............

BIG Bear
RNMM/AMM
Title: Re: Cox Foam wings
Post by: Bill Little on April 24, 2012, 03:03:50 PM
Just an idea but cover foam wings with tissue or lite silkspan with 50/50 white glue/water. Then you can rattle can paint on it and just sample paint. I use med. silkspand on foam Joe Just Carrier F-4-F and this worked dandy.

Hi Dan,

I have one of Joe's F-4-F, also.  I have heard of attaching the silkspan with water based glue but have never tried it.  Might as well do it now on one of these wings!

Thanks

BIG Bear
RNMM/AMM
Title: Re: Cox Foam wings
Post by: Bill Little on April 24, 2012, 03:05:36 PM
Not familiar with the Cox foam wings. How do they compare with the old Ace foam wings.? They came in straight and tapered style and were about 7.5" long per section and 5.5" at the root.

Hi Phillip,

The Cox foam wings are in two halves and sipped "flat".  You bend them over and glue the TE.  Not like the Ace wings that I remember being "full panels".

BIG Bear
RNMM/AMM
Title: Re: Cox Foam wings
Post by: sleepy gomez on April 24, 2012, 08:37:37 PM
I wrote the first article in American Aircraft Modeler mag in 1972.  I detailed cutting foam as well as how to finish.  Apply silk span or Jap tissue with a mix of 40% white glue and 60% water.  If you use enough white glue to seal the wing it can get heavy real fast.  Once the covering has dried, coat with a mix of Knox unflavored gelatin.  The mix must be hot (very hot tap water) Use one packet to 1.5 ounce water.  When done right you can pour lacquer thinner on your wing.  At this point any paint will work.  Always test.  I have used this method since 1971 and I still do to this day.  It is strong, light and inexpensive.

ps. Silk span makes a rigid wing.  On all but the thickest airfoil the use of silk will result in a flexible wing. 
Title: Re: Cox Foam wings
Post by: dankar on April 26, 2012, 08:54:19 AM
Wonder if any extra plastic wing tips are around. I have a used ME-109 stunter with very pale looks wings, but have the new wing skins. I'm sure old tips will split as soon as I try to remove them. Plane had a broke engine mount but after years found one. I don't want to make wood ones as I want to get it close to stock as possible. Even tough used alot it still looks very good.