Notices
Classic RC Pattern Flying Discuss here all pre 1996 RC Pattern Flying in this forum.

anyone building a king kobra?

Old 12-31-2007, 06:42 PM
  #51  
My Feedback: (18)
 
Join Date: Feb 2003
Location: Euharlee, GA
Posts: 1,828
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?

Good Looking work David...

Have Fun...

Chuck
Old 01-18-2008, 07:53 PM
  #52  
Senior Member
My Feedback: (2)
 
Join Date: Feb 2002
Location: Burlington, NJ
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?

When you said you glassed with Minwax, are you saying you used the minwax in lieu of either epoxy or polyester resin to soak the glass? I have a King Kobra that I'm interested in doing something similar with, and would like to glass the fuse- like you, mainly for building practice. I have a whole gallon of West Systems laminating epoxy and 206 hardener though, so I didn't know if I should use this or not. Did you glass over the plastic turtle deck, or just the balsa? Did you glass the wings and stab as well? I was thinking finish the fuse, then paint it with one of the Topflite polyurethane paints, then cover the wing, horizontal and vertical stab with matching Monokote.
Old 01-18-2008, 10:42 PM
  #53  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

yes, i sealed the fuse with sanding sealer, sanded and wiped clean with tack cloth and then layed down 3/4 oz fiberglass cloth and painted it with Minwax polycrylic. it dries in 20 minutes or so and then you can paint it again. sand smooth after 3 coats and repeat; paint 3 times and sand. after about 8 coats the glass weave has been filled in and you are ready for primer. since this is a water based finish, almost all of the weight evaporates. i have since noticed that someone on this forum was wet sanding, i've tried it and it works well. also, i have been told that you can add babypowder to the poly as a way to fill in the weave faster. i will try that shortly. after a coat or 2 of primer i use bondo spot putty to fill in any imperfections and prime again. almost all of the primer sands off, so there is very little weight gain. i should be in the primer stages this weekend and will post photos.

david
Old 01-19-2008, 01:00 AM
  #54  
Senior Member
My Feedback: (2)
 
Join Date: Feb 2002
Location: Burlington, NJ
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?

How did you deal with the plastic turtledeck? Did you glass over that?
Old 01-19-2008, 07:11 AM
  #55  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

sorry, i forgot you asked about that. i went ahead and used it as they showed. i just needed to move ahead with the project. i thought about that part for a long time. usually i rely on others for great ideas. i used ca glue for the complete installation. i leaned the fuse over and slowly drained thin ca under the deck onto the 1/8 strips. i am thinking about using epoxy/microballoons or bondo spot putty to fillet out the seam. i did all of this after i finished glassing the fuse.

david
Old 01-19-2008, 04:32 PM
  #56  
Senior Member
My Feedback: (2)
 
Join Date: Feb 2002
Location: Burlington, NJ
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?

Cool, thanks for sharing. I wasn't sure if you could glass over it or not. So, the minwax, this is just a can of the stuff you get at Home Depot? Specifically which minwax product? I've noticed they offer a "sanding sealer." Was that the one you used, then followed it up with another type of minwax? I'm assuming since this is water based, it's lighter than finishing/laminating resins, and now most people are using that now instead? How will it tolerate fuel? I apologize for all the questions, I've just finished reading all the Harry Higley's finishing books, and they're kinda out of date being published in the early 80's so I'm trying to get caught up with what you guys are all doing now.
Old 01-19-2008, 04:39 PM
  #57  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

please, i am not an expert. there are many many threads here and elsewhere that show this way of covering. and yes, the MInwax Polycrylic is in the stain section at you favorite home improvement center. it is the water based. there is also a oil based, you don't want that. the water based is in a blue can. whil you are there pick up some foam brushes. you can rinse them with water and use them many times.

with recent researching i have decided to do add the baby powder in 1 can and keep the other for thinning if i get the 1st can to thick.

david
Old 01-19-2008, 05:57 PM
  #58  
Senior Member
My Feedback: (1)
 
Join Date: Jan 2002
Location: beechgrove, IN
Posts: 107
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?

Guys, be sure you seal the balsa with something before using minn-wax to adhere the cloth. If you don't, since its water based it will warp the wood like you wouldn't believe. Otherwise it works fine, sugarfox
Old 01-19-2008, 06:10 PM
  #59  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

yes, i had said to use sanding sealer 1st. along with a light sanding afterwards and a good dust removing with a tack cloth. THEN you begin to apply the glass cloth and polycrylic.

david
Old 01-30-2008, 01:35 AM
  #60  
Senior Member
My Feedback: (2)
 
Join Date: Feb 2002
Location: Burlington, NJ
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?


ORIGINAL: sugarfox

Guys, be sure you seal the balsa with something before using minn-wax to adhere the cloth. If you don't, since its water based it will warp the wood like you wouldn't believe. Otherwise it works fine, sugarfox
With all that to be concerned about, why not just use polyester resin?
Old 01-30-2008, 06:21 AM
  #61  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

it it so easy to cover my plane this way i don't plan on trying any other way. the 1st time i tried it i was amazed at how smooth the primered finish was. i did the monocote when i was in the hobby yrs ago but always wanted a painted finish. i finished a long ago framed super sportster last yr in fiberglass and koverall this way and was very happy. btw, it still sits primered and ready to paint. it will be a practice paint plane just like my KK when i get them both ready for paint.

david
Old 02-02-2008, 08:21 PM
  #62  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

blatantly borrowing ideas from a much more accomplished builder than i, i have use 6 oz. fiberglass cloth strips to form my wing fillets. i used a tape base to protect the rest of the fuse and have painted the strips with fiberglass resin. i replaced the rough tape edging after drying and sanding to shape with a more form fitting strip of tape. this will form the fillet fill in shape and protect the fuse during sanding. i want to go with fiberglass resin and micro balloons fill in but i am at a loss as how to apply the mixture to the fillet base. any suggestions?

thx, david
Attached Thumbnails Click image for larger version

Name:	Zx70593.jpg
Views:	81
Size:	58.7 KB
ID:	868402   Click image for larger version

Name:	Dy80140.jpg
Views:	64
Size:	41.6 KB
ID:	868403   Click image for larger version

Name:	Gr92795.jpg
Views:	71
Size:	32.8 KB
ID:	868404   Click image for larger version

Name:	Ar99863.jpg
Views:	71
Size:	35.6 KB
ID:	868405   Click image for larger version

Name:	Ba50949.jpg
Views:	74
Size:	39.0 KB
ID:	868406  
Old 02-03-2008, 07:29 AM
  #63  
 
WEDJ's Avatar
 
Join Date: Feb 2007
Location: Stockton Springs, ME
Posts: 1,654
Likes: 0
Received 3 Likes on 3 Posts
Default RE: anyone building a king kobra?


ORIGINAL: dhal22

i want to go with fiberglass resin and micro balloons fill in but i am at a loss as how to apply the mixture to the fillet base. any suggestions?

thx, david
Apply w/ popsicle sticks, then use your finger dipped in thinner to smooth it out. Make it as smooth as possible while it is soft, it's a B**ch to sand when cured.
Old 02-03-2008, 07:36 AM
  #64  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

i assume fiberglass and microballoons are going to be easier to sand than epoxy and balloons. i need to do a trial run of bondo spot putty. would be easier to sand.
Old 02-03-2008, 08:56 AM
  #65  
My Feedback: (17)
 
8178's Avatar
 
Join Date: May 2004
Location: Atlanta, GA
Posts: 4,348
Likes: 0
Received 7 Likes on 4 Posts
Default RE: anyone building a king kobra?

Microballoons sand pretty easy. I use epoxy glue or polyester resin depending on what I’m putting it on. Just get it formed pretty close to what you want before it sets. I usually use a couple of coats with sanding in-between to build it up in layers.
Old 02-03-2008, 09:16 AM
  #66  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

great tip! i feel a lot better about building it up slowly. i'll give it a shot.
Old 02-07-2008, 04:02 AM
  #67  
Junior Member
 
Join Date: Nov 2006
Location: Marble Hill, GA
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anyone building a king kobra?

I have a chance to buy one from an individual and am about sure to do so. However, I need to know where to put the c.g. and the throws. Any info would be appreciated.
Thanks
Ran
Old 02-07-2008, 05:24 AM
  #68  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

the cg, according to the build manual is 5 and 5/16ths inches from the leading edge. no more than an additional half inch further back should be considered in the event you want a more aerobatic setup. the throws call for: elevator - 9/16ths up and down, rudder 1 5/8ths and ailerons 1/4" up and down. let us know how she flies.

david
Old 03-09-2008, 08:08 AM
  #69  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default RE: anyone building a king kobra?

a few updates on my not a real pattern plane build. at least the building has a lot of similarities with pattern planes. i glassed the wing with .75 oz cloth and Minwax polycrilic but i picked up a tip that i used since i glassed the fuse. after laying down and coating the glass with polycrilic i added baby powder to the polycrilic as a filler. then the poly filled in the glass weave so well i was ready for primer before i knew it. keeping the poly wet sanded between coats left the preprimed surface extremely smooth. i then shot a thick coat of filler primer and wet sanded that. i was tempted to leave the wing there but i have since went back and spot puttied some imperfections. so far i have 2 oz of weight build up of poly and primer. this measurement is after i layed the cloth down with 1 coat of polycrilic.
Attached Thumbnails Click image for larger version

Name:	Us53296.jpg
Views:	66
Size:	39.8 KB
ID:	898725   Click image for larger version

Name:	Sn41200.jpg
Views:	62
Size:	25.9 KB
ID:	898726   Click image for larger version

Name:	Lq38617.jpg
Views:	67
Size:	33.2 KB
ID:	898727  
Old 07-07-2014, 12:43 AM
  #70  
Senior Member
 
Join Date: Sep 2007
Location: Laveen, AZ
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by dhal22
yes, i sealed the fuse with sanding sealer, sanded and wiped clean with tack cloth and then layed down 3/4 oz fiberglass cloth and painted it with Minwax polycrylic. it dries in 20 minutes or so and then you can paint it again. sand smooth after 3 coats and repeat; paint 3 times and sand. after about 8 coats the glass weave has been filled in and you are ready for primer. since this is a water based finish, almost all of the weight evaporates. i have since noticed that someone on this forum was wet sanding, i've tried it and it works well. also, i have been told that you can add babypowder to the poly as a way to fill in the weave faster. i will try that shortly. after a coat or 2 of primer i use bondo spot putty to fill in any imperfections and prime again. almost all of the primer sands off, so there is very little weight gain. i should be in the primer stages this weekend and will post photos.

david
David sorry about jumping in to your build I was interested in the sealer you used is that also the Minwax brand?
Old 07-07-2014, 02:29 AM
  #71  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default

Yes Robert. I used a Minwax water based sealer. It works very well.
Old 07-07-2014, 02:41 AM
  #72  
Senior Member
 
Join Date: Sep 2007
Location: Laveen, AZ
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for the rapid reply, I have all three (kobra,kogar,and in the framing stage on this one) I gone back and forth with the finishing resin and the polycrylic See the Great planes F4 build he used a brand called Envirotex the water clean up seems the way to go. I did not recall if you mention that you have completed yours or maybe I missed it (I read and re-read just about everyone of the builds.)
Thank again;
Robert
Old 07-07-2014, 02:47 AM
  #73  
Thread Starter
 
Join Date: Aug 2006
Location: Roswell, GA
Posts: 5,711
Received 7 Likes on 7 Posts
Default

I finished mine and flew it a few times. It had a rough dead stick landing and I retired it. Please show us your KK here or in your own thread.
Old 07-07-2014, 03:17 AM
  #74  
Senior Member
 
Join Date: Sep 2007
Location: Laveen, AZ
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Default

I will it has had some down time as my Spring Air retracts were leaking so they are being rebuilt I'm told they were 20 years old. I did not want to skin the wings until I was sure they were working correctly. and about the same on the fuse need the nose gear. I will shoot some shots when I am a little further along and maybe I can get all 3 in. The little guy came in a bit heavy as I used regular servos on this one I will end up removing them and going back to the mini's I had in the first one. I met it's doom when the battery shifted and came unplugged at take off, when it went in I had to dig it out the spinner it was embedded about 8 inches needless to say not repairable along with most of the servos battery receiver had to hit well over 120 mph! The Supertigre G34 broke the needle and exhaust stack nothing else. Says something about good Metallurgy.
Again thanks for your help!!!

Last edited by robertwilkerson; 07-07-2014 at 03:26 AM.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.