So this is how we do Sig Koverall and dope!  
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So this is how we do Sig Koverall and dope! - 3/22/2003 9:08:47 AM   
rustyrivet


 

Posts: 599
Joined: 3/13/2002
From: Houston, TX, USA
Status: offline 		If this is it.....you can stick it in the mud!

Just finished a couple of weeks of almost completing my plane with Sig Koverall and Butyrate dope.

I'll choose doing glass finishes any day over this stuff! If any of you folks haven't used this stuff yet, let me prepare you with what to brace yourself for;
Peach fuzzing, stranding, and more peach fuzzing!

After much work, here's the process that has provided me with a very nice finish, but the hassels you can expect:

You apply Sig Stix-it adhesive to the perimeter of the smooth wood surface to be covered with Sig Koverall. You apply the koverall taught over the surface with the sealing iron in much the same manner as you would with Monokote. The koverall will adhere very quickly and firmly to the wood. You may then heat shrink the koverall to the surface you're covering. And shrink very uniform and nice Koverall does!

However, it's too bad you now have to cut the excess Koverall stuff from your work. Cause this stuff easilly and usually shreds and strands into many long fine "hair"at the seams. And fresh new blades galore, you better have in store. (But even then some stranding can occure). After the Koverall is applied, you start with the application of 4 or 5 coats of dope to fully fill the weave, sanding between coats. AND still everytime you sand the dope finish, you often fuzz the Koverall. And fuzz up it does!
Then of course you can proceed to prime and paint.

Yes with, a lot of fussing and special attention, you can get a really nice finish using this stuff. But if I have my choice, I will always prefer to use glass cloth and epoxy resin. It requires just as much sanding, but doesn't fight you all the way with exposed peach fuzz and annoying strands.

Anybody have a different opinion on it ? I'd like to hear it. Because evidently this stuff has been selling for years, and a somebody or two out there must like it.

< Message edited by RandallM. -- Mar 22 2003 6:21PM >
       Post #: 1

So this is how we do Sig Koverall and dope! - 3/22/2003 10:23:20 AM   
susquach


 

Posts: 294
Joined: 1/15/2003
From: kerrville, TX, USA
Status: offline 		Randallm,

you're right! Koverall can be a little exasperating to handle. But no worst than .75 oz glass. Next time you use it, if ever again, be sure to cut with a pair of very shape scissors. The fraying can be reduced, althogh not completely eliminated by sizing the cut edges with a light spray of Krylon clear. I usually fill the weave with a few thin coats of thinned latex wall paint, followed with Polyurethane color, but that's another subject.
Guess most folks continue to use Koverall due to it's price, and excellent performance. Just have to be careful applying the stuff.
Someone mentioned in a thread elsewhere that an updated Coverite is coming back on the market. Perhaps that will be the answer to your covering needs. If your experience is the same as mine, New and Improved usually means poorer quality and more expensive! Hope that isn't the case.
Have you tried Nelson's product (glider grade Ceconite) or Nylon? Some folks use Polyester dress linning with success. however, I've noticed that not all Polyester isn't created equal. When it comes to shrinking taught and staying that way, it's just hard to beat Koverall or Super Coverite ( assuming you can find it).

(in reply to rustyrivet)
       Post #: 2

So this is how we do Sig Koverall and dope! - 3/23/2003 12:01:58 AM   
rustyrivet


 

Posts: 599
Joined: 3/13/2002
From: Houston, TX, USA
Status: offline 		Ddubya's QUOTE:
---------------------------------------------------------------------------------
"Koverall Can Be A Little Exasperating To Handle. But no worst than .75 Glass"
-----------------------------------------------------------------------------------

Ddubya,

No, actually the glass cloth does not present these fuzzing and fraying kind of problems. The glass cloth transitions into a hardened like plastic substance once the epoxy resin hardens in it. The glass finish can then be sanded to leave a clean smooth surface without fuxzzing. Not so with Koverall and dope. When sanding doped Koverall, you have to be carefull not to sand below the thin dope surface, to the Koverall cloth.

And perhaps you have sharper scissors then me, because I haven't found a pair of scissors yet that doesnt cause a rough seam and fraying. Razor blades are the only way to go. (No biggie at $5. per hundred blades if this is a necessary procedure)
But even razor blades don't always leave an entire clean lenth of seam. When you hit the seam with the iron or sandpaper it often frays open and becomes a mess. You have to really dope over these seam edges and bury em solid!! (or gloss over the trouble spots with a dab of epoxy glue or CA)

As for the alternate materials and methods you mentioned, this only leaves more experimenting and results for me to worry about. I might find I have only substituted one evil or problem for another.

At least the KOVERALL system does work when you're willing to put in the extra fussing necessary. And with this perseverance, the finished product is very nice.
My point is, because of the fraying and fuzzing, it is a very persnickity method and way to finish a plane. More so than glassing a plane. (-which I actually enjoy doing)

I will try to avoid having to use koverall in the future. I guess I better find warbirds or sport planes in the future that are fully skinned with no open bays that prevent me from applying glass finihes. Or I'm liable to find myself being the only Top Gun participant to show up with 14 foot wingspan bomber covered in Monokote! (yuck!!!)

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So this is how we do Sig Koverall and dope! - 3/23/2003 12:50:05 AM   
susquach


 

Posts: 294
Joined: 1/15/2003
From: kerrville, TX, USA
Status: offline 		Randallm,

think you are right about "nameing one's own poison". It's a matter of figureing out the material that best suits your likes. As for cutting, I've always used a new pair of FRISCARS to do the cutting on koverall as well as glass cloth. Like you, glassing is the best way I've found to do a sheeted or "solid" surface. Even better than Coverite. The good thing about glass is that once it's there, it's there. Period. No wrinkles, puckers or blisters.

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Koverall - 3/23/2003 1:12:18 AM   
2fast


 

Posts: 301
Joined: 7/22/2002
From: Tyler, TX, USA
Status: offline 		I just covered an old Top Flite Headmaster wing with Sig Koverall and really have no idea what you guys are complaining about!

First of all I don't use "stix-it", I use Nitrate dope. Two coats on the bare structure with light sanding after each. Then lay the Koverall over the structure, overlapping about an inch or two all around. Then just paint 2 coats of thinned Nitrate dope around the perimeter.

The trick here is in the trimming. This is the way we have always done it with silkspan and silk. Get out the old sanding block and just run it around the perimenter and it will trim that Koverall neat as you please. Now paint another coat over the trimmed areas and sand lightly. Shrink with the heat gun and then repeat for the other side.

Now just seal the Koverall with 2 coats of Nitrate dope over the entire structure sanding after each and apply your color. If you want a glass smooth finish apply 2 or more coats of Nitrate dope mixed with a liberal amount of Talc to fill the weave. Sand between coats and finish with a coat of Nitrate to seal then apply your color.

Personally I don't totally fill the weave. I just apply the two coats of Nitrate and then color.

It's easy, quick, light and looks great!

By the way I apply silkspan to the sheeted parts of the aircraft like the fuselage and tail in this manner with great results.

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So this is how we do Sig Koverall and dope! - 3/23/2003 9:39:52 AM   
susquach


 

Posts: 294
Joined: 1/15/2003
From: kerrville, TX, USA
Status: offline 		2fast,

hey, no complaint here. Koverall is super stuff. What I ment to say was, a person just has to find the technique that works best for him. Personally, I use Stixit and fill with a few coats of thinned latex and color with polyurathane. The Stixit has been more compatable with latex than dope. Have settled on the latex as it can be worked in a closed shop during cold weather. That for open-bay type parts. Prefer glass for solid sheet areas because it stays put and really toughens the surfaces it's applied to.

(in reply to rustyrivet)
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So this is how we do Sig Koverall and dope! - 3/23/2003 10:15:10 AM   
rustyrivet


 

Posts: 599
Joined: 3/13/2002
From: Houston, TX, USA
Status: offline 		2fast,

Initially, I thought using this stuff would be like using that thin tissue paper covering I did years ago on the Guillows plane. I would let that moistened tissue covering dry and harden with butyrate dope, as it lay draped over the leading edge of the wing for example. I would then just gently sand it off from the length of that edge, nice and smooth. But Sig Koverall is a stringy and fiberous material, compared to that Guillows stuff.

I have not used Silkspan yet, but have examined it at my LHS. It reminds me much of the Guillows tissue paper I was referring to, and I bet it is easier to neatly cut and seperate at seams then the Koverall. But my 90 winged", 19 lb plane would not permit me to use lighter dutySilkspan.

From what I have observed from my own experience with Koverall, the fibers do not actually blend with the butyrate dope and become one hardened and sandable material. (like glass cloth and epoxy does)The koverall will become encased in the butyrate, but never actually mix to become one. All I'm actually doing is building a layered surface of dope over the koverall, and burying or encasing the fiberous seams and strands.

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So this is how we do Sig Koverall and dope! - 3/23/2003 5:27:39 PM   
2 Piece


 

Posts: 214
Joined: 2/27/2002
From: Winchester, VA, USA
Status: offline 		A trick I found very helpful to reduce the "fuzzing" around the edges when using stik-it. Is to apply a brushed on coat of nitrate dope, after you have ironed down the perimeter, along the edge that you'll be trimming off. This helps set the weave and practically eliminates all loose strands and fuzzing, plus it cuts better with xacto blade.
2 Piece

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Trimming Koverall - 3/23/2003 7:23:03 PM   
2fast


 

Posts: 301
Joined: 7/22/2002
From: Tyler, TX, USA
Status: offline 		You guys really need to try trimming the Koverall with the sanding block instead of razor blades or exacto knives! The sanding block helpes to eliminate the stray fibers and it helps to feather the edges so that the seam disappears after a few coats of dope (sanded between coats of course).

Just be sure that you apply a coat or two of dope over the perimeter to insure the edge is firmly glued down. Also be sure your sanding "strokes" are AWAY from the structure.

(in reply to rustyrivet)
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So this is how we do Sig Koverall and dope! - 3/23/2003 10:08:34 PM   
w0mbat



Posts: 373
Joined: 12/6/2001
From: Lake Havasu City, AZ, USA
Status: offline 		I agree with 2fast - I have used Koverall and Nitrate dope and never had a problem with fraying. I usually use sandpaper to cut the Koverall around the edges.

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So this is how we do Sig Koverall and dope! - 3/24/2003 4:29:29 AM   
RCPilot100



Posts: 582
Joined: 1/12/2002
From: Chelsea, MI, USA
Status: offline 		I have to vote for Koverall. I found it easy to work with and very durable. I have a 10-12 year old 1/3 scale Spacewalker and it sill looks like it did when I first took it out. I always am asked about the finish when I go flying with it. I also completed a 1/3 Laser 200 over the winter with Koverall and again had no problems. I guess it is all in the technique - I don't have a problem with it.

Dan

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So this is how we do Sig Koverall and dope! - 3/24/2003 6:57:47 PM   
NE0



Posts: 1170
Joined: 7/30/2002
From: Newark, OH, USA
Status: offline 		I noticed that those of you who are not having problems with Koverall are using Nitrate dope, while Randall was using Butyrate dope. Is that part of the problem? Does Nitrate dope bond with the Koverall into a harder, easier to sand surface? My understanding is that Nitrate should be used for base coats, and the Butyrate is designed for color application over the Nitrate?

I hope you can clarify this, I'm about to Koverall the control surfaces on a big warbird project and I don't want to run into the problems that Randall did (I've never used Koverall before). I "planned" to use Nitrate dope, then apply latex paints for color (matching latex used on the rest of the "glassed" plane).

Thanks,

Neo

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So this is how we do Sig Koverall and dope! - 3/24/2003 7:36:04 PM   
Jim_McIntyre



Posts: 2078
Joined: 4/5/2002
From: Claremont, ON, CANADA
Status: offline 		Nitrate to glue it to the structure, Butyrate to fuel proof and shrink;

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So this is how we do Sig Koverall and dope! - 3/24/2003 8:04:45 PM   
NE0



Posts: 1170
Joined: 7/30/2002
From: Newark, OH, USA
Status: offline 		Is the Butyrate required to shrink? Running gas, so is the fuelproofing still required? How does latex go down on either dope?

Neo

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So this is how we do Sig Koverall and dope! - 3/24/2003 8:21:36 PM   
rchazey2


 

Posts: 11
Joined: 1/11/2003
From: Omaha NE
Status: offline 		Does'nt nitrate dope adhear better to poyester than Butyrate dope?

Spray hair spray around any edges prior to cutting or use the dope to stop the fraying.

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