scratchonly

I use an olfa paper knife with snap-off blades for nearly all modelling and covering. TO TRIM CLOTH keep a fresh blade in the knife. I use koverall with varathane satin water base poly for all my covering jobs, for sticking and filling. I mix my fill coat 50-50 with the base color with latex paint. This gives some tooth so subsequent coats stick. I find behr the best. After letting the stuck on edges dry I go over them with a medium iron. Experiment with some balsa frames and surfaces before you start on the plane.

good luck

PointMagu

My Feedback: (11)

I've gotten the stab, rudder and elevator halves covered so far and I'm pleased how well the Stix-It works. I'm still fumbling with trimming and the advice on the knife is appreciated. Right now, I'm trimming with a pair of manicure sissors but even these leave "fuzz" all around the edges.

I'm wondering if I use butyrate clear over the Koverall to seal the weave that I'll still be able to spray enamels over it for my color coats. I realize nitrate dope doesn't shrink but I haven't any nitrate but do have 2 gallons of clear butyrate on hand.

I really don't know how simply spraying the Krylon enamel color coats directly onto the Koverall will look and I'm not wanting to have to layer several coats to fill the weave. Any thoughts on this?

I do realize that doping the fabric with clear butyrate will seal those "fuzzies" around the edges. However, will I be able to lightly sand these edges or am I stuck with what I have?

My clear dope is way thick and I'm breaking it 60-40 with thinner. Maybe even 70-30. It's in metal gallon cans and I believe it's made by Randolph. I bought 8 oz mason jars to mix so all I'm doing is pouring the measures in, capping and shaking like mad to mix it up.
Nice thing about glass...I can see what I'm doing! And..I can store my mixture in the same container...

I'll post a few photos of this, my 1st attempt at covering with Sig Koverall and Stix-It. I used to use silkspan and super dope years and years ago but I can't recall ever having the challenges with that material, (put on wet) and what I'm having with this stuff, put on dry.

PM

khodges

My Feedback: (1)

Don't thin it much. I wouldn't go more than 70% dope/ 30% thinner. Thick is what fills the weave, and thinning it too much means that many more coats to fill the fabric. If it's streaked with brush marks the first couple of coats, it will even out some as you apply the next coat, because each coat softens the one before it. You can thin the last coat a bit so it applies with less brush marks, or maybe spray it. The fuzzies will get taken care of as you apply the dope. Just very lightly sand the fuzzies with 320 -400 paper between each coat.

You shouldn't have any problem with enamel over well cured dope, mine is painted with Rustoleum. Just let the finished doped surface cure for a week before topcoating with the enamel. Do a test piece to be certain, and mist the first couple of coats lightly, then do a heavier coat. Trying to fill the weave with your color paint (the Krylon) makes the finish heavier, and will take a lot of Krylon , probably twice to three times as much to get the same smoothness of finish. Dope is basically cellulose acetate suspended in a solvent carrier, and it's designed to fill the weave, where regular paint is not designed as a filler.

You really ought to get some nitrate, the cover will get tighter as you dope it, and nitrate continues to shrink over its lifetime, meaning the cover will always be like a drumhead.

Stickbuilder

Krylon? Rustoleum? Never tried the stuff, but I do get great results with DuPont, Sherwin-Williams, Ditzler, PPG, but the best of all so far is Sikkens. The Sikkens brand comes out of Germany, but the quality is far superior to any of the U.S. brands that I have used. The stuff is Unholy expensive though. You can actually pay several hundred dollars for a gallon of the right color. I haven't bought any for the planes, but there was some left over from a porsche that our Body Shop repaired, and there was enough for me to try on a test panel. It looks like you could stick your arm in the paint up to your elbow. Deepest shine I've ever seen.

Bill, AMa 4720
WACO Brotherhood #1

PointMagu

My Feedback: (11)

Paints, like everything else, have their Yugo's and their Rolls Royce's....

There's no denying that the better the quality of paint, the more superior the finish. However, on a 40+ old sport plane, I'm loathe to invest more than the price of the basic covering materials and a decent paint job. No competition, no static judging, just plain 'ol Sunday flying fun.

I only have one good eye so my mantra has always been, stand-way-off, kinda-sorta scale...maybe, lol. I build and fly for therapy and relaxation. Worrying over exotic pigments just isn't in the equation.

Now if I were younger, wealthier and a whole lot more handsome, I might be tempted to go toe-to-toe with other builders and pull the plugs on the billfold and buy me some of that paint!

As it is, I'm old, slow and living the la dolce vita, paycheck to paycheck...

But, hey...we all's havin' a good time :-)

PM

PointMagu

My Feedback: (11)

Well, I shoulda known not to react too quickly. After application of 2 coats of butyrate, I hit the "fuzzies" with 320 grit and they disappeared! Just like fiberglass and epoxy...Man, I'm gettin' old.

I took your advice and applied the 2nd coat to the elevators with, "straight-from-the-can" viscosity. It brushed on like honey but dried nice and smooth. I decided to go ahead and apply the 1st coat(s) to the rudder and stabilizer likewise. One thing though, you sure go through the volume of dope applying it this thick! I used almost 2 full ounces just on these 3 panels!

The Koverall is becoming more and more opaque with each coat so I'm thinkin' we are filling the weave nicely. I had forgotton how fabric covered balsa feels once doped...brings back memories of how real models were once built, (lol).

Time is involved to get a decent finish, sure. But man, do I like what I'm seeing so far! Once I get the Robin covered, my next project is that big 'ol Hammerhead I have sitting in the basement, crying to be done.

The project continues...

PM

(thanks for all the words of encouragement and advice. I do appreciate the feedback)

floats

Hi A question to Khodges have you used Koverall on a reversed camber on underwing and if you have did you have any problems with it pulling away from the ribs.What would your technique be to applicate Koverall to these type of wings .I dont know which to use Koverall or Solatex. It has a 10' span 2'4" chord Thanks Doug.

PointMagu

My Feedback: (11)

Good question, floats!

My Hammerhead has an undercambered wing. It's an eliptical, polyhedral with a cord of 18".

I'll be curious to get the answer to this one too...

PM

scratchonly

Try doping the overhang that you wish to trim. When using the poly I make sure the overhang has a good coat. this should stop the fuzzies.

Stickbuilder

The secret to covering an undercambered wing using Koverall, is to apply 2 straight coats of Nitrate dope to the bottoms of the ribs, the leading edge and the trailing edge. When you lay the Koverall on the framework, try to smooth the wrinkles and sags so that they are minimized. Start at the root of the wing, and apply enough lacquer thinner to wet the fabric where you want it to stick. Rub the material down to the framework, using the tip of your index finger. Fairly quickly, the fabric will bond to the root rib. Proceed down the leading edge, and trailing edge to the next rib, rubbing the thinner coated material until it begins to bond. Do the same with the second rib, and then repeat. When you are ready to shrink the fabric, use the monokote iron and not the heat gun. The iron will allow you to better control the shrinkage, and you will not pull the material away from the rib bottoms. Note only shrink the material until it loses the bagginess. Do not overshrink the fabric. If you use the heat gun, I will promise you that you will pull the material away. If you are doing a true scale model, you could always rib stitch the fabric to the rib, but that's another can of worms entirely.

Bill, AMA 4720
WACO Brotherhood #1

ag4ever

So, when is the best time to drill for hinge-points?

I am ready to sand the model to get it baby bottom smooth, but should I go ahead and hinge the control surfaces now, or wait till it is covered. I plan to wait until it is covered to glue them on, but what about just drilling the holes?

Right now, I am inclined to wait until it is covered and painted to actually drill the holes.

scratchonly

Do it as soon as you can, so that you can correct any misalignment without a mess.

PointMagu

My Feedback: (11)

Here's my undercambered wing. There's alotta area on the wing. Since it's a polyhedral, I plan on using 8 panels to cover it all.

Do you think that the Koverall could be applied in a single large piece considering all the angles? I don't think so but i'm willing to hear other opinions, lol...

PM

Stickbuilder

You can easily do the wing in two pieces (one for the top, and one for the bottom. With an elliptical wing, such as this, you would have some problem getting enough material shrinkage in the tip area when attempting to use one piece.

Bill, AMA 4720
WACO Brotherhood #1

OsmanKhan

Hi,

Can someone help me locate a distributor / dealer for Sig's Koverall in UK. Tried the google way but without success. Thanks

mangolo

Osman,

If you can't find it you can buy at any fabric store dress lining material called Ultresa, we use it when we do not find Koverall, one advantage is that it is available in many colors, much cheaper and 60" wide.

Waldo

mangolo

Osman,

If you can't find it you can buy at any fabric store dress lining material called Ultresa, we use it when we do not find Koverall, one advantage is that it is available in many colors, much cheaper and 60" wide.

Waldo

sscherin

My Feedback: (1)

I picked up 5 yards x44" of polyester dress liner (about $10) to try out on my Sweet Stik.

Word of warning.. Your wife will be more than happy to go with you to the fabric store. Then she'll spend 8x more than you.

I'm still debating what to use for attaching the fabric..

Dope, Water based Poly or Nitrate Brushing Lacquer.

Stickbuilder

Be sure that when you buy your dress liner, you must specify that you want the liner that is not NOT pre-shrunk.

Bill, AMA 4720
WACO Brotherhood #1

funkymusic

I’m in the process of covering my Hog with koverall. I’ve put two coats of straight dope on the H-stab and elevators –sanding between coats. I’m impressed with the weight and feel of the surfaces. I’m stumped on reading the fabric to determine the ‘grain’. I’ve notice there seems to be a dominate, I’ll call it flow to the koverall, is that the grain? Also, along this flow the koverall doesn’t stretch as much, once again, is this the grain? Stickbuilder, khodges I could really use your help.

Also, what is the penalty if I wind up doing the opposite of the instruction, will have damaging effect on the plane?[]

PointMagu

My Feedback: (11)

The grain of Koverall runs parallel to the finished edge as it comes out of the package.

I've covered my Robin with the grain running spanwise on the wing so the shrink factor is greater, fore and aft, (I hope). The fuselage I covered with the grain running top to bottom. I probably wasted alot of covering doing this but when I did the stab, fin, rudder and elevators, I didn't check the grain, I simply used scaps and it shrunk up well and with several coats of clear butyrate, tauted like a drum cover.

Hope this helps.

I'm about ready to shoot my color coats. I want to use Krylon, Rustoleum or similar enamels right out of the spray can. Anyone have any feedback on doing this over butyrate?

(Sorry funkymusic, thought I'd take the opportunity to ask a question of my own, lol)

PM

funkymusic

You're good, besides I get what you were saying. Thanks!

Chuck

khodges

My Feedback: (1)

On smaller pieces, the "grain" isn't as important, but on long spans it really helps to run the grain longways. I have started covering my WACO tonite, and posting pictures and narrative on the WACO YMF thread in Antiques (Stickbuilder's thread). Rudder was first; going to do a wing next (72 inch span), out of one piece of Koverall.

ag4ever

So is it better to cover each piece individually or to put some part together and then cover them?

On the Hog Bipe, the vertical stabilizer and the horizontal stabilizer are faierd together with a shaped and sanded balsa block. Should I put the coverall on the surfaces, then glue them together, then fair them together with the balsa block, then cover the balsa block with Koverall, or should I glue the vertical on the horizontal, install the fairing block and then cover it? With them glued together, there will be more complex curves and corners, but it will become one solid piece.

I finally got my control surfaces hinged, and am almost ready to cover it. I just need to know what should and should not be assemble prior to covering.

khodges

My Feedback: (1)

I'd assemble the tail, then cover it. I would cover the H stab 1st (top and bottom); allow the edge of the material to "ride" up the beginning of the fairing, then cover the fuse and vertical tail, overlapping the edges of the cover from the H stab. about 1/4 inch. When you fill the weave, the seam will pretty much disappear.