Hi all. I'm doing my first Koverall and latex paint job and am wondering what to seal the covering with before painting it with latex house paint. I would rather use something that wont fry my brain or blow up my house. Butyrate dope has quite an odor! The glue (Sig Stix-it) is bad enough. Also, there are a few loose threads on the seams of the covering. when is the best time to remove them (sand them off?) and what is the easiest technique? Thanks for your input.

I talked to a fellow modeler at quite length about Koverall one day as it was the only covering he would use and his finishes were always a work of art. He said dope was the best material he had used to fill the weave. He suggested doing it in the garage to save stinking up the house. As far as the loose threads, he said he trimmed them with a razor blade after the first coat of dope had dried instead of sanding since that tended to just fuzz the edges even worse.

Hope that helps.

BTW, I'm going to cover my Ikon N'West 1/5 scale Cub with Koverall just as soon as I can get the ambition to finish the kit.

John

Use a couple of coats of nitrate dope - not just to fill the weave but to stabilie the material. As, Sig recommends!


RCPAUL

Roberts,

I had the same questions about Koverall a couple of months back. If you enter "Koverall" or "Butyrate" in the search you will find a wealth of information about it, as well as input on the same threads from folks using Nitrate dope.

I have completed finishing my plane with Koverall, dope, and primer. I went through almost an entire gallon brushing and spraying solely Butyrate dope in the process. It looks great, and I am proud of the finish. But personally, where others have used Koverall and love the stuff, I HATED working with it, and will avoid a doped Koverall plane in the future. -That's just my experience.

Thanks guys. I was really hoping to avoid the dope since my garage is in the basement. I painted a plane with automotive paint down there once but the whole house had a bit of an odor even though I used an exhaust fan (had to cut a hole in the garage door, dont tell my wife!). Everone slept like a baby that night though... I'm surprised it took a gallon of dope to fill the weave! I was really hoping for a less expensive solution to the iron on films and fabrics. By the time you dope it and buy two colors of latex paint I think you're sneaking up on the price of Coverite with about twenty times the work. Am I right? I dont know that I really want to fill the weave anyway, just seal it so it will accept paint. I'm doing a Waco bipe and I think the weave would look realistic.

I've used Koverall 3 times for the same reason you did, realistic appearing finish on bipes. Nitrate dope is the only good way to seal it. I liked working with the Koverall but I won't use it again, too heavy. From now on I stick with silk and dope.

As said earlier, the nitrate dope stabilizes the Koverall. Once it is stabilized, you can use any filler to fill the weave. I find the Koverall is better than the other fabrics after being painted - and cheaper. It is heavier than Moneykote, however.


RCPAUL

Roberts,
No you're certainly not going to save any money with the koverall and dope method over iron on coverings. It took a gallon for me to completely fill the weave on my 90" /1,325 Sq.inch wingspan plane. This took 5 to 6 coats of Butyrate dope, and another 5 coats of spray primer, with sanding in between all coats. But I set out to accomplish a very smooth finish. I wouldn't think you are going to need anything near a gallon if your not looking to fill the weave. (of course much of what I applied just gets sanded off in the form of dust as I sand the surface down to a glass smooth touch)
I personally much prefer working with glass cloth, and will try to avoid future projects that have open bays not allowing glass cloth.

I have had pretty good results from attaching the Koverall with Stix-it, then sealing the fabric with water-based polyurethane. A couple of coats, sanding in between. The WBP dries to the touch fast, but remains a little soft so best leave a day or so between each coat and sanding. Final finish was whatever you like, I used latex paint with a clear top sealer.

I wouldn't use Koverall on any project under .60 sized or where small wing area is an issue. It can get heavy, but you have to do your part and put down the paint gun.

Bob

I may give the polyurethane a try on some scraps and see how it turns out. Weight isnt an issue. The plane is the 1/5 scale Waco that Pica makes. I think there's something like 1200 sq inches of wing or more. I'm using a Quadra 35 for power. Doing a couple of coats of nitrate dope certainly wouldnt break the bank either. Looks like I'll have to do a little experiementing here and see if I can get the poly to work. I have some left over from redoing my hardwood floors. I'ts waterborne polyurethane but it's really watery. I'm wondering if I should try something a bit thicker like the minwax stuff. I know what you mean about it not wanting to sand for a while. I finish a lot of wooden moldings at work with Minwax poly and you've gotta let it dry or it'll just ball up on the sandpaper.

Gentlemen:

Three channel, MDS 25, 72" span, Koverite. Flies great.

Bill.

Another shot.

Nice job William. What method did you use to finish your plane? I'd figure dope since the latex cant hold up to glow fuel.

Roberts:

Koverall attached and sealed (after shrinking) with nitrate dope, butyrate dope for color and fuelproofing.

Except the rear eight inches of the bottom. About four years ago a nasty twig ripped it on landing, the repair was done the same as originlal other than the color coat, I got lazy and used a "Lustercoat" spray can.

The airplane is about fifteen years old, it is a testament to the long life of the fabric covering. It's been through several owners, I got it back after the nasty twig had done its thing. Repaired it, no damage since.

Incidentally, the MDS is the third engine in it.

Bill.

If using an unsealed polyester covering, such as Koverall, Supershrink Coverite, coat (clothes) lining material, the great thing about dope is that it not only seals the fabric, but will keep it tight for the life of the model and because most of it will evaporate, the remainder filling material (cellulose) is very light.
Nitrate dope can be used to seal and shrink, but not being fuel proof needs to be finished with butyrate colored dope or any type of paint.
The thing about nitrate is that it is very volatile, as in dangerous.
The same thing can be achieved by using butyrate from the start, believe you me, it works just as well, and it is fuel proof from the start.
If doing small models, use Sig's low shrink Butyrate, and you'll have no problem.
If dope is a problem because of smell, etc., you should not be using untreated polyester coverings.
I had a liking for Super Coverite, it already comes (if it is still produced) with glue on one side, so the need to apply dope to the bare surface was not needed, neither stixit or balsarite, and once the entire airframe was covered, a couple of coats of butyrate would seal the fabric and make it ready for painting.
This type of finish takes a little more time but it is by far the strongest and one of the best when it is all said and done, specially when doing scale models that used this same type of finish, although I have models of all metal big brothers, you can't tell what the finish under it is, as it looks just like a metal painted surface.
But dope smells and should not be used in confined and unventilated spaces, lots of vapors, they don't call it dope for nothing!!

Thanks for the input Walter. I've used tissue and dope a few times and really stunk up the house. I'm going to experiment a little to see if I can use water based polyurethane instead of the dope to seal the covering before using the latex paint. Hopefully I can find a more user friendly sealer.

Roberts,
I used Koverall on my TF Elder. I used Stix-it for adhesion and it worked pretty good. To stabilize the fabric I used Deft clear finish. From the label, it looks to me like nitrate dope in a spray can. It went on easy and I had no problem painting over it with acrylic paint. I used Lustre coat clear to fuel proof it. Nice finish and so far no problems.
I did apply both the deft and the lustre coat outside. I don't think we'll ever get something that doesn't smell for fabric covering. Good luck.
papermache

Thanks for the tip. Where can I buy it? Home Depot or Lowes??