Jim Messer

My Feedback: (2)

You didn't list the best covering of all - Ceconite. I started using it thirty years ago, and have never looked back. All my models are covered with Ceconite. All of them look brand new - even after hundreds of flights. Ceconite, dope, and latex paint is a good combination.

abufletcher

My understanding is that ceconite is a covering commobly used on full-scale aircraft and that koverall is essentially a lighter-weight version of the same thing. Is this correct?

abufletcher

Right. Here are the results of my little covering experiment. Thanks to the kindness of VonJ, I received a sample of polyspan and koverall and added those to my samples of Solartex Natural and Silver.

Both the solartex and the polyspan were very easy to work with. In fact, even though it was a new material applying the polyspan proved to be a no-brainer. I coated the frame with balsaloc and then ironed on the edges as I would with solartex. I then used the iron to shrink the fabric. As you can see, it has a "hand-made paper" look to it, but when "doped" with Minwax Polycrylic, it lost that paper look and offered a very nice surface for painting. On smaller models this looks like a perfect material.

The solartex Natural (a transparent off-white) looks like the real fabric it is. It also has a pleasing sheen to it. And it's dead easy. It also seems pretty light compared to the colored solartex, particularly the silver which is 100% opaque even when held up to a strong light. This very property might make the silver solartex a good choice for some applications, for example, when you don't want any light to shine through on a part of the model (rudders with non-scale structure come to mind). But I don't particularly care for the semi-rubbery feel (or the way this painted layer can "melt" if the iron's too hot). However, it is pretty close to the silver doped aircraft I saw at the RAF museum. But, man, it's boring looking!

The koverall with its traditional dope attachment (I used butryate as that's all I had available) was the most difficult to apply. I much prefer the idea of ironing on edges as opposed to doping down edges. Still once it was on, the koverall has a good look. It looks very much like the Solartex Natural. I don't care for all the loose threads along the edges though and it was difficult to cut with a razor while on the wing until after the dope had dried. So for example, making cuts in the fabric around the aileron cutout was difficult. With the solartex or polyspan all that's needed is a quick slash with a sharp #11 blade.

The last two photos in this test series show the Natural and the Koverall against a light source. The Koverall is a bit more transparent which probably also means it's a bit lighter. Once doped this transparency disappears.

For me, for now, I think I'll stick with solartex Natural, but maybe also use polyspan for small surfaces. I like the "authenticity" of the Koverall but I can't see a quality difference over the much easier to apply solartex natural. Also there's almost no point to comparing coverings without also including the system you'll be using to produce the finish. I like the solartex + Nelson's combo in general. But Steve's koverall + latex (+poly) looks great. For others maybe the Koverall+dope+epoxy combo makes sense.

Still, I guess it's all just about personal preferences for the kind of modeling you do.

smcouch77

Hi Don. When I covered my SE5a with Koverall, I used Stix It (Same as Balsa loc etc.) on the frame and ironed down the edges. I like the larger weave of Koverall. It dosen't fill up with paint as quickly as Solar Tex. Two coats of thinned down latex house paint (brushed into the fabric)and two coats of Poly and it's done.
Steve

abufletcher

There's no questioning the finish on your SE5a! I'll give a sample of the Koverall the "no-dope" treatment and see how I like it. Working with dope is just a hassle all around and I don't see any advantage in terms of scale appearance.

Do you mean that with the koverall (and your finishing paints) you end up being able to see a bit more "weave" and that's what you like? This sort of gets into "how slick were WWI dope finishes" are but I also like to be able to see a bit of fabric texture. My test with the polyspan + two coats of polycrylic + three thin coats of Nelson's (all brushed on) produced a surface that's a bit slicker that I would prefer on a 1/6 scale model but might look "scale" at 1/8 scale.

vonJaerschky

My Feedback: (3)

Nice comparisons. Thanks for posting the results.

abufletcher

I did a little "destruction testing" last night and while the untreated polyspan was easily torn (and poked through) the section treated with polycrylic and Nelson's was virtually indestructible. I could tear it off the frame but couldn't even begin to tear it through the middle. Very impressive!

eagledancer

ok here is my opinion, i use koverall alot, what i have found with the other iron on types, and yes i have tried several different ones is they tend to come loose end up heaver when painted then koverall, seams come loose. i have planes that are 20 years old with koverall and no sagging no loose seams. yes koverall is more labor to install and paint but by far the least maintance for years after. anything i build anymore that is 1/4 scale or larger that the full scale had fabric my model has koverall.

abufletcher

How do you work with the koverall? Do you dope down the edges or use stix-it? Do to go the full nitryate then butrate dope route?

khodges

My Feedback: (1)

eagledancer might have another opinion, or share parts of mine, but to me, using Stix-It really simplifies applying Koverall to the frame, both in ease of getting it to stick, and in less mess. Painting Stix-It to the framework only in the areas where you have a seam to iron down allows you to put Koverall on like you would any other iron-on fabric. You might have to apply a bit more over the first layer to get a better stick when you overlap the seam. I don't put Stix-It anywhere else except the seam areas. When you pull the fabric snug and iron it down, it will be fairly wrinkle-free except for creases where the fabric was folded in the package. When you start to iron it to shrink it, start in the middle of the wing chord first and go span-wise. This pulls the material tight across the span so it doesn't "sink" in between the ribs as much. Then, as you continue to shrink the fabric, it will "creep" over the untreated areas of framework, equalizing the tautness of the material. I never use anything but an iron to apply Koverall (or any other heat sensitive covering) because you can more precisely control how much heat you are applying and exactly where you are applying it. The fuzzy ends are easier to control with Stix-It, as you can iron them down better, but either way, after starting to fill the weave, a light sanding will eliminate the fuzzy ends and loose threads. Plus, careful cutting of the material along the weave minimizes the amount of threads. I hear people saying they use a single edge razor blade, or new hobby blade, to trim their material, but I use a GOOD pair of upholstery shears (scissors) to trim mine, and have very little fraying of the edges, and I can trim within a 1/16" of the area I have tacked down, which allows me to just "roll" the remainder of the edge down with my iron.

I know others have had good results using either oil-base polyurethane or water-base poly to fill and finish their fabric, but I still prefer the traditional dope methods. It DOES stink worse, which dictates using it in a well ventilated area, but dope continues to shrink throughout its curing phase, making the cover even snugger, where poly doesn't shrink at all. I use nitrate dope only, it shrinks more and fillsbetter than butyrate, and does not have the compatibility issues with other paints that butyrate does, if you desire to paint with something other than dope for a topcoat. Plus, if you use butyrate to fill, you're locked into staying with butyrate, as you can't put nitrate over butyrate, but you can do butyrate over nitrate.

I forgot to mention that I do apply at least one coat of nitrate to the uncovered frame prior to applying any Stix-It, and allowing it to dry throroughly. After you do your covering and shrink it, and begin to fill the fabric, this dope will soften and bleed through the fabric and rebond with the fill coats. This helps to bond the fabric to the "un Stix-It'd" sections, and prevents or lessens the incidence of pinholes in the fill material. Thinning the second coats of fill also seems to help.

TFF

I like to use the Stik-It mainly because I am lazy. When filling the weave, I like to make the first two coats nitrate dope, the first uncut the second thinned and then I move to butrate. Nitrate is thicker so it takes less. If I am doing a plane after WW1, will give a base coat of white or silver; silver used on real planes for UV protection and can help make colors opaque with fewer coats. I like to use double edged razor blades to do my trimming and I just got one of those large cutting mats and wheel cutter; heaven.

abufletcher

So do you actually use butyrate for the color coats? If not, why use butyrate at all? My understanding is that nitrate is not considered fuel-proof so that's why people coat with butryate, but that butyrate doesn't bond well with subsequent paint layers.

Honestly, I'm just not seeing enough advantage to a dope finish to put up with the health hazard. Sure it continues to shrink, but how important is that? Solartex seems plenty tight, so does the polyspan with polycrylic. I suppose we're talking longevity but that doesn't mean much to someone who's only been in RC for about 5 years and doesn't expect models to survive more than a couple flying seasons (due to piloting skills).

TFF

CA glue will kill you before the dope[]. The smell is airplane to me, but now I try not to do too much in the house unless it is touchup; I take it outside. The nitrate is used as a filler and glue. I actually give one coat of clear butrate over the nitrate to have a sealed base. Nitrate soaks into the weave better for some reason, but if you use glow you have to switch to butrate; also butrate is fire retardant nitrate burns; remember the hindenburg? That is why it is only used with the first couple of coats. It is a process, stits has a process too it just works better if you follow the whole thing if you use it.

eagledancer

i use the dope to attach the koverall to the framework. i usally have a small dish with some thined nitrate dope and dip my finger in and apply it and rub it in, this just seems to work better for me. then use a couple coats thinned dope to fill the weave. keep in mind i usally build 1/4-1/3 scale and use gas power in most so fuel proof is not so important. for top coats i have used latex, nelsons, and automotive polyurethanes over the nitrate. would also like to mention on planes that have a undercamber i usally do actual rib stiching to hold it in to the ribs. still have not found anything that really works well to hold it otherwise. i use razor blades to trim, the stray strings will sand off pretty easy after a couple coats of dope. then whatever is left is covered with rib tapes.

smcouch77

I guess I don't understand using dope "to fill the weave". Using thinned latex, you have to work it into the weave for it to stick. I try very hard Not to fill in the weave. Two thin coats of latex and two thin coats of Poly gives a nice light finish, and after two contest seasons with 10% Nitro the finish is still fine.
Steve

Boomerang1

I don't think people are trying to eliminate the 'fabric' look of the fabric, just eliminate pin holes.

When I apply Koverall I keep some balsa cement handy for sticking down stubborn sections. Balsa cement is just a thick dope (sounds like some people I have met! ).

I also keep a hot iron handy so you can shrink some of the overlaps like on tips as you go, shrink to go round corners BEFORE applying the dope to hold the edges down. - John.

TFF

When I am using "fill the weave" I am just filling the space between the fibers. Without sanding sealer or auto filler it would take a ton of dope to get rid of the weave. Dope is not repelled by the Koverall it soaks in easy.
Without filling the weave would be like trying to get a screen door to fly.

abufletcher

This is a good clarification about the meaning of "fill the weave." With traditional cloth there are indeed holes between the threads. I don't think that's the case with solartex because of the adhesive on one side and resin coating on the other. In this sense, there's no need at all to "fill the weave" with solartex. The koverall, on the other hand, is more open (though I still imagine that an undoped koverall model would fly) and the spaces between the threads need to be filled up with something.

As far as "eliminating the fabric look" I've seen doped finishes on actual aircraft that were as slick as monokote (or a glassy epoxy). But I think most of the WWI stuff I've seen has a slight fabric look so I wouldn't want to go overboard with trying to eliminate any sign of weave.

skyraider71

I'm learning a lot just by reading this thread, but I have a couple of questions. Does Solartex come
in Cub yellow? Can the natural Solartex be painted with fuel-proof spray paint such as Lustercote?

abufletcher

Solartex takes paint very nicely. For this reason, I'd decided that there's really no reason ever to use the colored versions for anything but a sport scale model. The silver might be useful as an opaque base and I suppose a dark color would be nice as the base for a dark color (possibly requiring fewer color coats).

skyraider71

Since I have no spray equipment, rattle cans are my only option. IF I go with Lustercote, how many coats will it take?
should I use a clear coat? This will be my first scale model (Sig 1/6Cub) so I have no experience with anything other
than ultracote.[sm=shades_smile.gif]

abufletcher

Here's a photo I did of some swatches of the different colors of solartex. Obviously, the colors in this photograph (as displayed on different monitors) can't be trusted completely, but it gives you an ideal. There is a Cub Yellow, BTW, which is probably pretty close. I laid the swatches over a page of text so you can get some idea of the transparency as well.

skyraider71

It looks like the Cub yellow Solartex will do nicley for my project. I just can't see putting film
covering on it. Thanks for the info.[sm=shades_smile.gif]

abufletcher

Just be aware that the Cub Yellow solartex is somewhat transparent which can be a problem if you have non-scale structure showing (or for example solartex up against balsa). If this sort of thing matters to you, you might need to go with the Yellow and then paint to a more scale shade of Cub Yellow.

ValRC

We presently feel the variant a material for covering the models, imitating fabrics prototype period WWI-WWII (material in cost KIT does not enter - See here).

Experimental sample (while go test, development technologies):

Short can say following

Material: percale
Weight fabrics: 90-130 on 1 kv.m (depending on density drawing)
Time of the covering comparable with film.

Short about plus of the material:
- an outer face as non prototype
- any colour scheme (the base blanching, colour any)
- clear small inscription
- cost commensurable with supermonocat.

Once again repeat, presently go test the material, in particular check to reactions on products of the exhaust.