Hello all! I have no desire to start the "monokote v. ultracoate v. fiberglass v. tissue" debate [img]i/expressions/face-icon-small-smile.gif[/img] I am sorta new to the hobby, I've been flying and crashing solo now for about a year, and the only plane that has lasted the distance is my ol' ugly hobbyco something-star trainer. It has been through our safety fence, bumped its nose after a hard landing turned into 5 or six "bounce & gos" etc... needless to say it is truly ugly, with packing tape covering 90% of the tail, and duct tape on the nose. I am about done builing my frist kit, and well, I've never covered before so I thought it would be a good chance to kill two birds with one stone. I'll use my trainer to... well, train me how to cover while at the same time extend the life of ol' ugly (and maybe turn it into a swan). So, I have decided on a multicolor scheme for the top of the wing. The leading 1/2 one color and the trailing 1/2 another. The short question made incredibly long is: Should I cover the whole top of the wing in one of the two colors, and then add a second layer of the other color, or can I cover a little more than 1/2 in one and over lap a little with the other? And yes, I am using monokote because that is what I have [img]i/expressions/face-icon-small-smile.gif[/img]

-Jim

As long as you have at least 1/4 inch overlap at each seam, you can do it in pieces. (some people may say less... but you really need 1/4 to 1/2 inch overlap)

Start at the rear, and work forward. The seeams should all overlap front to rear, so fuel isn't driven under by the airflow. reduces peel rate)

It is a good idea to paint the seams with a clear fuelproof pant such as Lusterkote. (Spray into the can top and apply tothe seam with a soft brush, don't spray the whole wing.) Technique to not have the paint show will take a bit of practice. "Camel hair" brushes seem to work best.

You may find the Monokote not wanting to stick to some parts of the old aircraft. This is usually from fuel seeping under the covering (prevented/reduced above) There is no 100% solution to the problem short of replacing wood. Heat will draw some oil out of the wood. (iron and paper towel: press towel on the wood, apply heat. Waste several paper towels...) Corn meal absorbs the oil well. (spread meal and place aircraft in hot area, such as car in sun.) Alcohol helps drive oil to the surface SOMETIMES.

The new plane... be sure to lightly sand all epoxy where you want the covering to stick. There's a surfacing wax (or something that acts like its got a wax...) in the epoxy, and the heat activated adhesive won't stick to it.

I have had great sucsess with seaming monokote. I have done 4 and 5 color designs that I stretch over open framework wings & fuses. I use a piece of glass (old bus windshield) to seam all colors together before installing on plane.

Mark the one edge for a 5mm seam. Lay the other piece on top of bottom piece and smooth out air bubbles.

Take a trim iron and fuse seams together-this is the trick-don't slide iron. Pick up and reposition every 1 inch.
look at the seam at an angle to the light. You will see when it is completly fused together.

Let cool and inspect seams carefully-go over any spots that you missed.

pull from glass perpindicular to seam.

Stretch over framework in normal manner.

Don't use Monokote trim seal liquid to seam-colors run and seams pull when shrinking.

I'd agree with 1/4 inch of overlap. You can either do it on a mirror as suggested above or if the spar location is suitable, cover the rear half of the wing to the spar and trim the cover flush with the leading edge of the spar and then use the 1/4 inch or so of the spar or spar web as the over lap to cover the front portion of the wing. If you built the wing right, this guarentees a straight line and is much easier than tacking the pieces together and transferring them to the wing. If the leading edge is sheeted, rather than open framed, its's even better as you can use the last 1/4 of the sheeting or spar for the overlap.

Using the spar as the overlap works well as it allows both pieces to be firmly anchored and sealed. Also the resulting 1/3 - 2/3 distribution of the colors is usually more appealing to the eye than a 1/2-1/2 split given the rule of thirds etc. You can also use a 1/8 inch trim stripe set back 1/4 inch from the seam. This can be the same color set into the other color or a third complimenting color. This tends to break the hard line of the two contrasting colors and again is more pleasing to the eye. It's adds a bit of depth to the seam and also will distract the eye from any minor imperfections in the seam which would otherwise be very glaring. Using a 1/8 stripe 1/4 into the forward color also provides the same 1/3-2/3 distribution in small scale and compliments the main color distribution of the wing very well.

Another easy to do trim thing is to use the leading edge color on the center section, which on most planes is also sheeted and therefore easy to cover in the same fashion as a covered leading edge. This leaves a rather hard 90 degree corner but this can easily be rounded. Make a round or oval template and then cut a piece of film to fit the corner. On my last aircraft I used an oval window from the little photo albums that come with your pictures from Walmart. I just marked the edge of the oval in the two spots where it ran tangent to each edge of the cover and used this as the template to cut the curved edge of the monokote. (Leave a 1/4 in front of and to the inside of the trim piece to get the required overlap on the leading edge and cente section). You then flip the template over to cut the mirror image piece for the other side. The oval shaped curve used lenghtwise with the span provides a very smooth continuous curve that compliments the wing. The trim stripe then follows this curve around and off the trailing edge. The only care required on the small trim piece is to seal from the corner outward to avoid trapping any air. Als when covering the aft section of the wing, only overlap a quarter inch or so onto the center section to avoid a large area in which air could be trapped when coverng the center section with the other color.

In any case, use a straight edge and a very sharp (new) exacto blade when cutting the piece(s) that will lay on top . Also don't get carried away with too much heat when sealing the final seam and run the iron parrallel to the seam not across it as this will tend to prevent you from pulling any color from one piece onto the other.

I like monokote and prefer it to most other films, but if you are covering a foam wing, I'd use econokote due to the lower heat required. It also has just a little more stretch, I think, over solid or sheeted surfaces and works better on tight compound curves on fuselages. The thing with either film is to work slow and keep pulling the film as you work around the curves and again get a 1/8 to 1/4 overlap on the seams between the pieces.

Jim , you got some great advice from those guys. The only thing I can add is some clean up advice. If you seam a light & dark color together they might bleed a little on the seam. On Monocoat the color is the glue and will run a little and get on your iron. Dont worry about it till your done, then take some Trimsolvent and wipe down the edges. It will take the bleeding right off. Also keep in mind . You will be able to see through the lighter color Monocoat to a certain extent. So make sure the darker color goes on top of your seam if possible.
later daveo

As mentioned above, if you have some areas that have had fuel soak into them, try this. Take any alphatic glue (I use Titebond II) and spread a thin coat over the area in question. Just use your finger and spread it as smooth and thin as you can but make sure all is covered. Let it dry and then iron on your monocoat. You will be surprised as to how well it will stick, even if you did not get all the oil out.