Prepping & Painting your Fuselage

Prepping and Painting a fuse. Allot has been said elsewhere about painting a fuselage. The biggest reason people fail in the paint process is simple; rushing to the next step, and not keeping everything clean. This is how I have done it for a long time, and really have not had any problems after doing it this way. There are allot of pitfalls to watch out for like pinholes, fisheyes, runs, and dirt. Hopefully if you try it this way, you will end up with a nice finish on the fuselage. There are other ways to accomplish this, but this works for me.

The first step in the paint process, if you did not read installing the woodwork, is to wash all the fiberglass parts with warm soapy water. This is to get rid of all release agent which may be hanging around. Primer and paint do not like to stick to this stuff, so the better the cleaning job, the better the finish. The final finish only comes out as good as the job you did underneath all that paint.

After the fuse has dried from the wash job, I sand down the mold seam on all the parts. Follow that by cutting out all of the openings you need in the fuse. After this, I construct all the woodwork needed to get the heli flying, and test fly in this configuration. The reason is simple, I want to test all the systems at this stage, so that after the paint job, I can reassemble everything and I know that it works. After the disassembly process, I wash the fuse down with alcohol to get rid of any contaminant present.

Since the seam line has been sanded, I sand the entire fuselage down with 320 grit sandpaper. If you are going to add any other exterior detail to the fuse like vents or caps, now is the time. I am looking to get rid of any shiny spots on the fuselage. Be sure to sand it good. I then take a red scotchbrite pad, and sand the fuse again, being sure to get into every nook and cranny on the fuse. This means all the panel lines and edges of the fuse. This is time consuming, but if it is not sanded, the primer and paint will not stick, and trying to repair this after the paint is a nightmare. Be sure to do all the edges of the top cap and tail pieces, and inside all the door jambs, if you have opening doors.

I then blow all the dust off the fuse, and wash it down with Prep Sol. This is available at most automotive paint stores, and it removes any junk left on the fuse. During this process, you should be wearing surgical gloves so as not to transfer any oils from you hands to the fuselage and parts.

I then rig up all my parts so that I can prime them. If you have no panel lines on the fuse, or you want more, take the 1/16 3-M fine line tape, and apply it on the areas you want the panel line to be created. After priming, remove the tape and the resulting area will be higher creating the panel line. Be sure not to sand these areas too much, or you will lose the panel line. I use a product called Pactra Prep, which is a lacquer based primer found in most hobby stores. This is available in spray cans. Depending on the size of the fuse, it usually takes two-three cans to do what I want. I spray a coat of the primer on every seam line. After allowing it to dry the recommended amount of time, I spray the entire fuse and seam line again. I let this dry for a day. I then go back and look for any imperfections in the seam line or fuselage. There is available in the hobby stores a product in a tube which is a green spot putty. I apply this to the seam line, if needed, and any other small imperfections which I find on the fuse and other parts. Do not try to fill large areas with this stuff, as it is made to only fill small pinholes or a seam line. Another product which you can use for anything larger is a Polyester Putty which you mix with hardener to fill large areas. This is available at automotive paint stores.

After spot fixing all the areas, I let this dry for a day to allow all the shrinking of the material to occur. If you only had to use the green putty, you can sand this with 320 grit, and sand only until the area feels smooth, and you feel no difference between the green putty and the fuselage. The spot putty can be sanded 220, and sand it the same way you did the putty, except after it has been sanded enough with the 220, go back over it quickly with the 320 to make it a little smoother. After all the areas I filled have been sanded, I sand the entire fuse again with 320 grit wet or dry sand paper, dry. Blow off all the parts and fuse, and put two more light coats of Pactra Prep on. I let this dry for a day. Check everything over to see if you need any more putty, and fix what is needed.

Now the fuse is ready for the final sanding, and I use 600 grit sandpaper for this. Take your time and be sure to sand everywhere. Blow off the fuse and parts and look at them closely. If the surface does not look smooth, sand some more, to get rid of the "orange peel" look.

When you are satisfied that it is sanded enough, go over the entire fuse and parts with a gray scotch brite pad. Be sure to get all the panel lines and crevasses. The pads will conform to most any shape, so be sure to get everywhere. When done, blow everything off. I am wearing surgical gloves this entire time. I wash the fuselage down again with the Prep Sol, which will remove the fine particles of dust left on the parts.

If you are going to install rivets, now is the time. I use 3-M 1/16 fine line tape to show where the line of rivets is going to go. Put on a piece of fine line on the fuse, and follow that line to the end. I do all the vertical seams on one side of the fuse, then go to the other side and match what I have done. I usually do around the doors where the glass will be installed and the front window frames. The tail boom is next along with the vertical and horizontal fin areas. By this time, the vertical rivet lines on the side of the fuse have dried enough for me to go back and do the horizontal lines. I do one line at a time starting at the top and working my way to the bottom. Using the tape as a guide is great to see where the rivets are going, and to see if you are going off track. I use a product called R-56, which is a glue for putting in windows. It dries transparent and like a hard rubber. I use a syringe, and once you get the glue flowing, it usually gives the correct amount of glue for each rivet. You are better off experimenting on a scrap piece of glass, to see the amount of pressure you need to maintain the flow, which will vary the size of the rivets. If you put on a row of rivets and do not like them, all it takes is a damp rag to wipe them off. You must wait till the area dries before putting on new rivets in that area again, or the water on the fuse make the glue run. When all the rivets are complete, wait at least a day before painting the fuse and parts. This will give the glue a chance to cure.

You are now ready for the paint to be applied to the fuse. I wash all the parts again with prep Sol, just to get any last junk off of them. The parts are blown off again, then using a tack rag, wiped down. Since I have been in the Auto Body business for 30yrs, painting has not really been a problem. With all the two stage systems at our disposal, spraying a multicolored paint scheme takes hours, not days, since when one color of the base coat only takes 15 minutes to dry before masking it off and spraying the next.

Most of you are not going to have this ability or facilities to spray your heli. Just the investment in the tools to spray are prohibitive. All the clear coats used in the automotive field today use isocyanates. This chemical if inhaled, fills the openings in your lungs causing permanent damage. A fresh air supply is a must. I know some people using this stuff in their garage at home, and it is just an accident waiting to happen as they expose themselves and family to this. I have done many paint jobs with spray cans, and while it is harder to do, you can achieve very good results. Patience is the key factor here, and do not rush to put on another coat before the last one has "tacked" up. Doing so just causes runs in the finish. Be sure to read the instructions on the can for the distance to hold it away from the model. Do not take your finger off of the spray button until you have gone beyond the area you are painting. Be sure to overlap each coat by 50%, and look at each area after you have sprayed it to see if it looks "dry". You also do not want it to be perfectly flat either. Somewhere in between is about right since the paint will "flow" and become flat and shiny. I usually do one side of the model at a time, stopping at the tail boom seam, then doing that next. Then move to the other side of the fuselage. Be careful where you start up again that you do not get an excessive amount of paint buildup. That is how you get a run.

If you do get any imperfections in the surface, you must wait until the paint has thoroughly dried before trying to sand it out. I use 1500 grit sandpaper for this when it happens. Once you have one color on the heli, mask off the second area where you want the next color. Use 3-M fine line tape to get a smooth, sharp edge. For a larger area, black electrical tape works well also. Be sure to push the tape down in all areas especially in the panel lines. I use my fingernail to "scribe" it down in these areas.

Do not use newspaper as a masking medium for large areas. It does bleed ink if it gets wet with the paint. You can buy masking paper in the automotive stores for this.

After all the areas have been painted, I put on any decal or markings. Then, I use a gloss clear coat by the same manufacturer of paint. This will seal the edges of the decals and give the entire surface of the heli a protective shell. You can also use automotive tape stripes if you clear over them, otherwise, the adhesive will not stand up to the nitro.

Once everything has been painted and clear coated and dried, I use SIG Dope to paint all the woodwork inside the fuse. This dries really fast and gives the inside a finished appearance. This comes in a variety of colors, and is fuel proof. It really makes the fuse stand out.

Now you can install the windows and other items on the fuse. For the windows, I have used watch crystal cement in certain areas and it works well, while in other areas, I have used a product know as "Goop", and that works also. Read the instructions on both products before using to see how it works.