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Old 08-15-2010, 11:52 PM
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mred33
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Default RE: Silk Covering Techniques


ORIGINAL: virgomoon

OH! I know what I was going to ask ..
How many coats of dope is enough? One of the guys at our field says "Dope it 'till it shines" .. but on the North Star wing, that was like 10-12 coats and I still had to take a paper towel soaked in thinner to 'buff' a shine to it. This is using 1:1 thinned butyrate dope.
Well now, that depends. What kind of finish are you looking to get? Do you want a show room finish that looks a foot deep and you can shave in, or are you just looking for a decent finish that you go fly all the time and don't care if it's not a really shinny finish. My normal finish is about 3 coats of clear and check it with a light in back of it and look for a stedy sheen all over it. If you see any spots of light that stand out, the weve is not filled there and you will need one or two more coats depending on the weve of the fabric you are using. The silk is going to have a weve to it and this weve is what you are trying to seal all over the surface. Just remember one thing. Paint is weight. The more you put on the more the plane will weigh and the worse it will fly. If you just have a very few dots that stand out hear and there, then it is time to prime it. This should finish the fill of the weve and those small open areas should all be filled with the primer coat. Use the light again after you sand the primer down and see if you have any of those dots that stand out still. If so, you can shoot some more primer just on those spots and then sand that area down to get the final fill of the weve. You should have VERYlittle primer left on the surface after you finish sanding it down and Imean very little. Primer is heavy and you don't want any more on the plane then you really need. It's really hard to tell you in words what the surface will look like when the primer is sanded off, but you should be able to see thru the primer in all areas like it is transparent. Mostly what you should have is clear dope left. If you have any ringing on the primer, you will need to clean that spot up as good as you can. It will ring when you have some kind of contamination there and the paint it not sticking to that spot. Isand with thinner or alcohol on those spots to try and get that off. The best thing you can do is use those disposable gluves when you first start your covering so you don't get oil from your hand on it.

Ilay my wing flat when Istart painting and don't do the other side until it is tack free on the first side and then turn it over and do the other side. Same with the fuselage, Turn it on it's side and do one side and then do the other. That stops a lot of the running if you get to much paint on one area. Runs and sags are a real bummer to get out and make it look good. I normally spot paint with primer if Isee a spot of light shimming through that area and then sand it off. What you are looking for is a filled weve and a flat smooth surface, not a shinny one. You don't worry about shinny until the last coat. When you put your first color coat on, that needs to be sanded down too with something like 400 used wet, but this is a lite sanding, not trying to cut through the paint. All you are trying to do is get it level and smooth. Don't even think about trying to get any coat shinny while you are painting until the very last coat. That's the one you what shinny. Ilike to use a base color of some kind. Sometimes Iuse white and sometime I use silver. It just depends on how I feel amd what I want to see. Some paints are translucent and I don't think you will ever get it to cover right without a base coat. Most colors are great and cover in one or two coats, but then there is that one that can bite you. Always start with the light colors and go to the darker colors after that.

Once you get a good coverage and it's sanded down good and there are no thin spots showing through, let it set for a couple of days. Now mask it off and start painting the trim on. Inormally spray a lite coat of clear over the tape to seal the edges so the trim colors will not bleed under the tape. If you are painting all straight lines for trim, the width of the tape doesn't make any difference, but it you are using curves, use a narrow tape for that. Inormally use 1/8" wide tape because it will bend good with out folding up in a turn. That looks pretty bad after you pull the tape off. Put enough trim color coats on to make it a good solid color and not thin in some areas. You want an even coat. Let it set until the paint is tack free and take the tape off by pulling in back over itself. DON"Tlift it straight up or just as bad , at an angle to you. You want that tape to cut through the paint as you pull it off. Now comes the fun part. You get to sand some more with 400 and then 600 and don't cut through the paint and take it off, you just want to take the ridges off where the tape was. If you run your had over the area, it should feel smooth all the way across. Now let it set for a couple of days and then get clear out again. I put two coats of clear on and fast. I just let the first coat get tacky and then put the second coat on and both of these should be wet coats. Be careful you don't get any runs in this coat. Now let it set for a couple of days and sand it down again with 600 snadpaper. All you are trying to do is cut the glaze off so it is not shinny. let it set for a couple of days and do that again with a couple more coats of clear. The first two coats I thin 50 50 and the last two Ithin a little more. Maybe 60 40 and make SUREyou don't get any runs in it. Now let it set for at least a week and two weeks is better. Now you get the polishing compound out and rub this coat to really make it shine. Some people call that rubbing compound, but it is the very FINEgrade of rubbing compound. Most of the polishing compound that I have used is white. Now you can get some really good wax out and put a good wax job on it. After you get done with this it should be nice and shinny. It should feel like plastic and should have a good shine to it. If you can find a solid past wax with 100% Caranuba wax , that is the best. I think Mother's is 100% or close to it. It cost a little more then the other wax, but it is much better.

The best finish Ithink is to skip the dope clear after the trim and use epoxy clear. I used to use Hobbypoxy on mine, but they don't make that any more. The still make epoxy paint though.

Now you can hang it on your wall in the living room and admire your nice shinny plane for a week or until you can't stand it any more and have to go fly it. Now go take a bunch of pictures of it before you fly it so you know what it looked like the very first time you flew it. You never know what is going to happen on that first flight, so take the picture first then go fly. After you land, clean it off and don't let that oil and gunk sit on the plane before you go fly it agian. Wype it down after every flight and if you use a nice cotten cloth, it should hold it's shine for quite a while. If it gets to looking a little drab, wax it down again and you should have a plane that looks new again.

Now that you have read all of this, go here and read this; http://www.airfieldmodels.com/inform...oxy_paints.htm
The last coat of clear should be done with Klass Kote to really make it fuel proof and you can start painting the plane with this right after the primer is ready to be painted if you want, or you can use their primer. The only problem with this paint is the amount of colors available. There are no where near the colors that you can get from dope. Check out this for the color selection guide; http://brodak.com/images/Shop/BrodakPaint.pdf One thing that is great about this dope is they have candy colors. I don't know if you have ever worked with candy colors, but they make a fantastic mess, or a fantastic paint job. Ihave seen some that look a foot deep and other that look like you know what. It all depends on how much work you put into it and no matter what paint you use, you are goign to put some work into it. You can also read this to get some more information. http://www.airfieldmodels.com/inform..._materials.htm

That site is full of VERYuseful information on all kinds of things. Just kick around and look at what they have and you may find that it has a lot more to offer then most sites and may take you a while to get through everything. Lots and lots of good information here.

However you decide to finish your palne, good luck. One thing to remember is this. If this is your first real finish other then iron on plastic, then you are in for some eye opening reading and work. It is not something that is done in one night or even a weekend. Painting a modle takes practice and the only way to get the experance is to do it. You can get a decent finish your first time if you take your time, but to get a really great finish takes a while to learn and you do have to learn how. It's not something you read about, it's you own effort that makes the finish and the more effort you put in the better the outcome. What ever you do, good luck and don't be afriad to ask.

Ed