Silk Covering Techniques
03-12-2010, 04:40 PM
#26
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RE: Silk Covering Techniques
A couple of additional thoughts.... You can work wet silk around the most complex curves without a wrinkle. Just keep it wet and work slowly.
Don't be concerned if the adhering dope blushes after you attach the wet silk. The blush will come out with later coats.
To avoid dope running through to covering be sure that your first coats are laid on the surface not brushed into. The dope will penetrate and flow nicely.
Spraying on the initial clear dope coats never seems to work well. On the other hand trim colors should be sprayed.
A very light sanding between coats with 400 wet/dry paper gets rid of the fuzz.
Silk can be dyed in a rainbow of colors with silk shoe dye available from dance clothing stores.
Only one coat per day.
Nylon is much stronger then silk and just about as easy to apply. However water will not shrink it. That means that your initial application must be wrinkle free. Nylon requires more dope to fill.
Don't be concerned if the adhering dope blushes after you attach the wet silk. The blush will come out with later coats.
To avoid dope running through to covering be sure that your first coats are laid on the surface not brushed into. The dope will penetrate and flow nicely.
Spraying on the initial clear dope coats never seems to work well. On the other hand trim colors should be sprayed.
A very light sanding between coats with 400 wet/dry paper gets rid of the fuzz.
Silk can be dyed in a rainbow of colors with silk shoe dye available from dance clothing stores.
Only one coat per day.
Nylon is much stronger then silk and just about as easy to apply. However water will not shrink it. That means that your initial application must be wrinkle free. Nylon requires more dope to fill.
03-13-2010, 10:44 AM
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RE: Silk Covering Techniques
My last glider was covered in silk stuck down with SIG Stixit, and that worked very well. however I deviated in that I didnt use dope, rather I used auto arcrylic clear, thinned approx 1:1 (50%) thinners only. i sprayed on about 5 very light coats wet on wet before the 1st sanding, then 2 more light coats wet on wet and got a nice finish. I didnt do anything specific for shrinking as the silk tightened up nicely with the first coats. I used the 5mm Habotai silk from Dharma too, I bought a bolt of the 55"wide, and will be buying a couple more bolts for upcoming projects.
The one drawback with silk is it is suseptible to UV degradation, But I have found I can get some UV inhibitors to add to my finishes, I'll post a link when I find then again. On the whole I dont think I'll use any of the iron on plastic crap again on any of my built planes again. I love how silk goes on without probems even around shaped wingtips etc, silk takes more abuse than plastics and I can paint and/or airbrush to my hearts content without worrying about the paints and dyes eating the covering. It may be more work and time consuming, but that I can live with.
The one drawback with silk is it is suseptible to UV degradation, But I have found I can get some UV inhibitors to add to my finishes, I'll post a link when I find then again. On the whole I dont think I'll use any of the iron on plastic crap again on any of my built planes again. I love how silk goes on without probems even around shaped wingtips etc, silk takes more abuse than plastics and I can paint and/or airbrush to my hearts content without worrying about the paints and dyes eating the covering. It may be more work and time consuming, but that I can live with.
03-13-2010, 11:51 AM
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RE: Silk Covering Techniques
I have been in and out of the hobby since 1940. I was most active in the 50's and the 60's. At that time the preferred covering material was dope with Jap tissue (not Silkspan) for smaller models.
I found silk/aerogloss to be far and away the best covering material for any airframe with a span greater then 50". Once one acquired a little experience with silk it became possible to use one piece of material to cover a structure which would otherwise demand multiple gores of the other available alternate. It was entirely possible to cover a turtle back and both sides of a built up fuselage perfectly with one piece of silk. I customarily covered a "V" dihedral wing with 2 pieces . One for left top and bottom another for right. Of course this would not work for an elliptical wing. I have covered wing tips with films and its difficult at best. a little pulling and stretching of wet silk and the job is accomplished ... perfectly.
For some reason the advice here favors applying the material dry or damp. I always pre-doped the structure with 2 coats of full strength clear Aerogloss. I soaked the silk in water blotted it and attached it sopping wet by brushing with thinned clear and rubbing it through the weave with my finger. I kept the silk wet by misting it with a spray of water. Because of warps it was important to cover both top and bottom of a wing/stab at once. Because the clear dope hardens the fibers it was easy to trim the excess silk away with a single edge razor.
For doping/finishing... I would brush on 4 coats of Aerogloss thinned to a brushing consistancy, light sanding with 400 wet/dry after to first 2 coats. I then I masked off the open area of the structure and applied 2 coats of balsa filler to the leading, trailing edges and center sheeting. This was sanded down and one or 2 coats of colored dope sprayed on, allowed to dry 3 or 4 days and then rubbed with polishing compound. The result a very serviceable and impressive finish.
I found silk/aerogloss to be far and away the best covering material for any airframe with a span greater then 50". Once one acquired a little experience with silk it became possible to use one piece of material to cover a structure which would otherwise demand multiple gores of the other available alternate. It was entirely possible to cover a turtle back and both sides of a built up fuselage perfectly with one piece of silk. I customarily covered a "V" dihedral wing with 2 pieces . One for left top and bottom another for right. Of course this would not work for an elliptical wing. I have covered wing tips with films and its difficult at best. a little pulling and stretching of wet silk and the job is accomplished ... perfectly.
For some reason the advice here favors applying the material dry or damp. I always pre-doped the structure with 2 coats of full strength clear Aerogloss. I soaked the silk in water blotted it and attached it sopping wet by brushing with thinned clear and rubbing it through the weave with my finger. I kept the silk wet by misting it with a spray of water. Because of warps it was important to cover both top and bottom of a wing/stab at once. Because the clear dope hardens the fibers it was easy to trim the excess silk away with a single edge razor.
For doping/finishing... I would brush on 4 coats of Aerogloss thinned to a brushing consistancy, light sanding with 400 wet/dry after to first 2 coats. I then I masked off the open area of the structure and applied 2 coats of balsa filler to the leading, trailing edges and center sheeting. This was sanded down and one or 2 coats of colored dope sprayed on, allowed to dry 3 or 4 days and then rubbed with polishing compound. The result a very serviceable and impressive finish.
03-14-2010, 10:27 AM
#29
RE: Silk Covering Techniques
ORIGINAL: qldviking
The one drawback with silk is it is suseptible to UV degradation, But I have found I can get some UV inhibitors to add to my finishes, I'll post a link when I find then again.
The one drawback with silk is it is suseptible to UV degradation, But I have found I can get some UV inhibitors to add to my finishes, I'll post a link when I find then again.
03-14-2010, 12:51 PM
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03-14-2010, 03:19 PM
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RE: Silk Covering Techniques
What a Thread,
I remember in the 70's a friends Dad showed us how
to cover using Silk pant hose and Dope.
I wish I would have paid more attention.
Bob
03-14-2010, 05:22 PM
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RE: Silk Covering Techniques
We used to buy large ladies silk scarfs for less the a dollar in the local Woolworth stores and use them on smaller models. Some of the scarfs were colorfully patterned and the result could be quite impressive!
03-14-2010, 05:24 PM
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RE: Silk Covering Techniques
I too liked the clear finish on silk, and using acrylics my clear was near whitish clear. The UV additive I used didnt affect the colouring to any degree.
I got to talking to an elderly modeller over the weekend. We discussed the issues of silk covering a lot and the UV degradation was one subject we discussed. He said that while they were aware of UV degradation, etc he said they dint particularly worry about it so much, though with clear dope finishes the covering could get brittle. The painted covering faired better. But then as today, the life epectancy of a model wasnt all that long with few surviving more than a couple years without major repairs along the way. He also told me that models back then were usually stored out of direct sunlight, usually up under a roof of shed/garage or in a cellar. All in all it was a good couple hours we enjoyed chatting and it looks I might have help when I build and cover my next glider
I got to talking to an elderly modeller over the weekend. We discussed the issues of silk covering a lot and the UV degradation was one subject we discussed. He said that while they were aware of UV degradation, etc he said they dint particularly worry about it so much, though with clear dope finishes the covering could get brittle. The painted covering faired better. But then as today, the life epectancy of a model wasnt all that long with few surviving more than a couple years without major repairs along the way. He also told me that models back then were usually stored out of direct sunlight, usually up under a roof of shed/garage or in a cellar. All in all it was a good couple hours we enjoyed chatting and it looks I might have help when I build and cover my next glider
03-14-2010, 06:03 PM
#35
RE: Silk Covering Techniques
ORIGINAL: qldviking
I too liked the clear finish on silk, and using acrylics my clear was near whitish clear. The UV additive I used didnt affect the colouring to any degree.
I got to talking to an elderly modeller over the weekend. We discussed the issues of silk covering a lot and the UV degradation was one subject we discussed. He said that while they were aware of UV degradation, etc he said they dint particularly worry about it so much, though with clear dope finishes the covering could get brittle. The painted covering faired better. But then as today, the life epectancy of a model wasnt all that long with few surviving more than a couple years without major repairs along the way. He also told me that models back then were usually stored out of direct sunlight, usually up under a roof of shed/garage or in a cellar. All in all it was a good couple hours we enjoyed chatting and it looks I might have help when I build and cover my next glider
I too liked the clear finish on silk, and using acrylics my clear was near whitish clear. The UV additive I used didnt affect the colouring to any degree.
I got to talking to an elderly modeller over the weekend. We discussed the issues of silk covering a lot and the UV degradation was one subject we discussed. He said that while they were aware of UV degradation, etc he said they dint particularly worry about it so much, though with clear dope finishes the covering could get brittle. The painted covering faired better. But then as today, the life epectancy of a model wasnt all that long with few surviving more than a couple years without major repairs along the way. He also told me that models back then were usually stored out of direct sunlight, usually up under a roof of shed/garage or in a cellar. All in all it was a good couple hours we enjoyed chatting and it looks I might have help when I build and cover my next glider
qldviking,
Example of a glider, time between the two pictures is about 28 years.
I did fly the ASK 18 many years without paintfinish. My brother did finish the wingtips and color and did make many flights with it after that.
Now back in my workshop for repair as result of an elevator failure the flight after the color picture is made.
Cees
03-14-2010, 06:10 PM
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RE: Silk Covering Techniques
All true... Actually we always blamed the brittleness on evaporating plasticizer in the dope. I don't know if anyone did a study on it. One thing is for sure the paper covered models were very subject to splits and such within a very few months of completion which sort of points to failure of plasticizer.
On the other hand I worked for JASCO in the 50's and they had all of Frank Zaics classic models in the display window or hanging from the ceiling in the show room. Some of these models were more then 10 years old, jap/Silkspan covered and not particularly brittle.
Zaic used nitrate dope with Castor oil as a plasticizer. He only applied on or two very thin coats of clear so the very limited evidence I have it points more to the dope then the covering material.
On the other hand I worked for JASCO in the 50's and they had all of Frank Zaics classic models in the display window or hanging from the ceiling in the show room. Some of these models were more then 10 years old, jap/Silkspan covered and not particularly brittle.
Zaic used nitrate dope with Castor oil as a plasticizer. He only applied on or two very thin coats of clear so the very limited evidence I have it points more to the dope then the covering material.
03-14-2010, 06:48 PM
#37
RE: Silk Covering Techniques
ORIGINAL: qldviking
I too liked the clear finish on silk, and using acrylics my clear was near whitish clear.
Message shortened by TF
I too liked the clear finish on silk, and using acrylics my clear was near whitish clear.
Message shortened by TF
Problem of an unpainted glider (clear finish?) is visibility. Especially under clouds! You need very good eyes and I did have.
Look the picture of 1980, wings partly, tail cone and stabilizer were nearly transparent without paint.
So for me there was no UV problem but IV problem (In-Visibility), and that is what I call experience.
Next step to discover for me was, how to paint and not add too much weight and destroy the flexbility of the silk covering especially for pattern planes with the vibrations of the glow engine.
Cees
03-14-2010, 10:14 PM
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RE: Silk Covering Techniques
when painting aircraft I use airbrushes rather than a spraygun and I use auto acrylics thinned down 1:1 with thinners. I never go for the super smooth slick finish as that does take a few coats. and I quite like the fine weave textured look. I have also liked the transparent look on built up glider wings and never paint them a solid colour. For visibility one colour that works well to my surprise was silver/grey, and all my gliders have the fuse belly and sheeted wing sections painted that. Why I use airbrushes is I can use a bare minumum of paint to give a reasonable finish, and it doesnt take that much longer. The one I used for coverage has a .5mm needle/nozzle and a 10cc cup which does cover a good area and sprays a 3-4inch fan. And yes, I own a variety of full sized spray guns. I just found airbrushes a good way to minimise paint usage.
03-15-2010, 07:08 AM
#39
RE: Silk Covering Techniques
I use a miniature paint spay pistol I did design myself. The capacity of the paint tank is 35 cc and that was most important because my models have all “Taurus†dimensions, 10 cc isn’t enough for one surface. I use alkyd paint and 25/30 % benzine (“wasbenzineâ€, Dutch).
First layer is a thin layer of primer see the picture 1 and 2 of the Taurus of 1961, picture 3 is the wing of the Taurus of 1962 with the same paint system after 5 years and many hundreds of flights.
The whole paintjob of the 1961 Taurus in my thread :Redesign and reconstruction of the Oldest Taurus on Earth.
http://www.rcuniverse.com/forum/m_79...tm.htm#8577684
Cees
05-23-2010, 08:37 PM
#40
RE: Silk Covering Techniques
For those of you who have used the Tai or Dharma 5 mm silk, can anyone compare these products in weight to the Esaki silk that I have been using ? I really like the heavier grade Esaki, but the cost is getting prohibitive for a larger model. My current project is a Custom Cavalier and it's going to take a LOT of covering material.
Thanks,
Dick
Thanks,
Dick
05-25-2010, 05:44 AM
#41
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RE: Silk Covering Techniques
I've looked at the Esaki and silk from Dharma.
I can't weigh them to check difference,scale won't read that small a difference.
The silk from Dharma has more threads per inch and is more closely woven.
I think because the threads are more numerous, it's stronger.
I also believe the weave fills faster on the silk from Dharma, due to the closeness of the threads.
Only a guess though.
Paul
I can't weigh them to check difference,scale won't read that small a difference.
The silk from Dharma has more threads per inch and is more closely woven.
I think because the threads are more numerous, it's stronger.
I also believe the weave fills faster on the silk from Dharma, due to the closeness of the threads.
Only a guess though.
Paul
05-25-2010, 07:20 AM
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RE: Silk Covering Techniques
I have found the Dharma silks to be the best for finishing. As pd1 stated, its a finer weave with a higher thread count, therefore taking less to fill the weave. If you want a heavier weight cloth look at dharma's range of habotai silks, its available in a number of weights and also widths too, and price is very reasonable for the quality. I buy my silks there (well my other half does ) in 11yd bolts and I find the 55" wide to be quite economical in usage. Even with paints etc i find it cheaper than monkeycote etc and its a stronger more durable finish too as well as being less of a headache to apply.
07-22-2010, 07:35 PM
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RE: Silk Covering Techniques
I was going to start a new thread, but figured this would be the appropriate place for this ..
I've been playing with silk doping a wing for a North Star. I have an old North Star wing to test on, so thought I'd try that first. Before that, I made a 6 inch square frame to get my feet wet wtih. I'm using 5mm Habotai silk from Dharma Trading and butyrate dope and thinner from an aircraft supply house. I've been using the dope thinned 1:1 for the entire process. I put 2-3 coats of thinned dope on the structure edges, then putting on the silk damp and going around the edge to tack it on, then covering the whole surface for each coat. I'm finding it's taking something like 8-10 coats to get the finish shiny as I'm told it should be and it does tend to run some (probably my bad painting technique). Should I be using the dope 1:1 thinned throughout the process? It just seems this is an excessive number of coats.
07-22-2010, 11:10 PM
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RE: Silk Covering Techniques
Awesome thread! Thanks for starting it up. I was just thinking about covering my VK Cherokee Babe in silkspan and dope. I'll try to keep up and post pics when I get to the covering stage!
Personally, I've only had experience with covering the old Guillow's kits in tissue and dope. I used to 'help' my dad build control line balsa models in the early 70's, but somehow the covering was always done after I went to bed and magically... before I got up the next morning.
Cheers!
Personally, I've only had experience with covering the old Guillow's kits in tissue and dope. I used to 'help' my dad build control line balsa models in the early 70's, but somehow the covering was always done after I went to bed and magically... before I got up the next morning.
Cheers!
07-23-2010, 02:26 AM
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RE: Silk Covering Techniques
ORIGINAL: virgomoon
it does tend to run some (probably my bad painting technique). Should I be using the dope 1:1 thinned throughout the process? It just seems this is an excessive number of coats.
it does tend to run some (probably my bad painting technique). Should I be using the dope 1:1 thinned throughout the process? It just seems this is an excessive number of coats.
08-12-2010, 06:55 PM
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RE: Silk Covering Techniques
Istarted out using silkspan on most of my planes, simply because it cost less then silk. It was .05 cents a sheet or .95 cents for silk. With what money Ihad then, silkspan won out. Most of the time it came with the kit though, so it didn't cost me anything for the covering. The only plane I covered with silk was my Smoothie and Nobler, both of which were great flying planes at the time. With our combat planes, silkspan was good enough because of the crashing we did. Once Igot into R/C, Icould afford the silk so switched to that. Ialways sanded my bare framework with 400 snadpaper before Ieven though about statring the covering job.
The way Icovered it was to wet the slik out GOOD. Like drown it in water. Ilet it set in luke warm water while Ipainted the frame around the area with straight clear dope and only Aerogloss was good enough for me. I never found another dope that Iwould use then. You really don't need to let it soak like that, but Idid it so it was ready when I was. Ijust had to pull it out, lay in on a towel and pat it out and then lay it on the wing. Once Igot the dope on the wing, Itook the silk out of the water and put it on a towl to dry it a little so it wasn't dripping water all over the place. Then I took clear again and using it straight and a brush Iput a coat of dope around the edge and rubbed it in with my finger good and got the silk stuck down good. Iuses a piece of silk cut to cover one half the wing on top and then cut 4 of them so Ihad all the silk Ineeded to cover the whole wing in one sitting. Any drying of the silk and I used a water bottle to spray some water on the open section of the silk to keep it wet. Once Igot the wing covered, Iset it up for the night. The next day Icame in and trimmed anything that Imissed the day before or doped it down good. I thinned my dope to 50 50 and started spraying the clear on for a good coverage and made sure it was filled all over and no pin holes. I used a light behind the wing to find pin holes. After I put 3 or 4 lite coats on and hopefully filled the weave, or as close as I could get it, I set it up for the night again. Iused a simple Badger air brush to spray with and got a good wet coat on it each time Ipainted it. When I was ready to put the primer on, about a week later, Ibrushed it on lightly and let it dry again. Ilet the primer dry for 3 or 4 days before I sanded it down, but more then likely didn't need to. I used 220 wet or dry to sand it with and make sure you don't sand down to the silk. Ialways used the wet or dry wet and plenty of water to get a good sanding job done. Then Istarted spraying on the base color and let it set over night between coats. Ithinned all my dope out 50 50 for spraying and it normally turned out pretty good. When it came time to trim, I would mask a section off and spray it with a lite coat of clear first and then spray the trim color. After Igot everything painted, Ilet it stand for about a week and then sanded it with wet or dry 400 and then 600 until it was nice and smooth. Then I put 2 or 3 lite coats of clear on and let that sit about a week before I took it out to fly. A few times Ilet them set for about a month before I flew them. I did polish a couple of them, but it didn't make them last any longer. One thing about using silk on anything is to work the wrinkels out as much as possible. A little tiny wrinkle may come out after it is dry and painted, but there is no garentee it will, so you need to get them out before you let it dry for the night.
Later when Super Coverite came out Istarted using that and Iloved it, but didn't care much for MonoKote. I did use it and still do on planes I don't care about that much or if I am in a hurry to get one flying, but I would still rather paint one then use plastic any day of the week. Idid use Hobbypoxy for a little while over the clear dope, but it turned out to be a little heavy. Iwent back to Aerogloss and didn't look back. I loved painting a plane while putting plastic on one kind of turns me off, but Ido it once in awhile anyway. I'm not crazy about it though. I would still rather have silk or Super Coverite on my plane then plastic any day. Iknow Super Coverite is a little on the heavy side, but I only do the wings with that. The fuselage is normally fully sheeted, so I just use silkspan on that and then paint it.
On an open frame fuselage, I would use silk to cover everything. Silkspan or even jap tissure was not good enough for me. Ijust never got one to hold up long enough for my liking. Iwas always punching holes in it some place. If the fuselage was completely sticks and open I would start on the bottom and glue the silk on one stick really good and then wrap it around the fuselage to the bottom again and glue that end down. I would keep the silk slightly damp for about an hour before I let it dry out all the way to make sure the glue was holding good and give it a chance to dry first. Then you start the painting all over again.
Ihad to stop flying for a few years while work kept me from enjoying it. I just didn't have time for models then. I started back again about three years ago and am getting my plane building cought up. Some of them are covered in Monokote, but the rest will be silk and dope. Iguess Randolf is about the only one left now. I hear that Sig is not really dope any more since they changed their formula and I won't even try it. Since Aerogloss is gone along with the kits, I build a lot from plane or short kits with a few full cut kits thrown in. I tried a couple of BARF's but really don't like them. I went back to the Kaos and Super Kaos and have a kit of the King Altair half built that needs to be finished. I also am build some OLDTIMERS like the Super Buckaneer, Super Brigier, and a few others, but I'm not really interested in the new crop of planes where everything is cut out of lite ply with holes big enough to put my hand through and then Monokote over that and it is supposed to hold up. Yea, right. Iam going more and more to electric lately anyway, so I can build the old planes a little lighter since I don't have an engine pounding away in there. I'm building my first undercambered wing now with the Buzzard Bombshell and Ithink if Ipaint Balsarite on it first it should stick down pretty good. I guess I'll find out pretty soon when I go to cover the wing. I put cap strips on all the ribs, so I should have enough area to stick it to.
Ed
The way Icovered it was to wet the slik out GOOD. Like drown it in water. Ilet it set in luke warm water while Ipainted the frame around the area with straight clear dope and only Aerogloss was good enough for me. I never found another dope that Iwould use then. You really don't need to let it soak like that, but Idid it so it was ready when I was. Ijust had to pull it out, lay in on a towel and pat it out and then lay it on the wing. Once Igot the dope on the wing, Itook the silk out of the water and put it on a towl to dry it a little so it wasn't dripping water all over the place. Then I took clear again and using it straight and a brush Iput a coat of dope around the edge and rubbed it in with my finger good and got the silk stuck down good. Iuses a piece of silk cut to cover one half the wing on top and then cut 4 of them so Ihad all the silk Ineeded to cover the whole wing in one sitting. Any drying of the silk and I used a water bottle to spray some water on the open section of the silk to keep it wet. Once Igot the wing covered, Iset it up for the night. The next day Icame in and trimmed anything that Imissed the day before or doped it down good. I thinned my dope to 50 50 and started spraying the clear on for a good coverage and made sure it was filled all over and no pin holes. I used a light behind the wing to find pin holes. After I put 3 or 4 lite coats on and hopefully filled the weave, or as close as I could get it, I set it up for the night again. Iused a simple Badger air brush to spray with and got a good wet coat on it each time Ipainted it. When I was ready to put the primer on, about a week later, Ibrushed it on lightly and let it dry again. Ilet the primer dry for 3 or 4 days before I sanded it down, but more then likely didn't need to. I used 220 wet or dry to sand it with and make sure you don't sand down to the silk. Ialways used the wet or dry wet and plenty of water to get a good sanding job done. Then Istarted spraying on the base color and let it set over night between coats. Ithinned all my dope out 50 50 for spraying and it normally turned out pretty good. When it came time to trim, I would mask a section off and spray it with a lite coat of clear first and then spray the trim color. After Igot everything painted, Ilet it stand for about a week and then sanded it with wet or dry 400 and then 600 until it was nice and smooth. Then I put 2 or 3 lite coats of clear on and let that sit about a week before I took it out to fly. A few times Ilet them set for about a month before I flew them. I did polish a couple of them, but it didn't make them last any longer. One thing about using silk on anything is to work the wrinkels out as much as possible. A little tiny wrinkle may come out after it is dry and painted, but there is no garentee it will, so you need to get them out before you let it dry for the night.
Later when Super Coverite came out Istarted using that and Iloved it, but didn't care much for MonoKote. I did use it and still do on planes I don't care about that much or if I am in a hurry to get one flying, but I would still rather paint one then use plastic any day of the week. Idid use Hobbypoxy for a little while over the clear dope, but it turned out to be a little heavy. Iwent back to Aerogloss and didn't look back. I loved painting a plane while putting plastic on one kind of turns me off, but Ido it once in awhile anyway. I'm not crazy about it though. I would still rather have silk or Super Coverite on my plane then plastic any day. Iknow Super Coverite is a little on the heavy side, but I only do the wings with that. The fuselage is normally fully sheeted, so I just use silkspan on that and then paint it.
On an open frame fuselage, I would use silk to cover everything. Silkspan or even jap tissure was not good enough for me. Ijust never got one to hold up long enough for my liking. Iwas always punching holes in it some place. If the fuselage was completely sticks and open I would start on the bottom and glue the silk on one stick really good and then wrap it around the fuselage to the bottom again and glue that end down. I would keep the silk slightly damp for about an hour before I let it dry out all the way to make sure the glue was holding good and give it a chance to dry first. Then you start the painting all over again.
Ihad to stop flying for a few years while work kept me from enjoying it. I just didn't have time for models then. I started back again about three years ago and am getting my plane building cought up. Some of them are covered in Monokote, but the rest will be silk and dope. Iguess Randolf is about the only one left now. I hear that Sig is not really dope any more since they changed their formula and I won't even try it. Since Aerogloss is gone along with the kits, I build a lot from plane or short kits with a few full cut kits thrown in. I tried a couple of BARF's but really don't like them. I went back to the Kaos and Super Kaos and have a kit of the King Altair half built that needs to be finished. I also am build some OLDTIMERS like the Super Buckaneer, Super Brigier, and a few others, but I'm not really interested in the new crop of planes where everything is cut out of lite ply with holes big enough to put my hand through and then Monokote over that and it is supposed to hold up. Yea, right. Iam going more and more to electric lately anyway, so I can build the old planes a little lighter since I don't have an engine pounding away in there. I'm building my first undercambered wing now with the Buzzard Bombshell and Ithink if Ipaint Balsarite on it first it should stick down pretty good. I guess I'll find out pretty soon when I go to cover the wing. I put cap strips on all the ribs, so I should have enough area to stick it to.
Ed
08-13-2010, 12:21 PM
#47
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RE: Silk Covering Techniques
mred, thank you so much for your post. My fiance and I were picking over every word last night as we're attempting to learn the art of silk and dope covering. I think we're quickly becoming covering snobs, lol. So much so that we just stripped all the Monokote off a Super Sportster ARF last night to cover it in silk.
We do, however, have a few questions:
1) Our NorthStar test wing. I've attached a few shots of this wing. We silk and doped this wing using 1:1 thinned butyrate dope throughout with a paintbrush (no airbrush) using about 8-10 coats. It looks shiny on the non-painted side and the painted side is only a thin coat of Colorplace spray paint (cheap WalMart stuff), so it's not fully covered. We then went to test the fuel-proofness of this covering by just dripping some 10% 2-stroke glow fuel on it and let it sit for about a few days. We noticed a couple things. First, there seemed to be some spots where the oil had apparently soaked through (IMG_0440 is a zoomed out view that shows the darker soak spots, IMG_0441/442 shows a closer view of these areas). There are some runs in there, too, which I think is just putting the dope on too thick or too quickly, I'm not sure. Did we just not get it thick enough? The whole thing was shiny before we did the fuel test. Also, on 0444 and 0445 there are some areas you can see in the reflection that are 'raised' a little bit following the splatter pattern of the fuel we tested with. You can't really *feel* the bumps, but the fuel seems to have interacted with the dope. Is this normal? Is there anything else we need to be aware of?
2) You mentioned using an airbrush. We have a small model airbrush kit for use with small plastic models for our younger boys. Would you suggest a larger unit with a larger paint canister? Can you suggest any particular models?
The file names mentioned didn't come through, apparently, on the image views. The series starts with IMG_0438.JPG and goes through IMG_0445, in order.
We do, however, have a few questions:
1) Our NorthStar test wing. I've attached a few shots of this wing. We silk and doped this wing using 1:1 thinned butyrate dope throughout with a paintbrush (no airbrush) using about 8-10 coats. It looks shiny on the non-painted side and the painted side is only a thin coat of Colorplace spray paint (cheap WalMart stuff), so it's not fully covered. We then went to test the fuel-proofness of this covering by just dripping some 10% 2-stroke glow fuel on it and let it sit for about a few days. We noticed a couple things. First, there seemed to be some spots where the oil had apparently soaked through (IMG_0440 is a zoomed out view that shows the darker soak spots, IMG_0441/442 shows a closer view of these areas). There are some runs in there, too, which I think is just putting the dope on too thick or too quickly, I'm not sure. Did we just not get it thick enough? The whole thing was shiny before we did the fuel test. Also, on 0444 and 0445 there are some areas you can see in the reflection that are 'raised' a little bit following the splatter pattern of the fuel we tested with. You can't really *feel* the bumps, but the fuel seems to have interacted with the dope. Is this normal? Is there anything else we need to be aware of?
2) You mentioned using an airbrush. We have a small model airbrush kit for use with small plastic models for our younger boys. Would you suggest a larger unit with a larger paint canister? Can you suggest any particular models?
The file names mentioned didn't come through, apparently, on the image views. The series starts with IMG_0438.JPG and goes through IMG_0445, in order.
08-13-2010, 01:42 PM
#48
Senior Member
RE: Silk Covering Techniques
This may have been said before, but for sanding silk or paper finishes over open wing bays, use steel wool rather than wet or dry sandpaper. Run a magnet over the wing after you finish tp pick up the metal fuzzies.
08-13-2010, 02:47 PM
#49
Senior Member
RE: Silk Covering Techniques
Virgomoon
Neither nitrate or butyrate dope is completely fuel proof.
Nitrate is not fuel proof at all.
Butyrate is supposed to be fuel proof. It is exhaust proof, to a point.
And it is fuel proof to a lesser point.
You have to wipe spilled fuel immediately or at the least you will get a stain.
Some of the poly urethane and epoxy finishes are a lot more fuel proof than dope.
I used to coat my planes with Hobby Poxy in the nose area to help with fuel proofing.
Now I do only electric, and I don't have to worry anymore.
Paul
Neither nitrate or butyrate dope is completely fuel proof.
Nitrate is not fuel proof at all.
Butyrate is supposed to be fuel proof. It is exhaust proof, to a point.
And it is fuel proof to a lesser point.
You have to wipe spilled fuel immediately or at the least you will get a stain.
Some of the poly urethane and epoxy finishes are a lot more fuel proof than dope.
I used to coat my planes with Hobby Poxy in the nose area to help with fuel proofing.
Now I do only electric, and I don't have to worry anymore.
Paul
08-13-2010, 04:30 PM
#50
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RE: Silk Covering Techniques
RE: Jim
OK, no flamin' the newbie here, but are we talking that fine industrial steel wool (http://www.amazon.com/Industrial-Gra.../dp/B001H4TLA8) or standard 'sink' steel wool?
OK, no flamin' the newbie here, but are we talking that fine industrial steel wool (http://www.amazon.com/Industrial-Gra.../dp/B001H4TLA8) or standard 'sink' steel wool?