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        Help! Silk vs Iron on

#1 Cliffc Oct 09, 2012 01:33 AM

Silk vs Iron on
 
]I've recently returned to the hobby after building some planes in the mid 80s. It's probably a cliche but on retiring I bought several kits that I lusted after back in the day and now have my only little airforce of boxes. In particular I've got a Sig Liberty Sport and an Aristo Craft Grumman F3F-2. As both of these kits are off the market I am going to beg the indulgence of this forum to treat them as Vintage kits.

Here's my problem - both kits are designed for silk covering. the Aristo-Craft instructions just talk about it under the catagory of things not included but the Sig Instructions actually caution against iron on coverings. The F3F appears to have been an all metal plane and the Republic sport a fabric covered plane. I'd have been inclined before reading the instructions to use a plastic iron on and a fabric iron on respectively for these planes. I've never built with silk having gone from Jap Tissue in the 60s to iron on coverings in the 80s.

Is that a good idea or should I just use silk and dope? Any experienced based recomendations or threads or article references that could be provided would be appreciated. These are both neat kits and I want to not only do them justice, I want then to be strong enough when finished to be reliable. Your assistance is appreciate. Cliff Campen

#2 brokenenglish Oct 09, 2012 03:04 AM

Hi Cliff, all this has been discussed many times over the past 30-odd years!
The only doubt that needs clearing is that you have to decide whether the basic aircraft structures actually need the rigidity contributed by a doped finish, or are they sufficiently rigid, on their own, to accept the lesser rigidity of iron-on? This especially refers to the flying surfaces of course. Most of us won't know the kits you mention, so only you can decide.
If the designs are reasonably robust, you'll be OK with iron-on. If in doubt, a fabric "tex" iron-on will be slightly more rigid than smooth film.

#3 bossee Oct 09, 2012 04:31 AM

Hi,

SIG Liberty Sport - that is a nice plane!
http://www.kavanrc.de/instructions/s...bertysport.pdf

I think it would be OK to use fabric based film like Oratex, Glosstex/Solartex and smilar.
http://www.oracover.de/index.php/kat..._aircraft.html
http://www.solarfilm.co.uk/

But SIG Koverall and dope would probable be better so You get little more strength to the structure.
http://www.sigmfg.com/cgi-bin/dpsmar..._20Covering_01

For the Aristo Craft Grumman F3F-2, if it has balsa planked surfaces all over the fuselage and wing/stab, You can use 25 gram glass cloth and for example Pacer Z-Poxy Finishing resin or Deluxe Materials EZKote
http://www.zapglue.com/epoxy-resins/
http://www.deluxematerials.com/index.html
http://www.horizonhobby.com/webapp/w...pe=productgrid


/Bo

#4 Edubarca Oct 09, 2012 08:27 AM

In my opinion, both of these kits can be covered with plastic iron on materials. I know very well the Aristo Craft Grumman F3F because I have the plan. This model was designed by the genius Walter Musciano who designed not only the F3F but other models to be kitted by Aristocraft both for control line and radio control. Mr. Musciano's airplanes were always designed with structures that can resist everything. I haven't seen the SIG so I can't be 100% positive that it can be covered with Monokote or similar. I have recently tested with great success an iron on covering made in China and sold by HobbyKing and others, very cheap and with excellent quality. I call it "ChinaKote". I always prefer to cover with iron on mostly because they are applied in a fraction of time with beautiful results as compared to silk and dope method which is very time consuming. I also consider repairs. Reconstructing a crash with Monokote is much faster and the repairs are almost invisible as compared to a rebuild with silk and dope. I agree that if the structure is rather weak, it might need silk (or similar) and dope covering for additional strength, but the majority of radio control kits can stand iron on materials. I also mention the fact that iron on coverings are MUCH LIGHTER, an important issue to consider especially where I fly at 2.650 meters above sea level

#5 Edubarca Oct 09, 2012 08:29 AM

Quote:

Originally Posted by Cliffc (Post 22951327)
]I've recently returned to the hobby after building some planes in the mid 80s. It's probably a cliche but on retiring I bought several kits that I lusted after back in the day and now have my only little airforce of boxes. In particular I've got a Sig Liberty Sport and an Aristo Craft Grumman F3F-2. As both of these kits are off the market I am going to beg the indulgence of this forum to treat them as Vintage kits.

Here's my problem - both kits are designed for silk covering. the Aristo-Craft instructions just talk about it under the catagory of things not included but the Sig Instructions actually caution against iron on coverings. The F3F appears to have been an all metal plane and the Republic sport a fabric covered plane. I'd have been inclined before reading the instructions to use a plastic iron on and a fabric iron on respectively for these planes. I've never built with silk having gone from Jap Tissue in the 60s to iron on coverings in the 80s.

Is that a good idea or should I just use silk and dope? Any experienced based recomendations or threads or article references that could be provided would be appreciated. These are both neat kits and I want to not only do them justice, I want then to be strong enough when finished to be reliable. Your assistance is appreciate. Cliff Campen

I would like to have if possible a scanned copy of the Grumman F3F parts, specially the fuselage formers. They are not on the plan and are not easy to develop due to the strange shape of the fuselage. Can you get them scanned? I would appreciate this very much

#6 LesUyeda Oct 09, 2012 10:00 AM

"Silk vs Iron on "

Silk and dope is the lightest covering you can achieve, but labor intensive. Iron on's are inherently heavier, (then does it matter for us), but much easier to apply. That having been said, there is NOTHING to compare to the look and feel of a silk/doped airframe.

Les

#7 Cliffc Oct 09, 2012 10:23 AM

Silk vs Iron on
 
Gentleman, thanks for the replys. I was pretty sure that this was a topic with a lot of mileage on it. There's a nice thread on RCgroups on the F3F done with an Ultracoat aluminum look finish which I admired quite a bit. It's a cute fat little plane although I'd like to add ailerons to it.

As for scanning the fuselage forms I could do that and I'd be pleased to do that. Please be patient. I've got to get them out of the sheet as there isn't enough contrast in the sheets to scan well. This will take a little time because it's almost Halloween and I've got a load of stuff to do for my wife's haunted house. I can do it with my own scanner so it's no big deal - if I can remember how it works. :-)

I may have some questions when I chase some of these threads in detail.

Regards Cliff Campen

#8 papermache Oct 09, 2012 10:34 AM

Cliff,
Either one would do the job. It's up to you on which one you use. I would use Solartex for fabric surfaces and flat colored film for metal surfaces. Just be sure you set your temperatures properly for the brand you're using. This will mean reading the instructions (a practice that seems anathema to many in the hobby). A silk and dope finish is a thing of beauty to be sure, but it is about 5x the work of an iron-on. Besides, if your wife doesn't like the smell of dope, then iron-ons are definately the way to go. Have fun whichever way you decide.
Papermache

#9 Cliffc Oct 09, 2012 02:08 PM

Silk vs Film
 
In looking into the F3F-2 fuselage forms for Edubarca, I discovered that the fuselage forms and spines are all 1/16" ply! As this is a sheeted fuselage I don't think I needed to worry too much about what I cover it with. The wings are balsa and I may need to be a little more reserved but it apears fool hardy to have worried. I'll just send the scans to Edubarca via a private message unless someone else would like them. This is a bigger plane than I would have thought so there will be several pages of scans. The kit is beautifully cut, I pulled apart 6 or 7 sheets of die cut parts very quickly with only one splinter.

I'd heard that these kits tended to build heavy - I can believe it. Regards Cliff Campen

#10 Cliffc Oct 09, 2012 03:14 PM

Silk & Film - F3F Fuselage Forms
 
7 Attachment(s)
Edubarca - I got held up on my wife's project so I worked on yours. I am not the wizard of the scanner and these have a heavy shadow on the leading edge (of the scanner) and are very faint on the trailing edge. They look useable to me as there is enough of the trailing edges to fair in a smooth curve and the knotches are shadowed enough even in the trailing edge. Spines F-15 and F-17-1 are too large to scan. If you can't get them off of the plans advise and I'll draw a reference line on each of them and scan them twice.

Caution these were scanned to a US letter sized format (8 1/2 X 11") and will come out distorted if printed to an A4 sized page with the fit to page command print them to size.

I wanted to send them privately but the private message format doesn't support attachments. If you need something else advise. I'll scribble down the part numbers that are ply as there are a number of small pieces, dihedral braces, gussets etc that are ply. You'll be sawing a long time on these so remind me if I don't have the list for you in several days.

If you look at these and feel that some of them are two faint I can reverse them and scan from what was the trailing edge in this set and between the two scans you should be able to resolve the part pretty effectively.

#11 Edubarca Oct 09, 2012 06:24 PM

Thank you very much. Cliff, They are all workable except perhaps "Fuselage 4" which does not show the shape of formers. If you want, you can write to me to edubarca1946@gmail.com. This server has a 50mb attachment capacity. The printing is no problem. I'm not going to print these formers. As soon as I'm ready to build the model, I vectorize the parts so they can be cut with my laser cutting machine so I don't need paper printing at all. Again thanks,

Regards,

Eduardo

#12 JMP_blackfoot Oct 11, 2012 12:13 AM

2 Attachment(s)
Quote:

Originally Posted by LesUyeda (Post 22953406)
Silk and dope is the lightest covering you can achieve, but labor intensive. Iron on's are inherently heavier, (then does it matter for us), but much easier to apply. That having been said, there is NOTHING to compare to the look and feel of a silk/doped airframe.

You can have the best of both worlds with doped silk over Doculam, which makes things much easier.
Dope the airframe wherever covering will be stuck.
Apply Doculam over the open areas.
Then apply silk wet and stick down with 50% dope. No run through, no streaks and the result is very nice.
This works with tissue also.

#13 Sundancer Oct 11, 2012 04:59 AM

3 Attachment(s)
Couldn't agree more JMP, silk or tissue over doculam is excellent, and doculam is much cheaper than modelling films, sticks better, shrinks better and is easier to apply. The finish has the torsional rigidity of a tissue/silk/dope finish, but with good puncture resistance too. The Sopwith Triplane below is covered in Esaki Liteflite tissue over doculam, doped then sprayed with Flair Spectrum paint. The model is now at least 12 years old and the finish is holding up very well. The modified Puddlemaster is covered in yellow lightweight Modelspan tissue over doculam with a plain clear dope finish and the front one of the pair of 2 metre soarers is silk over doculam finished with tinted clear dope to deepen the colour, whilst the other, lightweight, model is tissue over 10 micron mylar with a clear dope finish.

#14 Edubarca Oct 11, 2012 08:41 AM

Quote:

Originally Posted by LesUyeda (Post 22953406)
"Silk vs Iron on "

Silk and dope is the lightest covering you can achieve, but labor intensive. Iron on's are inherently heavier, (then does it matter for us), but much easier to apply. That having been said, there is NOTHING to compare to the look and feel of a silk/doped airframe.

Les

With all due respect, I don't agree that silk and dope is the lightest finish possible. I say this based on my own experiments. The silk and dope method is lighter if you apply just one or two thin coats of dope, no paint, no decorations. But if the model is to be painted in order to achieve an attractive livery, several coats of dope must be applied and several of paint which all together come out quite heavy. Chinakote or Monokote or any other iron on is one step, one weight and that's it. Naturally, a small model will be heavier (such as Tomboy or smaller) but a model like the Junior 60 or similar will definitively come out lighter with iron on. I have made my own investigations on this and I can fully sustain my opinion.

#15 Edubarca Oct 11, 2012 08:59 AM

I agree that silk and dope has a beautiful finish not attainable with film type iron ons. However, there was a material from Coverite that had a fabric finish. I don't know if they still make it.


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