David Davis Posted July 20, 2022 Share Posted July 20, 2022 I realise that you can dope tissue over doculam but has anyone tried doping polyester dress lining over doculam to save on dope? Mate of mine is about to start building a Radio Queen and given the price of Oratex we are thinking of using polyester. On the other hand will tissue over doculam be suitable for a model as big as a Radio Queen? The model has an 82" or 2.08 metre wingspan. I also realise that some people have used water based floor varnish to stick the tissue to the doculam to good effect . Any views? Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted July 20, 2022 Share Posted July 20, 2022 I did remember 50 years ago a polyester made silk replacement came out but the weave was thicker than silk, not as good as silk. Quote Link to comment Share on other sites More sharing options...
Anthony Scott 2 Posted July 20, 2022 Share Posted July 20, 2022 60 years ago I covered control line combat wings with "paper nylon", it was meant for petticoats but was excellent for my purpose. I also flew on the Town Moor. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted July 20, 2022 Share Posted July 20, 2022 Polyester dress lining has also be proposed as a cheap alternative to Peel-Ply, the peel-off epoxy-glass overlay material. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 21, 2022 Share Posted July 21, 2022 20 hours ago, David Davis said: I realise that you can dope tissue over doculam but has anyone tried doping polyester dress lining over doculam to save on dope? Mate of mine is about to start building a Radio Queen and given the price of Oratex we are thinking of using polyester. On the other hand will tissue over doculam be suitable for a model as big as a Radio Queen? The model has an 82" or 2.08 metre wingspan. I also realise that some people have used water based floor varnish to stick the tissue to the doculam to good effect . Any views? Hello Dave. Have you tried or thought about using matt laminating film on the Radio Queen ? The matt 75 micron film would be fine for a model of this size and no polyester needed. The matt film already looks like doped tissue and when shrunk and ironed onto ribs etc will give stiff airframe. No loosening in the sun or wrinkles . Has adhesive applied like covering film and doesnt stick to itself like some films. Cost is about £30 for a 100 meter roll so will last a long time or share it with club mates. If you do try it just a couple of tips . Leave enough over lap around compound curves to allow for a good grip for pulling. Use covering iron on med to tack in place and on max to fix , you won't burn through it. Use hot air gun to get good finish on wing tips or compound curves , trim excess off and with iron on max seal down edges. Sealed down edges are almost impossible to lift unless heated unlike covering film. The matt variety takes paint very well without any prep apart from a wipe with some alcohol . Ps . As the temps used a higher than normal coverings a pair of cotton glove are advisable especially when using hot air gun For hot air gun I mean a modelling type turned upto max. The DIY type of guns get a lot hotter so be careful . My sample is still in the green house and after three and a bit years shows no signs of any degradation or loosening. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted April 4, 2023 Share Posted April 4, 2023 So I've been doing a quick refurbishment (🤣🤣 nothing I do is quick!) On a genuine KK super sixty that is covered in doped nylon or polyester 'silk ' and for some reason decided it would be a good idea to remove the old fuel proofer/paint/dope with thinners, a decidely messy job.Now this turned out o.k, none of the covering came away and remained tight. it needed doing, no,really it did ! not the best picture but you can see the difference with the doculam and uncovered section Again not the best picture, completed underside.So instead of sticking the tissue/nylon/silk over the doculam try it the other way round for a instant fuel proof finish,with a saving on dope as you only need apply a couple of coats of 50/50 to tighten and no fuel proofer. When I have finished all the covering I'll post some more pictures Quote Link to comment Share on other sites More sharing options...
Lima Hotel Foxtrot Posted April 5, 2023 Share Posted April 5, 2023 To add to these posts that don't really address the original question... A guy I know uses Hobbycraft dress lining material in place of tissue or anything else and swears by it. Quote Link to comment Share on other sites More sharing options...
Enmanbern Posted January 16 Share Posted January 16 (edited) For a Radio Queen with an 82" wingspan, it might work well. Some have had success with water-based floor varnish for tissue on doculam. Also, consider exploring Polyethylene Terephthalate Plastic in BoPET Film – could be a solid alternative. Edited January 16 by Enmanbern Quote Link to comment Share on other sites More sharing options...
John Laird Posted January 16 Share Posted January 16 I have used doped polyster dress lining - that was quite heavy - would have been a bit lighter over mylar but still on heavy side. I then moved onto chiffon - much lighter material - over mylar. I doped it on dry - might have been better doping on wet to minimise wrinkles. The blue vagabond came out very nice with that covering. The cerise red enlarged vagabond was also covered with chiffon but it wrinkled slightly. Finally, I now use polyester faux silk - probably lightest of all. Also a very close weave, so it doesn't need much dope to weather seal especially over mylar. Cost of the silk is about £2 / running metre 40/60" wide. Shrinking thinned dope used was 40% dope/60% thinners or thereabouts. I covered my big 96" span Cumulus with polyspan - the wings were very strong and stiff - and the light covering was quite adequate for the large model. However thru time, the doped polyspan gradually shrunk and the top covering started to split. Being naturally lazy, I put a layer of doculam - mylar - over the top of the polyspan and that did the trick and also gave instant waterproofing. I am not sure about putting it over a material such as faux silk as shrinking the doculam over the material might cause material underneath to wrinkle. I attach a link to my blog on RCGroups vintage forum which illustrates some of my models with the coverings described above. There are links in the blog to some of the model builds for more detail. Note that all the materials are polyester based which goes well with dope. I think all the solartex coverings were polyester based. You can heat shrink the material to tighten it up before doping and also after doping if any wrinkles develop. https://www.rcgroups.com/forums/member.php?u=153227 hope this is useful John 1 2 Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 17 Author Share Posted January 17 Thank you gentlemen for all your responses. In the end we found out that we had sufficient Solartex and Oratex to cover the Radio Queen. Having sorted out problems caused by excessive power from the motor, the balance point and inadequate rudder travel, the model now flies very well. We're only waiting for some better weather. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.