TheFlyingCrust Posted February 16, 2013 Share Posted February 16, 2013 Hi All. I've been toying with an own design big glider for a while to use as a camera platform and, since I've done foam cutting in the past am considering making my own veneered foam wings. I've also signed up for the Mass Build and want to make a wing thick enough for retracts on the Tucano using the same prcess. I want to do some tests to decide on strength/weight/practicality of materials which may be of general help to others. I've got several ideas as to the "veneer" to use and plan on experimenting on some standard samples. Whatever foam I decide on I'm considering the following options :- 1.5 or 1 mm balsa (but max length available is a nominal 4 ft and 6 inch wide) Kitchen Worktop laminate - Formica (8ft x 4ft sheets x 0.4mm) but where to get it. Ditto GRP sheet. Microply - but its damned expensive. Obechi veneer. My LHS sells it but only 1.2m x 300mm Pine veneer from this place. Sheets about 2.5 metres I'll also be experimenting with brown paper, lightweight card and direct application of glass cloth onto foam. This whole thing might not get done until well in to Spring but your thoughts and suggestions will be greatly welcomed. No point in "reinventing the wheel" .Obviously once I've done tests I'll publish the results here. Tests will be on white foam aprox 15mm thick (but all from the same sheet for consistency of tests) and 3 inch by 2 feet. Trap one end and load the other until failure. Please excuse the mixing of imperial and metric units. Should be interesting. Wish me luck. Ian Edited By Rentman on 16/02/2013 17:39:26 Quote Link to comment Share on other sites More sharing options...
kc Posted February 16, 2013 Share Posted February 16, 2013 Obeche veneer should be easily obtainable, try the Yellow Pages for veneer suppliers. Art Veneers in Mildenhall used to be a good source that could supply larger sheets. Mahogany veneer has sometimes been used. Formica is surely too heavy and not flexible. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 16, 2013 Share Posted February 16, 2013 Obechi or balsa would be my choice......use very long scarf joints & stagger them to get the span you require...... Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 16, 2013 Share Posted February 16, 2013 Depending on the surface smoothness of the foam then (and don't laugh) consider tinned down epoxy covered with clingfilm (the industrial grade ). Any bubbles trapped on covering can be got rid of with a pin .I suppose come to think of it you could try Solartex but I've never tried it . Quote Link to comment Share on other sites More sharing options...
TheFlyingCrust Posted February 16, 2013 Author Share Posted February 16, 2013 Believe it or not Formica at the thickness stated is quite flexible. On worktops manufacturers roll it round the front of the worktop and I've got hold of edging strip in the past and I've been able to form a 1 inch radius with it. But it may be too brittle in the event of an "arrival". Also it will only require minimal finishing so weight saving there. Like the thinned epoxy clingfilm idea. Think I'll add it to the list. But I wouldn't be able to shrink the Solartex. Styrofoam is only good for about 80 c so shrinking the covering would be a no-no. I guess you were thinking of that in place of the clingfilm. Ian Quote Link to comment Share on other sites More sharing options...
kc Posted February 17, 2013 Share Posted February 17, 2013 Well maybe some Formica can be bent around a tight radius, but the stuff that used to be used in kitchens was very britttle and could snap suddenly when working with a sheet. But there were several types - genuine Formica and also Wearite had an aluminium foil layer incoroporated which helped heat resistance. Maybe there is a flexible type now to mould worktops. The thing about veneer or ply is that you use the grain to advantage - to bend one direction but not the other. Formica presumably will bend either way which is not what we need. A list of weght per sq foot and cost per sq ft would be interesting. I see that SLEC sell 1/48th ply which is cheaper than 1/64 ply. You did not mention Depron. Maybe Depron etc should be considered. For low aspect ratio wings ( power models) I reckon thin card with wood spars & LE &TE wpould seem worth trying. ( remember the Regal Eagle kits? ) Or foam covered in Brown Paper /PVA with wood spars. Gliders may need the strength of epoxy / glass. Quote Link to comment Share on other sites More sharing options...
Jimbo565 Posted February 17, 2013 Share Posted February 17, 2013 Regarding Formica,A special grade called Post Forming is requred to bend around a bench top and this requres heat to allow the laminate to bend without cracking and a specilised M/C is needed to do the job. Just some info if anybody is interested,Formica is nothing more than sheets of brown paper treated with Phenolic resin and a decorative surface sheet treated with melamine placed in a big press and left there for around one hour at 8ooo tons pressure and around 180Degs of heat and there you have it. The pack when it goes into the press is around 3/4" thick and when pressed its around 1/16" thick,its is then sanded back to its final tolerance How do i know this ? I worked there for 33 yrs. I would use Obechi veneer to skin the wings JC ne23 laminate dept Quote Link to comment Share on other sites More sharing options...
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