Mark's 2mm thick genuine Depron.

Because I have so much of it I thought it would be nice to have a little file on the stuff
I bought 2mm thick because I think we can reduce the size of our current two cells planes a little and use the 70mA cell with a geared motor or use 50mA cells with a D/D KP00.
In the olde days of Depron I just drew round a template and hey presto - a wing! No sanding it down which generated all that static. I remember just painting on it too, the last Corsair I made would not take water based Acrylic at all well, and it looks a bit of a mess.

I have just done a couple of tests on a piece of the new genuine 2mm which is the same size as one wing on the 13.5" span Corsair. Just one of the Corsair's wings is 2.5mm thick and weighs 2.5g and the MD2 depron weighs 1.5g - a suppressing 60 per cent weight saving there. So we could save 2g on the wings and two grams on the 70 mA cells for a like for like with my direct drive Corsair already, plus making it a tad smaller, say 5g weight saving for the same power, plus a new carbon prop - whoopee!

The MD2 has a very noticeable stiffness in one direction so it might be easier to roll over into an airfoil - Bernard used to just bend his wings over a former over night without heating it, now he moans about cooking it in the oven to get it to bend. I am pleased to say the MD2 takes water based Acrylic well too, even when it was well thinned with water - good news.

I have put a piece on my wing-you-like, former in the warm airing cupboard over night and it is reasonably bent this morning. If you want to use this method make a former which over bends the foam to allow for it to spring back a little.

I have now made several rectangular wings "blanks" in the oven. I found the new MD2 foam is more sensitive to temperature. I pre heated the former to get the underside of the foam hot, this is very important as it tends to curl up when warmed up, so you have to heat both sides. I had my electric oven on 50 degrees and I had a piece if news paper covering the top of the foam so it did not get too hot on the top surface. I cooked it in the middle of the oven for 60 to75 seconds and it came out slightly curled up. I am happy with this little curl as it act as dihedral on my new Spitfire, while the centre section of the wing is relatively flat and scale'ish looking.

More advanced uses might be vac forming Spitfire fuselages - well,  if they can make chip
trays with it ....

Mark
16th  Feb, 2002 ,

ps - FliteHook sell all the sizes of genuine Depron