Frank Day Posted October 22, 2021 Share Posted October 22, 2021 Hi, Can anyone clarify what Depron is. I'm planning a few mods to a model it is old school polystyrene essentially - Robbe Concorde. Last time I did anything it was balsa, ply and tissue. Is depron the slightly shiny rubbery, bendy stuff rather than little bobbles stuck together. I believe these are the technical terms! Quote Link to comment Share on other sites More sharing options...
Don Fry Posted October 22, 2021 Share Posted October 22, 2021 (edited) Depron is a polystyrene, is just not made by moulding bobbles together under pressure, but uses some sort of foaming technique. Edited October 22, 2021 by Don Fry Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted October 22, 2021 Share Posted October 22, 2021 (edited) To add to Dons info Depron is very flat expanded polystyrene, so no bobbles as you say. But it is very stiff and not rubbery, so maintains its airfoil, but will crack with sufficient impact. Remember your last fish and chip tray, very stiff, for lightweight flight construction. Edited October 22, 2021 by Denis Watkins Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted October 22, 2021 Share Posted October 22, 2021 Where can you get depron from nowadays and in what sizes, mail order please ? Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted October 22, 2021 Share Posted October 22, 2021 41 minutes ago, Rich Griff said: Where can you get depron from nowadays and in what sizes, mail order please ? Servo Shop Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted October 22, 2021 Share Posted October 22, 2021 The slightly shiny rubbery, bendy stuff rather than little bobbles stuck together is EPP expanded polypropylene. Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted October 22, 2021 Share Posted October 22, 2021 Depron is normally available from the balsa cabin. Quote Link to comment Share on other sites More sharing options...
Frank Day Posted October 22, 2021 Author Share Posted October 22, 2021 Many thanks guys, the sheets I have are EPP, I was told they are Depron but I had my doubts. I'll try a couple of the outlets suggested. Converting my Robbe Concorde to EDF, fan mounts from balsa/ply and the main visible structure/panels from Depron Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted October 22, 2021 Share Posted October 22, 2021 10 minutes ago, Frank Day said: Many thanks guys, the sheets I have are EPP, I was told they are Depron but I had my doubts. I'll try a couple of the outlets suggested. Converting my Robbe Concorde to EDF, fan mounts from balsa/ply and the main visible structure/panels from Depron EPP is still useful Slightly heavier, but for example, indoor models are more likely to survive as EPP is more resilient/ bouncy Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted October 22, 2021 Share Posted October 22, 2021 Thanks... Quote Link to comment Share on other sites More sharing options...
Allan Bennett Posted October 22, 2021 Share Posted October 22, 2021 I've been building a model for a few months now, using a combination of 'depron' I bought about 15 years ago and some bought by a club member more recently. Part way through the build I realised that one of them is slightly rubbery while the other (the older one, I think, though I'm not 100% sure) is harder and crystalline. The harder one is easier to sand down to shape without tearing. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted October 22, 2021 Share Posted October 22, 2021 That sounds right. I think of Depron as a balsa substitute, and it will break. But it’s light, consistent and strong for its weight. The EPP will tear, tough, but not a fan. Bit like a crashed foamy, how far to trust? Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted October 22, 2021 Share Posted October 22, 2021 (edited) In fact the original Depron (it is a trade name) is no longer made. It was actually extruded expanded polystyrene. Not only was the sheet surface smooth and flat but it also had a top and bottom denser 'skin' which gave it properties not unlike softer balsa but at 1/4 the weight. Originally intended as insulation for the construction industry it proved uneconomical to produce despite its popularity in the modelling world. The original Depron was white in big 1200x800mm sheets either 3 or 6 mm thick. Later grey was added but it was not as stiff and finally 2mm thick in white. The current expanded foam sheet (it is also made by Depron) eliminated the process that created the denser skin so as a result it is a bit lighter but considerably more flexible. Being polystyrene it is very sensitive to the solvents in glues and paints so requires true 'foam safe' versions. Edited October 22, 2021 by Simon Chaddock 2 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.