Here in my country (Europe) the only available foam for me is Dow blue extruded Styrofoam.
I am afraid about delaminating +++++++++++++++++++++++++++ Hello Alex You are getting a good response to your question. Some of the information will conflict as each person gives you what they believe is best. I suspect that you may be more confused after this then you were before. I have been using these products for 20 years (30 years for Styroam /polystyrene) My contribution The negative side of blue foam is: a) Fuel will dissolve stryrofoam. b) Blue foam releases harmful gases when it burns. There are solutions to both of the above. Other than the above I firmly believe that blue styrofom is as good as polyU in every respect (or better) provided that you understand it and use it to its best advantage. Most KR's are built with a "single sided sandwich" using relatively thick chunks of polyU foam. Full attention is given to the outer surface and little attention is given to the inner surface. Have a look at: http://home.hiwaay.net/%7Elangford/swings.html The builder makes every effort to remove unwanted (surplus) foam from the inner surface and then provides a glass skin on the inside - thus a true sandwich construction. This builder uses PolyU (no problem in the USA) but you can do the same with your blue foam and achieve the same results with a THINNER core material if necessary. I suspect that Mark L is using material of about 1kg per cubic foot, but you can use blue foam of double that weight (4lb /cub ft) but cut it to half as thick - and still be smiling. You can also cut your foam with a hot wire (I regularly do) provided that you take every precaution NOT TO BREATH THE SMOKE. There is a particularly good KR web site where the builder used hotwired blue foam wing sections (with weight reducing cut-outs) for the wings. I tried to find this reference for your benefit, but I cannot remember where I saw it - maybe one of the netters will know and tell us. In the meantime - have a look at http://www.whisperaircraft.com/ website. I think I am correct in saying that all of the work was done with Styrofoam. Dene Collet (Port Elizabeth SA) is familiar with this project and may have better information. Take care and good luck Steve J Zambia Askies"at"microlink.zm -----Original Message----- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of Alexander Birca (MD/RMD) Sent: 16 June 2004 11:43 AM To: 'KRnet' Subject: KR> Foam type Dear KR-netters, After much time spent on the foam issue decided to ask for helping to all of you. It has a VERY-VERY small cell structure and I am not sure if I could use such kind of foam in wing construction since. I had seen many types of foam used by all of you (on your sites), some of you seems to use such kind, but I am not sure. There is no question about other type of foam with relative large cell (1-2mm), just fill the cell with micro and the laminate. How in case of tight cell, the epoxy is not absorbed at all by my foam, so the laminate Is just glued on. But on the specimens I had done it is very easy to tear off the laminated fiberglass. May be I am not right, may be in a large an closed structure as wind is every thing will be OK? The question is, may I send to some one of you (who will accept) some specimens of my foam just for appreciation, is it the same type as you have there in USA or not. Or may be some one understand me right what type of foam I am referring to and will explain me a little bit more about. With best regards, Alex Birca, Moldova _______________________________________ to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
