[EMAIL PROTECTED] wrote: > > In a message dated 2/7/00 12:58:35 AM Eastern Standard Time, > [EMAIL PROTECTED] writes: > > << I can usually get rid of this when the covering is put on, but it really > bugs > me. What is the cause? What is the solution? I've always had a problem > with this and never seen an answer. >> > > Seems to be worse with pink foam for me. I believe (read can't prove it) > that it has to do with the moisture content of the foam. Remember the > "extruded" variety is different than the "expanded" variety. The bowing is > more of a pain to my psyche than anything else as it is countered "usually" > by a weight placed here and there. > > I have cores that were cut sometime ago (read months/years) that curled/bowed > when cut but are now straight and true. The only difference is in the > storage of the foam (damp garage vs dry shop and temperature variations). > > Someone on the list with a better chemical understanding of the cell > structure of foam could either prove or disprove this theory. > > +Stan Lewis > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and >"unsubscribe" requests to [EMAIL PROTECTED] From what I've been told the bowing/warping of the foam as it is cut comes from the stresses that are built into the surfaces of the foam as it is extruded. As it is cut these stresses are relieved by cutting the top,or bottom surface and the cores and beds bow. Somtimes in opposite directions. This shouldn't be a problem if you are bagging wood or glass over the core and put weight on it and set them back in the beds to keep them flat/straight during the process. RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
