There are still mysterious and unexplanable things going on with your bagging efforts. I'll just give you some more observations from my bagging experience and I won't try to reconcile it with your experiences.
Back in the dark ages, around 1994 when I learned how to do vac bagging, I was taught to use Dow grey foam and I wasn't taught to use a regulator on my vacuum pump. Grey foam is about as "punky" (my word) as extruded foam gets, about the same as Foamular 150, actually. My vacuum pump in those days (and today too) could pull about 26" ( one atmosphere =about 30" for any eurodudes reading this). I figure I must have made a few hundred wings for Frank Weston, all from grey foam and all subjected to the full fury of my unregulated continuous duty vacuum pump. Today I still use a continuous duty vacuum pump without a regulator. I do use a bleed valve, however, when I use any foam lighter than Foamular 600/Hi Load 60/ spyder foam. I crack open the bleed valve until I get about 22" on my vacuum gauge. To this day I still don't bag anything with less than 22" of vacuum. It is my experience that lots of things turn out better with lots of vacuum and not much that's bad happens with lots of vacuum. The foam I use today is exclusively Foamular 250 and Foamular 600. I agree that it makes no sense to use Foamular 150 or the equivalent blue foam (Dow score board) if Foamular 250 or Dow square edge are available. There is almost no difference in weight but a noticeable difference in strength. In all of my high-vacuum bagging experience I have never seen a "foam worm". So for me, the mystery remains. My main purpose for this post is to avoid the beginning or propagation of a mythology about the hazards of high vacuum in the vac bagging of foam core wings. Phil RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
