<<As you know from my video, I place the cores in the mylars, then the mylars go inside a release film/breather envelope, this then goes in the bag. The beds are outside the bag. I can't tell for sure from your post, but it sounds as if you might be putting the beds inside the bag or perhaps are not using the top bed at all. If you are not using the top bed and are placing weights directly on top of the vac bag, this could cause dents to appear in the wing. Many years ago I tried putting bricks directly on top of the vac bag without using the top foam bed. The weight of the brick and the uneven surface of the brick caused dents in the top of the wings.>> Hmm, need to look at the breather and bed locations. I've been putting the core in the mylars, putting that sandwich in the lower bed, covering with the upper breather, then placing this stack on the lower breather in the bag. So the bag contacts breather on both sides but the lower core separates the lower mylar from the breather. The lower breather extends to the vac inlet. The upper bed is used outside the bag and then a very modest weight is placed on top of that(3/8" plywood scrap which - just a tad longer than the spanwise dimension of the bed). The weight is just to keep the cores flat. Since the defects appear mostly on the upper surface, I've assumed the lower breather was working OK. Maybe that's not a good assumption. Epoxy is well mixed so I don't think that's the problem. <<Too much vacuum on softer foams can cause the entire core to get compressed a few thousandths of an inch. It can also cause tips or leading edges to get crushed in odd ways when the mylar extends past the foam and cannot conform readily to the curves.>> I'm not running full vac - maybe about about 20in. The LE and TE are coming out fine, even with a bit of overhang from the mylar. Sounds like pressure is not likely the problem. Appreciate the comments. We'll go back and do it EXACTLY as in the video and work from there. Maybe it's trapped air that somehow diffuses to the upper mylar and gets stuck?? - Dave R 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.
