If you asked 10 people here I’ll bet most of them would tell you to reconsider the use of accordion bottles. I could be wrong. It might make a good poll. I tried one one time, but now fall into the forget it camp.
Air infiltration through plastic (or any barrier) is linearly proportional to the difference in pressure between the two sides of the barrier. Therefore, the best thing you can do is to fill a bottle to the brim and make sure it isn't capped under negative pressure. The accordion bottles I've looked at cause a significant negative pressure and the flexible plastic joints would eventually weaken and become suspect. Furthermore, the plastic they are made of isn't that great when it comes to being a good air infiltration barrier. PET plastic is much better. The PET material used in soda bottles is so flexible that squeezing out a little air probably doesn't result in much negative pressure. That, and the fact that they are made of PET, is undoubtedly the reason most people go that route. Soda bottle caps, however, aren't made out of PET and because of this some people use a layer of Saran Wrap under the cap. As a plastic, Saran is one of the best as far as air infiltration is concerned; right up there, or better than, PET.
One thing people need to be careful of when reusing bottles is to pay particular attention to the bottle cap lining. Linings are designed based on the class of chemical to be stored in the bottle (i.e. different strokes for different folks). Most general purpose photographic bottles use some sort of high density plastic that is acceptable (but not necessarily optimal) for any application. When reusing a non-photographic bottle, make sure the lining of the cap is compatible with what you are using it for.
Last edited by Denis K; 10-28-2009 at 01:03 PM. Click to view previous post history.