<div dir="ltr">Dirk,<br><div class="gmail_extra">"Ähnliches löst sich in Ähnlichem" in English is "like dissolves like." Its good to know the German phrase. <br><br></div><div class="gmail_extra">Thank you for your detailed speculation on the problems with parafilm. I think we all agree that the Teflon liners generally work best, when they are available. <br>
<br>Your comments remind me again how much the materials used to make metal and plastic lids vary from one country or region to another. I have also encountered these differences working with collections in Latin America. The basic lesson is that the best solution to a problem for one collection is not always the best solution for another collection. It each case, it is important to understand the locally available materials, to know exactly how the lids fit (or do not fit!) on the jars, and to devise good strategies based on the materials you have to work with.<br>
</div><div class="gmail_extra"><div><br></div><div>Silicon is another good example of a material that varies widely in its composition. I try to avoid silicon greases for the reasons you have explained. <br><br>In the US we can buy some silicon-based caulking compounds designed for use around sinks or for outdoor application that work reasonably well to seal jars. I have attached an MSDS for one such product (Spectrem) that I have used to re-seal old battery jars. Can you get similar products in Germany? There is, of course, one serious caution--as Dries van Dam has frequently pointed out, silicon is not as resistant
to oxygen and water vapor permeance as some other materials, but for many applications it is easier to work with and replace.<br></div><div><br></div>
--John<br></div><div class="gmail_extra"><br></div></div>