The single most viewed page on Talking Tobacco is my article “Pipe Filters Explained”. When I wrote that, I didn’t really pay attention to an interesting subject – When is a filter not a filter?
In my previous article, I addressed the kinds of filters that are meant to be used in a specific kind of pipe. 9 mm filters are designed to go into pipes made specifically for their use, as are 6 mm filters. Brigham’s Rock Maple filters will only fit their pipes, and although the Savinelli balsa filters can be adapted to work in any 6 or 9 mm filtered pipe, they’re designed to be used in a Savinelli.
But what about filters for unfiltered pipes? Do such things even exist? The answer depends upon what your definition of a filter is.
If your interpretation of a filter involves removing a significant amount of particulates from the smoke, then the short answer to the question is “no”. But if controlling moisture while removing a small amount of particulates, or keeping tobacco bit from getting into the airway, then the answer becomes “yes.”
There are two products that are similar in function, but very different in the types of material used. These would be Denicool Filter Crystals and Erik Nording’s Eriksen Keystones. They way they’re used is identical. Take some of the product and put it in the bottom of the bowl and pack the tobacco directly on top. They both will absorb excess moisture, will allow the pipe to breathe a bit more freely, and will remove a small part of the particulate matter from the smoke. The big difference is in the materials. Denicool uses molded nuggets of a silica-based material which are highly absorbent. They’re uniform in size and shape and can be used more than once, if you’re so inclined. Keystones are made of very absorbent bits of reddish clay, but because the clay will become soft after taking on moisture, they’re a “one and done”.
Another item in this category is the Philtpad. This is a molded piece of chalk that’s semi-spherical in shape with crossed ridges. Drop one in the chamber and the ridges raise the Philtpad up so it won’t block the airway. This serves two of the purposes of the above two items – removing moisture and allowing good airflow, but these devices do little to remove particulates from the smoke. That said, they can be reused more than either of the other products.
The final item in this category only serves one purpose. Pipe screens fit into the bottom of the chamber. These small circles of brass screen only serve to keep small bits of tobacco from coming up into the airway. This should only be a problem with very dry tobacco or pipes that are very open, like a corn cob. Some people feel better using them, and they certainly won’t hurt the smoke, so if you like them, keep using them.