rhonda, Sounds like you got fun times ahead experimenting. I mentioned perlite mainly because you seemed to want white and I think it's less dense and therefore lighter weight than vermiculite. However, I do like the way vermiculite affects the working texture of the mix and the gold fleck effect on the finished pieces. Perlite is a little more difficult to polish and a lot harder to carve. I use both with sand or peat (sand for solidity, peat for porosity and hopefully quicker mossy growth) in varying proportions (usually 1 part sand to 2 parts vermiculite-perlite mix). You're just not going to know ahead of time what's going to suit you best. Vibrating the drier mix does seem to have a densifying effect (even while it liquifies and looses its shape) and I think it eliminates any dry spots. There is certainly an effect - I'm just uncertain whether it's for better or worse. I think I'll try it both only in the mixing bowl & thumb-tamped into the mold and then for a longer time in the mold, just to see.

Just wanted to report back that I picked another gallon of cherries to add to my 5 quarts of too-thick pie filling. I reprocessed in two batches. The first time, I wasn't thinking and left the cherries in the syrup while returning everything to a boil. Those started to fall apart. The second time, I strained the cherries out and reheated just the saucy part. (I boiled the new cherries for one minute, and reheated the previously canned ones in the microwave so they would be hot when I added them back to the sauce.) The second batch looks better than the first, but I now have six quarts and three pints of pie filling with good seals that ring a nice clear note when tapped. I thought the filling looked pretty thin, but I would rather have the seals than the thickness. I might make a test pie and determine whether my dad should add some thickener before baking. I'll give him the better-looking jars, maybe saving enough of the pretty filling to make the Thanksgiving cherry pie for the relatives. Thanks so much for all the help Carol, I really appreciate the dialog and advice! I ended up keeping the jars in the fridge for two weeks before reprocessing, but the jars were sealed enough that I had to pry them open, so I felt ok about it. Thanks! Melissa

You'd have to pull the top cover to see what I am talking about, but you don't have to pull the cover to install an air vent. The reason I say about the air vent is because I recently installed an auxillary boiler in my garage and its air vent was at the ceiling, the highest point in the house. Everyday I would hear the air going through the pipes, yet the air vent never bled it out. I finally realized that is was the air in the dome of the boiler and I bled alot of it out through the pressure relief valve that day. Everyday I crack the valve and a tiny bit of air still comes out, but the system is now whisper quiet. As long as you have circulation, your air scoop and air vent will bleed out the air. And any that is trapped in the dome of the boiler can be handled as I explained above.

Hi, I know it's been 8 months since you folks were discussing this, but hopefully one of you who seems to know these systems and their components will happen to see this follow-up --- your discussion was the best I've seen, and I'm hoping one of you can offer some ideas about my gurgling system. I've bled all three loops in my system, both by doing what one plumber who worked on the system a few years ago called a "power purge" (hook up a garden hose to the drain valve for each loop and let water flow at full volume through the loop until the water flows smoothly, i.e. no more sputters) as well as using the bleeder valves in each loop. When I use the bleeders, no air sputters out, making me think I have all the air out of the loops. But when the pump first kicks on in the morning, you'd think we were in a sub filling our dive chambers. The sound of water flowing in the pipes sounds like the system is empty and being charged. The system did not have this problem last winter, but I drained it recently because I moved one of the baseboard radiators. Having read all the earlier comments in this thread, I have an idea I'd like to run past people, but of course, I'm open to anything else anyone has to offer. As it is, my Extrol is installed at the end of a dead end extension, contrary to the installation guidelines printed on the label. The reason I initially doubted that that's the problem is that the Extrol was that way last winter and the system was fine. However, the one possibility I'm wondering about is whether, when I drained the system a few weeks ago, too much air got up in the pipe that leads up to the Extrol, causing something like this to happen: after the system has been on a while, the air compresses up in the pipe that leads to the Extrol, and the system quiets down, but when the system is off for a while and the pressure in the system drops (because the boiler's not firing, i.e. overnight when we turn down the heat), the air de-compresses and pushes back down into the feed to the loops, thus causing a significant amount of gurgling when the pump first starts to push water through the loops; once the air has circulated back around to the tee that leads to the Extrol, the air is eventually all captured back up in the Extrol (and the pipe leading to it) and stays compressed there until the system pressure drops low enough to allow it back out of the pipe into the circulation feed. Sounds completely whacked, I know, but I'm at a loss for how the bleeders can stream completely air-free water, i.e. no sputters whatsoever, but every morning, it sounds like there are huge air pockets in the pipes getting pushed room by room through the loop --- and then it stops. Any thoughts or suggestions? Thanks, Mark