ASK OUR EXPERTS

As most folks are well aware, an attempt to achieve a more self-reliant lifestyle often involves a good bit of problem solving . . . and much of the time, there just doesn't seem to be a ready supply of answers to the questions that come up. We're pleased to present, then, the following column . . . in which a number of well known individuals from various areas of expertise (such as gardening, alternative building methods, hydroponics, water toxicity, and wood heating, to name a few) have agreed to act as "consultants'.' for you.

If a question concerning some aspect of self reliant living has you stumped, send it to Ask Our Experts, THE MOTHER EARTH NEWS, 105 Stony Mountain Road, Hendersonville, North Carolina 28791. Please don't expect personal replies, though. The most frequently asked questions will be answered here and here only-so that we can all benefit from what these folks have to say.

I have a Lakewood stove and, after reading your article on draft controls (issue 77, page 40), I installed a Field barometric draft control on the stovepipe, positioning it 12 inches above the stove.

Before the draft regulator was added, my chimney required cleaning once a week, but I can now run the stove for at least a month with no appreciable buildup in the pipe. However, just recently a layer of creosote has accumulated on the back of the control, causing the regulator to be unbalanced and making it stay open. (The control was factory-set.)

How can I get the creosote off the control and avoid this problem in the future? Can I mount the draft regulator below the stove outlet in order to prevent the buildup, and still have the regulator work?

Creosote buildup on the interior surfaces of a barometric draft control is a common occurrence. And you are correct that the weight of the accumulation on the hinged flap can effectively change the draft setting of the device. In addition, creosote deposits can cause the flap to stick in the closed position. Neither of these conditions is particularly hazardous, but they can decrease-or eliminate-the effectiveness of the draft control.

Cleaning is possible. Most barometric draft controls can be disassembled. Some of the creosote can be brushed or scraped off, but in most cases, a solvent (such as Cleans Up) will be helpful for removing sticky deposits. Your suggestion of installing the device below the stove outlet of your rear exit stove is a good one. I have not tried it myself, but I think it will work to eliminate most of the creosote buildup, without diminishing the original draft-controlling and creosote-reducing functions of the device. (The reason creosote accumulates in the barometric draft control, while the control reduces creosote buildup further up the chimney, is primarily the result of inadequate mixing of the air and smoke in the control itself. Because of the flow patterns inside the device, pure, undiluted smoke is in contact with much of the interior surface.) Jay Shelton.

Jay Shelton is the director of Shelton Energy Research and the author of three books and many articles heating For a description of the publications available from SER, send a self-addressed, stamped envelope to Shelton Energy Research, Dept. TMEN, P. O. Box 5235, Santa Fe, New Mexico 87502.

Our family is planning to build a two story cordwood house in the Northeast, and we're considering adding insulation to the air spaces between the log-and-mortar walls (as mentioned in the article "The Thermal Efficiency of Cordwood Walls" in MOTHER NO. 79) and to the mortar mix itself. Is this a common practice? Also, what proportion of insulation (and what sort of material) should be added to the mortar?

Sawdust is probably the most costefective insulating material available. When used to fill the space within the wall, it should be buffered with hydrated lime (three shovelfuls of lime to a wheel barrowful of sawdust). Lime acts as a preservative, an insecticide, and a dehydrator.

Any sawdust added to the basic 2-112 to 1 mortar mix (the ratio of aggregate to cementing material) will lower the compression strength of the wall. However, I feel you can safely add 50% of the total volume in sawdust.

Using shovelfuls for measures, the following recipe will make an average mixer load: 1 part portland cement, 3 parts hydrated lime, 10 parts sandy gravel, and 7 parts sawdust. Although adding insulation to the lime mortar mix will have only a minimal effect on the R-value of the wall, the added sawdust will have two other important effects. First, by retaining moisture within the mixture, the tiny wood particles help the matrix cure more slowly, resulting in a stronger wall. Second, they build up the basic batch, thus allowing the mix to go a little further . . . which is a significant consideration in these times of tight money. Jack Henstridge.

Jack Henstridge, the author of several books on stack wood construction, is the director of the Indigenous Material Housing Institute. For information about the institute, write to IMHI, Dept. TMEN, RR 1, Oromocto, New Brunswick, Canada E2L' 2G2.

I recently bought a 6-1/2-acre parcel of land that has a pond on it. However, my new water hole has a leak at the base of the dam, which causes the water to seep out at the bottom on the back side of the barrier. I want to stock the pond, but can't do so because of the fluctuating water level. Is there anything I can do to seal this leak, short of draining the pond and reworking the whole dam with a bulldozer?

Leaky ponds are like most ailments, in that preventing the problem is a lot less expensive, and easier, than curing it. There are three types of remedies, however. The surest-but most expensive and time consuming-method is to drain the pond and repair the dam. This Could involve complete reconstruction remarking the case (a good dam should have a central core of impervious soil extending from the waterline to below the bottom of the pond), or simply compacting the existing structure with a seeps-foot roller. Less costly, but still requir ing pond drainage, is the application of dispersants or a clay blanket to the dry pond bottom. (Dispersants are chemicals that break down the bottom soil into tiny particles that will plug any seepage points when the pond is refilled. The most common one is plain old sodium chloride.) Finally, the simplest but least certain way to seal a leaky pond and perhaps the method you're after-is to add bentonite clay to the water.

Bentonite is technically described as a "hydrous silicate of sodium composed chiefly of montmorillonite". It's the montmorillonite that counts, as this type of clay has the ability to absorb several times its own weight in water, swelling to as much as 20 times its original volume! Consult an agricultural supply store for your closest source of the material. The clay isn't expensive, but you may need a lot of it, and freight costs can be prohibitive if it isn't available nearby.

The generally recommended dosage of bentonite is about one pound per square foot of pond surface, but as much as twice that amount should be used on very porous soil or in extremely deep ponds. The best way to apply the clay without draining the pond is to mix it with water to form a slurry, which is then spread over the pond surface from a boat. Because of the weight of the material and the labor involved, though, bentonite is commonly spread directly on the water in granular (not powdered) form. In any case, the grains will sink, and the force of the escaping water will draw the expanding material into the leaks, sealing them.

If you are certain that the only leak is near the dam, you can use a smaller amount of bentonite and do a spot application. (Note, however, that though you see water escaping only at the base of the dam, it's still possible that the entire bottom layer is leaking and flowing toward the dam.) Small, well-localized seepage points can also be sealed with cinders passed through a 1 " screen.

There are two other possiblities that should be mentioned. Since you state that the problem area is "at the base of the dam", I can't rule out the likelihood that the pond is actually leaking along the drainpipe . . . a common occurrence. In this instance, the only real solution is to drain the pond and reinstall the drainpipe, making sure to compact the soil well and put in an antiseep collar. It may also be that, if your pond is relatively new, it simply hasn't had enough time to seal itself naturally. Heavy stocking and fertilization will hasten this process.

Obviously, this is very general advice that may need to be adjusted for local soil conditions. For more specific information, contact your local soil conservation service office.-Bill McLarney.

Bill Mcl.arne3; Ph. D. is a founder of the New Academy Institute and its sister organization, N4;S4, a. Costa Rica.S the author 3j three books on aquaculture and numerous technical papers and articles about fisheries and aquatic biology. He currently divides his time between directly NAISA, consulting, and free-lance