Why do calabash pipes need rest?

I have zero firsthand experience, but my reading suggests that a gourd might be preferable to mahogany because A) it doesn't impart flavor and B) can be cleaned.
As for the rest period, I suspect that it has more to do with the interplay between the three materials (meer bowl, gourd/mahogany, cork fastener) than any single element in the pipe. You're dealing with three different heat-expansion rates, three different moisture absorbency rates, three different drying rates, three different responses to any cleaning effort...you get the idea. So it could be that most are just playing it safe.
On the other hand, I see users on this forum in past threads suggesting that once it's cooled and the bowl is wiped, it's ready to go.

It is my understanding that a gourd calabash does not need to rest.

My source is The Book of Pipes & Tobacco by Carl Ehwa Jr.

I'll dust it off and look it up before my next post in this thread.

Did you see the IMP meerschaum sale on SPC? Anyway, gourds need periodic rest like any meerschaum, though not as frequently as briar. The gourd should be flushed with high proof drinking alcohol weekly if smoked heavily and allowed to dry, but no extended rest period is required. An ocassional application of lanolin to the cork seal will keep the seal nice and conditioned, and after prolonged use, the bottom of the meerschaum bowl will become soft. Fix this by removing the bowl, invert it on a flat surface, and ignite it with a match or lighter. When the flame goes out, allow it to cool, and place it back into the gourd.

Very welcome. It does indeed sound like you will be getting a meer tamper.

Gourd Calabash pipes do not need to rest if they have a meerschaum bowl. I get a perfectly dry smoke every time, even after 2 bowls in a row.

I had a calabash and smoked it constantly, cleaning occasionally out of a sense of duty, not because the pipe didn't perform optimally.

I checked the Ehwa book (above), and chasingembers nailed it on all the important points. Ehwa suggests that the gourd 'bash is a good deal if you can't afford a large rotation of briars, because you can push it a lot harder -- like several times a day. They do, however, need rest and periodic cleaning.

Sounds very intriguing, now I'm more interested in the gourd calabash.

Fix this by removing the bowl, invert it on a flat surface, and ignite it with a match or lighter. When the flame goes out, allow it to cool, and place it back into the gourd.

Click to expand...

One very ignorant question for the above treatment (I don't own any meerschaum pipe): a meerschaum bowl can be ignite with flame? Say... even without adding Rum to it? And when people ignite it, or put it on fire, do they do it from the top (inverted) or below (Like a candle light shield)?

My experience is with northern and brass. I have 3 and smoke them as I wish. The reason they are gourd is it makes the large smoke chamber light in weight. The purpose of this large chamber is to cool the smoke. Personally I would not be interested in one made of anything but gourd. The ones made of wood were originally made to supplement a gourd market that had become expensive due to supply and demand. Some are know being made of better briar, but I do not see them as practical. To each his own If I am going to buy briar I prefer so many other shapes.

The meerschaum cup is occasionally removed and inverted to properly burn off

the resins and tar that collect beneath the bottom orifice of the cup.

Do not try to hold the cup upright and burn off the crud with a match or lighter.

If you do, the bottom of the cup will be permanently soiled with soot. Harmless, but ugly.

To the original poster, when you do finally pull the trigger on a calabash you can do far better than mahogany on a $200 budget, in particular the 70-90s era Pioneers you see constantly on eBay (with the plastic "top hat" shaped shank extension and vulcanite stem with the little flare towards where it meets the extension). These are quite well made and a fine smoke, with a real pressed meer bowl (virtually all production 'bashes, even higher end like Bauer and Strambach, are made with pressed not block). The exceptions are the carved or decorated gourds with the very flat profile bowl insert, these bowls were made of plastic or porcelain, but they still smoke just fine. A good sized meer bowl pioneer can be had for around $100 on eBay. Many have been smoked so much they're near falling apart, it's best to let these pass and wait for one in great condition, I've even seen one or two that were totally unsmoked! Just last night I watched an excellent example go for $86.50.
http://www.ebay.com/itm/Large-Meerschaum-Bowl-Calabash-Gourd-Sherlock-Holmes-Pipe-Stem-/351393034433?pt=LH_DefaultDomain_0&hash=item51d0a830c1&nma=true&si=Waiiuw%252B9AD1jITyCBa04Cr%252BMQO8%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
If you're looking for something a step up but still sub $200, you can get a very nice Strambach from a few German sellers. I ordered a 'bash from this merchant just last month and had an excellent buying experience.
http://www.ebay.com/itm/Calabash-Pfeife-Strambach-Vienna-Big-Gros-ohne-Filter-/111580079442?pt=LH_DefaultDomain_77&hash=item19fab0e552