Replies

1. 
   David_Thomas | Feb 07, 2001 09:35pm | #1

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   The relatively stiff stuff is what everyone uses because it is a buck or two per stick. The important points when using it are to make careful 45 miters at the joints and seal it up with tape if you had to split the perforated seam. Electrical tape is okay (cut with scissors or knife, not pulled apart by hand) but 10 or 20-mil pipe wrap (2" wide, really sticky, black plastic tape, lasts a long time) is better. Put as many lengths on the pipe run as you can before soldering. By not splitting them, it will be a more substantial installation. A "mini hacksaw" that takes a 5 or 6" blade in a triangular chromed frame (about $5) is ideal for cutting to length and cutting miters. Fits in your back pocket, has fine teeth and doesn't snag/cut your clothes or hands like some small saws.

   The better stuff is a softer, thicker material (sorry, I'm not recalling the polymer type just now). It is less like the polystryene foam trays Safeway sells meat on and more like ensolite backpacking sleeping pads. But it is hard to find and $4-6 per stick. But you can slide it around one or two 90's and overpack it on a pipe run and hold it in place with vise grips as you sweat the next few joints. Then pull it around the joints to full length and you can do the whole run without having to split any lengths of insulation and all the butt joints will be tight. And there will be no seams at joints either.

   If I'm getting kind of anal about this it is because 1) you asked, and 2) I installed about 80 domestic-hot-water solar systems back in the 1980's and spent a lot of time crawling through attics and closets insulating the pipe runs.

   I'm impressed that you'll have recalculating lines - I've had trouble find a good hydraulically powered slide rule - all of mine are manual. :-) Beware Breaktime's spellcheck! Do you really mean 3/8" recirculating lines and not 1/2" or 3/4"? 3/8 is small for even one fixture. Unless the 3/8" run is just the return run - then it's cool. 1/2" ID insulation (for 3/8" copper) will be harder to find than normal 5/8 and 7/8" ID for 1/2" copper and 3/4" copper / 1/2" galvinized, respectively. -David

1. 
   Dave_Richeson | Feb 10, 2001 04:21am | #2

   *Armorflex is the stuff, David. Any good plumbing supply or HVAC supply should have everything from 1/2 inch to 3 inch in stock 5 foot lengths. They will have the wrapping tape also. Good stuff.

2. 
   Gert | Feb 10, 2001 04:21am | #3

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   I've been looking for info on insulating interior hot water supply pipes.
   I want to insulate all the hot water supply lines to my new second floor as
   well as the 3/8" recalculating lines. I would like to know what the most
   highly recommended pipe insulation materials are.