Does anyone else have experience insulating windows with plastic shrink film bought direct (not in the standard kits)?
In past years I bought the boxed kits of shrink film window insulation from 3M or Frost King. These seemed pricy and don't come in sizes that work well with my old windows (ca 1860). The kit that worked best came with 2 sheets 62x210" (157x533 cm) and 2-sided tape (168 ft = 51.2 m). Still, I always ran out of shrink film or tape and left some windows uncovered because I didn't want to go buy another complete kit.
This year I set out to find a source for the shrink film. Some research determined that the material is most likely PVC (crinkly like cellophane) and not polyolefin (soft like Saran Wrap) of 75 gauge thickness (0.00075 inch = 19 um). PVC shrink film is available in 'short' rolls of 500 ft (150 m) length and a range of widths. These were all 'centerfold' rolls, which means the film unfolds to twice the width on the roll.
sources found included:
"75GA PVC CENTERFOLD SHRINK FILM"
$21.44 for a roll 500 ft long x 18 in. wide (36 in. wide unfolded)
$35.66 for a roll of the same dimensions
I went with the Reynolon shrink film from Pack-n-Tape because: 1) they are an authorized 3M dealer, 2) Reynolon seems to have a reputation as a premium and dependable product, 3) a roll was available at a warehouse in a nearby state, so shipping was only $9.46, 4) I could order online.
Experience: the Reynolon shrink film worked like the material I have used from the kits. The one difference is that you have to unfold the plastic. This can be difficult as the edges are flush with each other and the 2 layers cling tightly to each other.
: What I couldn't find was a cheap source of 2-sided tape with backing paper. The best I could do was buy rolls of Frost King Shrink Window Mounting Tape (1/2 in. wide x 54 ft long = 12.7 mm x 16.5 m) at a local Meijer superstore for $3.12/roll, including tax.
Cost of materials:
: 0.32 $/m^2, or 0.30 $/m of 36-inch wide film (my windows vary in width and any extra width is just scrap, so the cost per unit length is most relevant)
: 0.20 $/m
Compare this to the cost in 2007 of $26 for the Frost King kit for 10 windows. Assuming the tape cost is the same in the kit or purchased separately, buying the film in roll form provides the same 16.72 m^2 of shrink film for $5.35 as compared to $15.76 in the kit. Clearly savings are possible when buying shrink film by the roll.
n1. These costs are accurate only if all of the material is used. For me, the flexibility that comes with having plenty of material beats the downside of some possible waste. If a film gets damaged (cats, kids, flying object...) beyond patching, I can pull out my roll and replace the film.
n2. Shrink film can be reused if taken down carefully and then applied to a smaller window. The film is stretchy, so you might even be able to pull it out to the same size. The maximum heat shrink capability is about 40% and I had only a few small wrinkles after the second use and heat shrink.
n3. Storage time? I have no idea how long the shrink film will last. I store the roll in my basement (cool, dark, dry). The roll has enough film for about 6 years of insulating windows. This means I can give some to neighbors and friends - always nice to share the goodies!