# Will 1.2 mm thick plastic shrink with a heat gun?

**URL:** <https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230>\
**Category:** Factual Questions\
**Created:** [September 22, 2015, 7:17pm UTC](https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230 "2015-09-22T19:17:15Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![CT\_Damsel](https://avatars.discourse-cdn.com/v4/letter/c/dfb087/32.png) [@CT\_Damsel](https://boards.straightdope.com/u/CT_Damsel)\
**Post date:** [September 22, 2015, 7:17pm UTC](https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230/1 "2015-09-22T19:17:15Z")

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My house is old and the windows are 3’x5.5’ inside. Previous years I have covered them inside with window insulation kits. This year I can not find any that are large enough.\*

I found 4 packs of outdoor storm window kits [on Amazon](http://www.amazon.com/gp/product/B000CSK6FY?psc=1&redirect=true&ref_=ox_sc_act_title_7&smid=A3KGL656G0ULE2) that note they need nails and framing strips when installed on the exterior.

Does anyone here know if that thickness of plastic would shrink the same way indoor kits do?

Thank you for reading

\*one patio door kit will cover two windows; but is much more expensive than two separate 3x5 window kits.

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**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\
**Post date:** [September 22, 2015, 7:42pm UTC](https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230/2 "2015-09-22T19:42:33Z")

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Shrink plastic is typically measured in mils (thousands/inch), not mm. 1+ mm plastic is likely to just warp or sag when heat is applied.

I had a rental with old, leaky sliding windows, and I simply made a small wooden frame to fit inside each wall frame, then stapled clear plastic across it. I got 3-4 winters out of most of them, occasionally having to replace one or another. “Clear” painter’s film and dropcloths will work. You don’t really need special window film unless you want window-like transparency, and most of mine were for bedrooms anyway…

WOW jeebers, did they make a difference, though, even in a fairly mild climate.

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**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\
**Post date:** [September 22, 2015, 8:33pm UTC](https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230/3 "2015-09-22T20:33:03Z")

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What he said ^.

If it’s shrink-type plastic, that will be clearly denoted. If it’s not shrink-type plastic, it won’t shrink – it will melt. Not gonna work.

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**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\
**Post date:** [September 23, 2015, 1:10am UTC](https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230/4 "2015-09-23T01:10:54Z")

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Depends. If they made the plastic by stretching it, then heating it will almost certainly make it shrink. Though, if they didn’t intend it for this purpose, it won’t necessarily work as neatly as the stuff intended for that.

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**Author:** ![CT\_Damsel](https://avatars.discourse-cdn.com/v4/letter/c/dfb087/32.png) [@CT\_Damsel](https://boards.straightdope.com/u/CT_Damsel)\
**Post date:** [October 2, 2015, 6:37pm UTC](https://boards.straightdope.com/t/will-1-2-mm-thick-plastic-shrink-with-a-heat-gun/732230/5 "2015-10-02T18:37:36Z")

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Thank you everyone. I finally found the “shrinkable” in a size long enough for the windows without too much waste on the width.