Will 400mm Shrink Fit?

[rg12]

I have a 26cm wide, 7cm tall pack.
A 400mm shrink (flat) which has a 255mm diameter fit my purpose if it shrinks usually to half?

 

[eee291]

Why wouldn't it?

If you do some simple math the circumference of the battery is 66cm and the heat-shrink is 80cm.
Should work just fine.

 

[rg12]

Why wouldn't it?

If you do some simple math the circumference of the battery is 66cm and the heat-shrink is 80cm.
Should work just fine.

I know it fits in it but the shrinking ratio (considering it's shrinking to half)...
Sometimes it's thicker/sometimes thinner depending on how much it has to shrink.
So maybe the question is what is the rule of thumb to get the best result in order to not have it be too tight and sometimes get torn under heat etc

 

[rg12]

Why wouldn't it?

If you do some simple math the circumference of the battery is 66cm and the heat-shrink is 80cm.
Should work just fine.

I know it fits in it but the shrinking ratio (considering it's shrinking to half)...
Sometimes it's thicker/sometimes thinner depending on how much it has to shrink.
So maybe the question is what is the rule of thumb to get the best result in order to not have it be too tight and sometimes get torn under heat etc

EDIT:
btw, is there a special technic to avoid wrinkles while heatshrinking large tubings?

 

[eee291]

I've had it rip on me when I was just heating it up like an idiot. You have to go for the biggest area, away from the corners so it doesn't tear right away.
If you get some wrinkles then you wait till it cools off and try heating from the ends of the wrinkles.

The least likely way to have your tube break is to buy one that has a thicker wall and a finished shrink ratio that is just a bit smaller than your battery, but those aren't easy to find nor cheap.

400mmx0.12mm shrink tube is pretty cheap on Aliexpress, I think its worth a shot.
https://www.aliexpress.com/item/PVC-Heat-Shrink-Tubing-Wide-350-355-370-373-380-400-405mm-Diameter-Flat-Electronic-Insulation/32985968167.html?spm=2114.search0104.3.1.66a73fe4Yi0Ek6&ws_ab_test=searchweb0_0,searchweb201602_9_10065_10068_10547_319_317_10548_10696_10084_453_10083_454_10618_10304_10307_10820_10821_537_10302_536_10059_10884_10887_321_322_10103,searchweb201603_52,ppcSwitch_0&algo_expid=b0dfaa8f-6ed1-4d89-a536-531552e1032d-0&algo_pvid=b0dfaa8f-6ed1-4d89-a536-531552e1032d

 

[rg12]

I've had it rip on me when I was just heating it up like an idiot. You have to go for the biggest area, away from the corners so it doesn't tear right away.
If you get some wrinkles then you wait till it cools off and try heating from the ends of the wrinkles.

The least likely way to have your tube break is to buy one that has a thicker wall and a finished shrink ratio that is just a bit smaller than your battery, but those aren't easy to find nor cheap.

400mmx0.12mm shrink tube is pretty cheap on Aliexpress, I think its worth a shot.
https://www.aliexpress.com/item/PVC-Heat-Shrink-Tubing-Wide-350-355-370-373-380-400-405mm-Diameter-Flat-Electronic-Insulation/32985968167.html?spm=2114.search0104.3.1.66a73fe4Yi0Ek6&ws_ab_test=searchweb0_0,searchweb201602_9_10065_10068_10547_319_317_10548_10696_10084_453_10083_454_10618_10304_10307_10820_10821_537_10302_536_10059_10884_10887_321_322_10103,searchweb201603_52,ppcSwitch_0&algo_expid=b0dfaa8f-6ed1-4d89-a536-531552e1032d-0&algo_pvid=b0dfaa8f-6ed1-4d89-a536-531552e1032d

Yeah when it's too big I get the wrinkles but I can't hold 20 different measurements right now for each custom pack...
About wrinkles, when ever I try to heat it and pull a bit it tares