[burnttoast]

Hello all, this isn't a question about welding, but about why in freezing weather, does all the power cords to my power tools and welder get stiff. my workshop is in a unheated garage, and every winter time before I can do any work, I have to loosen up the cords. does anyone know the answer to this? Thanks

[Oscar]

Because if they didn't, things would be way too easy. Mother Nature likes making things difficult for us mortals.

[tweake]

i can't recall off the top of my head, but its basally a characteristic of many plastics. the usually put plasticizes in it to make it flexible. so exactly what type of plastic used makes a difference at cold temps.
at very cold temps you can have real big problems especially if its under pressure. soft compressed air lines can go brittle and snap.

downunder we have another issue, UV. our UV is substantially higher and many plastics will get "eaten" if left out in the sun.

[noddybrian]

Mostly an issue with cheap PVC insulated cables - over here at least there are better more flexible versions in plastic often sold as " arctic " cable but rubber is by far the best - many quality power tools still come with a good length of rubber cable on where the cheapo stuff has like 4foot of nasty Chinese plastic ! it largely comes down to price though most materials suffer being less flexible when cold - it's just a matter of how much.

[ljdm1956]

Hello all, this isn't a question about welding, but about why in freezing weather, does all the power cords to my power tools and welder get stiff. my workshop is in a unheated garage, and every winter time before I can do any work, I have to loosen up the cords. does anyone know the answer to this? Thanks

Dunno, whatever formula they use for the insulation on the cords must be the same in our bodies, cause in cold weather my body sure does seem to stiffen up!

[snoeproe]

I have some orange coloured cables that are outstanding in cold weather. They stay soft all the time at almost any temp.

[Arno]

I have some orange coloured cables that are outstanding in cold weather. They stay soft all the time at almost any temp.

Quite likely this cable uses a silicone based insulator. It doesn't get as hard under cold condtions as rubber or PVC insulation does. (and like PTFE it's pretty much impervious to most solvents, UV, etc.)

The reason most regular plastics (like PVC) go hard/brittle under low temperatures is that their pliability and flexibility comes from long molecule strands that slide along each other helped along by smaller molecules from additional plasticizers. At low temps these long molecules don't want to move along so much anymore and start to clump together so the material gets progressively stiffer and stiffer as temperatures drop.

Below a certain temperature (usually called the 'glass transition' temperature) such plastics become fully hard and will break/shatter when bent or hit (search youtube for some liquid nitrogen videos..). Once they warm up the material becomes pliable again, but of course any breaks will remain... (natural rubber actually keeps it's pliability longer than most man-made ones but it's downfall is usually lack of resistance to UV and solvents)

Silicone materials work with much smaller molecules that are much more loosely bound, so even at low temperatures (and fairly high too) it remains pliable. It also doesn't have plasticizers which can pose a health risk in themselves.

However, it can be softer and more susceptible to cuts and abrasions so often a woven glass fibre is used in exposed wiring insulation to provide an abrasive barrier, or silicone is mixed in with rubber and other plastics to lower the glass transition temperature and provide a wider temperature operating range for various plastics. (eg. winter/snow tyres are made with a mix of rubber and silicone compounds)

Bye, Arno.