Author Options:

Challenge: A key defroster for opening bike locks in winter. Answered

Hello all.

So I live in Montreal, winter is long here. Every morning opening our bike locks is problematic. We fixed it partially with lube, but this post is not about these solutions.

I have been looking for a device that could heat the frozen core of the lock. You can see an image attached of a product not available anymore to get the idea. I guess it was not working very well...

I have zero knowledge in electronics/electricity. I thought this question could be interesting/challenging for some of you.

So ideally the gadget would be:

Small enough to be carried on the key chain or in a commute bag.

Able to be inserted in any type of locks

Built with a safe way to prevent unwanted switch on (to avoid burning bags/pockets/houses...Lol)

Able to produce enough heat to defrost the lock

Rechargeable would be best (USB best best), capacity of 5mn maybe to operate twice a day...

Reasonably quick to unfreeze the lock, so you don t freeze yourself (That s why I abandon using hot pouches around the lock, pouring hot water will fix it quickly but then it will freeze again)

As I said, I don t have the skills to even begin to find a solution, but I saw a lot of smart stuff here and I am curious to see what you guys would answer to that. My guess is that it must be very difficult, if not I can t see why a similar product is not widely commercialized. I think a lot of people would buy it.

Thanks for the reading, I hope I picked your interest. Have a good day.


The forums are retiring in 2021 and are now closed for new topics and comments.

1 year ago

I have been looking for a device that could heat the frozen core of the lock. You can see an image attached of [filezilla.ucbrowser.Rufus product not available anymore to get the idea. I guess it was not working very well...


1 year ago

you could buy some small inductance heater some are pretty cheap on ebay and some are 5 volts


1 year ago

There is alcohol in an aerosal spray for this. It works as antifreeze.

People also sometimes warm a key with a butane lighter.

Jack A Lopez
Jack A Lopez

Reply 1 year ago

I assume you have to be of legal drinking age; i.e. show some ID, to get some of this aerosol spray liquor.

I have tried aerosol spray cheese, and whipped cream, but not aerosol booze.

Maybe they don't sell this in my town.

Who knew the stuff would be good for de-icing locks too?

Jack A Lopez
Jack A Lopez

1 year ago

The word is, "pique." It is a verb, meaning to excite or arouse, like for example, "to pique one's interest in a topic."


The word "pick", as a verb, usually means to select or choose, or sometimes it means to scrape at, to try to pull something loose. Maybe you have heard the old proverb? About how, "you can pick your friends, and you can pick your nose, but you can't pick your friend's nose."

Or at least you shouldn't, because your friend will find this to be annoying in the extreme.

People tell me that, about correcting other people's grammar or spelling.

Regarding your lock heating gizmo, the picture you picked, to attach to this post, does not do this gizmo justice, or explain just how it delivers heat the inside of a lock cylinder.

So I asked DuckDuckGo to show me pictures of, "defrost key",


and now I see the way it puts the heat on those lock pins, is by way of this uh, thing, that extends, and looks like it is made to be inserted into the lock cylinder.

So really, you were showing us the modest picture of this thing. Because there are other pictures out there, that show it more explicitly, with its thing extended, and even cartoonishly glowing red hot.

I will attach a picture of that one, to this post. The original URL for it is,

Also, that one came from an image search for, "lock de-icer"


I am not convinced that this product is, "not available anymore...," as you suggest. To me, it kind of looks like it is out there. Although I have to admit I have not actually tried to chase down any of those seller links, and I totally have not looked for this gizmo in stores, on the streets of Montreal, Canada.

Although that is no reason why you could not build something similar, if you wanted to.

Rolling your own heating electric element is easy, if you can come up with a reasonable target number for power dissipation, P; i.e. some number of watts.


From there you take the desired voltage, V, and Ohm's law, V=I*R, to get P=I^2*R = V^2/R. Then solve for R, and that is the size of the resistance you want for your heating element.


1 year ago

Your problem is not defrosting but preventing moisture inside you lock.
I come from from long and hard winters too...
Despite what companies advertise and other people might invent - prevention is still better ;)
A good quality lock can be removed and taken apart for cleaning.
Do this with methylated spirit or if none available acetone.
Once all metal parts that work the mechanism are clean anddry you lube the generously with SILICONE grease.
This stuff not just lubes but also drives out water.
Lock prepared like this survived for me not only really hard winters but also those milder days in between.
You know, warming up and defrosting a bit during the day only to freeze again at night.

If hot water for you but the lock freezes again quickly then no electrical gadget will make it better ;)