Hopefully a relatively simple answer is forthcoming Would a small blowtorch stain or scorch a concrete wall and if so, what would the mark look like?
Oh definitely!! The shape of it would depend on what kind of angle the torch was held at. If it's straight-on it would look pretty round, if it's at an angle it would be elongated like a stretched-out oval, but smaller where the nozzle was closer to the wall and bigged out where it was farther away. I can draw up a quick sketch if you want. And maybe a little trail runnming upward above it of scorch-age, from the intense heat rising from the spot.
Say, for arguments sake, the blowtorch was being used to break a padlock. The padlock is a few inches from the wall. What kind of shape are we looking at?
Actually just google for 'Scorch mark from torch on wall' and you'll see all kinds. It actually gets much more crazy than what I described.
And there would be a sort of stencil-shape of relatively unscorched wall behind the padlock, padlock-shaped, but of course very distorted because the torch was moving around. But because the torch was probably moving around for a while the overall shape would be a big weird blotch, maybe like several somewhat round-ish blobs joined together.
It'll bubble the paint. We used to blowtorch beehives to kill spores, so I'm a blowtorch expert, haha. (not really) It does bubble the paint though.
And yeah, looking at the google page, they all have upward-reaching trails due to rising heat and smoke.
Borrow a blowtorch and a concrete wall and see what happens before a member of the local constabulary comes along and busts you for vandalism. Two life experiences for the price of one.
or just try it on a discarded cinder block. It definitely leaves a mark. It should be easy to find photographs online like Xoic suggests, though.
Leaving aside any sooty scorch marks, how would a blowtorch break a padlock? It would just heat it up. I think the usual way to break a padlock (apart from simply hitting it with a hammer in the right place which is shockingly effective) is to go the other way and freeze it with liquid nitrogen to make it brittle (and then hit it with a hammer...)
Yeah, a blowtorch isn't going to do much to a padlock. A $20 pair or bolt cutters would make quick work of it though.
Haha. I stand corrected. That took forever though. And you'd need to saw through it while it was still attached to, which might limit mobility. Bolt cutter gets it done in 3 seconds. Good to know there's a backup method, though!
If you were to use a tightly focused torch like a cutting torch and played it narrowly just on the hasp (or whatever it's called) like that you wouldn't have an image of the enitre lock on the wall, just a blotch of blackened soot with an image of the rod itself runing through it as a mostly clean area. You might get a bit of the upper edge of the lock at the bottom of the scorch mark.
For the purpose of the story, the padlock in question is heavy duty enough to withstand bolt cutters.
