Good smoke for testing drafts?

[Graigwen]

We normally take about 10 with us at a time in a small watertight container. Plus you need to carry a lighter. They have proved excellent for work in Longwood Valley sink. I don’t advise smoke pellets. We only tried these once at another digging site. They produced far too much smoke and exiting in a thick fog was interesting.

Thanks for that information.

There is a method even worse than smoke pellets. I was once involved in burning an old tyre underground when long distance transmission was anticipated. Certainly not environmentally friendly and vast amounts of foul smoke produced that emerged from every tiny crack in the ground locally.
.

 

[JAshley73]

Are cigars and The Macallan 12-year not an option...? I can't think of a finer way to pass a few minutes in a cave.

 

[wormster]

Are cigars and The Macallan 12-year not an option...? I can't think of a finer way to pass a few minutes in a cave.

What about a huge blunt and a tin of special brew - mine explorers favorite

 

[JAshley73]

What about a huge blunt and a tin of special brew - mine explorers favorite

Not my style, but I'm sure it would get the job done.

 

[alanw]

Another daft idea from Mr O'Doc was to inflate a big weather balloon to stop the draught or reduce the area it came from.

That made me think of chimney balloons. A visit to a seller's website also turned up this Smoke Pencil Draught Detector. Not cheap at £52.50 though.

 

[ZombieCake]

I bought one of these portable smoke machines for film making. Packs into a case about the size of a house brick, and runs off unprotected 18650 batteries.

SmokeNINJA

The SmokeNINJA is a battery powered, wireless handheldmini smoke machine, designed for Photographers, entry-level Videographers and Content Creators.

smoke-ninja.com

 

[braveduck]

Maplins canned smoke !

 

[2xw]

Thank you everyone for the mix of useful and entertaining solutions. The best answers seems to be a mix of both.

I am still considering the balloon-in-the-passage idea especially as we get towards paddling pool season

 

[Boy Engineer]

Another daft idea from Mr O'Doc was to inflate a big weather balloon to stop the draught or reduce the area it came from. We have to put up with this nonsense.

This is a thing (as the youngsters say). https://www.petersenproducts.com/ar...-worlds-largest-undeveloped-uranium-mine.html