I need a flexible tube to connect a forge to a blower

Factual Questions
1

I need to pick up or improvise a piece of flexible tubing to connect a hair drier to a small forge I built. I need to get this today, and I want it to be as cheap as possible. one possibility I have thought of is a piece of pant leg. I have also seen some flexible metal ducting about 2" in diameter, but I don’t know where to get it on short notice. The walls of the tube have to be flexible enough to be clamped by a hose clamp and at least 2" in diameter. Does anyone have any ideas?

Thanks for your help,
Rob

2

There’s a reason they call the stuff “duct tape.”

Put on a sock. Put duct tape all along the outside, but loose enough that you can slide it off. Cut the toe open. Don’t blame me if it catches fire.

3

I just bought some 3" flexible metal duct for my pellet stove at Home Depot. It was $7 for eight feet.

4

You can get flexible metal tubing with bellows-like walls for Drywer outputs at hardware stores. That’s much larger than 2" generally, but it meets your other criteria – it’s flexible and can be hose-clamped. hey might have smaller diameters as well.

You might also try a well-stocked hobby shop.

5

Flexible dryer ducting is usually aluminized mylar and probably shouldn’t be used at temperatures much over 200-250C (The good stuff won’t ignite until about 325C, but it will fail before that, especially with flexion and vibration, and a lot of those ducts aren’t made of “the good stuff” because your clothes could be scorched/melted by dryer air at 200C (400F) and the thin walls of the duct allow good cooling by outside room temperature air.

I hope it works for you, but it may eventually fail at the forge connection, which sounds like it’s going to be a metal pipe that may exceed 200-300C. If it fails, a second option is silicone sheet (or putty or goo rolled out between two sheets of wax paper) isn’t expensive, and can be rolled into a tube closed with inexpensive silicone gasket sealant (high temp RTV silicon for engine gaskets is available at an auto parts store). The drier tubing is probably better, but it’s nice to know that you have other options, especially since you may only need to cast a silicon “adapter” or connector for the last 6-12 inches.

6

I should say that I haven’t fiddled much with fabricating automotive gasket silicone in unexpected ways since I was in my 20s. My recent experience in fabricating silicon is from making molds and cooking tools with food grade silicone, which goes up to ~550F (300C). It’s pretty similar from what I recall.

Rolling out a sheet/tube from food grade silicone between two sheets of wax paper is a pretty standard kitchen technique for fancy pastry cooks, so it’s not just mywacky idea. I’d imagine that the really high temp silicones might come in handy for a lot of things, working around a forge

7

Mine isn’t – it’s solid aluminum. Nobody accordion-pleats mylar.