Plastic Hoffi chimney ??????

[flemish]

Would this work I can get a 20' x 12" for half the $$$ of metal?  I would only need 12' or so.

[Steve Sells]

umm, Seriously ???  you want to use plastic?  Besides it will most likely melt all over?  dont forget that plastic can burn at low temperatures.  Let us know how that  turns out, but please try it away from other buildings.

[njanvilman]

And when plastic burns, it give off toxic gasses. 

[Jim Coke]

Have a fire extinguisher handy and a clear path to the door...

[notownkid]

Please Video this it certainly would be worth watching.

[Frosty]

Just have the fire department and EMS standing by, you're going to need them.

 

In a related aside: a wood stove BURNS wood, they're NOT made of wood.

 

Frosty The Lucky.

[flemish]

I get the pic. I was told that the square box that goes through the wall does not get hot. just wanted your input.

[Eddie Mullins]

I don't see a pic in your post, but I assume you are talking about the chimney? If so, like the rest said, no plastic, but what I used, as have others, is tin roofing. You can get used free or cheap if you can find it, or 1 new sheet isn't too pricey. Roll it up and screw/rivet into a tube. Yes galvanized tin can give off fumes if hot enough, but I have not found the tin to have even gotten warm to the touch. My box through the wall however does however get quite warm for the portion adjacent to the fire.

[ThomasPowers]

Did you talk with the local HVAC companies about used ductwork from commercial re-do's?

My 10" spiral seamed heavy duty ductwork ran me under US$20 for a couple of 10' sections.

Also do you need to meet code? If you do and you don't then your insurance company can disavow any knowledge of all those payments you have made over the years and just say "tough" if anything happens...

Ductwork also sometimes shows up at a Re-store in my experience; however the cheapest would certainly be to forge a couple of bottle openers and visit your local HVAC folks...

[Frosty]

Flemish: Please accept my sincere apology I was out of line mocking you for your question.

 

Sometimes I get off on a bad tack and get carried away. I just couldn't imagine anyone asking if plastic was appropriate for a smoke handling system. If it turned out you were a youngster and rather than be made fun of again just gave it a try the next time you had such an idea. Were something like that to happen all of us who'd been so sarcastic would've been at least partially responsible for damages or injuries incurred by an accident.

 

I make no excuses for my words, I will try much harder to be responsible next time such comes up.

 

Frosty The Lucky.

[flemish]

Flemish: Please accept my sincere apology I was out of line mocking you for your question.

 

Sometimes I get off on a bad tack and get carried away. I just couldn't imagine anyone asking if plastic was appropriate for a smoke handling system. If it turned out you were a youngster and rather than be made fun of again just gave it a try the next time you had such an idea. Were something like that to happen all of us who'd been so sarcastic would've been at least partially responsible for damages or injuries incurred by an accident.

 

I make no excuses for my words, I will try much harder to be responsible next time such comes up.

 

Frosty The Lucky.

Frosty not young, just trying to think out of the box.  My wife does a job and I help so I don't get paid. (she can't do it by herself) Trying to get a forge set up with out spending to much money I don't really have.

[Frosty]

How are any of us to know a person's age without being told? If I'd known you were an adult a little rubber chicken slapping for asking about a plastic smoke stack might be in order. (I'll get back to helping you brainstorm a suitable stack soon) But some of these things can be dangerously serious, maybe even deadly serious. I've always been very safety cautious, even in my reckless youth I looked to precautions.

 

For a bit I'm thinking a number of us were having too good a time with your question, I know I sure let the quick half of my wit get away from me. The real danger being how will young folk who may be just feeling their way into the craft feel about asking questions with potentially disastrous consequences? A point in fact is a question that was posted yesterday or the day before. A young man asked if he could use a ceramic mug to melt bronze and pour into a concrete mold. Perhaps if he'd read our replies to your question first and been as sensitive as a teen can be, he wouldn't have asked and just given it a try. Had that happened it could've lead to injuries from scaring, painful all the way to lingeringly fatal. Perhaps burned his family home or heavens forbid the apartment building with the family on the 3rd floor home and asleep.

 

I know it's not a thing for some folk but I won't take that chance, too much can ride on it. It's one thing to get a loud and strong negative response to a question but something entirely different to be mocked. I just have to remember to ask myself THE magic question next time I see one like yours. "is S/HE SERIOUS!?" If the answer the voices in my head tell me even maybe, I need to take into consideration the potential before I let my fingers run so far ahead of my brain.

 

Any who, My new position on questions is to THINK the serious WHAT IF before I reply. I'm hoping more of us do as well. I may not be very pretty but I do like being able to look myself in the eye in the mirror.

 

Frosty The Lucky.

[Frosty]

Okay, new reply. A coal forge doesn't typically make near the waste heat a charcoal forge does and is NO comparison to a propane forge. The hood and stack doesn't get as hot as a person would think unless it's a BIG fire. Still, it needs to be fire proof even if it doesn't really need to be insulated like a wood stove's stack. It's why a person can get away with using galvanized stack so long as it's not right at the fire. Unfortunately 300f isn't unexpected and before it reaches that plastic is going to be dripping. Well, any plastic a normal person can afford. You also need to be aware soot can build up in a stack and catch fire. Stack fires are no fun but are pretty easily controlled if you're on top of it.

 

Not paying more than a person needs to is a fine old blacksmith's tradition, I'm pretty sure the first person to forge a copper nugget haggled over the price. Do you know anyone in the HVAC business? They probably toss more ducting than a person would ever need every time they do a remodel. Same for builders and if you see a restaurant being worked on asking can't hurt. A restaurant remodel would be primo, most of that ducting would be stainless.

 

You might be able to bribe the guys at the local salvage yard or dump with donuts to keep their eyes open and set stuff aside for you. Donuts and the occasional letter opener, card holder, coat hooks, etc. are just good PR and being on folks good side is a good thing. Seriously, all you're talking is channeling smoke once it's away from the forge fire so as long as it's metal and the right diameter it doesn't make a huge difference what kind. It could be aluminum irrigation pipe, well casing, old piling, a light/flag pole, etc. Heck if it is tall enough it doesn't need to be really very large around. You could roll up salvaged steel roofing and it'd work a treat.

 

The through the wall section is a bit more demanding but not a lot. An old ungalvanized mailbox or two pop riveted together for length might be the ticket. Rural mailboxes can be pretty darned large you know. You can remove galvy by soaking it in vinegar.

 

The possibilities are just a matter of recognizing them when you see them.

 

Frosty The Lucky.

[flemish]

Thanks everybody. I am new to this and wanted something that wont rust out and I guess I got some wrong info off of the net.  Thanks Frosty Your answer was Very helpful. 

          Flemish.