Flue dog-leg angle?

can't imagine it'd be critical somehow - whatever is easiest/appeals?

(I'd wager even horizontal would work OK)

JimK

JimK submitted this idea :

I think you might be correct - I can find ready made enamelled flue angle parts, with an angle of 135 or 90 deg.

I suggest you think 45 degrees or steeper, but make provision for drainage of condensate at the bottom of the outside vertical bit

....usually achieved by a T piece on it's side, so condensate/rain/? gets collected in the lower, bunged portion - bung periodically removed so condensate etc easily removed.

Also both the vertical and "horizontal" parts of flue easily swept with this T piece arrangement....similar to a "soot door" in masonry chimneys.

Cheers JimK

that's an illegal flue then.

steel box section.

Shouldn't worry, mild steel won't last long anyway. If the rust from the outside doesn't get it, the corrosion from the condensed flue gases inside the single skin will. Not sure what you could apply to mild steel that would take the heat to protect the outside.

so what is "stove pipe" made of then? it's single skin, cuts with a hacksaw, 1mm thick, painted with er.. stove paint....er.

Once flue is warm there won't be any flue gas condensation - which will occur in *any* cold flue at start up...

I agree for longevity mild steel will not last as long as stainless but for a workshop heater flued "straight outside" surely it'll get things going for a while?

JimK

JimK wrote on 19/01/2010 :

It is only for occasional use and it is around 3mm wall x around 75mm square box. I'm sure with its planned use it will last a lifetime.

stainless

Yes, but the regs now insist on a twin wall insulated flue to prevent condensation - sad isn't it!

AWEM

so, erm... how does a cold twin walled metal flue prevent condensation as compared to a cold "single wall" stove pipe (that conects said twin wall to actual stoves!) - not the old "air gap" works as insulator bollox shurely??!

Cheers JimK

....having thought - are you on about the rigid stainless type flues, premade in sections to assemble?

JimK

Steel lasts for years and years on workshop stoves. The flues are short, combustion is inefficient so (if you're burning any resinous softwood) there's still some happening much of the way up the flue. Your problem there is more likely a glowing red flue, not a rusted out one.

Graphite grate polish. Aerosol exhaust / engine block paint.

Its filled with high temp insulation..looks a bit like rockwool. The flue inside heats up remarkably quickly.

The steel is stainless, so it doesn't corrode, and the whole is airtight and the outside is cool. So it no fire risk to anything.

Itr doesn't tend to soot up, and if it does catch fire, well there isnt any place for it to escape except up, and the outside doesnt get red hot.

Which is why its virtually mandatory for a new installation.

seen that before. Quite alarming. As it sxited sdtraihjt througjh a wooden roof..

Nothing.

Its bloody dangerous to use it. Even cast iron will crack.

Adam

ARWadsworth expressed precisely :

Yes I will do some photos, but you will need to be patient - it is a slow job.

I'm not sure I understand this. Are you saying that you have made a stove out of a gas bottle, or it is shaped like one, or that it will be fired by a gas bottle? Sorry, I've got a thick head with catarrh at the moment.

What fuel will it be burning?

Dave

Dave laid this down on his screen :

It made out of an old gas bottle, a bit like a pot belly stove.

It is intended to be multi-fuel, scrap wood and waste oil.

Here are a few URL's I have come across...

link) were interesting IMHO...

looking forward to further posts/ test results etc

Cheers JimK