Mild steel tube as flu

[noff]

We are about to fit our new 9kw multi fuelonto our barge to replace the Firefox 5 which has struggled valiantly to warm us this last Winter.

I have read and read again almost every thread I think there is on flues/hearths etc and the Firefox ran happily and safely for 3 years.

I have been given a 3m length of 6'' mild steel tube approx 3mm thick which fits perfectly into the collar on top of the stove. and can be cut to size to fit the twin wall adaptor.

My friend said he has just fitted his new 5 Kw multifuel (smaller flu) with similar steel tube.

I think it will corrode very quickly as it is not enamelled or vitrous coated ..am i right or wrong . ??

 

I am very tempted to use it as its a great fit/length and free but I do not want to take it all apart again next year full of rust and holes..

I trust your learned selves will once again help me on this.??

[blodger]

I only have experience of this and a previous boat with a stove/flue and replacing a cast iron flue with mild steel because of a crack but I think in the main canal boat flues are not enameled or whatever just blacked.

[casper ghost]

I've used mild steel flue pipe before. It is fine and actually lasts longer than the usual very thin flues.

[noff]

thanks for replies.. would certainly save me a few pennies

[blackrose]

I would expect a mild steel flue with 3mm wall thickness to last a good few years. At least 5 or 6, perhaps more.

 

Edit: Remember that the flue pipe should not fit snugly into the stove and deck collars - there should be a few mm gap all around for expansion which you fill with glass rope topped with stove cement on the stove collar and glass rope topped with high temp silicone on the deck collar.

Edited January 24, 2011 by blackrose

[noff]

thanks Blackrose. yes there is a few mm space between stove collar and steel flu so should be ok .. will fill with the high temp sealant.

Why do you not recommend the silicone on the stove collar and advise cement?

Edited January 24, 2011 by noff

[blackrose]

thanks Blackrose. yes there is a few mm space between stove collar and steel flu so should be ok .. will fill with the heat 'proof' sealant.

 

The high temp silicone only goes up to about 350 C. Although it gives a better finish and does not crack like fire cement (which goes up to about 1200 C), high-temp silicone is not really designed for the stove top collar seal - however, a lot of people do use it for this job. I sealed mine with fire cement and then smeared a layer of high-temp silicone over the top to stop it cracking - the best of both worlds!

[churchward]

We replaced our stove pipe and roof collar (cracked) 2 years ago. The original had been in the boat for 12 years so mild steel of around 3mm thickness lasts quite a long time.

[noff]

thanks y'all ... Blackrose I think I will follow your concotion of cement/silicone. Yep , pleased that the general consensus is its ok to use the 'tube'