what happens if i use regular concrete mix?

[Atzerath]

I started building a prototype furnace yesterday to be used with coal...took an old metal trashcan, drilled a hole through the side to create an inlet for a blower and then built a pipe system's so my blower eventually blows upwards...to hold all this into place a took an old bag of ready concrete mix...the just add water kind.
What could go wrong I started to wonder last night...I'm guessing that the fall out won't be that bad but the actually explosion might wipe Belgium from the face of the world...maybe even germanland, duchtland and frenchieland...but I could wrong and it might just 'crack' or something along those lines...

 

[Noitoen]

Don't worry, if you survive, you can come to live in Portuguese land

 

[Tin Falcon]

No No nO. concrete lives and dies by moisture. heat causes steam. steam expands concrete explodes get the picture never never should concrete be exposed to high heat . Even a concrete floor on a foundry is dangerous and should be avoided.
tin

 

[Ken I]

Like Tin said - concrete will explode - no exceptions.

Line with firebricks / fireclay.

Ken

 

[Herbiev]

And if the wind blows south, even Aussieland

 

[ChrisLister]

If you say Belgium will be blown away tell me when you start becourse I live in Westmalle

Chris

 

[kf2qd]

Regular cement hardens by a reaction between the cement and water. It also holds some water just in the porosity. Cement also continues to cure for a long time so it takes a while for the calcification process to finish.High heat just breaks down the cement and turns it to powder. Fire clay, on the other hand uses water to make it sticky so it can be packed and formed. It is then allowed to dry for a period of time and then fires at low heat, first to dry it and then begin the process of firing the surface. Some fireclay will even glaze over which makes the surface a bit more durable. If you apply too much heat, too soon to the fire clay the water contained therein can flash to steam and make a mess of your carefully formed refractory.

Water and heat are not a good combination anywhere around foundry related work.

 

[purpleknif]

Just be sure to post the video on you tube. :fan:

 

[Atzerath]

Remember that I said prototype...apparently the steel trashcan I used is so much steel as I thought...next time do the magnet test...
Anyhow, I had built it so I had air blowing up into the fire but due to the size I used a tin can that I had cut out bottom and top so I had a tube..I placed it over the venting hole and built my fire in this tube to create a smaller fire..I knew the tin would eventually get burned and some heat would go sideways but didn't worry about it until I noticed that a spot on the trashcan was melting...didn't take much apparently..
It did work though so my setup is good, it'll only need more durable material...

Westmalle you say Chris??
Not so nearby but maybe one day we could meet up with zapjack and have our first annual model engineer convention...just given me time to actually build an engine


Aussiland is safe and my first choice in the list of countries that I would escape to if the cops find out...

 

[ChrisLister]

@Atzerath

Could we do but I'm in the stage of building my first boiler and engine. So have to wait a little.

Will start this winter with a foundry. Just looking around now

Chris

 

[scooterman]

I have built three prototype furnace units for my foundry work, one being electric and the other two for gas or oil. The materials used for the liners or interiors have always been of high temperature commercial refractory mix. When you mix this and pay close attention to the ratio of water to the product in the instructions, it makes for a fool proof long lasting furnace barrel. To use anything eles is a very good recipe for a very bad situation and at extreme temperatures the probability of serious injury or loss of life, property and what ever eles that could result from an explosion is always present!

 

[tel]

Looks like you have got the answer - in a word DON'T! It gets very hot in there and regular concrete will not stand up to it. Castable refractory is easy enough to find - even here in the wilds of Oz - and potter's supply place will be able to sell you a couple of bags.

 

[Atzerath]

@Atzerath

Could we do but I'm in the stage of building my first boiler and engine. So have to wait a little.

Will start this winter with a foundry. Just looking around now

Chris

I'm working on my foundry first by accident. I had the tools to build a foundry but no bits for my lathe...

Thx for the input guys, i'll search heat proof concrete/cement.first i'd need a vessel to put the stuff in though...