I'm building a home/hobby forge and i got 4 pieces of fiber refractory pieces for replacing fire brick in boilers through work, 15*19*2. It just has to be cured and it should harden. 

Can I use beaded sheet metal to encase it? I've been reading if it heats up above 200 degrees Celsius it could give off zinc poisoning. Any suggestions on walls for the forge as i don't own a welder?

I don't think it would get that hot, but i thought i would get some opions. 

Thanks

Mike

Welcome to IFI... have you read this yet? READ THIS FIRST

It will help you get the best out of the forum. Do not use anything galvanized for the forge. Where in the world are you located?

Read the Forges 101 thread.

I am in Toronto Ontario

On ‎12‎/‎29‎/‎2018 at 11:42 AM, MikedMck said:

Can I use beaded sheet metal to encase it? I've been reading if it heats up above 200 degrees Celsius it could give off zinc poisoning.

The boiling point of zinc (the temperature at which it makes fumes) is 1670 F. If your forge shell gets over 400 F there's something very wrong. You would have to keep the sheet metal away from exhaust openings. Guys use zinc coated car mufflers that way without problem.

I became a multi-certified welder in the early seventies, but still pop rivet or screw forge parts together. welding should be the last option for heating equipment.

I am in Toronto Ontario

 

I'm a HVAC mechanic and have had to install duct work, or change it over the years.  So I'm no stranger to sheet metal. I kind of thought it would be a unique forge given my work background. 

It would not be unique. Frosty has been recommending stove pipe and pop rivets for forge building for years. Sheet metal also lends itself to construction of box, "D", and oval forges. Let's not forget coffee-can and paint-cab forges. It is safe to state that welded forges are more exception than rule.

Any access to stainless wood stove chimney?

Nope. Not likely in Toronto.  

Thought i should call the HVAC wholesaler where i got my refractory to see what it was rated for. I was told 1250 F continuous.  They couldn't tell me what it was called.   Do i need to line or wrap it with Koa wool, or plan on a smaller forge and double up my 2inch bricks?

 

Mike

1250 F continuous is about half what you need if it will be exposed to or a short distance away from direct flames.  1250 degrees C would be marginally acceptable. How do you plan to use that refractory?

I was planning on making a box with it, and pointing the burner in through the top. Still not sure what the dimensions were going to be.  I got it at a great price so i wanted to make the most of it.  Still reading the forums to get a guage of what kind or what size of burner to put in. 

If you plan to line the inside of that box with ceramic fiber blanket and then seal that blanket with castable refractory or a Plistex/Matrikote type of coating then it should be fine.  I would not use it in any place with direct flame impingement.  Just because you have something or can get it for cheap/free does not mean you have to use it or that it will not cost you more in the long run.

Once you calculate the volume of your forge with all the layers included then you can determine the number and size of burners you need.  A general rule of thumb for a well-built forge is one 3/4 inch diameter burner per 350 cubic inches of forge chamber.   I heartily endorse using a naturally aspirated ribbon (multi-port) burner, but there are a lot of good options out there. If your forge is not mobile and you don't mind having a powered blower for the forge then a blown burner is one of the easiest things to build and to alter the forge atmosphere.  If you don't want to be tied to power then a naturally aspirated burner is probably what you want.   In either case the ribbon burners are quieter and generally smoother running with more even heat, but there is more up front cost or effort in building them.  To me it's well worth the effort, but that's just my 2 cents.

Thanks for the information