gas forge liners

[wyosixshooter]

I'm looking a building my first forge. I'm sure this question has been ask a thousand times but what is the best thing to line a 10x10x14 forge with? I've been looking at duraboard, insboard , and superwool ht ceramic blanket. Will be doing some forge welding so kinda leaning to the duraboard , insboard. so I don't have to coating stuff.  I think this is what some of the commercial forge makers like NC are using?

[swedefiddle]

Good Morning P,

Hey Wayne, are you able to ship to Canada? I been playing phone tag with the local HVAC/boiler company to try and find out if i can get the needed refractory through them but would like a back up plan.

What part of BC are you making shadows? I can probably get you going in the right direction.

Neil

[Frosty]

Welcome aboard Wyo 6 gun guy, glad to have you. If you'll put your general location in the header you might be surprised how many of the Iforge gang live within visiting distance.

Is 10"x10"x14" the outside of the shell or the inside of the forge chamber you're shooting for? For the most, commercial companies are the only folk needing or even able to use a forge that size. We have a number of professional bladesmiths here several published authors and world class bladesmiths in fact. Maybe one will chime in on the size forge they use.

When forging you don't want to heat much more than you can work in one heat, 6-8" length is in the ball park. Unless you're working really big billets 10" wide and tall is a seriously huge space to heat and a long way from the HOT forge wall and the stock.

Gas forges don't heat your work with the flame, they're called "reverberatory" because the flame heats the forge liner and the liner heats the work with IR radiation. The inverse square law applies so the farther the stock is from the wall the less effective the transfer. Sure the shear area of a liner that size will  make up for distance through the amount of radiating surface but the fuel to keep it all hot!

If you're thinking about mass production you might want to check out a Johnson Appliance trench forge, they're designed for large scale commercial production and properly operated will indeed reach welding temperature. Many folk don't believe they will but they are actually choking at how much  fuel it takes to get one that hot or don't want to convert to propane and pay that bill.

I'm not trying to discourage you, I and most of us would rather see you succeed. I think you're just getting into the craft and making a regular beginner's mistake and thinking a blade forge needs to be as long as the blade. Not true at all, there are other ways to ensure even temperatures in long pieces and getting a good even temperature in a big forge is trickier than one might think.

There's a good reason many of us old timers have so many old forges gathering dust in and around our shops. Wanna learn from our mistakes?

Whichever way you decide to go we're here for you.

Frosty The Lucky.

[Dogsoldat]

Prevenge,  last time I ordered insulation and ITC-100 I bought it from Tuckers Pottery Supply in Richmond.  So depending just where you are in BC  they could be right next door.  At the time the prices were reasonable.

[Prevenge]

... my post disappeared I guess. Hopefully this isnt a repost. Thank you for the replies and sorry for the thread hijack.

I am located up in Quesnel. I wish to avoid ITC-100 if at all possible as buying plistix or metrikote from the states would still be cheaper than buying ITC locally. One thing I am wondering about that Tucker's supplies is Vesuvius Super 3000 Kiln Cement ....any reason why that couldnt be used over top of 1" wool in a BBQ tank forge?

[wyosixshooter]

I guess my question is what is a better liner?

[Prevenge]

4 hours ago, wyosixshooter said:

I guess my question is what is a better liner?

I cannot personally answer that question because the forge I am using is my first gasser. I am sure there are slight differences in the ceramics but I think that the refractory rating is the main factor to consider and I would imagine that they are all fairly similar beyond that. Mine is currently lined (poorly) with duraboard with bricks on the bottom. I find that heat wise it works fine but I would advise you to listen to Wayne's advise. The duraboard is very delicate and begins to decay very quickly even if you are careful not to damage it. I think it is still recommended that you use a rigidizer on any of the ceramic wools or boards to prevent this or use a castable as a top layer. Also I have read that if you do not do this the ceramic fiber can become airborne and be nasty for you if it gets in your lungs. I know mine began to turn powdery recently which is why I am looking to refit it.