My first forge

[Pokemandela]

Hello. I am trying to build myself a gas forge. And i have no idea what to use inside it. I have read about using perlite, concrete and sand, and other tings and later on reading somewhere else that thats no good. What do you guys recommend? Preferably something castable. 

[Charles R. Stevens]

Castable refractory or ceramic wool. None of the home brew stuff has the durability or effecency.  

This will help you understand. Consider this an interactive pear reviewed treatise on gas forges writen buy real world experts not you tube X-spurts 

Wayne Cole is a member who can help you sorce small amounts of insulating refractories, rigidizers and Ir reflective coatings.  

 

this will also help, as the gas torch is wholly  inatiquit   

 

this is a simple, scale able burner, 3/8 or 1/2 work well on coffe can forges buy all accounts. 

Take time to read the stickies in the gas forge section, once you have the basic knoledge (good knoledge) you will then be able to ask more informed questions. 

[Pokemandela]

Thanks! 

[Charles R. Stevens]

Absolutely.

[Mikey98118]

You need to find a steel (preferably stainless) pipe or tube that will fit tightly over the brass flame retention nozzle on the little propane torch and cut off a part that is a little longer than your present nozzle. Gently tap the part over that nozzle, and use the torch as your forge burner that way; otherwise, your present flame nozzle will probably melt in short order.

[Irondragon Forge ClayWorks]

Welcome to IFI Pokemandela:

First of all forget about using perlite, concrete & sand (dangerous). Definitely read the sticky's. Most of the advise on Youtube are either wrong or worse also dangerous.

If you will edit your profile you may be surprised how many of the gang are near you and a lot of answers are location dependent.

[Pokemandela]

Thanks for the advice. https://www.homedepot.com/p/Rutland-25-lbs-Castable-Refractory-Cement-Tub-601/300981816. Would this work well to make the forge with? Or do i also need the kaowool with it? 

I have read alot of the stickys. But still confused. Im Norwegian and i dont understand what everything is. Since its called something different in Norwegian :-P 

[Charles R. Stevens]

You need insulation. If you were building an industrial forge that worked 3 shifts 6 days a week mass would be ok, but not for us. You need a castable refractory insulation or ceramic wool. This is a high density product and a little in the low side even for a thin reinforcement of mor delicate materials. I have melted hard fire bricks with coal and charcoal. Honestly look at wayne's website 

[Pokemandela]

Wayne? 

[Charles R. Stevens]

http://www.waynecoeartistblacksmith.com/ a member who buys industrial size bags and buckets of material and repackages it in smaller sizes for home forge builders. 

 

[Frosty]

Welcome aboard Pokemandela, glad to have you. 

I don't know what furnace supplies are available in Norway but being northern with real winters I'll bet there are plenty. Years ago I made a few phone calls and got hooked up with a company that services furnaces and sells supplies to other HVAC companies. Since then I haven't paid for ceramic refractory blanket as they are required by law to use new materials off the roll and they are left with dumpster fulls of blanket they have to throw away.

You want to use two layers of 1" 8lb. for the outer insulating liner. Then you want to cover the inside surface with about 1/2" of a water set, high alumina castable refractory. This provides a liner that will withstand direct flame contact and the chemical action of molten fire welding fluxes.

Last is a "kiln wash" this provides greater resistance to high temperature chemistry and is an IR re radiating material, it absorbs heat and re radiates it more efficiently than standard hard refractories.

So, yeah, forget things you've seen YouTubers use, say and claim. Concrete has no business closer to the inside of a forge than the shop floor. Perlite CAN be made to work but takes more work than it's worth. Making your own refractory isn't something worth the effort though a couple guys here have been working up something that has promise. Won't go into that one till they have it worked out it'd just confuse people who don't need more confusion.

Current Iforge threads on the subjects are "Forges 101" and "Burners 101."

Frosty The Lucky.

[Mikey98118]

Refractory cements differ as much as castable refractories do. One thing they all have in common is a  complete absence of grog. Grog is needed to provide dimensional stability, to keep a thick layer of refractory, like a forge hot-face from cracking apart under repeated thermal cycling. Refracory cements are made to glue refractory bricks together, with thin layers.

[Pokemandela]

Great info! What should i use outside of the wool and refractory to the opening of the forge gets really big if i only use those things. Just gotta find out what castable refractory is in Norwegian. Hah. I thought it was the same as refractory cement. 

I found refractory mortar. And refractory adhesive. Any good? 

Green = blanket. Red = castable refractory. What should blue be?  :-D im still stupid. Anyone got a picture showing the layers of something similar? I dont want it to explode and kill me. Heh

[Charles R. Stevens]

i assume we are looking at a #10 can, another can or spacifically the bottom wold work. Either use the can opener sideways to cut the end off with a lip or cut the can so that about a 1/2" remained to be pressed into the original. With the clamps the first method is easier. All you need then is a hole cut in the lid slightly larger than your head linnner. Another method used is to buy a pair of soft fire brick (they are insilative and of higher temiture rating than hard brick used in fire places. 

 

[Pokemandela]

I have a stainless steel pipe thats 17cm diameter. Could that work as the inner layer with kaowool outside it? The can is about 40cm diameter. Its a little bigger than i wanted but the best i could find

Would this work? Firebrick in the pipe. Stainless steel pipe. Kaowool. And refractory mortar? Sorry for being the slowest in the world. 

[Charles R. Stevens]

Stainless melts at about the same temp as plane steel, I wouldn't try and use it as a liner. 

[Pokemandela]

Ah ok. And the mortar is useless as liner? Struggling with the castable refractory part. Hard to find apparently. And i have to order kaowool from ebay. 

I found some mats for mufflers. Can withstand temps up to 1200 degrees celsius. That should work or? 

[Binesman]

Blue=ceramic fiber blanket (kaowool or other brand) green=castable refractory (kastolite, mizou, etc.) Red=kiln wash (matrikote, plistex)

[Pokemandela]

Ah ok. And the refractory mortar is not the same as castable refractory? :-P 

[Pokemandela]

Think i might have found something here. 

[Binesman]

I havent spoken/read german in 20+ years and that does not look like the high german i learned.  If you can read the bag the primary thing youre looking for is it can handle temps up to 3000f

[Charles R. Stevens]

Lots of stuff is considerdmcastable refractory. Obviusly refractory means it resists high temp and castable means it can be pored or packed into a mold. 

What we need for a forge gas forge not running 24 hours a day is insulation, tempeture resistance, mechanical strength to damage and resistance to cracking from thermal cycling. 

Materials that perform all there's tasks are expensive, wile items that can provide a few are less expensive. So you have to read the labels. 

A proven and inexpensive desighn has been to use ceramic wool insulation with or without rigidizer a thin sleeve of castable refractory and an IR reflective/flux resistant wash. 

So the refractory needs to resist forge heat a forge that gets to 2200f will need a refractory with a margin of safety, say 2500f) be hard enugh that bumps with stock won't damage it and resist thermal cycling. The "grog" refers to my Mike is a term use daily in ceramics and poetry, the addition of somthing (typicaly ground up fired clay in the case of pottery) to resist cracks may be as. Little as 10% or as much as 50%. The refractory cement you started looking at is desighned for fire places and wood stoves, and probably lacks bothe the resistance to thermal cycling and temp resistance. The only way to know for sure would be to call them. 

For refrence, a hard fire brick for a fireplace exposed to a charcoal forge fire

[Mikey98118]

Refractory grog can be made of anything from pottery to firebrick, which has been ground down to small particles ( ex. as fine as beach sand). It is usual for high alumina refractory to contain high alumina grog. An insulating high alumina refractory will also contain miniature bubbles of alumina or silica, which also helps with dimensional stability; this is probably why the Kast-O-lite brand of castable refractory is extra tough.