LPG forge design. In need of advice/constructive criticism.

[Christian Clough]

Good afternoon. First I would like to say thank you for your time also that I am quite new to this website. I have indeed read over many many forums or blogs on here. Aside from all my blacksmithing books, I find this website really informative, educational and also entertaining. I started collecting materials so I can do some smithing in my spare. In which fluctuates throughout the year. I'm pretty sure I can build this new forge I have in mind. I am just looking for more experienced advice and criticism from some of the Pro's around this website. So if anyone has any input it would be appreciated very much.

Questions

1. I have seen many forge shells. In which vary in wall thickness. From thin sheet metal to 1/4 inch or so thick. I have a few 16 gauge 12x24 inch sheets of mild steel. I want to make a Mobil unit. One I can take anywhere without too much hassle. Is 16 gauge realistic to make a forge shell with?

2. I have 2600°F rated ceramic wool insulation. 1x12x24 blankets. I want to wrap 1 piece around the side walls and floor of the forge. Placing a fire brick on the floor of the forge but on top of the layer of ceramic wool. Making a U shape with a brick in the middle pretty much. I would like to be able to forge weld eventually. That's why I planned for putting a fire brick at the bottom. As I've read fluxes eat ceramic insulation like no ones business. Would 1 inch of this ceramic wool be ok for this forge? with the outside dimensions being 7x7x12  and the inside dimensions with both C.W and fire brick coming to 3.5x5x12 inches. I believe that's a total inside volume of 210 cubic inches. Small enough to use a single atmospheric burner. 

3. Now. I just got a pint of ITC-100HT shipped here. I do not want to waste a single gram of this stuff though. So I'm just trying to make absolutely sure I plan this out as well as I can. Treating ceramic wool is a must. Especially from the horrific things I've read about not using it properly. To treat or prep my insulation. I need to seal the c.w. do I NEED rigidizer? Is it a must have or can it be worked around. HYPOTHETICALLY could I use hi temp stove and furnace cement made into a slurry or watery paste to sort of paint over the ceramic wool with. Until desired thickness is met. Or should I order something that specifically says refractory cement? All I have locally unfortunately is imperial hi temp furnace and stove cement and some Rutland fireplace cement. Both temp ratings are a bit different. In which doesn't make me feel very confident in really using. But that's why I am here asking you guys and gals. I've herd of plistix, kast-o-lite, k bond, satanite etc

4. What is the difference between refractory cement and furnace cement?

5. Could I use itc-100ht by itself to rigidize and or seal the ceramic wool? Or would that not be enough protection.

6. I have heard about gas forges needing a draft for better functioning. I have designed a basic shell with open ends. Openings being 3.5x5 inches. Could I just use firebricks to close the openings. Or would insulated doors be a better option? I have a possible sketch or draft of doors for my forge. The front door would be have an opening of 2x5 and the backside opening being 1x5. I figured I could plug the access openings up if I needed to by using firebricks. 

I tried uploading some drawings I have made of the forge I would like to make. I apologize for the lengthy questions. I understand not everyone likes to read novels. But genuinely appreciate your time and appreciate any feedback you may have.

[Mikey98118]

Forges 101 is a permanent thread with information touching on every question you asked here, and much more that you didn't.

You started out stating that you want a forge to run on natural gas, and then went into how to make it portable; since NG is usually run with fan-blown burners it is a poor candidate for portability.Also, unlike pumped NG from a utility, the compressed fuel in a cylinder is very extensive in many places, because there is no demand for it.

[WayneCoeArtistBlacksmith]

I personally do not like square forges.  With a round forge you can more easily cast the interior and induce a swirling of the heat in the forge and help reduce hot spots.

Let me know if I can help you.

You can find my contact info on my profiles page.

Wayne

[Frosty]

Welcome aboard Christian, glad to have you.

I don't know where to start with your ideas  and it'd be too easy to think of them as less than constructive.  I have to point out mistakes first though. First, sure 16 ga. is plenty for a shell, even a coal forge table. No, what you describe for a forge liner isn't so good on many levels. 1st. 1" of blanket isn't enough, you really want two layers of 1". NO fire brick floors! They don't survive welding flux much better than unprotected ceramic blanket, they're a powerful heat sink meaning it takes a lot of fuel to get it hot and being only slightly better insulation than limestone it takes a lot of fuel to keep it hot.

I sure wish you'd asked before spending all that money on ITC-100 it's not intended for what we use it for. It's intended for large industrial furnaces as a high temperature chemical shield and has almost no resistance to being rubbed off. Plistek or Metrikote (see Wayne) are similar but different products designed to protect furnaces that take the kind of abuse we heap on them. They fire hard and provide both chemical and abrasion protection while the high zirconia content provides good IR re radiation. 

A common early mistake most of us make is to try in make THE, equipment, tool, shop layout, whatever. You know THE one yes? It's THE one that'll last as long as we're doing this stuff. The perfect . . . whatever is an illusion there ain't no such critter outside of the head office in heaven. We have to use what works. How do I know to say with authority? I can't count how many gas forges I've built though I have 4 deaders collecting dust in the shop, a couple that are functional, my main shop forge is soon to be retired a new soon to be replaced by ribbon forge r2 and a number boxes with experimental . . . rems.

If I were to offer advice to a new fellow I'd tell him to do anything BUT design his own first forge whatever the fuel, coal, charcoal, wood, feed corn, propane, etc. Find a set of plans with good reviews and download or buy a copy. Then FOLLOW just that ONE set of plans. If you have questions ask the guy who made them. Asking a forum with 45-50k members spread among 150 countries around Planet Earth WILL get you a whole bunch of helpful suggestions from folk who don't have a clue. 

Don't mix and match designs until you've made a few, forges, burner, airplanes, etc. A lot of the guys who have good designs spent years making mistakes so you don't. Forget Youtube, it's a breeding ground for poor to frighteningly dangerous devices and practices.

If you run into a problem give us a shout.

Frosty The Lucky.

[Binesman]

Frosty and wayne covered it prerry well.  Read forges 101 it will answer tour questions.  Waynes website has a set of plans you can follow.  The one question you asked i feel requires a direct answer insteadof guidance to an area that has the answer.

15 hours ago, Christian Clough said:

. Could I use itc-100ht by itself to rigidize and or seal the ceramic wool? Or would that not be enough protection.

No!!!!!!!!!!!   You must ridgidize your blanket.  Use either commercial ridgidizer or a mixture of fumed silica+water and make sure to realy get it deep down in the blanket.

[Frosty]

11 hours ago, Binesman said:

Frosty and wayne covered it prerry well.  Read forges 101 it will answer tour questions.  Waynes website has a set of plans you can follow.  The one question you asked i feel requires a direct answer insteadof guidance to an area that has the answer.

No!!!!!!!!!!!   You must ridgidize your blanket.  Use either commercial ridgidizer or a mixture of fumed silica+water and make sure to realy get it deep down in the blanket.

NICE typo man! I love a good typo, put a smile right on my face.

Good catch on proper rigidizing, ITC-100 is neither a rigidizer nor liner refractory. 

Frosty The Lucky.

[Binesman]

Yeah sorry i post frommy phone most of the rime and i got fat fingerslots of typos

[Christian Clough]

Fantastic. I really appreciate each and everyone one of your responses. Makes me feel a little start struck just about. I kind of had an idea I would get answeress much like the ones given. Sometimes I get to feeling like I'm getting gold fever. Just in a more blacksmithing sort of way.. if that makes any sense.was curious if I could get by with what I had at that moment. In one hand I just want to start heating up some steel and start getting a better relationship with my hammers by pounding on some steel and forming/developing better and better technique . On the other hand I'm not the type of feller to waste anything by poor or unsafe practices.nothing will be started untill I have everything needed, including supplies and a plan with all my steps for fabrication and safety. I swear sometimes I can hear my father's and grandpas voice saying "always measure twice and cut once, or "if you dont do it right the first time you'll end up just having to go back and do it the proper way anyhow ". So again thank you kindly for all y'alls knowledge. Not just in this thread but the other million threads I've read over.. well not millions but slot. I have visited waynecoes site a number of times. Enough to bookmark it for fast access. In which I'll be headed to after submitting this reply. I'll be getting some rigidizer and or fumed silica. Metrikote as well. Am I have quite enough ceramic wool. I can defiantly go with another inch layer. I just wasn't sure if I could get by on just the inch layer. So thank you for clearing that up frosty. Thank you all mikey,binesman,frosty, and Wayne coe. 

[Binesman]

If you want to pound some metal in the mean time for "practice" check the solid fuel forge section.  Theres directions for trench forges and all sorts of others you can have running in a few hours.

[JHCC]

17 minutes ago, Binesman said:

If you want to pound some metal in the mean time for "practice" check the solid fuel forge section.  Theres directions for trench forges and all sorts of others you can have running in a few hours.

Very much this. A JABOD (Just A Box Of Dirt) forge and a sack of hardwood charcoal are cheap and readily sourced. 

Also, get in touch with the New England Blacksmiths Association. There's one member (IFI's own @notownkid) who lives over in Woodstock and can probably give you a heads-up on what's available locally.