forge design questions

[biggp]

Hello, I'm new to the IFI community. I'm getting into blacksmithing and picked up a second hand forge, cutting a few corners to get started. But as I am working on it and learning more I'm wondering if I should start anew and change designs. I'm looking for some commentary and guidance on the design of this forge 

The forge is quite large. The internal cavity is approx 7.5" x 7.5" x 21". I don't like the burners, so I'm either going to machine or buy some Frosty T type. However, the internal cavity is so large that I think even three burners would be too little BTUs. I have sealed the interior kaowool that was in the furnace with satanite but I'm thinking I might need to wrap another layer of kaowool and another coat of satanite to reduce the internal volume, or insert some firebrick to reduce the volume. 

Do you see any major issues with the design here that I should be weighing? I am at the point where I feel like I might want to scrap and start with something smaller. 

[ThomasPowers]

Rather than scrap it why not keep it for when you need a big one and make a smaller one for "normal use"?

[White Nomad]

The cheapest option would be to, as you said, add some more firebricks to the bottom to decrease the internal volume of the forge. But as it is, it would be ok to use for small objects to practice hammer technique and learning to control the workpiece

[Frosty]

Welcome aboard Biggp, glad to have you.

Looks like a forge built by someone who didn't know what they were doing. I don't blame you for not liking the burner shown. 

How much work/time and money do you want to put into the forge? If you have basic shop skills and tools building a T runs about $10 ea. to get one that works like it should. The ones for sale online are a crap shoot with odds against. They're so easy to make lots of guys are selling them without knowing the basic principles that make them work. 

No, don't add more brick. Even if it wasn't a poor way to reduce volume in general more brick would block your doorway and pass through. 

Add Kaowool to sides and roof, rigidize THEN apply the flame face, Satanite is a good product. Why not add Kaowool to all four sides? You don't want to block the doors, remember? If you were to pull the existing brick and replace it with rigidized Kaowool you could get away with 3 layers of 1" for better insulation where it's most desirable and not make much difference to the doors. 

You're just getting started, what are you going to do with a 21" long forge? That's crazy long, especially to learn the basics of the craft. 10" is more than you'll reasonably use if you don't get yourself involved in projects only a beginner would think good. So, cut in half for 10" and 5.5" x 5.5" is a large but reasonable forge. Shortening it is as easy as folding Kaowool and fitting it in the center. Rigidized of course and plastered with a good flame face refractory, your Satanite.

Thomas's suggestion is good, put this one aside and build a small forge to learn in, the big forge can keep dust off the floor or a shelf until you need the beast. You'll have plenty f practice making burners before then and with a little modification you be able to make it workable with two burners, you'll never need welding heat in that cavern.

Frosty The Lucky.

[biggp]

Hey all, thanks very much for the quick responses and for your thoughtfulness.

Frosty are you suggesting, regarding shortening the forge, that I could stick a thick sheet of kaowool or insboard halfway and just use the front half of the forge? That's a very interesting idea. Do you think I could leave a small gap under it to slide longer work in, while leaving the back side of the forge unworked? It might be difficult to get satanite on the back side of that sheet as I don't have great access into the back side of the forge. but I'm sure I could make it work somehow. Would it be safe to use the back side of the forge along with the front, if they were separated, with another burner perhaps for a heat treat on a longer piece? I have the two burner ports on the front that I could use with the shorter tube. I would still probably like to reduce the internal volume, and I appreciate the recommendation of more wool versus more brick. 

I think I will try my hand at building burners eventually, but for now I will likely pick up two of them online from someone who is more experienced than me, just to get started. 

You have all been very helpful. Thanks so much for the welcome and information.

[Frosty]

Yes, just make a sliding wall from Kaowool to block the forge where you want. No need to coat the side away from the flame with hard refractory though it will make it slide more easily. Be careful to make the inside reasonably straight and even and you can put the partition wall in or remove it from the main  forge door. Oh YES put a matching pass through in the partition! Sure a little flame will blow into the half without a running burner it's no thing. Use it to temper slumped glass or similar, there is always uses for a hot but not forging hot space.

Were I going to use it I'd make another large door for the back so I could access the not so hot chamber, be good for a number of things. I'm blanking right now but I use a chamber of my too large shop forge that has some flame from the active chamber bleeding into it frequently. Slumping glass and heating finished pieces to brass brush after I've brushed the scale. The lower temp doesn't produce scale like bringing it to higher temps, 400-500f is more than enough to burnish with a brass brush. Putting thin steel in the main chamber can bring it to rapid scale temps surprisingly quickly. 

Do you have or have access to a drill press? That's about the most complicated piece of equipment you need to build a T burner. I'm not plugging it because it has my name on it I'm recommending it because it's easy, effective and only requires basic shop skills. Have you looked at the plans posted here?   https://www.iforgeiron.com/topic/43976-t-burner-illustrated-directions/

Frosty The Lucky.