heat treating/forge question

[mikemeteor]

I am in the process of smaking a small "one brick" gas forge for small heat-treating and forging jobs associated with building MLers.

A couple hours spent with the source of all human knowledge (the internet) and about $25 worth of common materials has given me what I think is a serviceable atmospheric burner.

I am welding up a frame from angle iron for a hard firebrick housing.
The chamber will only be about 3"x5"x9" deep.

My question is: do I need to suspend the workpieces off the bottom with stand-offs? or can I simply lay them on the firebrick floor ?

Any insight on where and how to orient the burner when installing into the firebrick chamber ? Top mount or side mount ? Aim it at the work piece, or swirl around ?

thanks. Any insight on these micro gas forges greatly appreciated. I figure the blademakers here know all this stuff cold.

/mike

 

[44-henry]

I assume you have probably gone to Ron Reil's pages and studied the forges on that site. I have one that is a rectangular shaped forge with the burners mounted on the top pointed straight down. It works, but not that great. Most of the ones that I have seen have the burner coming in on the side. I might add that I have two very high end gas furnaces in my lab at the university and both of those have the burner coming in the side. Our melting furnace has the burner placed on the side to swirl the flame around the interior of the forge and we have used this to melt cast iron in the past rather quickly.

I am far from an expert on forging, but I generally try to have my parts on standoffs off the furnace floor. I think they heat more uniformly this way. Maybe not but it works for me. I do the same to parts that I put in the heat treatment oven (and melting furnace) as well. I am sure you will get better responses from those more knowledgeable than me shortly, good luck with your project.

 

[LRB]

Even heat is your goal. Do whatever it takes to get there, or as close as you can.

 

[Black Hand]

I thought these things used the refractory bricks instead of the hard bricks? At least all the ones I read about did.

If indeed hard, please post a link. I can't get the refractory (soft) firebricks where I live.

 

[mikemeteor]

Black Hand -

The "I Forge Iron" forum http://www.iforgeiron.com/ has lots of chatter on forge and burner design, altho like many forums, it's often hard to find a specific rule of thumb (e.g. burner placement and stand offs.... maybe that indicates there IS no rule of thumb ! :shocked2: ).

It appears to me, from reading several posts, that "serious" brick forges do use the soft bricks for the walls, and hard bricks for the floor.
Hard bricks heat slower and require more BTUs to get to temperature and thus are less efficient, or so I read.
However, given my small chamber and infrequent light duty use, I figured I'd just go with the more readily available and less finnicky hard bricks, and maybe coat them with ITC100 on the inner surfaces.
Burning a tad more gas with the hard bricks won't bother me, at my planned limited frequency of use.
I don't plan on forge welding.

I think the IFI forum gives lots of sources for soft firebrick. under $4 a brick IIRC.
Give it a look-see if you're in the market.

Thanks Wick - that seems to suggest a small stand-off would help.

/mike

 

[LRB]

Personally, if it were me, I would make a charcoal forge from a hibatchie or a large truck brake drum, and feed it air from a hair drier or vacuum cleaner. I made one from a shallow cast iron sink years ago, but given time, the cast iron will crack.

 

[mikemeteor]

I assume you have probably gone to Ron Reil's pages and studied the forges on that site.

Thanks Alexander. I had not been to Ron's pages, but I have now, and they are a wealth of information. Thanks for the tip. :hatsoff:

Wick, I wish I lived in an environment where a more traditional coal forge was feasible.
As it is, I fear my neighbors, as well as my family, would not appreciate me firing up a coal forge in our relatively cramped neighborhood. When I retire to some country acreage with a barn/shop, it'll be a different story :thumbsup: .
/mike

 

[THOM]

MeteorMan :

here's a few sites to help. http://www.youtube.com/watch?v=qOqgVfgpvH0

http://www.youtube.com/watch?v=qlKwhIuMdrM

http://www.youtube.com/watch?v=84PSz-VAg9U

http://www.anvilfire.com/FAQ-artic...tm&titleName=anvilfire.com Blacksmithing FAQs

Another way is to get a clean paint can; line bottom and sides with kaowool, spray with hardener, and enter your burner at an angle so flame swirls.
forge will be a bit bigger; then you can heat larger objects.
I hope this helps.
limpinfrog

 

[50cal.cliff]

Trueflully the best heat comes from an indirect flame in a small forge. Take a look at the last post and the last link the flame is shooting up not down onto the object.
http://www.anvilfire.com/FAQ-artic...tm&titleName=anvilfire.com Blacksmithing FAQs

A circular forge with the flame pointed upwards is really the best. It creates a vortex of the flame and that way you don't get a hot spot. That is hard to do in a small rectangular chamber, (create a vortex) but by pointing the flame upward as in that link. You can at least some what eliminate a hot spot as the item on the floor is not directly in the flame but will consistently receive the same amount of heat!

This is pics of mine:

]

It is being converted to run off of a PID and use a solenoid to control gas! So as you can see I have a lot more time and effort and money into that one.


For what you are talking about doing a small brick forge or a one brick forge is an ideal proposal!

 

[mikemeteor]

thank you sirs.
based on those videos, I guess I am not making a "one brick" forge, I am making a small brick forge (out of 5 or 6 hard firebricks) whose chamber is about the volume of one brick.
Think I'll aim the burner in an indirect manner, hoping to get some swirl from a rectangular chamber.
It can always be adjusted.
My goal is to be able to forge my own triggerguard.
I'll post some pics when I get it done.

 

[THOM]

MeteorMan :
Not to confuse ya; BUT......
Another "on the cheap" way is to make a small charcoal forge.Not briquets, just charcoal.
Tim Lively and Tai Goo do all kinds of forge work with one.
Some clay - a pipe with holes drilled in it- Wife's blow dryer ( when she's out shopping ! )--
and whammo; yer in business.
Look this up; and you might be surprised how easy a solid fuel forge is to make.
Hope this is of some help.
limpinfrog

 

[mikemeteor]

making incremental progress on my mini forge.
frame is from a discarded bedframe I salvaged off the curb.
using soft firebricks.
chamber is about 3.5"x5" x 8 inches deep.
burner will come from one side of the top, angled so as to swirl around the chamber.
have ordered Plistix and will coat the entire inner surface of the fire chamber.
I'm working on the burner mounting system now - that will be welded onto the frame.
will also put a thin sheet metal skin around the sides and top --- i have some large olive oil tins that will give it the old world look:shake:.
I also have a kiln shelf to lay in the bottom and some half-inch standoffs.
I know it's a far cry from the rigs pictured above !
so far I have about $60 total in it (including the burner) - and I think I'm about done purchasing.
any critique or tips is more than welcome.
heck, I can even take some chop-busting if its called for.

I do have one question - I know some folks put a hole in the back so long stock can pass thru.
Is a hole needed for "breathing" too?
In other words, if you weren't going to have any long stock, would you still vent the back wall ?
Right now mine is solid. thanks.
/mike

 

[flattail]

:thumbsup: Nice looking forge! You are feeding air in with the flame, a large "dragon's breath" will come out the front, but no extra hole is needed. Will love to see your results.
Ed

 

[gus13]

MeteorMan, not to be a killjoy but I agree with Wick on the brakedrum/hair dryer forge. especially for the frequency you are thinking of using it! while I am not a blacksmith at all a friend of mine did make one using just that method and it takes up almost no space, he uses it right in his garage with a very small firebox (about the size of an ammo can, though I don't know what he actually used for it)so it wouldn't be - or have been :wink::grin: that intrusive for your family or neighbors! plis it makes it very easy to disassemble and "store" should the need arise. next time I'm over there (and if I can remember too!) I'll take a few pics of it for ya.

 

[50cal.cliff]

Now I know what happened to my bed rails that used to be in my storage shed! :hmm: :rotf: :rotf:

It does my ole heart good to see that I am not the only one who re-purposes things. Why build a leg when you two good ones right in front of you! :applause: