Looking to build a forge

M

Meathooks

Joined
Jan 14, 2019
Messages
5
Hello,

I am new to the forums but through my Google searches have ended up here a few times.

I am looking into building my own knife making forge. I know there are lots of ideas, videos, and plans out there, but it's all getting confusing. I was hoping to get some good recommendations from builders/users in this forum.

I will be starting out in my garage but eventually moving to a shed/shop. I would like the ability to forge small and large knives and am willing to build forge myself. I'm thinking propane (2 burner?) is best bet right now, but am open to any suggestions.

Can you all point me to some plans, give feedback on do it yourself forges and experinces?

Much appreciated.
 
Look in the stickys. There is a section of burners and forges.

About 16-18" long is all you will need.
A chamber of around 4-5" is plenty big enough. That means a 16/18" by 8/9" pipe shell
Use 2" Ins-wool.
Make your ends from Ins-board.
You only need one burner.
Blown is better than venturi.

HighTempTools & Refractory has everything you need ... even burner kits.
 
What part of the world are you in? That will help folks determine how to best answer your questions. I used an old 20# propane tank for the forge housing and a single burner is all that's needed for a similar sized forge. I agree with Stacy, blown is easy.
 
I neglected to welcome you to Shop Talk. Fill out your profile so we know where you live and a bit about you. There may be other makers near you that can help or offer free stuff.
 
Meathooks said:
Hello,

I am new to the forums but through my Google searches have ended up here a few times.

I am looking into building my own knife making forge. I know there are lots of ideas, videos, and plans out there, but it's all getting confusing. I was hoping to get some good recommendations from builders/users in this forum.

I will be starting out in my garage but eventually moving to a shed/shop. I would like the ability to forge small and large knives and am willing to build forge myself. I'm thinking propane (2 burner?) is best bet right now, but am open to any suggestions.

Can you all point me to some plans, give feedback on do it yourself forges and experinces?

Much appreciated.
Click to expand...
 
I am in theUK and a 75 years old newbee of 12 months approx.

My main help has been from forum experts and Youtube.

I have attempted everything on a shoestring as all my few knife sales money has gone to my favourite charity, other knives I have given away.

I go to local car boot sales and buy up old leather briefcases and recycle the leather of which less than half is useable.
I used old Sheffield steel files to practice on as they were the best 1095 steel but hard work.
My son scrounges hardwood for my scales.

For my furnace I recycled storage radiator bricks with a few new furnace bricks, forgot the name.
I just stacked them together leaving a breathing hole, an entrance for knives and place to put my propane torch into.
It is not quite long enough, but I managing.

I wold like a 2x72 but as I am not an expert, not selling many knives yet I do not think it wise to make such a big spend on one.

I would also like a bandsaw.

Here in the UK finding used machines is dodgy and in short supply.

The main thing is I amimvproving with your help and I LOVE DOING IT.

Best wishes

Flagg.
 
I built a handful of LP forges and each one has worked a little better than the last one. Stacy's advice is an extremely helpful distillation of the information you'll find out there. If you stick w/ those parameters you will not go wrong.

I can only add that, from a money-saving standpoint, the biggest issue was finding a forge body; i.e., the housing into which you'll put the inswool and to which you'll affix your burner. Compressed air tanks worked well for me, before I started fabricating my own out of mild steel (not economical at all if you've got to buy the steel, but nice to make it custom to your needs). You can get a 5 gallon compressed air tank from HF or HD for about 30 bucks. The dimensions are just about right. It already has feet welded to it. You'll have to cut off each end (I used an angle grinder and cut-off wheels--they are very dangerous, be careful!). You can also use an angle grinder w/ an abrasive flap disc to sand off the paint, otherwise it will slowly burn away at the entrance/burner port; not too big a deal b/c your forging area should already be VERY well ventilated, but something to be aware of. Finally, you'll have to cut a hole for the burner. I used a cut-off wheel for this as well.

Good luck!
 
Just to give you an idea. I built a forced are forge last year and this is a ballpark on the cost:



And this is what it looked like:



It's far from perfect... My burner angle isn't exactly how I'd like and I used 2'' thick wool (should have used 2 layers of 1'' thick). The thing gets very hot. I've accidentally melted mild steel in it. Any HT'ing I do with it requires the doors to be open, it to be running @ ~0.5 psi, and a muffle pipe.


Edit: "Cart Wood" was obviously replaced with a steel cart.
 
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Nice looking forge! Thank you for the spreadsheet.

Looking at your costs of parts and guessing at the time it took to build, how does this forge compare?

http://www.diamondbackironworks.com/catalog/item/2754775/4753617.htm

This is where the comparison of time, parts, and the learning experience, vs a possibly comparable in box unit is hard? Thoughts?

I have no issues building, and not afraid to work with my hands and power tools, but if an in box unit can be functional, efficient, and cost less money, with the same general output,the choice is difficult.
 
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Ok, so price comparison wise we have:
http://www.atlasknife.com/product-category/forges/ combi moni forge at $285 or $320 with temp thermo couple

https://mathewsonmetals.com/shop Metal Smith forge $370

Do It Yourself at ~350 to $500 based on the parts list above.

Can I get some pros and cons, from experienced bladesmiths, of each, and of a DIY vs Buying already built and ready to go?

This forum is nice and really appreciate the feedback. There is so much to think about going into this journey.

Anyone in the Denver CO metro area?
 
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What I’m in the process of building, I bought a 100k burner from atlas knife, found an 8 inch piece of heavy walled pipe from the local welding shop, cut a hole for the burner, need to weld up some legs, get some inswool and satanite, and start putting it together, maybe it will cost me 120$ total for parts. I have a few things I need to rig up. Or I could have spent 500$ and bought one set up already. But I will be using this for hawk heads. I need one bigger than the atlas mini I already have.
 
Allow me to comment, I don't have the Atlas forge, but do like the looks of it. I've got a couple other forges, one a dual burner "factory" built - don't remember where I ordered it. The other is a homemade job from a 20 lb propane bottle with homemade burner. I suspect I've spent enough building the homemade forge with burner to have purchased the Atlas forge. BUT - I've learned a lot with the design and building. That took a bit of time I could have been making knives. Since I enjoy building tools almost as much as making knives I don't consider it time wasted.

For solely knifemaking I do think the Atlas forge is about the best "bang for buck" around. There are several design factors I like, the way the burner in angled in, the small diameter interior.

Ken H>
 
This is all very interesting, can I assume that you guys with the expensive forges sell a lot of knives, sales in UK are very slow,
 
A good forge can be built for the cost of the insulation materials (wool and satanite) plus about $100. While 2" of insulation is better if the forge will run for hours on end, 1" will suffice if you are just a hobbyist.
A simple small forge can be built for around $50 total with some scrounging skills.

The only items you need to be of a specific type and quality are the insulation (Ins-wool/Kao-wool/mineral wool or UK equivalent) and the refractory (satanite or UK equivalent like Plistex). The rest can be any sort of stuff.

The shell can be anything that is not going to melt. A tin waste bin, old fire extinguisher, old oxygen tank, old propane tank, old air tank, metal 5 gallon paint pail, etc. It doesn't have to be heavy or pretty. I saw one forge made with the shell made from rolled up chicken wire. Scrap yards have hundreds of items that will work.
Small forges can be made with a large coffee can, 1 Sq.Ft of insulation wool, a pound of satanite, and a good plumbers torch.

If you have a good supply of soft firebricks (like from the lining of a burned out pottery kiln), you can make a rectangular forge, or angle the sides of the bricks and line a round forge. (The Atlas forges have K-26 soft firebrick lining)

While a fancy burner is great, a simple venturi or blown burner can be cobbled together from the stuff you find in a couple friends garages. Junk yards are again a great place to find stuff to use. Any pipe fittings from 3/4" to 1.5" will likely work. Small burners can be made with 1/2" pipe.
Black iron pipe is the type pipe you want ( or stainless) for the burner tube, but the rest can be galvanized.
Blowers can be many things if you are on a budget. Old larger size hair dryers, blowers from furnaces, small electric leaf blowers, old shop vacs, surplus blowers from ebay, etc. The manifold ( piping from the blower) and air gate valve can be PVC. You need steel once it gets to the elbow before the gas insert point.

This is a list of the basics for a decent basic forge ( off the top of my head):
14" to 16" shell of 7"-8" pipe (or anything about that size).
2 feet of 24" wide Kao-wool/Ins-wool (or 4 feet for a 2" thick liner).
10# satanite ( or equivalent) - get 20# if you can afford the extra $20, it is useful for many things.
A simple blower fan of some sort that delivers a good flow of air ( at least 50CFM)
12" of 2" pipe
2" elbow
2X1" bell reducer
2" gate valve (or 1")
12" of 1" black iron ( or stainless) pipe
a short nipple to fit the gate valve
1" tee
1X1/4" bushing ( or 1X1/2")
1/4" or 1/2"gas valve and nipple to screw into the Tee
Gas line fitting for the gas valve (welding hose fitting)
propane regulator that goes from 1-30PSI
12 foot propane hose
20# or larger size propane tank

A few firebricks ( hard or soft) will do for the front and back walls. You can use the cut-off pieces of ins-wool and some satanite to make covers with ports for the ends and hold them in place with the bricks. Some chaps just use the uncoated wool on the ends.

That sounds like a big list, but I bet you could find half of it in a few weekends of scrounging friends junk bins, visiting some flea markets, and going to the hardware store. You can drop by a plumbing and heating shop and often get free small pieces of pipe, maybe be allowed to have old pipe fittings from their scrap bin, and scrounge gas valves from old water heaters.
 
Great list!!

Would you happen to have some sort of build plan or design. I'm not familiar at all with building or working with propane burners, but I am handy, have quite a range of tools, and a willingness to build it. I would just need guidance and plans.

Very much appreciated!!! Thank you Stacey.
 
Look in the stickys as well as use the custom search engine. You will find may threads on making forges and burners.
I know I have posted several sketches of forge and burner design, as well as others who have re-drawn them with drawing software.
Kevin Cashen's website has good forge info.

The blown burner is very simple: You need an air source of at least 50CFM and not more than 150CFM.
You need a manifold to take that air to the burner. 2" to 3" is the normal size. You will have to put some sort of plate/adapter on the end to attach the blower.
You need a gate valve to regulate the air flow.
You need an elbow to turn the burner toward the forge (normally, the blower and manifold are below (or above) the forge and the manifold is vertical.)
You need to reduce the manifold to the burner tube dimension with a bell reducer.
You need to bring the gas into the burner tube from the side. (usually a 1/4" fitting with a tee)
You need a way to regulate the gas flow ( usually a 1/4" needle valve)
****** see below
You need a burner tube about 8-10" long to go into the forge and end just shy of the inner chamber. Heavy walled pipe of sch80 or stainless is good for burner tubes. Cut the end flush and chamfer the inside a tad to make for a smooth flame.
The forge has a burner port where a piece of pipe is welded to the shell to affix the burner. It is typically a piece about 1.25% the size of the burner tube and has three nuts welded to ot for the thumb screws or bolts that clamp on the burner. Schedule 80 pipe is good here.

***** In a well designed burner, there is an expansion and mixing chamber after the gas insertion and before the burner tuber. This is merely two bell reducers and a 3" pipe of pipe. (something like 1" to 2.5"). This isn't required, but makes for a better blown burner

A forge is a tube or box that is lined with high temperature insulation wool, and the wool is coated with about 1/4" of refractory cement.
The ends are either solid caps with insulation and cement or hard firebricks that are stacked or slid on steel channels to open and close the front and back as needed.
The stacked/sliding brick method is gaining popularity because it makes the entire build easier and allows for infinite and instant variation of port size.
If using fixed ports in the ends, about 3"X3" is a good size. Some folks coat the forge lining with an additional coat of ITC-100 ( or similar), but it isn't really needed for most forges.

Just a technical note, the forge must have some amount of port space to let the hot burnt gasses escape. A closed chamber with an ignited gas inside is called a BOMB! Generally, you need a total of about 12-15 sq.in. of port space for a full running forge.
 
He may be having trouble finding pics of propane forge builds. There were several I looked for that had no images anymore.
 
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This is my crude propane gas torch forge, I do not have a frame. it works
 
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