Forge questions. Lots.

T

thegeek574

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Sep 3, 2010
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Everyone,
I am loving this hobby and am spending more and more time on it every week. I am ready to spend some more money on it, and the only real choices were a grinder and a forge. The first things I would think to need would be a bandsaw and a drill press, but my angle grinder works just fine, and I have access to a mill-that-doubles-as-a-drill-press. I was thinking grinder, but I realized that it would be hard for me, with a relatively small amount of income (not by choice) to keep myself supplied with belts. refilling a 20# propane cylinder every couple of months would be more practical. besides, who doesn't like smashing hot steel? here come the questions.
1. I was thinking about the choice between a horizontal and vertical forge. I have a horizontal and it seems that it is really hard to keep it from having hot spots. also, a vertical allows you to HT things of any size, and becuase I won't be heat treating anything over about 12 inches, then I think I would be just fine. however, I am not sure if the horizontal has any serious advantages that I should know about.
2. should I go for a venturi burner or a forced air burner? I think both work, but I am not sure if one has any serious advantages. I am going for simplicity, and so one burner is the limit unless you can convince me that 2 is just as easy, easier, or totally worth the effort.
3. I am going to be basing my forge off of this: http://http://www.dfoggknives.com/forge.htm. can I get away with 1 inch of wool, 1 inch of castable refractory and ITC 100?
4. I heard that if your run a forge off of a 20-25# cylinder of propane then you will freeze the tank after any length of time. is this realistic?
5. as far as anvils go, I have a chunk of railroad track and and a 5x2x17 chunk of 4140 that I have available. what was I was thinking was grinding the top of the railroad track flat and then welding the 4140 on top and using it as a little anvil. are there any problems with this?
6. I will have all of this on a cart. I would like to fabricate it if possible. what would you suggest?

EDIT: forgot to mention budget. I am thinking spending 200-250 on the project.


there will be more to come. thanks,
Steven
 
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this is forced air. I saw it and played with it. 3 # pounds of gas pressure was running 2500 degrees and he had plugged one third of the burner holes.
 
Geek. The 4140 would be best used on end like Rick Marchand's anvil. You want more mass under the hammer.
There's a couple knife shows this weekend so some of the people with advice won't see this till tomorrow.
If you go with forced air burner I think you'll be happier. I have a few screwed fittings and nipples I can help you with, mostly you will just need a blower.
Maybe even try a few knives that are forged finished on the flats to save belts.

Also, there's a guy who sells cheap 2x72's on the'Portland Craigslist. Might wanna look at those
Maybe do like Chuck,Who ran only a disc for years, and run a disc until you can get a better grinder. I'm loving my 9". It really gets stuff flat.
 
hmmm. interesting. I was wondering why few people were saying stuff. At this point, the decision to not go with the grinder was as much to slow me down and make me spend the time as it was because of the belt/disc cost. I will work on the 4140, but I am seeing that I can get a large chunk of 4140 for about 70 bucks on the bay. that sounds pretty good as an anvil. however, I will use the other chunk of 4140 for the time being. I am seeing that forced air is pretty much universally accepted as the more efficient, but that is just from a bit of research.

thanks all. I would appreciate all the input I can get.
 
I'm sure I could come up with another piece of forklift tine for you. I think some of my pieces are 3"x9" and weigh 80# or so.
That should be plenty of face for you.
 
Steven,

I like my horizontal forge. The vertical forge is very popular but it does have some limitations. Mainly the size of the billet you can put through the door. If you remember my forge does not have a door on the front. I just stack up bricks to create the front of the forge. This allows me to make a billet as large as the inside of the forge can accept. HT on a vertical forge would be difficult on a piece larger than the depth of the forge. On the horizontal if you leave the back open and do the brick stack thing again you can HT much longer blades that the vertical. The hot spots can be taken care of with proper nozzle placement.

I also prefer a blown forge. I have tuned mine and am able to control it from 1200f to 2500f without the use of a solenoid valve and controller. If you remember when you came down, the forge ran for over an hour without any manual adjustments and held 1544f when we finally decided we no longer needed it. It does have a thermocouple and controller but is not automatically controlled. You can also use a 20# cylinder. Just get a bucket large enough to put the bottle in and fill it with water. Again proper construction and tuning will help reduce excessive propane use.

If you wanted to come down for a one on one class we can put a forge together for you and I can give you some pointers on how to tune it up properly.
 
Raymond Richard posted a thread here a few months ago about a small vertical forge he'd built with a really simple but effective venturi sidearm burner. I thought it was a pretty easy to build looking thing, and it got HOT, too. It was made out of a propane tank... here's the link.

http://www.bladeforums.com/forums/showthread.php/852827-Small-vertical-forge-and-burner

Here at Bladesmiths forum board, he goes into more detail on the construction and fields some questions.
http://forums.dfoggknives.com/index.php?showtopic=20058&st=0&p=187450&fromsearch=1&#entry187450
 
I saw that before, and I exchanged e-mails with him. the only problem is that I would like the ability to forge weld, and this really limits that. I might convert my current forge to this, though.
 
OK, two more questions

1. for a vertical forge, does it need a top? I can't tell on most of of them. if it does, then does the top need a hole? I can't see.

2. I am too cheap to buy a burner flare when I am putting this together for a shoestring, and so I just made a burner flare out of firebrick. are there any problems that immediately come to mind?

for clarifications: I am not intending for this to get above 2200 degrees becuase I am not willing to spend a ton of time tuning it and a ton of money getting it perfect. this is my old forge that has been ripped and has become a vertical forge. As soon as I can scrape together the dough I will be going for a large blown ribbon burner forge.
 
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Yes the vertical forge needs a top. Can't tell you how the brick flare will work, I don't use one. Also there should not be any reason your forge cannot reach 2300f+. When are you planning to get to this? Maybe we can have another mini hammer in and do forge builds. Any other takers?
 
Sure. I'll come. I hunt elk next weekend but am free after that. I have my forge welded but not lined. I'll have it fired soon I hope. I also salvaged a burner blower off of a water heater soninnownhave everything to get it going.

Steven, if you do a Venturi burner I have 12' of 1" SS pipe that we can make you a flare from.

Are you doing a blown, or Venturi??
 
this little build is a venturi. it is because I got the parts for the actual burner for a grand total of 8 dollars. the blown forge will be coming as the money does.
 
Steven

You mention you have a $250 max budget, if you came down we can build you one heck of a forge for that. Might even be able to scrounge up a blower. We could even do some forging while we wait for the refactory to dry a bit. so long as you have the outer tube, I think I might have the rest. Let me know if you want to do this.
 
I will work on it. I don't know what my budget is. I will get back to you when I do. that number is based on a good guess, but it could be affected by a couple of factors, including the possible sale of a knife.
 
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