Knife making

[JonnyMac]

Im slightly obsessed with the youtube vids of forging and mildly considering building a small forge...
I have 3 questions to those in the know.
How long on average does each heat period take (in the forge)?
Roughly how many times does it have to be worked to get the shape right for an average 4" blade?
What is the purpose of the white powder that get sprinkled over the blade occasionally?
Thanks y'all

 

[zkling]

Depends on the size of the stock and how high your forge is running.
There is a range you want to work the steel, not too hot and not too cold.

Depends on the size of the stock and your final, pre grind goals/blade shape. As well as the drawing equipment you have, all by hand? Power hammer? Press with drawing dies? Again you want to work it before it gets too cold (risk cracking). The more you can do per heat, the less time it takes overall.

Sorry, but very open ended questions.

Flux, to prevent oxidation, primarily when welding.

 

[JonnyMac]

Yes i realize the number of variables.. thats why i asked for general numbers.
So if more details are required for an estimate lets say a 1sqft forge with forced air from a small 18v blower and a 500g piece of mild steel being hand pounded.. making a small 4" through tang blade...

 

[flyingblind]

White powder sprinkled on is most likely Borax. Sodium tetraborate Na2B4O7

 

[Superbec]

I have the same "slight" obsession haunting me for quite a few years now. Never had the space to attempt any forging yet but very soon I will have all the space I need.

Should I go for a coal or gas forge? Running costs matter mostly and ability to forge weld (damascus in the future aka "asap")

I'm pretty sure this will be my one and true hobby, so I'm not going to cheap out on initial investment but want some real world advice what's cheaper for the long run , coal or propane?

 

[d.mcfarland]

Gas will get hotter than coal. I've seen some redneck outdoor forges put together that are awesome and inexpensive.

 

[mopar440_6]

I'm also mildly into knife making and my cousin has done many more than I have. I haven't done any forged blades yet but I highly recommend Wayne Goddard's book about knife making.

http://www.amazon.com/Wayne-Goddards-Knife-Shop-Revised/dp/0896892956/ref=sr_1_1?ie=UTF8&qid=1452355718&sr=8-1&keywords=wayne+goddards+50+knife+shop

 

[kwoswalt99]

Gas will get hotter than coal. I've seen some redneck outdoor forges put together that are awesome and inexpensive.

I don't exactly know which will get hotter, but a coal forge will be plenty hot.

 

[...]

my brother in law has recently got into the hobby... He built a small coal forge in his back yard that seems to be working fine for him right now... I've been building the kydex sheaths for his knifes, which I've found to be pretty fun too.

 

[zkling]

Yes i realize the number of variables.. thats why i asked for general numbers.
So if more details are required for an estimate lets say a 1sqft forge with forced air from a small 18v blower and a 500g piece of mild steel being hand pounded.. making a small 4" through tang blade...

General number? 1/2-2+ hours starting with a hot forge and done by hand. Not trying to be argumentative on this, but it is akin to asking how long does it take to change a alternator per say. Well some are right there and easy to get to, others, not so much.

The starting bar stock is going to play a large factor as well as desired knife shape and characteristics. Not to mention how close you want to get before profile grinding, if at all?

Drawing out a ball bearing, cube or even round bar stock is alot more work and thus time consuming than starting with a saw profiled piece of flat stock that just needs the bevel(s) forged in. Additionally the alloy can play a huge part in the amount of energy needed to work, even at temperature.

 

[Bob Warner]

How long on average does each heat period take (in the forge)?

If you started with bar stock it takes just a few minutes to get to forging temp and shorter time for each reheat. Different steels are also harder to move than others.

Roughly how many times does it have to be worked to get the shape right for an average 4" blade?

Again it depends on what you start with and your skill. I've been making knives over 20 years and can probably forge faster than a beginner because I can make more use of my hits and can probably hit harder and more consistently than a person that is starting out. Also, the steps in forging if not known can cause problems such as trying to do the second step before the first.

What is the purpose of the white powder that get sprinkled over the blade occasionally?

Most likely you have seen this while people are welding to make pattern welded steel (Damascus). It is most likely one of two things, 20 mule team borax or anhydrous Borax. It is used as flux when welding to clean the steel. It is not the only thing you can use but the most common.

Superbec
I suggest you build a gas forge because they do not require constant fire maintenance. Also in a lot o cases propane is easier to access than coal. If you do go coal try to find a source for good clean coke. I disagree with the statement that gas will get hotter than coal.

Please understand that all the tools are there to make knifemaking faster but are not required to make knives. I made my first 20 knives with files and sandpaper. Don't believe the people that say you have to have a belt grinder and/or a 300 pound anvil. Make knives with what tools you have and add tools as you need them.

 

[Ainsley]

I make knives using stock removal technique on a 1x42" belt grinder. I'd love to get into forging as well as a larger 2x72" grinder but I lack the space, money and time to get on that.
My grinder, good for starting out:

 

[JonnyMac]

Big thanks to Bob, that was exactly the kind of amswer i was looking for...

 

[Bob Warner]

Good, glad to help.

 

[zkling]

Big thanks to Bob, that was exactly the kind of amswer i was looking for...

 

[Superbec]

Superbec
I suggest you build a gas forge because they do not require constant fire maintenance. Also in a lot o cases propane is easier to access than coal. If you do go coal try to find a source for good clean coke. I disagree with the statement that gas will get hotter than coal.

Thanks Bob .. I completely overlooked the fire maintenance now when I think about it it sounds like it's going to slow me down , I saw some of your work on weldingweb a few years ago, have a great 2016.

I get the keys from my new house/workplace in 2 days

 

[jimgood]

I disagree with the statement that gas will get hotter than coal.

I second that.

Thanks Bob .. I completely overlooked the fire maintenance now when I think about it it sounds like it's going to slow me down , I saw some of your work on weldingweb a few years ago, have a great 2016.

I get the keys from my new house/workplace in 2 days

Propane is so much easier to deal with than coal. I was a farrier. I started out with coal in school but got talked out of it by the farrier supply house I went to after I graduated. I never looked back. I still have my forge that I bought in 1987. Simple, compact. I don't have to track down a coal source and find a place to store it. I don't have to empty the forge of ash. No smoke. No fan. I keep my forge on a rolling stand and wheel it outside, hook it up to a small propane tank when I want to use it. Easy peazy.

 

[JonnyMac]

Uhhhhh Jim.... I think some photos are required!!

 

[Wocka]

a forge has been on my to do list for awhile.
started to make one out of a coffee can, but I'm not sure if it will do the trick.

 

[great white tj]

Here are some pic. of my coal forge.

 

[Amitygravel]

That is a slick set up you have there great white tj !