measuring the temp in a 2 brick forge

Fletch Helical

Fletch Helical

Joined
Sep 29, 2009
Messages
1,614
Just wondering, I've noticed that some steels (O1 comes to mind) that are mentioned require a sustained soak time between 1450 and 1500. What do you use to measure the heat in the forge?

I don't know of many thermometers that you can easily find that reach 1500 degrees (if there is a site you guys get them please post it). What tutorials I've seen so far seem to suggest using a magnet to determine when the blade is ready. So I'm guessing you can't just slap a magnet on something like O1 and quench it once the magnet doesn't stick can you?
 
Those tutorials should be taken offline!

You can buy a high temperature thermometer for $5, goes to 2300 degrees.
 
Well I must suck at the internet because any search I've been running is giving me several hundred dollar infrared thermometers. Most of which top out at like 1500 degrees.

Anyone have a link or supplier I can check out?
 
Fletch Helical said:
Well I must suck at the internet because any search I've been running is giving me several hundred dollar infrared thermometers. Most of which top out at like 1500 degrees.

Anyone have a link or supplier I can check out?
Click to expand...

Search for a ceramic-enclosed Type K thermocouple.
 
I am going to make a one post entry here;

I can't understand why people respond to questions that they have no idea about.
A type K thermocouple with a ceramic sheath will cost more than $5, and even if you got one at that price, it is only the thermocouple, not the reading device. A PID can be used to read the temperature. A PID and thermocouple combination will run about $50 on ebay. This is what most knifemakers use. The same PID can later be used to control the forge to hold a set temperature.

A search on PID controlled Oven, PID controlled Forge, etc. will get you a lot of info on how these systems work. You don't have to control the oven/forge to use the PID as a high temp thermometer.

A two brick forge is so un-regulated that a thermometer would tell you little. The magnet trick is to tell when the blade has crossed over into austenite, at about 1350F. You use a magnet on an extension wand ( pick up magnet) .These cost about $3 at HF. Touch the magnet to the blade frequently, and when it stops sticking, the blade is at 1350F. Heat a little redder in color to get to about 1500F. For O-1 and steels that need a soak time, it is very hard to do in a two brick forge, but try to keep the blade the same red color for several minutes. The best thing to do with a small forge like yours is to use 1084/1084 steel. When it gets a little hotter than non-magnetic - quench it then and there. It being the eutectiod, does not need a soak time.

Please read the stickies at the top of the forum page. There is a lot of help there. For searching this forum, use this engine:
http://www.google.com/cse/home?cx=011197018607028182644:qfobr3dlcra
It searches the blade forums.

cotdt,
You seem to be answering these questions as if you are a long time knife maker, but the answers seem to be from a teen age troll. I don't know you, but you say in your profile that you like to stir up controversy. Giving bad advise is not controversy, it is just plain wrong. I would like to ask you to knock it off.
This is not an attempt to get into an argument , it is a statement to try and keep the quality of advise on this forum at the level people expect to find here.

Stacy
 
So you are an advocate of the magnet, Stacy? It has never worked well for me so I would not recommend it. I'm not a long time knife maker, but I do have my own experience with a miniforge so yes, I have my own advice and sorry if you disagree. Personally, I use color to judge temp, but the OP asked about a thermometer.

I enjoy reading about your extensive experience Stacey but you crossed the line in your post. A Type K thermocouple w/ceramic did cost me $5 (shipped), won it on eBay not too far back. Any voltmeter can read it. It is you who are accusing others of lying whenever their experience is not the same as yours.

12345678910 said:
Show me where?
Click to expand...

The post above yours is the Buy-it-Now version of something similar to what I got for my electric oven.
 
cotdt said:
So you are an advocate of the magnet, Stacy? It has never worked well for me so I would not recommend it. I'm not a long time knife maker, but I do have my own experience with a miniforge so yes, I have my own advice and sorry if you disagree. Personally, I use color to judge temp, but the OP asked about a thermometer.

I enjoy reading about your extensive experience Stacey but you crossed the line in your post. A Type K thermocouple w/ceramic did cost me $5 (shipped), won it on eBay not too far back. Any voltmeter can read it. It is you who are accusing others of lying whenever their experience is not the same as yours.



The post above yours is the Buy-it-Now version of something similar to what I got for my electric oven.
Click to expand...


So let me make sure I get this, using a magnet with a steel like 1084 which requires no soak time, is caveman smithing, but using a K type thermocouple with a voltmeter is perfectly normal?:confused:

Fletch (I like to think you chose that name because of the movie, I love that movie:)) If you are using a 2 brick forge I recomend you get some 1084 and follow the directions Stacy gave you about the magnet.
 
The thermocouple kit I got from Harbor Freight works well or is at least gives the same readings as the PID on my oven. I don't remember what it cost with the unshielded wire thermocouple, but it had to have been no more than $30, I'd say. It's not on the website, but the item number is 92242 if you find it in-store. I wanted to get a better thermocouple, and, fortunately, the electrical unit takes the standard type-K mini plug.
 
cotdt said:
So you are an advocate of the magnet, Stacy? It has never worked well for me so I would not recommend it. I'm not a long time knife maker, but I do have my own experience with a miniforge so yes, I have my own advice and sorry if you disagree. Personally, I use color to judge temp, but the OP asked about a thermometer.

I enjoy reading about your extensive experience Stacey but you crossed the line in your post. A Type K thermocouple w/ceramic did cost me $5 (shipped), won it on eBay not too far back. Any voltmeter can read it. It is you who are accusing others of lying whenever their experience is not the same as yours.
Click to expand...

:eek:
 
So you're into the cost of a voltmeter also - by the way, PIDs are actually tested to be within a certain range of reading a thermocouple, multimeters are not. Then you have to consider the quality of the meter and so many other variables. Aside from the accuracy of the device, did anyone ever consider how little accuracy one will have in a forge of this size?

By the way, if you own one and know how to use it and are willing to recommend it, why do you only judge with colors?

Despite how justified and correct you think that you are, most of your posts seem to paint your information in a very unfavorable light.

You did mean multi-meter right?
 
Last edited:
Sean Cochran said:
Fletch (I like to think you chose that name because of the movie, I love that movie:)) If you are using a 2 brick forge I recomend you get some 1084 and follow the directions Stacy gave you about the magnet.
Click to expand...

Part of the name comes from that, it hybrids between that and the fact I am a long time archer... With a similar personality to that character, I like to joke around a lot.

Stacy, thanks for the info, I didn't realize that O1 would be so tough to treat in a 2 brick. When I originally signed up I checked some of the stickies but there are quite a few dead links in there and tbh I kind of gave up on it.

69 thanks for the links


Another noob question (and I realize that certain individuals can achieve different results with different steels but).... What is the difference in the quality of a blade made with 1084 vs O1?

I'm planning on trying to make a decent hunting knife doing stock removal (my first knife and might be a bit ambitious but whatever).

Thanks again in advance.
 
I just started getting second year reports in on a 1084 hunter I built for a client. Nothing but good reviews from him and every hunter that he has let use the knife. It will work fine for your purpose. I believe that most end users will not be able to tell the difference between the two steels.

This will be compounded if one uses the same heat to non-magnetic and quench in oil method on both 1084 and O1. The O1 will harden, but what point is there in using it if you're only getting 70% or whatever of the possible performance vs 90% or better out of the 1084. Unless you're hammering out your knives, O1 is also quite a bit more expensive than 1084 so I can't see any point in using it under many circumstances.

Using a steel suited to the tools available to you is always the best route. Learn how to heat treat 1084 very well and it may even outperform some of the marginally heat treated O1 knives out there.
 
Thanks for the reply, makes a lot of sense. Especially the part about the 1084 treated to it's fullest or as close to compared to another steel at a lesser % of it's capability.


Besides, assuming I don't totally suck it's not going to be my only knife so plenty of time to come to play with other materials when I have some experience.

Thanks again to all who have helped.
 
You must log in or register to reply here.
Back
Top