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Hello guys ^_^ ,


I'm Emanuel. I'm a Brazilian and I'm very interested in knife making. I'm entering the journey of bladesmithing with my brother, we will build a little shop together.

I have 3 books coming my way from Amazon (The Jim P book about the bladesmithing basics, the 50$ knife shop and The Backyard Blacksmithing) a few days and have been doing the reading on this forum for a week or two (i've a lot of free time right now, as I'm a response from a job interview). So I've read most of the basics from the beginners forum, but I still have some specific questions that I will ask in this post.


First question (more of a tip asking): I've a right shoulder bursitis (it's like a permanent tendinitis), do you guys have any tips for hammering style so I don't hurt it more? As a doctor order, I've to do excercises and I think hammering would qualify as a pretty awesome one.


Second Question: What would be safer for a forge in a house with kids? (Not that I will let kids play around the forge or any of the gear, but accidents happen and I want to minimize it as much as I can). :excl:


Third question: I found many info about Venturi Burners and Blown Burners, but some of it was conflicting (specially about the psi involved). How much PSI is needed to run a Venture Burner? Do Venture really have a better temperature control? Can they get to welding temperetures? (I won't try my hand at welding at firt, but want to know that because I don't have enough space to build a dedicated forge to each task). And finally: Is this one a safe Venturi design http://www.rayrogers.com/venturi.htm ?


Fourth Question: This is a picture of our usual kitchen gas canister, it has around 28lb 10oz of butane/propane mixture. Would it be a nice cannister or is it too small? With this cannister, will I generate enough psi to run a forge (my main interest is doing a venturi one)? In the space I've available to build my little shop, I'm thinking about putting it outside of the shop, dig a hole through the wall and put a hose to attach it on the burner (for safety reasons, if it blows up, it will be outside with a 8" concrete and brick wall between me and the cannister). Would it make it safer? :huh:



Finally, my proposition: Could we try to create a pinned topic for steels and their equivalence on other steel name tables that aren't ALDO? I mean, for the most common steels used for bladesmithing (1095, 15n20, etc). We could post the steel and it's composition, and each of us find it on its country table. And after that, we create a unified table with the steels and their names on as many tables as possible. (I can try to explain better if needed :) )


Thanks for your time. Sorry for the long post and any english mistakes! If I find myself with more doubts, I will try to keep them all here ;)


Best regards,

Emanuel Araújo

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Greetings and welcome.


1) As bladesmiths/blacksmiths we all struggle with wrist/elbow/shoulder issues. The best advice I can give, and I've had any number of chronic shoulder problems, is not to over do it. If it hurts, stop. In the end, there may be things you just can't do, unassisted. That is when you have to be creative. You'll want to look at some of the simple power hammer designs, down the road.


2) If you are talking about having the forge in the house, DON'T DO IT! Carbon Monoxide is a killer. If you are talking about having your forge in a garage or shed, then the question has to be safer than what? Hot things, sharp metal, spinning tools, all of those things go with making knives. It's hard to make it "safe".


3) This pinned topic http://www.bladesmithsforum.com/index.php?showtopic=25573 talks about blown burners. The real advantage to Venturi systems is that you don't need power. Aside from that, I don't think they give you more temperature control. Depending on the design, you need between 5 and 30 psi. Yes, you can get welding temperatures, if the forge is sized correctly for the burner, and if you have the right amount of insulation. I can't comment on the burner design, my computer won't let me go to Ray's site.


4) Those size tanks will work, however, if you run hard, or for a long time, the valves tend to ice up. The bigger tanks don't do this. You can gang several smaller tanks together and that will solve the icing problem. If you have the right regulator, then you will have the psi needed to run the burner. The native pressure in the tank is something like 100 psi, but aside from regulating the pressure, the regulator also protects you from flashback into the tank. I like having my tank outside, and safety is part of it. Tanks don't explode (usually) but they can leak, and propane in confined spaces can be explosive.


5) Sounds good to me.


Don't worry about your English, you did just fine and we'll muddle through somehow.

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First question: Hold the hammer loosely, don't use a death grip on it. Also, do not put your thumb along the top of the hammer handle. The idea is to minimize shock running up the hammer handle and into your arm and shoulder. Holding the hammer loosely does not allow the force to transfer. The weight of the hammer is what does the work, your arm just lifts and guides the hammer. Take a look on the web for Uri Hofi, he is a blacksmith from Israel and has developed a method to hammer with minimum impact to the body. Found a

on Youtube.


Second Question: The safest thing to do with kids is to take your time and educate them about the dangers. The next thing is to try to get them to help you with the work. Once mine realized how much work forging is, well... They are quick to find something else to do now! Third, develop good work habits, come up with a startup and shutdown routine and follow it religiously. For example, you will eliminate quite a bit of safety risk if you make a habit of disconnecting the propane bottle after every forging session and inspecting all seals, valves, etc. (visually inspect seals and spray everything down with soapy water to check for leaks) before starting again. Between that, and locking up your work area, you and your children should be quite safe.


Third question: You are seeing a range of PSI for venturi burners because, one, they will use more gas for things like welding as opposed to general forging and, two, not everyones forge is the same volume nor do they all run the same size of orifice in the venturi. Yes, they will get to welding temperature especially if well tuned by someone who knows what they are doing. I would not say that a venturi burner has better temperature control, a properly tuned setup, either blown or venturi, should be about the same when it comes to control over temperature.


A number of different variables affect venturi burners. A few of them are the size of the furnace, the orifice size of the burner, the PSI of the propane, and the task that you are performing i.e. welding or forging. A venturi burner works because the force of the fuel gas injected down the barrel of the burner causes capillary action to draw air as well. Therefore, the more forceful the stream of fuel gas the more oxygen the burner pulls. In theory, a small orifice with a high pressure of fuel gas will work the best but, the orifice must be large enough to inject enough fuel for the size of chamber being heated. One knifemaker I know of runs his venturi burners directly off the tank pressure, no regulator at all. I understand the rational behind doing so however, it does not seem as safe or as consistent as using a regulator. That said many people do not thoroughly understand venturi burners and run them with an orfice that is too large and at too low a pressure, then complain that they do not perform like a blown burner.


Fourth Question: That size canister will run a small forge but, will probably freeze up if you are trying to weld. I used one about that size before finally getting a 100lb. tank. Sooner or later you will want a bigger tank. My advice is to save the hassle and just get the bigger tank to start with.


Proposition: There are a number of websites that already offer the information you are talking about. Many of them wish to sell you a membership to access the information however. international steel designation chart this is the results of a Google Image Search.



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Thanks for your respones. I'm not thinking about having the forge inside my house. Me and my brother (he is an architect) are projecting it to stay in a room that's in my backyard. It's made of concrete and bricks, just as the house, but we're planning on putting exhaust fans around the walls to get the monoxide out. Is that a bad idea? That wouldn't be a shed or a garage, but would be out and away of the house (and, of course, I will use a mask all the time of work).




Thannks B. Norris, will look up to it and I intend trying to educate the children about the dangers of a forge too, but for the start I'm worried that I have to learn first, than I will be able to educate them.
I intend to develop that routine too.

Edited by Entravix
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Thanks for your respones. I'm not thinking about having the forge inside my house. Me and my brother (he is an architect) are projecting it to stay in a room that's in my backyard. It's made of concrete and bricks, just as the house, but we're planning on putting exhaust fans around the walls to get the monoxide out. Is that a bad idea? That wouldn't be a shed or a garage, but would be out and away of the house (and, of course, I will use a mask all the time of work).

The shop in the backyard, is it already built or is it something you are planning to build? If it is already buit a few fans wouldn't hurt. If it is still in the planning stages, just having a space at the floor and up near the roof, to allow air to circulate, is adequate. Many knifemakers prefer to have two shops, or at least two rooms in the shop. One for hot or dirty work and the other "clean" room for finishing etc. My hot shop, if I lived near the equator, would not need walls except as a means to control lighting but, then I'd probably forge a lot at night when it is cooler. Keep in mind that 90% of making a knife is finishing it.



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It's a room already built, we're planning for at least 2 fans each wall, high up top. And it has a huge window (my house dates from 1930 or so), but this window won't ventilate much, just let some air in. We don't have a lot of free space for a clean room design, I will try to create one or think of something in my journey, but for now I will have to stick with this room I've :wacko:

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A dust mask is a good idea, but it won't protect you from CO. You need to ventilate the space, and you need to make sure that your fans aren't pumping the CO into the house. We all need to be careful about CO with these kinds of forges (well, any kind of forge, really), not just in the space it's running in, but in the spaces around it. CO can kill you pretty damn quick. Several years ago we had a bad winter storm. It was very cold and power was out in much of the western part of the state. A family had a generator running in a garage, partly to keep it from being stolen, partly to shield the neighbors from the noise. It ran out of fuel and one of the sons went in to refill it. He collapsed from the CO, his brother ran in to drag him out and he collapsed, one more family member went into to drag them both out and he collapsed. All three died and it took rescuers several hours to vent the garage enough to make safe entry.


Please be very careful, little ones are much more susceptible to CO than adults.



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A couple of years ago we had a member close up his shed for the winter and ran his forge. He went out to work at the forge and the next thing he knew he was waking up on the couch and he couldn't find his glasses or his shoes. He went back out to the forge and found them there. My best guess is that he go drowsy and took off his shoes and glasses and laid down on the forge floor for a nap. Evidently the floor was uncomfortable or too cold so he got up and went inside the house. If he hadn't, he probably would be dead now.


The fans need to be behind the forge blowing it's exhaust out a door. If you can't do that move the whole forge outside. Another solution would be to install an exhaust fan that will give a very high rate of exchange of air. A carbon monoxide detector would be a good idea too. The shed that I have my forge in has wall of open windows on three sides.



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  • 3 weeks later...


I want to jump in and add a bit of information to these answers:


First, I think you will be fine with installing a couple fans on two walls near the ceiling, as long as one set pulls air into the shop from outside and the other side blows air out of the shop. That will take care of any carbon monoxide build-up. The danger is when the shop walls won't let air move in and out of the shop so it traps the carbon monoxide.


The burner you posted a link to: can work, but that style is hard to properly tune and isn't as efficient as the design in this pinned Venturi burner topic: http://www.bladesmithsforum.com/index.php?showtopic=26862

You can do either the Blown burner Geoff linked or Venturi, both work well and give good control of heat once you use them a bit.

The advantage to a Venturi, like Geoff said, is that you don't need power for a blower.

The advantage to the blown burner is that some people find them easier to tune because the air and gas are controlled separately, so you can adjust one without changing the other.


I think Bruce and Geoff answered your other questions well enough I don't have anything to add.

Hope you are able to get things set up to start bladesmithing, it's a fun journey!



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I would honestly go with solid fuel for most work. I don't know how much wood/ charcoal or coal is in Brazil but if it is like New England wood and charcoal is going to be lots cheaper, and more fun (a real fire has a bit more charm than a gas forge).

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