Jump to content

New member. Thought I would start with Show and Tell


Recommended Posts

It worked! I'd use parchment paper and not wax paper if I did it again. 

IMG_20200707_211310.jpg

  • Like 1
Link to post
Share on other sites
  • 2 weeks later...

Here it is, folks. All finished as the peak of summer smacks us for 106°F days. The cart is rated for 220 pounds, rolls like crap because it's Harbor Freight, and I put kitty litter under the forge for added heat resistance/ fumblage. There will be caster modification in the near future. The quench tank is a soda keg from Pepsi (got it through homebrewing.org). There is the start of a Mainz Gladius on the "anvil" face I've been wanting to finish. I hope to start a new show and tell soon with that process. Until then, thanks for the support and information and hopefully this build helps someone out there. 

IMG_20200717_171006.jpg

IMG_20200717_180923.jpg

IMG_20200717_171019.jpg

Link to post
Share on other sites

Good looking build, but I cant see how the burners can cleanly draw air with the threaded 'T's looks a terrible burner deisgn imho -

 

Once you have used a proper hot  gas forge you will realise what you should be looking for, after 1/2 hour burn a well balanced  hot, forge should just be a wall of white at the door you cant look at, no analysing dragons breath! 

 

Hopefully you don't take this as overly critical of what you have achieved so far, but when you nail it with balanced burner and chamber design, and it hits the 'white wall' at about 1300c  you will understand! :)

 

edit....

You could improve the performance of the burners by 'gas flowing' them, same as you would improving a cylinder head. ie, grind all the threads out of the 'T's , and smooth the radii from the 'T'  into the main burner tube where the gas is injected.

Edited by John N
additional info
Link to post
Share on other sites
Posted (edited)

I've been in contact with Frosty throughout the build and he never suggested grinding out the threads. He said I should more go by the sound of the burners and that they should be LOUD and the dragon's breathe should be slightly yellow to clear. They get incredibly hot, so bright yellow hot within 10-15 minutes that you can't stare in it or be blinded. They're so loud that a neighbor of mine said you can hear it from 5 houses down and I couldn't hear him while trying to explain that to me. I have yet to run it for more than 15 minutes as I've got a lot of personal stuff going on keeping me from the forge. 

I don't find it overly critical and actually welcome the opinions/ suggestions. This being said, why would you want your forge white hot? I would think that you'd burn up your steel in no time flat running those temperatures. 

Edited by Eric White
Link to post
Share on other sites

Eric,

If you don't mind me asking, I'm new to forge building and getting ready for a similar build and design myself, does the door leak any flame around it ? I like the hinge and latch design, looks to work very well.... do they just butt up against one another and seal tightly  ? Or does one overlap the other and fit tightly  ? Thanks with any help on this.  

Todd

Link to post
Share on other sites

Mine butts up pretty tight but there is a slight amount of heat loss around it. The best way that I've heard to mitigate that is to use plastic wrap when applying the satanite. When the satanite is wet, put the plastic wrap over it on each side and shut the door and allow it to dry. I DIDNT do that on mine and I pay for it with small cracks every once in a while. I chamfered the second layer of kaowool in the forge to slightly protrude into the concave door. 

 

A lot of the forges I've seen don't open and it is certainly not necessary to hinge it but for large projects (axes in particular) I wanted to be able to open the forge to get around the narrow port in the front. 

 

If you have any questions, don't hesitate to ask. I'm new and won't pretend to be an expert in the subject at all. There are a lot of great smiths on this forum that may chime in and I'll do what I can to help :D

Link to post
Share on other sites

A couple of suggestions for any new forge builders: if your time is more important than your love of tuning burners, buy a Black Beauty or two from anvilfire.com. they're $50 assembled.

Also, a brick floor is fine, but be aware they act as heat sinks. This means your forge will take longer to heat up at first, and longer to cool down at the end of the day.  Not a big deal for a full time smith, but if you have limited time and have to haul your forge in and out of a shed or something it becomes an important detail. 

Link to post
Share on other sites

Thanks Alan and Eric for the info. As a new member here I'm finding a wealth of knowledge and information the more I dig through old posts... so helpful.  What else would be suggested for forge flooring if not using brick if you don't mind me asking Mr. Longmire ? I will definitely look into the Black Beauty burners. Thanks again 

Link to post
Share on other sites

Most use bubble alumina or Mizzou to build the forge floor up to a level surface. As I understand it bubble alumina is a little more rigid/ robust and flux resistant if planning to use flux while forge welding. 

 

I may look into buying some black beauty burners when I can swing the cost. They're cheap and looking through the anvil fire site, I like how much precision goes in to their manufacturing process. They sound solid 

Link to post
Share on other sites

Kast-o-lite.  Totally fluxproof, lighter than mizzou, cheaper than bubble alumina, less cracky than Satanite. Put at least an inch atop at least an inch of wool for the floor, and amything above half an inch atop wool for the rest.

Link to post
Share on other sites

Kast-O-Lite 30: The number needs specifying.

 

Kast-O-Lite is the trade name of a range of insulating castables. The number that follows is the rated temperature in hundreds of degF. Kast-O-Lite 30 is rated for 3000 degF. 

 

As a general rule, the higher the temperature rating, the higher the Alumina content (Alumina content is a big factor in flux-resistance) and the higher the thermal conductivity (higher conductivity = poorer insulator). 

 

There are certainly a Kast-o-lite 23 and a 25, probably others too. I'd hate for someone to search for Kast-O-Lite, buy 23 because they don't know the difference, and end up with a dribbly mess instead of a forge lining.

  • Like 1
Link to post
Share on other sites

https://www.hightemptools.com/castablerefractory.html at the bottom of the page, or http://www.waynecoeartistblacksmith.com/Forge_Supplies.php are two sources that support bladesmithing.  Very little of the stuff you need for this hobby is available at a hardware store!  Sometimes you get lucky if you live in a larger town with a boiler repair business or a pottery supply shop, but that doesn't happen often.  

Link to post
Share on other sites

So I got out to the forge today! Let it run for about 30 minutes, got a few hammer strikes in to the Gladius and then got sketched out about the forge. Once the internal temperature got orange hot, the burners stayed lit very well. Before that though I had one blow out from a slight breeze coming through. I had some smoking/ outgassing from the paint happening so that made me decide to turn it off. I'm going to try again tomorrow and hopefully my nerves will settle to allow me to try a longer session. I get this way with new hobbies lol. 

 

Is there anything that I should inherently watch for that just screams DANGER, SHUT IT DOWN? Or is it just my nerves getting in the way? 

Link to post
Share on other sites

Something that is quite likely to happen at some point is that you'll get the flame running back up the burner tube. It can be pretty worrying if you are not expecting it.

 

The air/fuel mixture needs to be moving towards the forge faster than the flame-front can move through the mixture in the opposite direction. 

 

The flame-front speed is not a constant. It varies with temperature, pressure and air:fuel ratio. 

 

With your burner (which is a Naturally Aspirated design without an adjustable choke), the air: fuel ratio is effectively fixed. The mixture pressure (as distinct from the gas pressure upstream of the gas jet, which is what your regulator controls) is reasonably constant: it will vary with atmospheric pressure and you may see another inch or so of Water Column in the forge if you are giving it the beans and have the opening restricted.

 

When you start with a cold forge, it can be difficult to get the flamefront speed high enough (or the mixture speed low enough) to keep the flame stable. As the forge gets hotter, the flamefront speed increases and the flame stabilizes. 

 

At some point, things can get hot enough that the flamefront moves faster than the mixture and runs back along the burner tube until it runs out of mixture to burn and goes out. Gas will keep flowing and will draw more air and mix with it. The mixture will flow along the burner tube until it reaches the hot forge, ignites and repeats the cycle. As the flamefront moves along the burner tube, it will heat it up a little. This will make the mixture a little warmer the next time, increasing the speed of the flamefront. 

 

The noise is something like a pulsejet. If you catch it quickly enough, you can often turn up the gas pressure to increase the mixture flow and break the cycle. Don't pussy-foot about if it happens. Double the gas pressure for starters, which will give a 40% increase in mixture flow (Gas flow through a jet varies as the square root of the pressure doubling the pressure will increase flow by a factor of root2; 1.41). 

 

Once you know what you are looking for, you can establish the minimum pressure your forge will run without burning back without unnecessary anxiety.

 

 

Link to post
Share on other sites

Thanks again Alan for the help with the info on the links, I just got some Kast-o-lite ordered and ready to order some burners and wool now. I think I'll try some Black Beauty burners for my first build. 

Link to post
Share on other sites

Timgunn,

 

Wow that was a lot of information to digest lol. I kinda follow you on most of it but what I take away most is if I ever experience flame back, which I haven't experienced yet and hope not to but realistically probably will, I should look to increase the pressure at the regulator. I've been acting under the impression that regulating the pressure somewhat regulates the temperature within the forge. I should probably just get the notion of controlling temperature out of my head and focus on the stability of the burners for the volume of the the forge I have built first and foremost. 

 

When the paint started to smoke, I instinctively turned the pressure down (because in my head I said "holy **** It's going to burst into flames" and wanted to lower the temperature) and did hear a change in the burners. They got much quieter and sounded like they were sputtering thus I turned the pressure back up. 

 

In hindsight I wish I had not have painted the damn thing....

Link to post
Share on other sites

Todd,

 

Like I said, there a lot of awesome people on here that are great sources of information. I'm glad that you're getting a fair bit of the negatives from my build so you can avoid them on your end. 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...