Matt Watson Posted December 7, 2018 Share Posted December 7, 2018 Quote Link to comment Share on other sites More sharing options...
NelsonR Posted December 7, 2018 Share Posted December 7, 2018 Nice! this is very similar to a build I'm putting together right now to replace my old forge. Let me know how it works! Quote Link to comment Share on other sites More sharing options...
Matt Watson Posted December 8, 2018 Author Share Posted December 8, 2018 7 hours ago, NelsonR said: Nice! this is very similar to a build I'm putting together right now to replace my old forge. Let me know how it works! Will do hopefully I can get it running in the next week Quote Link to comment Share on other sites More sharing options...
Another FrankenBurner Posted December 8, 2018 Share Posted December 8, 2018 Those bricks look like they might be the dense heavy firebricks. Do those bricks weigh 7 lbs or so a piece? Quote Link to comment Share on other sites More sharing options...
Matt Watson Posted December 8, 2018 Author Share Posted December 8, 2018 Yes I believe they are probably close to that. They are the hard fire bricks definitely a pain to work with but should last for a long time. The forge weighs somewhere around 50-60 lbs I thing Quote Link to comment Share on other sites More sharing options...
Latticino Posted December 8, 2018 Share Posted December 8, 2018 Looking into my crystal ball I predict your next post about this forge will be either why doesn't my forge get hot enough, or why does it take so long for it to heat up. The answer will be lack of insulation and too much thermal mass. Good luck experimenting though, and be safe with your burner and gas train design. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 8, 2018 Share Posted December 8, 2018 You know your forge will last a lot longer if you never thermal cycle it. However the usability of it as a forge goes way down. A hard firebrick forge can take over an hour to come up to full heat and will stay hot for a long time after you shut it down. They are generally used for production work when the contact heating of large numbers of pieces is a bit plus and the extra gas cost is somewhat mitigated by running it full time. (Some large commercial forges only shutdown and cool off once a year for a couple of weeks for standard maintenance/rebuild.) A forge lined with an insulative refractory, (soft/light firebrick, kaowool, etc) will heat up to using temps a whole lot faster and then cool down to "safe" temps fast when it's shut down. Saves a *LOT* of time and money. Can you share with us your thinking on design desiderata that ended up with that design? I assume you will be using it outdoors to deal with the exhaust recycling issue right? Quote Link to comment Share on other sites More sharing options...
Another FrankenBurner Posted December 8, 2018 Share Posted December 8, 2018 The reasons I asked about the brick have been covered by the last couple of posts but I will add some to them. I am no expert and this post is simply the details as I know them currently. There are a few different types of "firebrick" which all have their own pros/cons. These heavier fire clay bricks are typically used for their durability with heat but their insulation value is poor. The other end of the firebrick spectrum is a very light (ounces), very porous, soft fire brick which has better insulating properties but with the type of thermal cycling they see with a forge, they turn to rubble in short time. Mikey has brought up the K26 brick as being somewhere in between as a brick which has some insulating value and some durability. I am using the K26 bricks armored with kast o lite as my baffle walls but have not used them long enough to know about their long term durability. I was using bare K23 bricks prior and in a few months they turned to rubble. The light bricks and k26 bricks are also more expensive typically. There is a balance between mass and insulation which, as ThomasPowers was getting at, can be selected for the desired operating properties. We like insulation because it keeps as much heat in the forge as possible which helps attain higher temperatures, quicker, with less fuel. We like mass because it retains heat which makes the forge temperatures more stable and because it can be much more durable. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 8, 2018 Share Posted December 8, 2018 Well put. Quote Link to comment Share on other sites More sharing options...
Matt Watson Posted December 9, 2018 Author Share Posted December 9, 2018 On 12/8/2018 at 9:59 AM, ThomasPowers said: You know your forge will last a lot longer if you never thermal cycle it. However the usability of it as a forge goes way down. A hard firebrick forge can take over an hour to come up to full heat and will stay hot for a long time after you shut it down. They are generally used for production work when the contact heating of large numbers of pieces is a bit plus and the extra gas cost is somewhat mitigated by running it full time. (Some large commercial forges only shutdown and cool off once a year for a couple of weeks for standard maintenance/rebuild.) A forge lined with an insulative refractory, (soft/light firebrick, kaowool, etc) will heat up to using temps a whole lot faster and then cool down to "safe" temps fast when it's shut down. Saves a *LOT* of time and money. Can you share with us your thinking on design desiderata that ended up with that design? I assume you will be using it outdoors to deal with the exhaust recycling issue right? I really just went with what was easily found at my local stores so I can replace things when needed. But I also assumed since the cubic inch of the forge is under 350 that it would get hot rather quickly I didnt consider loosing heat. However I could always use all of the thinner bricks and add a couple layers of that kwool as a thermal insulator.. it's my first forge and I really just wanted to throw something together that would work so I could smash some hot metal at home rather that waiting every two weeks to go to my local club. Quote Link to comment Share on other sites More sharing options...
Frosty Posted December 9, 2018 Share Posted December 9, 2018 Nobody's really saying you shouldn't do it the way you wish or can afford or with what's available. We're just pointing out more effective methods and why. Don't take it personally, any time one of us posts an idea we get critiqued by the gang. I've avoided some grand mistakes that way and appreciate it. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 10, 2018 Share Posted December 10, 2018 Try it and hopefully compare it with other types and decide what works best for *you*. We often point folks starting out to the JABOD forge and using lump charcoal as you should be able to build/mke that for a couple of dollars... Quote Link to comment Share on other sites More sharing options...
Matt Watson Posted December 10, 2018 Author Share Posted December 10, 2018 2 hours ago, Frosty said: Nobody's really saying you shouldn't do it the way you wish or can afford or with what's available. We're just pointing out more effective methods and why. Don't take it personally, any time one of us posts an idea we get critiqued by the gang. I've avoided some grand mistakes that way and appreciate it. Frosty The Lucky. Frosty, I dont take anything personally and I assure you I appreciate every little bit of information that someone throws my way. I'm the type of person who will try things that are known to work and then try to modify it for me. It doesn't always work and I dont know alot but I do like to learn and try to know a little about alot of different things. I'm ADHD so I am always doing different things. I was a machinist and welder for a couple years and then changed career paths when my company went with cnc machines it took the joy out of making things. I also do woodworking and jump back and forth between old ways and new. I will probably do the same with this. Though I never even considered that the insulation between the different bricks would make a difference. I simply assumed the harder ones would hold heat better. I also was thinking of this as the flame heating the piece and the interior just helping to contain the flame and somewhat controlling the heat in a centralized location. I may get some kwool and put it ou the outside between the all thread and brick walls and over the top to maybe help insulate it better. But they may not work at all. Again I appreciate all the insight I can get and dont be afraid to be blunt I'm a big boy and my feelings aren't fragile! 51 minutes ago, ThomasPowers said: Try it and hopefully compare it with other types and decide what works best for *you*. We often point folks starting out to the JABOD forge and using lump charcoal as you should be able to build/mke that for a couple of dollars... Thank you I plan on building a coal forge later on but I did this one for what I thought would be easier. On 12/8/2018 at 9:59 AM, ThomasPowers said: You know your forge will last a lot longer if you never thermal cycle it. However the usability of it as a forge goes way down. A hard firebrick forge can take over an hour to come up to full heat and will stay hot for a long time after you shut it down. They are generally used for production work when the contact heating of large numbers of pieces is a bit plus and the extra gas cost is somewhat mitigated by running it full time. (Some large commercial forges only shutdown and cool off once a year for a couple of weeks for standard maintenance/rebuild.) A forge lined with an insulative refractory, (soft/light firebrick, kaowool, etc) will heat up to using temps a whole lot faster and then cool down to "safe" temps fast when it's shut down. Saves a *LOT* of time and money. Can you share with us your thinking on design desiderata that ended up with that design? I assume you will be using it outdoors to deal with the exhaust recycling issue right? The design I went with was originally one I saw that didnt require welding and was used with the soft bricks. I then found out that my friend would let me use his welder so I modified the design to a sturdier frame which can simply replace bricks when they break or wear out. I also decided that in this configuration I could add/subtract bricks to allow for larger and smaller stock and in Hope's that with the smaller inside would require less fuel to operate. Another reason i designed it this was was i can simply add another burner to it at any point that I feel I need one such as the case with the larger forge and not having to build another separate forge. This is my first but I am seeing that I need to make another one with the same design but slightly larger frame so I can add kwool insulation before I add the brick may also design a sidewall that can be put into place for the wool as well that will help to retain the heat. I am very pro one off producer of many different things not all work and some even fail big time but every now and then I hit one out of the park and I believe it's worth the effort. Quote Link to comment Share on other sites More sharing options...
Another FrankenBurner Posted December 10, 2018 Share Posted December 10, 2018 I did not mean to be discouraging in any way, quite the opposite. As Frosty stated, there is nothing stopping you from using your forge as is. It will demand fuel is all. If you are new to blacksmithing, you will take more heats as you are learning the basics which compounds the fuel cost. Just something to know up front. If the fuel costs ever become prohibitive, the forum has the thread Forges 101 which contains lots of information to help build a forge which can lower fuel costs. An example of the knowledge contained in Forges 101, you stated that you thought that the flame was heating the piece directly and the forge helped contain the heat. Here is a quote from Mikey on page 2 of forges 101 which helped how I thought about it: Quote It only takes a moment's comparison of the heat loss through exhaust openings with heat loss through forge walls to make it clear that just insulating the forge alone is a waste of time... You are insulating the forge to trap heat in it it for a particular reason, and that it to super heat its internal surfaces into high incandescence; hopefully into the white hot range. Any efficient forge is a radiant oven first of all. The burner flame is primarily a heating element for that radiant heat transfer; not for heating stock directly; get that straight in your mind, or give up all hope of knowing what you're doing in gorge design. You also don't want the flame impinging on your piece as it can cause more scaling. You made mention of the joy being taken out of making things via the cnc machines. This makes me think you enjoy making with your hands. For me, blacksmithing is therapeutic and mesmerizing. I hope it brings you a similar joy. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 10, 2018 Share Posted December 10, 2018 I work with computers all day; at the end of the day hitting something with a hammer, repeatedly, is quite therapeutic.... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.