ADodds720 Posted June 2, 2018 Posted June 2, 2018 Hi everyone, Im currently designing my first forge and hit a snag. I've looked around, but haven't quite found the answer I am looking for. I am going to use a 3 burner, naturally aspirated setup, and am curious, what the experts think about NOT using physical flare within the forge, ie no pipe, but instead forming the flare shape with the refractory. On the exterior, I plan to weld bungs to my forge tank, which my 3/4 burner pipe will thread into. On the interior, Im thinking about just molding a 2" dia hole with the refractory to serve as my flare, if this makes sense. Has anyone else done this, or am I being stupid? Additionally I am trying to find ball valves for the plumbing side of things, but it seems everywhere I check (Lowes, McMaster-Carr, Ace, etc...) only seem to carry propane rated valves with a max rating of 5psi. From what I understand, Ill need around 20-25psi for initial lighting, so these valves will not work. Where is everyone finding theirs? Ive used this project as an excuse to practice my 3D modeling, So ive attached a couple pictures to try and make sense of my Flare question. Any advise is greatly appreciated. Thanks to all. If its of any concern regarding the pictures, The blueish-purple areas represent 2 layers of 1" kaowool and the inner most white area represents the refractory. Quote
Mikey98118 Posted June 2, 2018 Posted June 2, 2018 First, you have too many burners for the forge length. One would be right; two is pushing things; three is going to choke the burners enough to reduce their effectiveness, and possibly enough to blow out one or more of the burners., unless your leave both ends of the forge wide open; in which case you will end up with a very high fuel bill. You don't want ball valves on each burner; you want needle valves on them. The drawings are fine. Quote
ADodds720 Posted June 3, 2018 Author Posted June 3, 2018 Please correct me if im wrong, but from what I understand these burners will heat an area of approx. 350 cubic inches. I did a rough calculation of the area within my forge and it came out to a little over 1,000 cubic inches, hence the three burners. My forge will be about 12in wide, 18in deep with a height of about 8-1/4in. Burner spacing is 6in center to center. If im incorrect, then that's great - less materials to purchase. If needle valves are what i need, then awesome. From pictures I saw online, it looked like everyone was using 1 ball valve per burner, plus 1 main shutoff ball valve, and only a needle valve operating the idle circuit. Below is one of the many examples I went off of. What do you think about my Flare idea? Would it be acceptable to form it with the refractory, or should I have a metal flare within the forge? Thanks again. Quote
Irondragon Forge ClayWorks Posted June 3, 2018 Posted June 3, 2018 Welcome to IFI...The experts will be along shortly. In the meantime I suggest reading this thread. Quote
John in Oly, WA Posted June 4, 2018 Posted June 4, 2018 Casting the flare into the refractory can work if it's the right shape - generally 12:1 taper is considered right. That's what I did in my forge and it works fine. Quote
Mikey98118 Posted June 4, 2018 Posted June 4, 2018 I'm really booking forward to watching your forge in action, so go right on ahead and to just what you like. Quote
ADodds720 Posted June 4, 2018 Author Posted June 4, 2018 John, So, according to my math (which i highly doubt) a 12:1 flare ratio with a 3/4" Burner and 2" Kaowool plus 1/2" refractory comes out to just a hair under 1" diameter. That can't be right, can it? I would think the flare would need to larger than that, then again, my math isn't great. Mikey, thanks for your words. I hope you don't think Im questioning your advice, im just another new guy, nervous about messing up. It might be a payday or two before I can start making some real progress, but I will be sure to post updates. One last hurdle remains however. Maybe the rules with propane are a bit different than what I know, but I can't for the life of me find the proper plumbing supplies I need. Ive checked Amazon, Propane warehouse, Lowes, and a couple local stores (one of which laughed me out the door) and I just can't find 1/4, 3/8, or even 1/2NPT propane rated 1/4turn valves that are rated for more than 1/2psig. I can't even find needle valves period. Are others here getting away with using these in their setups? I work with hydraulics at my fulltime job, and have seen many a valve burst due to pressurization issues, so I tend to get a little timid regarding things like psi. With that being said, im wondering if the propane world works a little differently since I cant seem to find what im looking for. Can anybody recommend an online supplier perhaps? Quote
Frosty Posted June 5, 2018 Posted June 5, 2018 Forget about big box stores and go to a HVAC supply and do NOT tell them what you're using them for. They have liability issues to consider giving advice to untrained people making gas burning appliances for home use. In the real world of home appliances nothing uses more than a few ounces of pressure so none of their valves, etc. are "rated" for high pressure. Just buy a 1/4 turn ball valve rated for propane in the size you need. As an old xxxx who's made a few of these things my advice to you is. Follow a proven set of plans and do NOT mix and match you don't know enough to experiment. I'm not trying to be mean I'm being honest, as drawn your design is going to be extremely inefficient. The waste heat will drive people out of a 40' x 60' shop building if the CO doesn't get them first. Don't sweat it, we all over build the things, I've made lots of forges and my last one was silly too large. I have my fingers crossed my next one will be more reasonable. Frosty The Lucky. Quote
ADodds720 Posted June 5, 2018 Author Posted June 5, 2018 Got it. And to everyone here, I appreciate the advice. Frosty, you are absolutely correct. I do not know enough or have the budget to experiment, which is why Im here :). Currently, my design is based off what material I have to work with along with all the great advise Im getting from you all. The forge body itself is larger than i really need, but its what I have to work with. Based off of the common volume equation I read here, I thought 3 - 3/4" burners was the way to go since the volume of my forge will be around 1000 cubic inches. And just for clarity, the back of the forge has a 2x8" breather with a patio, so i can block it off as needed with a brick. The front of the forge will be closed off with a hinged door (it doesnt show in the pictures a posted, I hid it for clarity) It will also have an opening 4x8" with a patio. i will post another pic. So, with the info I have been given, it sounds like having three burners is overkill. Got it. Ill drop down to 2 and adjust their positioning. As for the heat loss, Im hoping the lid in the front and a brick on the patios can take care of that. Please, I welcome all the criticism I can get. Its how i learn, and I am having a blast learning all about this subject. Quote
Mikey98118 Posted June 5, 2018 Posted June 5, 2018 Here is my best advice for that size and shape a forge; Use a ribbon burner in it. Quote
ADodds720 Posted June 5, 2018 Author Posted June 5, 2018 Ah, yes. I was just wondering if maybe I should go that route. I considered it initially but landed on this naturally aspirated design because it was simple (or so I thought) but with all this talk about my forge size, I suppose I shall give the ribbon burner some more thought. Luckily, i got all the time in the world to complete this, and im enjoying the ride. Quote
Frosty Posted June 5, 2018 Posted June 5, 2018 You can always add another layer of Kaowool to reduce the volume and the added insulation will improve efficiency as well. Oh and lose the firebrick floor use another layer of kaowool and a LITTLE extra hard refractory for the floor. Fire brick is too great a heat sink and really poor insulation so it takes more fuel to get hot and stay hot. The burners pictured are pretty simple and if you screw them to a multiple outlet block you have a naturally aspirated ribbon burner. See the "NARB lives" thread for my happy surprise with how well a T burner drives a multiple outlet (AKA ribbon) burner. You can make a multiple outlet burner any shape you want within reason, I'd be surprised if you could make really long say 20" with 21 burners on 1" centers. Using numbers from the NARB just for discussion sake. You can make rings, buttons, arcs, etc. shape burners. They're really common for glass work. Frosty The Lucky. Quote
John in Oly, WA Posted June 5, 2018 Posted June 5, 2018 I come up with a taper roughly 1.05" to 1.375" in a 2" span based on 3/4" sched. 40 SS pipe with an OD of 1.05" and the end of the burner inserted 1/2" into the forge. Quote
ADodds720 Posted June 6, 2018 Author Posted June 6, 2018 Frosty, i was hoping to use soft birck with a coat of ict-100 (i believe, starting to get products mixed up) that way i had an easily replacable wear surface. I also wasnt sure if filling that area in with refractory was a good idea, since im understanding i should only need about a 1/2in layer of it, built up in layers. I thought that would take me ages to do. John, thanks for the info, i dont know why, but when i thought 'flare' i figured like a 45degree taper to a massive diameter. Im suprised to see how little is actually required to be effective. Neat! Got some steel cut at work today (i get it at scrap pricing) so im excited to get going on this. The only problem is, im getting swamped with other things so in the mean time its just going to sit there, mocking me. I feel like a kid around christmas who found his parents hiding spot; i know what presents im getting, but i still have to suffer the wait lol. On another note, is the kaowool pretty compressable? I was wondering if the weight of refractory would affect the kaowool, thus affecting the forge area. Im sure its a non issue, but am curious nontheless. Quote
Frosty Posted June 6, 2018 Posted June 6, 2018 Unless you buy K 26 fire brick, soft fire brick degrades quickly due to rapid thermal cycling above their rated max temp. Level the floor with kaowool and cover it with a slightly thicker layer of Kastolite 30. If you use Kastolite the stuff is concrete hard at 3,000 f. and being an alumina refractory is pretty immune to forge welding flux. This method works and works well. Honest. You could buy enough material to build 2 forges for what one can of ITC-100 costs and it's not designed for what we do. ITC 100 is a release agent kiln wash to prevent things like glaze or spattering melted metal, glass, etc. from sticking to the inside of a furnace. It just happens to work OKAY in a propane forge, by OKAY I mean, better than nothing. Talk to Wayne Coe he sells reasonable quantities of products for reasonable $. Plistex or Matrikote are designed for what we do and are a small fraction of the price. Wayne's good people drop him an email or give him a call. Try for dinner time and tell him I told you to. Frosty The Lucky. Quote
John in Oly, WA Posted June 6, 2018 Posted June 6, 2018 A 45 degree taper would be a 1:1 ratio. 12:1 is pretty shallow. You rigidize the kaowool. That makes it well...rigid. Then it won't compress so easily when coating it with kastolite 30. Also, you apply the 1/2" of kastolite all at once. Not built up of many layers. It handles and works like concrete. Quote
Frosty Posted June 7, 2018 Posted June 7, 2018 That's 1:12, meaning it increases one dimension number in 12 times that number in length. For EXAMPLE, a 1" diameter starting dimension would increase 1" to 2" diameter in 12" length. If it were a roof a 12' wide pitch would fall 1' from the peak to the eaves. Were we talking a 12:1 ratio taper a 1" diameter start would be 12" diameter cone 1" high. It'd look like a cymbal, a High Hat? I know I'm being a Mr. picky butt but what the hey Mikey can't take the title unopposed can he? Frosty The Lucky. Quote
Binesman Posted June 8, 2018 Posted June 8, 2018 Here's my question. What do you intend to use the forge for? I see this constantly with people I talk to that are new. "Oh im going to get a 24" long 3 burner forge" why!? Dont get me wrong they have there purpose but most peiple dont need anything of that size. So if money is a factor look to making a smaller more reasonable forge that will cost substantially less now AND in the future. Quote
Mikey98118 Posted June 8, 2018 Posted June 8, 2018 So true; he can always build a larger forge later on, and the first small forge will continue to be useful; but it doesn't work worth beans the other way around. Quote
John in Oly, WA Posted June 8, 2018 Posted June 8, 2018 You're right Frosty. I drew it correct and said it backwards. Picky is important, as the devil's in the details. Reminds me of Spinal Tap and their Stonehenge stage prop. My house's roof would look a lot different if I wrote the ratio backward. LOL Quote
ADodds720 Posted June 8, 2018 Author Posted June 8, 2018 okay, time to respond to some posts. Sorry, im busy at work, so i havent had the chance to check in on my thread for a couple days. Frosty - understood. Kastolite with no itc-100 or fire brick. im still kind of wanting some sort of replaceable wear surface though, ive read up and a lot of people mention using kiln shelves. Maybe thats something i could consider? John - haha, i new about the rigidizer and totally forgot, duh. i get the brain farts every know and again. also when i wrote that last post i was thinking of using sanatite, given that was what everyone seems to use when i first looked into building the forge (via youtube.) They said to build it up in layers. Starting to sound like kast-o-lite 30 is the better material, I was not aware you could cast it all at once. Thanks for that tidbit of info. As for the taper thing, yeah, math has never been my strong suit, so i was kind of going off of what i had in my head. Binesman - heres my back story. im a spontaneous builder. it started when i was in highshool. My friends and i were in an old arcade at the mall, all the machines were beat to crap and barely running. I (being the smart ass I was) stated 'I could build a better arcade than this.' Of course, my friends bet me I couldn't. 9 months later it was on display at my graduation party. Jan. 2015 I saw a snippet on youtube from How It's Made on building canoes. I thought, 'I could do that'. Oct. of that year I put my 16' cedar strip canoe on the water for the first time. Now, im watching videos on knife makers, blacksmiths and all kinds of other things, and again, im thinking 'That looks effing fun.' Those are just a couple examples, but that pretty much brings me up to now. For my first build with the forge, i plan to go simple and make a knife or two. im also from a family that likes to shoot. we have hundreds of pounds of lead biscuits laying around because my grandfather used to cast his own bullets. He doesn't anymore, due to age and lack of means to do it. However, I would like to learn how to do that, so a forge might come in handy for melting down those biscuits. Im also primarily a wood worker, and would love to make my own set of tools like chisels and what-have-you. And who knows what i might want to build in the future, god knows i have a history of randomness. But by far the main reason Im building a forge is because its something completely new to me, as of 2 weeks ago i had no real knowledge of, and thats exactly the kind of thing that appeals to me. i love learning new skills and stepping out of my comfort zone. as of now, i know my forge will be larger than what i need it for, but the future holds many suprises. Lifes about the journey, not the destination. Im building it the size it is because my grandfather had an old compactor drum sitting in one of his farm sheds and told me to make use of it. As for money, im committed to this, so im willing to fork out the dough. The only problem i have is that I only have so much 'fun money' in my budget per paycheck, so it might take me a bit to save up. So far i have most of the steel I need. So, upon reading up on Frosty's NARB Live's, im pretty set on going that route. Im just working on modeling it up in CAD (practice is practice) I do plan on sticking to the plans. Currently, Im trying to find out the typical heatable area using a burner of that size. I see Frosty tested his in an approx. 365 cu/in forge, but is that the optimal size? What to do, what to do... NARB, FARB, qauntity, and forge size. All this stuff running through my mind, I can feel my brain turning to mush. Quote
Buzzkill Posted June 8, 2018 Posted June 8, 2018 Sometimes ya just gotta make a decision and run with it. As I'm fond of telling people, if you're having trouble deciding between absolute best and second best for your needs and you pick "wrong" you're probably still not far off the mark. Quote
ThomasPowers Posted June 8, 2018 Posted June 8, 2018 I would like to mention that a lead pot would be much superior than a forge for casting bullets... My grandfather cast several tons of lean using an old top of a cabinet gas ring---He had a bait shop and casting sinkers and tying flies and leaders was winter work. Quote
Frosty Posted June 11, 2018 Posted June 11, 2018 You aren't the first newcomer to a craft that tries to redesign proven effective tools and equipment for what s/he THINKS works better and heck, one in a couple thousand actually comes up with an improvement. I call that opinion unpolluted by knowledge. One serious note before I just sit back and watch. NO, do NOT melt lead in your forge! They're WAY too hot, lead will be vaporizing before the main mass liquifies and then the crucible will be seriously overheated. I don't know how many sinkers I cast from wheel weights on the Colman camp stove when I was a kid and that got hot enough to make it boil when I experimented or got distracted. I've always been a tinkerer and like you (maybe) I've never seen a device or tool I haven't automatically started redesigning in my head. I learned long ago to keep most of them in my head or on paper. I've never really come up with something new, minor adaptations yes, new? NO. Narb is just an adaptation of known commercially made, naturally aspirated, multiple outlet burners, you can buy off the shelf. The T burner is an adaptation of an ancient induction device I made to be easy to make with a minimum equipment list. It's not an invention or discovery. I put the two together simply because there is no good reason to need a high static pressure to make a multiple outlet burner perform so I did a little tinkering with disposable test units till I balanced the air flow through the device. I'm not trying to discourage you but I'm mostly going to just sit back and watch, heck I'll be happy if you DO come up with something useful. I don't see anything right now but you never know. Frosty The Lucky. Quote
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