Jimmies Posted August 27, 2018 Share Posted August 27, 2018 I'm just putting my first forge together and I have a couple of 7kg butane bottles. I've cut the top off and the inside diameter is 24cm. If I'm thinking of using 50mm ceramic blanket and a single burner, is the remaining space too small for anything useful once I get past my very beginner's stage? Cheers Quote Link to comment Share on other sites More sharing options...
JHCC Posted August 27, 2018 Share Posted August 27, 2018 What size is the burner, and what volume can it reasonably heat? If you use 50mm of blanket (2" to we benighted heathens) and another 12 mm or so (½") of rigid refractory, that would give you an internal diameter of 11.6 cm (4½") and an internal cross-sectional area of 105.68 cm² (16-3/8"²). Multiply that cross section by the internal length to get the volume. A 11.6 cm / 4½" internal diameter should be perfectly adequate for lots of smaller projects and basic knifemaking. As you progress to larger projects, you may find yourself needing a larger forge, but starting small is good. Quote Link to comment Share on other sites More sharing options...
ianinsa Posted August 27, 2018 Share Posted August 27, 2018 just think of it as the first of many and consider this your "economic" one it will possibly be the go to unit anyway. Quote Link to comment Share on other sites More sharing options...
Jimmies Posted August 27, 2018 Author Share Posted August 27, 2018 The bottle is only 31cm deep/long so I will also create a door at the back for when I need to. The burner will be 3/4 venture one, I was just wondering if this was too small and would leave me building a new one too quickly Quote Link to comment Share on other sites More sharing options...
JHCC Posted August 27, 2018 Share Posted August 27, 2018 If the bottle is 31 cm deep and you leave the back open, that gives a working volume of 3,276.18 cm³ (200 inches³). A 3/4" Frosty T-burner will heat up to 350 inches³, so if your burner is similar, you should be fine. Now that that is all out of the way, welcome to IFI! If you haven't yet, please READ THIS FIRST!!! Quote Link to comment Share on other sites More sharing options...
Jimmies Posted August 27, 2018 Author Share Posted August 27, 2018 I'll get on it now JHCC Quote Link to comment Share on other sites More sharing options...
Hans Richter Posted August 27, 2018 Share Posted August 27, 2018 Welcome Jimmies, Just add a 30lbs propane bottle forge to my tool yard because the 20lbs was not wide enough to take the slightly 'bigger' stuff (S-hocks, fire pokes, etc.) You prepare a 15,5lbs propane bottle forge. Nice for nails, spikes, small knifes. But as already said all depends on the work pieces you want to forge now and in the nearly future. Good luck & Cheers, Hans Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted August 27, 2018 Share Posted August 27, 2018 If your internal volume is around 200 cubic inches, you'll probably want to drop down to a 1/2" diameter burner. A 3/4" burner might be a little overpowered for that volume, which means wasting fuel and possibly not having the low end turndown temperatures available that you might want. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted August 27, 2018 Share Posted August 27, 2018 A 3/8" burner could be comfortably turned down enough to work. A1/2" burner can probably be turned down enough, but no guaranties. Quote Link to comment Share on other sites More sharing options...
Jimmies Posted August 31, 2018 Author Share Posted August 31, 2018 First firing of burner...lowest setting on regulator at the start and then opened a little. Needle valve in the middle Not sure if this is any good and also need to get a regulator with a psi gauge. Is there anything obviously an issue here? 20180831_173736.mp4 Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 1, 2018 Share Posted September 1, 2018 That is an excellent flame; you have no problem. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 2, 2018 Share Posted September 2, 2018 Well . . . Yeah, that beautiful flame isn't in a forge! Do you see the 3 burn zones, Mike? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 2, 2018 Share Posted September 2, 2018 I see a very high amount of combustion in the primary flame, with a minor secondary flame. But as you pointed out, it isn't mounted in a forge; when it is, I expect that secondary flame to be easily consumed. Is this flame perfect? No; but it is very far into the more than good enough zone It was you that taught me not to let the desire for perfection interfere with what's practical; that is a highly practical flame. I predict it will end up heating a very successful forge. It is so slightly reducing that if you blinked you'd miss it. Quote Link to comment Share on other sites More sharing options...
Jimmies Posted September 3, 2018 Author Share Posted September 3, 2018 Thanks guys - The forge is being built and I hope to have that ready in a week or so....just waiting for parts That vid was the first fire of the burner with the regulator only open a bit, when the regulator is fully open it really powers out. my regulator goes from 0.5 to 2bar and I'm using a needle valve up near the burner to try and control the flow of gas. I will get a psi gauge soon so I can get values for the output near the burner. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 3, 2018 Share Posted September 3, 2018 It occurs to me that there is no reason you should see this flame as I do, Frosty, because you followed a different burner path to the expertise you have achieved. So, what do I see that you can't about this flame? If you look at the flame's forward edge, it doesn't form a point; instead it is blunted and has many points, somewhat like a brush or broom. This is one of the configurations I experienced in my early burners. The back edge of the flame, where it exits the nozzle, is clear; it has no white in it. If the flame color was completely blue, it would have shown total combustion; as it is, there is just the faintest hint of green, showing a slightly reducing flame; this is confirmed by the faint secondary flame, which is as ghostly as a tertiary flame; but in this case it only goes to show how minor the amount of fuel was that escaped combustion in the primary flame. If the flame retention nozzle could be slid backward unto the mixing tube 1/8" more, the flame would probably burn perfectly; that isn't in the cards for a screw on nozzle. Nonetheless, I expect the forge heat to take care of such a minor problem. Quote Link to comment Share on other sites More sharing options...
Jimmies Posted September 3, 2018 Author Share Posted September 3, 2018 Below is the flame at full power...it is much louder and longer than the first clip 20180903_141736_1.mp4 Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted September 3, 2018 Share Posted September 3, 2018 Video format type unknown Quote Link to comment Share on other sites More sharing options...
Jimmies Posted September 3, 2018 Author Share Posted September 3, 2018 Hello Steve, I can see it find in my browser on PC and phone, is there an error somewhere? Cheers Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 3, 2018 Share Posted September 3, 2018 Running Google Chrome on Windows 10---no problem seeing/hearing that video clip. Quote Link to comment Share on other sites More sharing options...
MotoMike Posted September 3, 2018 Share Posted September 3, 2018 no problem windows 10 with edge Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 3, 2018 Share Posted September 3, 2018 This flame is as poor as the first one was good; a fine example of everything you don't want to see, with all three flame envelopes, and heavily reducing. Quote Link to comment Share on other sites More sharing options...
Jimmies Posted September 3, 2018 Author Share Posted September 3, 2018 This is why having the experience of others is so useful...the only difference I am noticing is a longer flame Is there a technical/in depth document or post I can read to understand what I'm looking for in a flame? Is this a fuel/air mixture issue or a design problem. The first clip was with the regulator near it's lowest setting (0.5 bar) Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted September 3, 2018 Share Posted September 3, 2018 you would be unlikely to see such a document because flames vary so much between different burner designs; there is no incentive to work that hard making a survey. Most people care about their own design and little else. The Burners 101 thread goes into what to look for in a flame, but the comments are scattered over 50 pages. Quote Link to comment Share on other sites More sharing options...
Jimmies Posted September 4, 2018 Author Share Posted September 4, 2018 I'll take a look in there and see what I can learn Thanks Mikey98118 Quote Link to comment Share on other sites More sharing options...
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