natenaaron Posted March 28, 2016 Share Posted March 28, 2016 Here is what I have grill sized propane tank 4 inch hole cut for a door 2.5 inch hole cut for a back door two inches of ceramic insulation .25 inch satanite one coat of ITC 100 Frosty T-burner without flare and nipple cut down 1/8 inch The burner is into the forge 1 inch so not past the insulation at all. I have the burner aimed just short of center and have a nice vortex. I only have blue flame (think this is the problem but not sure what to do about it) Tank connected to hose through HP regulator that does not have a gauge so I could not tell you what pressure it is running but I turn it up high and still not getting the heat. My math says one burner is on the upper side of fine. My math could be wrong I've tried to get a video of the forge burning but with the blue flame being blue I'm not able to get a good shot. I am able to get enough heat to forge with. That is not a problem. I am not getting to white where, if I understand what I have read, I need to be to weld. Any thoughts. Quote Link to comment Share on other sites More sharing options...
jacob's hammer Posted March 28, 2016 Share Posted March 28, 2016 my propane tank not done yet but i'm going with two 3/4" t burners. i think one works per 350cu/in and 20# tank is 580 cu/in i believe. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted March 28, 2016 Author Share Posted March 28, 2016 Did you do your math after the lining was added? Not questioning you just making sure we measured the same thing. I came in just under 350. I am no mathematician. Just ask the 2 college algebra teachers whose classes I failed. At this point I think I just need to start over. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted March 28, 2016 Share Posted March 28, 2016 Have you tried completely blocking off your pass through hole in the back with insulating fire brick or some coated kaowool? You will want as little heat escaping the chamber as possible. Depending on your diameter you could also try another layer, or partial layer of kaowool to decrease the volume, but you'd still have to at least rigidize and coat it with ITC. I'm not sure what effect the satanite lining already in place would have on it though. Is the flame light blue or a deeper blue? You can try choking off some of the air to see the effect on the flame color. When it starts to turn greenish you're into a reducing flame, but it will not burn as hot as the blue flame, so you don't want to go quite that far. For the Frosty T the distance the mig tip sticks down into the opening towards the burner tube affects how much air is drawn in with the propane. If that's already tuned as close to ideal as you can get it then you may be looking at a second burner to reach the desired temps. With any luck, Frosty or Mike will join in here and help you get where you want to go. Quote Link to comment Share on other sites More sharing options...
Dodge Posted March 28, 2016 Share Posted March 28, 2016 If you are using a standard 20# propane tank with 2" of insulation throughout, your forge chamber volume is about 794.43 cubic inches. This is base on an approximate diameter of 12.5" and a height of approximately 18 inches. 2" insulation would reduce this to 8.5 diameter x 14" chamber. Formula for volume of a cylinder is 3.14 x radius squared x height. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted March 28, 2016 Author Share Posted March 28, 2016 That would be it then. Darn it! Time to start over. Chock it up to a learning experience. No way to successfully cut another hole in it. I would have to plug the old one and cut two new holes in in it. Thanks folks. Glad I got an answer before any of the curmudgeons came out from under the bridge. Quote Link to comment Share on other sites More sharing options...
wpearson Posted March 29, 2016 Share Posted March 29, 2016 go from a 3/4 to 1" burner Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted March 29, 2016 Share Posted March 29, 2016 If it were me I'd probably try to salvage that build. A drill with a hole saw can make a couple new holes. You can plug the old hole with some scrap kaowool and patch it with a little satanite on the inside. That would still be pushing the limits with two 3/4 inch burners though. If you're going to use the same shell and do a rebuild, then 3 one inch layers of kaowool would give you about 6.5 inches inside diameter for about 465 cubic inches of volume at 14 inches in length. That's still too much for a single 3/4 inch burner, but well within the parameters for 2 of them. If you do the rebuild you might want to consider cutting one or both of the ends off to decrease the length unless you need to heat over a foot of stock at a time. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted March 29, 2016 Author Share Posted March 29, 2016 I actually have another tank cut up already, and this one can be set aside for other purposes. I won't tear it down. I have enough supplies to build a couple more forges. After some soul searching and thinking I am going to explore the brick pile forge and what it will take to make a coal forge. Not because I think they will be easier but because they may fit the style of work I want to do, more appropriately. Ornamental work can get pretty big and the gas forge just feels too small. We will see. Thanks for the advice. Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 29, 2016 Share Posted March 29, 2016 PIctures? One of the flame before the forge is up to temp, another sideways so we can see the dragon's breath and one of the whole unit, forge and burner. Your list of things doesn't say much about how it's put together. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
CoyoteGear Posted April 8, 2016 Share Posted April 8, 2016 You could add a castable refractory into the bottom to make a level floor & reduce some of your internal volume. Don't know if it would be enough. To change anything though. Quote Link to comment Share on other sites More sharing options...
ThorsHammer82 Posted April 8, 2016 Share Posted April 8, 2016 why not just fill in more of the empty space with more kaowool to reduce the volume of the chamber? no need to added burners and cut holes. Or add a burner more from the side closer to the front to help with the vortex, and get the needed heat input. leaving no need to completely redo the whole build. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted April 8, 2016 Author Share Posted April 8, 2016 On 3/29/2016 at 1:33 PM, Frosty said: PIctures? One of the flame before the forge is up to temp, another sideways so we can see the dragon's breath and one of the whole unit, forge and burner. Your list of things doesn't say much about how it's put together. Frosty The Lucky. Forgot about this thread. Got busy researching the new forge. I will post some pictures in the next day or so. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted April 9, 2016 Author Share Posted April 9, 2016 Here are some pics. It is very hard to get pics of the dragon's tongue because it is a very light blue purple no matter how high I turn up the gas. The blue flame is blue no matter what too. All of my tech seems to be rebelling against me today. Short of firing up photoshop nothing would save the images right side up. no idea what I am doing wrong. If the images being upside down is an issue I will do what I can to right them. Quote Link to comment Share on other sites More sharing options...
swedefiddle Posted April 9, 2016 Share Posted April 9, 2016 Your Burner is too small, You are not passing enough Gas!! Eat more Beans!! Seems you have been modifying suggestions and now can't figure out what went wrong. Be bold, try something else. Neil Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 9, 2016 Share Posted April 9, 2016 The dragon's breath is blue and minimal. If you reduce the volume it will help but filling with cast refractory is just adding thermal mass to suck up BTUs to no good. You can put in another layer of ceramic blanket, rigidize it and kiln wash it to MUCH better effect. It'll lower the volume and increase the R value. making the doors smaller will help a BUNCH. My first thought and probably best solution is build a 1" T burner. A 1" is generally good to bring 600-700 cu/in to welding temp, it'll ROCK yours, you'll be keeping it turned down. Remember it's better to have it and not need it than need it and not have it. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted April 9, 2016 Author Share Posted April 9, 2016 I feel like I am chasing my tail with this one. I have done so many things wrong on it, that something else will just go wrong. Next weekend, god willing I will be starting a new one. This time I will admit that I have no idea what I am doing and NOT try to improve anything. I will follow the advice gleaned from here and some help I have gotten from a very helpful smith, no longer on here. Lessons learned the hard way is the story of my life. This one will stick around just in case. but the next will be much better because of the lessons. Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 10, 2016 Share Posted April 10, 2016 Been there Nate, don't be discouraged. The important factors that determine what you can Expect your forge to develop are: Volume and burner size ratio being the most important then doorway size, then insulation and lowest on the list IR reflective finishes. I don't know how you're going about this but a really important practice is changing ONE thing at a time then test and fiddle. Changing more than one thing can open a can of worms that's just luck to resolve. I've been messing with a new forge for way too long right now. I've posted pics of it sort of a more portable cut down version of my shop forge. Two 3/4" T burners I set into 3/4" floor flanges in the roof. Well, there's where I started getting fancy I tipped the burners back with 45* elbows to get the air intakes farther from the opening and exhaust. Last in my folly I cast a flare into the roof refractory. HUH? Frosty put a flare on his T burners? Uh yeah, I put flares on them, I figured what the hey. Worse still I made the "flares" Fan nozzles too so they'd make a sort of flame curtain to make more even heat and maybe even a barrier to outside air. Sound confusing? You should try getting any of it to work properly. What I'm finding is when I find something that ain't right and change it I'll have unintentionally changed something else too or overlooked an easy to bump thing like jet alignment and lose a day fiddling with the wrong thing. Even though I've stripped almost ALL my "improvements" it's still not cooperating. Better but not right. <sigh> I've been messing with this thing off and on for close to a year. Maybe I get a little cross with folks for not following directions or advice because I don't even follow procedures I KNOW to be the easiest fastest way to trouble shoot problems. If I could compose music I'd write, "Outsmarting myself . . . AGAIN." Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
natenaaron Posted April 10, 2016 Author Share Posted April 10, 2016 I'm not discouraged I just know not to chase the pot. I would rather forge than fiddle with the forge. I will post my forge design and explanation later this week. I am hoping folks chime in about things before I put it together. Quote Link to comment Share on other sites More sharing options...
swedefiddle Posted April 10, 2016 Share Posted April 10, 2016 Good Morning, Keep a Log. If you change more than one thing, which was the driver of the Change? Don't be afraid of Testing as long as it is done Safely. If you want a sure-fire Forge, Purchase one that someone else has already learned from their mistakes. The biggest mistake is not keeping a memory Bank, called a Log. There is no such thing as Failure, it is just procedures that don't work as well as your Success'. This simple procedure is consistent with many things in Life. Some people call this R&D. What is an Invention, It is just an amalgamation of thoughts in a sequence that hasn't been proven before. Eureka!!! I have heard, that someone said that previously!! Neil Quote Link to comment Share on other sites More sharing options...
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