Aman Posted November 13, 2008 Share Posted November 13, 2008 I am making a gas forge. I have seen several people use small propane tanks. My question is, do you have to use an adjustable regulator or can you control the flame with a needle valve or something like that? Also is it necessary to have a pressure gage? Thanks Quote Link to comment Share on other sites More sharing options...
Woody Posted November 13, 2008 Share Posted November 13, 2008 yes it is necessary to have an adjustable regulator and yes it is also necessary to have a pressure gauge. Quote Link to comment Share on other sites More sharing options...
David Einhorn Posted November 13, 2008 Share Posted November 13, 2008 Yes, no other options, you must have a regulator and pressure-gauge. Quote Link to comment Share on other sites More sharing options...
Pleasant Lea Forge Posted November 13, 2008 Share Posted November 13, 2008 (edited) ... My question is, do you have to use an adjustable regulator or can you control the flame with a needle valve.... is it necessary to have a pressure gage? Thanks Aman, Yes, you do need the regulator, but can incorporate a needle valve to say set up an idle flame control for example. The regulator's purpose is to control the tank pressure, stepping it down from about 90PSI to a working pressure of 5-15PSI. No way around this. A needle valve's main function is to control the rate of flow. Edited November 13, 2008 by Pleasant Lea Forge Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 13, 2008 Share Posted November 13, 2008 You do not need a pressure guage; most of them are 10-50% off anyway so they are basically specific forge specific; ie you find out what works for your forge and it's pressure guage allows you to set it up that way again easier---until the guage gets bumped and changed. You do need to be able to tune your forge by eye and ear though; guages LIE! Now a regulator is highly suggested as it makes for a more constant delivery of gas. I had a friend use a needle valve once without a regulator and as the tank's volume of propane changed he had to mess with the valve a lot to try to keep the same burn he wanted. Note that adjustable propane regulators are available that are much cheaper than acetylene regulators. Make sure you don't get a propane grill regulator as they are preset quite low. Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 13, 2008 Share Posted November 13, 2008 Neither are "necessary" but they make things a lot easier for you. As said, gauges aren't particularly accurate but what they will do is give you consistent marks so repeating forge conditions doesn't require eyeball adjustments and the time lag involved. A good quality needle valve will indeed work just fine but you not only enter into the same inefficient realm of eyeball adjustment but as said tank conditions (pressure) changes mean you'll have to adjust as necessary rather than set it and forget it. So, necessary? No. Recommended? Oh yes, very much so. I've tried it all four ways. Frosty Quote Link to comment Share on other sites More sharing options...
Woody Posted November 13, 2008 Share Posted November 13, 2008 "You do not need a pressure guage; most of them are 10-50% off anyway so they are basically specific forge specific;" Thomas, do you mind telling me where you got your information? Several years ago when I was involved in tank trailer inspections, one of the things tested were pressure gauges. They were checked against a certified gauge that was recertified every 6 months. The pressure gauges tested were very accurate. Quote Link to comment Share on other sites More sharing options...
Aman Posted November 14, 2008 Author Share Posted November 14, 2008 Thanks for all the help. I will be getting an adjustable regulator this weekend. I will try to get the forge put together and get some pictures. I am sure I will many more questions and problems. Still I am excited to be getting into this. I have always been interested in blacksmithing. Again, thanks alot God Bless Aman Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 14, 2008 Share Posted November 14, 2008 Look for a 0-30psi propane regulator, you aren't going to need one that goes to 50. You can usually find them at good hardware stores and gas suppliers. Frosty Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 14, 2008 Share Posted November 14, 2008 I got my information from a talk given to our blacksmithing group by a welding supply company. They claimed that regulators tend to get bumped a lot and gauges suffer. I have also seen a number of identical forges-built in a workshop--all show different pressures on their gauges to get the same result in the forge; though this could be due to manufacturing variability. I was also part of an ISO certification process where we had to callibrate *everything* regularly and keep a record of it. (Of course "everything" did not include tank trailers in my case.) Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 14, 2008 Share Posted November 14, 2008 I can speak for the variance in burner construction. I recently, (Last spring) built six 3/4" burners of my "T" design. I used my lathe to ensure alignment and matched everything as closely as possible. Every single one burns differently, not a lot but noticeably. Frosty Quote Link to comment Share on other sites More sharing options...
Aman Posted November 14, 2008 Author Share Posted November 14, 2008 O.K. I got the forge built. It is a brick forge made using six and a half bricks. Two on bottom, two on top, one on each side, and a half filling the hole in back that can be removed if i need to work with long pieces of stock. I used the BP0191 burner. I used rubber hose and no needle valve. I have a 0-30 high pressure regulator. I am not sure what the fire is supposed to look like. I have played alittle with the regulator. My flame is blue and loud. It hits the opposite wall and rolls both up and down. My next step is to put some stock in it. Just wondering if it all sounds right so far? Thanks Aman Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 14, 2008 Share Posted November 14, 2008 I've attached two pics. The first one is my old pipe forge and the burner is burning rich, more rich than you really want one to. The second pic is a Fisher burner and the color of the flame indicates neutral flame. You want to tune your burner just slightly rich which will be a slightly more pastel color blue than the flame on the Fisher burner. What size burner did you build? If the forge volume is too small it will make it difficult to tune the burner. A volume of 350-400 cu/in requires one 3/4" burner to make welding heat. Less than 200 cu/in and back pressure can make problems and you'd be farther ahead using a 1/2" burner. Frosty Quote Link to comment Share on other sites More sharing options...
Aman Posted November 15, 2008 Author Share Posted November 15, 2008 I used a 3/4 burner. Made it just like the BP0191. It looks lik I have about 134 cu/in. I used a 1 1/2 to 3/4 reducer to make the burner. Should I get a 1 1/4 to 1/2 or can I just step the 3/4 down to 1/2. Thanks, Aman Quote Link to comment Share on other sites More sharing options...
Aman Posted November 17, 2008 Author Share Posted November 17, 2008 O.K. here is what I have.... I put a railroad spike in it today and after about 8 min. it was alittle red. I also put a mower blade in it and could not get it bright red either. Am I asking to much for this forge or do I not have something adjusted right. After looking at Frosty's flame, I wonder if mine is adjusted right. It has the same blue, but doesn't look like it has the same force. Any advice or comment would be helpful.... Thanks Aman Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 17, 2008 Share Posted November 17, 2008 It's running rich probably because the jet is slightly off center, it's hitting the bottom of the tube as seen in the picture. Frosty Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 17, 2008 Share Posted November 17, 2008 OK: The problem is that you are using hard firebrick which is not very insulative and a great big heat sink. Expect to run you burner for an hour or two just to heat the forge up enough to start heating stock in it. Put a liner of soft firebrick or kaowool and you will start seeing a lot more heat in there! Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 17, 2008 Share Posted November 17, 2008 You're right Thomas, hard brick does take much longer to come to heat. Unfortunately even soft brick won't come to heat with a mistuned burner and taking a second look I realized that in addition to the jet being misaligned it's too much burner for the volume and back pressure is hindering induction too. It needs at least half up to twice the volume of the current configuration OR open both ends so it can breath. Regardless, insulation is a huge efficiency booster. Frosty Quote Link to comment Share on other sites More sharing options...
Aman Posted November 18, 2008 Author Share Posted November 18, 2008 Thanks guys, I am going to work on it and see what I come up with. I did not know there was a difference in the bricks. Can I get kaowool at most hardware stores? I did adjust the the jet some after taking this picture. Thanks again, Aman Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 18, 2008 Share Posted November 18, 2008 Try a furnace supplier, if they don't carry it they should know who does. A ceramic supply should as well but it'll be more expensive. Suppliers like Jay Hays will mail it to you as well as ITC-100 and other various forge supplies, parts, kits, etc. Frosty Quote Link to comment Share on other sites More sharing options...
Aman Posted November 18, 2008 Author Share Posted November 18, 2008 O.K. I shouldn'y need much. Do you think I need to make the forge bigger? I don't plan on doing big stuff yet. I also plan on building a coal forge sooner or later. Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 18, 2008 Share Posted November 18, 2008 A 3/4" burner fits 350-400 cu/in of furnace volume depending on variables. Putting one in a furnace with too small a volume will produce back pressure that will effect it's performance significantly. A too large burner CAN be tuned to run in a small chamber but you'd have to completely retune it if you opened a back door and reduced the back pressure. How many cu/in is your forge? It's something you need to calculate before you build the burner. Frosty Quote Link to comment Share on other sites More sharing options...
Aman Posted November 18, 2008 Author Share Posted November 18, 2008 A 3/4" burner fits 350-400 cu/in of furnace volume depending on variables. Putting one in a furnace with too small a volume will produce back pressure that will effect it's performance significantly. A too large burner CAN be tuned to run in a small chamber but you'd have to completely retune it if you opened a back door and reduced the back pressure. How many cu/in is your forge? It's something you need to calculate before you build the burner. Frosty After you gave this advice earlier, I measured the chamber and found it to be About 135 cu/in. I then made my burner a 1/2 in burner. I can remove the back door. I also just ordered some Kaewool to insulate it. Any and all advice is recieved Thanks Aman Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 18, 2008 Share Posted November 18, 2008 That should be about right for a 1/2" burner. Ask anything you need to, I'll do what I can. Frosty Quote Link to comment Share on other sites More sharing options...
Aman Posted November 20, 2008 Author Share Posted November 20, 2008 I'm waiting on the Kaowool. Then, I am going to get back at it. I have been collecting lots of scrap steel and files and such. Can't wait to hammer away Thanks Aman Quote Link to comment Share on other sites More sharing options...
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