ok, so I started the burner

S

SirMendor

Joined
Jun 21, 2009
Messages
31
here it is so far.
3675778625_5bc89a7e15.jpg


It's not quite done yet. Gotta figure out how to attach the blower and the propane hose, will do that in the coming weeks.

I got two ball valves and ouch! Didn't think they'd be $7.29 each. Over all I spent just under $30 on it so far.

If anyone has ideas how to fix my two newest problems, please let me know.
 
what size pipe are you using? it looks like 1 inch from the picture. i built one from 1 inch and it doesnt get hot enough. i am thinking its because the pipe isnt big enough for the gas and air to mix properly.

jake
 
1/2", it's not gonna be a very large forge and it's forced air so it should get plenty hot enough.

I don't plan on the body being more than 12" long and 8" wide.
 
I think 1 1/2" to 2" pipe would work much better even for your forge size. Your mixing chamber should be at least 1.5 X the size of your delivery pipe. It will be very hard to get any type of air volume down 1/2" pipe. Just my .02 cents...

Eric
 
Mike,
The folks here are trying to tell you that a 1/2" pipe won't work for a blown burner. Please listen to them.
1" is a bit anemic, 1.5" to 2" works better. 1/2 is way too small.

As to how to hook up the propane line. It is usually a 1/4" pipe fitting. Just put a reducer on the ball valve. BTW, a 1/4" needle valve works far better for regulating the gas. The gas line can be 1/2" or 1/4".

The air can be regulated by a gate valve, or a ball valve, but as said, the air line should be a minimum of 1.5". The blower should deliver at least 60 CFM, and 90CFM is better.

Stacy
 
ok, so is the burner part ok then? Or do I really need to scrap then entire project? Couldn't I just put a series of reducers behind the T section to build up to 1.5" or 1.25"?
 
the restriction imposed by your pipe will be too much backpressure for a normal blower to overcome and still deliver enough air for complete combustion. If you are feeding it with a shopvac you might be able to make it work, but most squirrelcage type blowers are not designed to work against static pressure

-page
 
I didn't figure on an squirl just yet I figured a cheap hairdryer should work until I can afford better stuff. This is all just to get me going.
 
am i missing something, or is there a jet of some sort in all that pipe. needs an orifice of some sort....
 
oldold,
You are missing something......that is a blown burner, and there is no jet. The blower would connect to one valve, and the gas to the other. As said by the commentors, it is built wrong and won't work well as is.
Stacy
 
I know ya'll said my burner wouldn't work cause it's too small but I found this http://www.rayrogers.com/miniforge.htm It's a blown mini forge with pipes the same size as mine. Guess with the right blower it will work.

Now, this isn't a "I told you so" just thought I'd let ya'll see this.

~Mike
 
Since I do not use a forced air burner, I am going to give you a link to another forum this is a gate valve for a forced air burner and and the system. Take a look at it and maybe you can see what folks are talking about.
The first link is on how to build a gate valve out of wood for a blown forge. However a large gate valve will do it to.

http://www.rayrogers.com/gatevalve.htm

The second is on actually the forge with the forced air setup. Maybe this will help yo work out your problems.
http://www.rayrogers.com/forcedair.htm
 
I found his mini forced air forge page already, that's why I think mine will actually works since it's the same size as mine, atleast the pipes are. I'll try it anyway. If it doesn't work, I'll build bigger.

Hey guys, I'm they kind that needs to try things out for themselves. If I fail, I fail. I'll dust myself off and rebuild.
 
The reason that mini forge is working is that the blower is actually a pump and it pumps the air through the pipe. I honestly say that if you can return the parts and get what you need you should. most plumbing places are great with taking stuff back even with out a receipt. how i did mine was 1.5" from the blower into a T that had a reducer on it to take my small ball valve and gas line. then from the T i used a bell reducer and changed the size to 2". then used a 4" nipple out of the bell reducer. then i attached a 2" to 1" bell reducer to the nipple and then some 1" to the bell reducer for the burner tube. worked great. i am redoing my set up now as i have a larger blower and need to changes things up. but the people here are very knowledgeable and just want to help. I don't know if a hair dryer could push enough air through that long of .5" pipe and still have enough air for the heat needed. I think you said your forge body was going to be 13" long by 8" or something. the one i have is 14" long i think by 8" around. now that leaves me with 5.5" inside space as i used only 1" thick insulation and then some other stuff. but i can tell you right now that a .5" would not power my forge at all. that mini forced air forge you saw could run off just the propane torch with so so results. and a .5" pipe is going to give you at least as much as the torch probably a bit more, maybe double. now the blower i have could push the needed air through a .5 pipe but its a very high end blower and retails for $350.00 cheapest online price as it puts out a lot of pressure. I'm not trying to get you down its just why not go with something you know or others know will work. when i made my first burner i posted a picture of it and quickly was told how to fix it. i tried it and had problems. so i listened and made it how i was told and it worked great. I think that math is something like this. A Reil type burner puts out around 135000-140000 btu's and it is a 1" ventury burner. this burner is rated for around 250 cubic inches of space. so that means to have a forge that is able to hit the temps you would want you would need around (135000 btu/250cu/in=) 540 btu per cubic inch to hit welding temps. I know you might be thinking " I don't want welding temperatures", just keep reading. The propane torch that all the small mini forges use puts out i think 2700 BTUs with propane and a little bit more with map-gas. so that means you are able to have a forge with a volume size of 5 cubic inches that could technicality hit welding temps. So 5 cubic inches is about what a one brick forge is with a small chamber. but the brick forge is a lot less efficient then a wool lined forge and so really the 540 btu per cubic inch is quite underrated for that type of forge. so even if your burner could put out 3 times what the torch does your still looking at 8100 btu which divided by 540 is 15 cubic inches and your forge would be 339 cubic inches if the chamber size is 6" by 12". you would need like 60 propane torch's to reach welding temps. now all the math in the world does not tell the whole story. you can very these numbers a bit and still come out ahead. but if you are really wanting to make a good forge and i'm guessing you are. then take the advise from others and my self in good faith that we really do have good intentions and want to help.
 
I thank you all for the advice, but as I said. I just need to try it out for myself. Just the kind of person I am. Besides, I'm sure I could make something else out of these parts if the burner doesn't work.

I'm thinking of shortening the nipples and putting a larger bell on the back just before the ball valve. I know the gas line will work, Stacy even said so I think. Don't quote me on that though.

I have some ideas on modifying it so that it might work better. I just wanna test it out before rebuilding.

And I decided on the paint can forge anyway, much smaller area to heat than I was originally thinking.

Like I said guys, I'm a bit stubborn and gotta try it out myself. if it fails then I will rework it as all of you have suggested. But until then, just gotta try.
 
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