Lon,

What size blower are you using (How many cubic feet of air)? I use an 80 cubic foot bower on mine and have never had that problem. That said, I built a small forge and tried a 15 cubic foot blower. As soon as the forge got hot it would blow back like you described.

Dale

Any pictures of your set up? How far back is the gas injected? Lin

im not sure how many cfm blower i have i know it was used to inflate one of thoes inflatable advertisments that looks like a man only about 50 feet tall....ill take some pics and post them

ok here you can see the set up

Lon,

I think that you should back the nozzle out of the forge body. I bet that the steel nozzle is getting hot enough to ignite the gas before it exits the nozzle. When I build a forge, I butt the nozzle against the outside of the forge body.

Also, the blower looks to be way larger than is necessary.

I had the same problem a couple years ago and, just as Steve said, when I backed the burner out a bit the problem went away.

Seth

Hi Lon

My forge setup is similar to yours however, I did not reduce the pipe size. My pipe is a snug fit into the forge body. It appears from the picture that the reducer is at the end of the pipe in the forge. If your plans call for this reduction, you may try screwing a piece of pipe in the reducer and as was said earlier move the pipe back and seal up around the pipe.

One thing about blown forges is that what you force into the forge needs to come out and it will follow the path of least resistance. If you don't have a big enough opening (that you put your steel in) in your forge the 2000 + degree air may try to excape past your pipe (burner). This will heat up your pipe and cause the problem you describe. If you have a lot of heat escaping along your pipe, you need to seal it up better or have a bigger opening in your forge.

Brian

I am new to the blown forge setup. I just recently added a blower; so I'm still tweaking mine as well. My only comment is that those bounce house blowers are some kind of powerfull. We've got one for our kids and I considered using it but decided it was too much.

My blower(squirel cage type with 1/6 hp motor) is working but it seemed to be putting too much air in, because I had to turn the gas up really high to get an appropriate mix/burn. It also shot heat quite a distance out the front. If I turned the gas down, the blower actually had a cooling effect and made a huge cold spot in the back of my forge. I have diverted some of the air now; and can run a lower fuel setting getting a super hot forge. I'm not sure of the exact temp but its hot enough, I've already burnt a piece of steel; looked like a sparkler. I'll have to be more attentive, but as I said, I'm still learning how to use it.

|quoted:

I am new to the blown forge setup. I just recently added a blower; so I'm still tweaking mine as well. My only comment is that those bounce house blowers are some kind of powerfull. We've got one for our kids and I considered using it but decided it was too much.

My blower(squirel cage type with 1/6 hp motor) is working but it seemed to be putting too much air in, because I had to turn the gas up really high to get an appropriate mix/burn. It also shot heat quite a distance out the front. If I turned the gas down, the blower actually had a cooling effect and made a huge cold spot in the back of my forge. I have diverted some of the air now; and can run a lower fuel setting getting a super hot forge. I'm not sure of the exact temp but its hot enough, I've already burnt a piece of steel; looked like a sparkler. I'll have to be more attentive, but as I said, I'm still learning how to use it.

im thinking of shutting off the intake of the blower a bit too mine is doing the same....im afraid that the extra heat will start a fire in the shop up next to the celing of the shop...thanks for all the helpful advise ill be working on this over the next few days

Lon

I did that at first too. It worked fine but I was concerned with the strain placed on the motor; dont know if its justified, but I didn't want to burn it up. So what I ended up doing was splitting the line just past the blower with a Y and then but a valve there to allow adjusment by dumping/diveting the air flow. The motor gets a normal intake and has no pressure build up while I just control the flow to the forge.

Like I said. I don't know if putting a strain on the motor would cause any issues, but it sure seemed to be getting hot to the touch. Now, not nearly as much. All it cost me was a couple of bucks for the Y.

The best way to control air volume on centrifugal and squirrel cage blowers is to put a damper over the intake. Just cut a piece of thin material (micarta, plexiglas, sheet-metal) and attach it to the blower with a single screw/bolt at one edge. Then, control the air flow by adjusting the damper to shut off a portion of the blower intake area. This won't do any damage to the blower motor.

it worked wonderfuly pulling the burner back outside the forge chamber did the trick thanks guys!

i to had all these problems and you guys have given all the answers i would have,there is just one other thing you can do to regulate the flow is get a dial speed control for it,this is what i did and it works great! i heard of guys using dimmer switches for this but i don't know how that would work.

Hi everyone,

I have a very large blower on my forge. Much larger than those shown. I put a "Y" on the outlet before the gate valve to the forge, attached a damper to the excess air side and then a flexible metal dryer vent hose to it. This hose is routed up and attached to the forge to blow hot gas away from the forge opening. When the gate valve is open all the way and I still need alittle more air to reach welding heat, I can use the damper on the hose to send a bit more to the forge. It ain't real pretty, but it has worked for me for 15 years. I have thought of getting a smaller one just for the forge, but then would need another one for the forge door. Just what I do. Dan