School Me On: Forge Burners

[Phil Dwyer]

....When looking at the set up, I keep thinking that using a T fitting and cap similar to a side arm burner would be easier to put together from the standpoint of ensuring proper alignment down the center of the pipe leading to the forge.

I believe we did use a T with a tapped plug for the one he helped me build.

Another question is... I noticed that IG drilled a 1/8 hole in his 1/4 gas "sprayer" whereas ABANA drilled a 1/16 hole. Does it make a difference?

I wonder that too.

 

[T Blade]

...., and the flow of air would have a bit more turbulence, but would those factors be significant enough to rule it out as an alternative for someone who isn't sure they could line up the fuel tube as accurately?

Actually in a way you want the turbulence, which is used a mixing area, the more the fuel is mixed with the air (vaporized) the more efficient the combustion. IG's and the others are just examples of the setup, centering is not nearly as much of an issue with a forced air system then it is with the venturi types. As far as the 1/8" drilled pipe cap, it is also not an issue. I tried one on my forge and since have removed it. My forge reaches temps in excess of 2200oF no problem.

Just to give you more to think about, here is a link to Don Fogg's forge building page. Don is one of the premier knife makers (may I say) in the World. Don likes to construct vertical forges, I have one of his type forged and it also welds like the dickens , and you don't get the dreaded "hot spot" mainly because your are above all the fire.

http://www.dfoggknives.com/forge.htm

 

[sunshadow]

Another question is... I noticed that IG drilled a 1/8 hole in his 1/4 gas "sprayer" whereas ABANA drilled a 1/16 hole. Does it make a difference?

I use a 3/64th hole so I can get a little pressure on the gas feed line which makes it easier to fine-tune mixtures

-Page

 

[jawilder]

About the forge liner... Will 2" of insulation be the same as two 1" layers. They are both rated at 2400 from ellis

 

[Fred.Rowe]

I don't want to hijack this thread, but I have a question about the forced air sets I'm seeing. They all appear pretty similar and the part that riases a question is the elbow where the gas is inserted into the air stream. They all appear to be like IG's and a 90 degree elbow drilled out with a peice of 1/4" black pipe welded in. When looking at the set up, I keep thinking that using a T fitting and cap similar to a side arm burner would be easier to put together from the standpoint of ensuring proper alignment down the center of the pipe leading to the forge.

I understand that it requires a few extra plumbing bits, and the flow of air would have a bit more turbulence, but would those factors be significant enough to rule it out as an alternative for someone who isn't sure they could line up the fuel tube as accurately?

I used tees with reducers for the gas injector on one side of the tee.
Each burner should have its own needle valve so each burner can be adjusted separately. There are many ways to make it happen and each person has their own approach. I agree with you that the tees are one of the easier methods.

Fred

 

[Fred.Rowe]

About the forge liner... Will 2" of insulation be the same as two 1" layers. They are both rated at 2400 from ellis

There is no difference between the two, but the two inch in a single blanket stays in place better than two 1" sections. When you go to coat the surface with refractory cement the two inch stays put better. The one inch layers will tend to sag with the weight of the cement.

Fred

 

[Salem Straub]

One inch wool is IMO a bit easier to install and repair- but either way will work. (With two layers, I've been able to just replace the outer layer as needed to save cost.) I like venturi burners because I don't have to have a blower running to do a quick forging project and because they are easier and cheaper to build for a beginner, also IMO. They make a good travelling setup if you like to go out and do demos, and they can be tuned to be very efficient.

That said, I weld in a blown forge because I have a Don Fogg type vertical pipe forge (I'm totally sold on this) with a cast inner liner for greater durability and flux protection. It takes a good while longer to get the liner up to heat with venturi than using a blown burner and really putting the boots to it. Also since the flame is below the workpiece it works well for even heat to get a large swirling flame in the heat chamber and it seems blown works better for that. I do feel that blown burners are easier to control and superior for welding. There are just pros and cons to both for me, I do some general blacksmithing and it's nice to have a portable setup that's user friendly.

 

[jawilder]

I use a 3/64th hole so I can get a little pressure on the gas feed line which makes it easier to fine-tune mixtures

-Page

I started gathering parts for my blower yestrday and have questions.

I used a 1-1/2" to 3/4" Tee with a 3/4" to 1/4" bushing to attach the LP line. The 1/4" nipple I got was galvanized b/c finding 1/4" Sched 80 nipples are like finding Hen's teeth around here

Q. Does the 1/4" nipple HAVE to be black pipe since it is connected to a galvanized Tee? How hot does the burner get after it passes the black burner tube connected to the forge?

Q. Since I am using a Tee to bushings to nipple with gas, does the 1/4" nipple still need a plug with a hole drilled in it to "jet" the gas or does the needle valve do that upsream?

Q. I picked up a Schedule 40 PCV ball valve to control the airflow where I see most people use a Gate valve or Blade valve. I assume that since most parts are galvanized up to this point, I don't have to worry about my PVC overheating? It was available at $16 from TSC for half the price over brass

Thanks

 

[sunshadow]

I started gathering parts for my blower yestrday and have questions.

I used a 1-1/2" to 3/4" Tee with a 3/4" to 1/4" bushing to attach the LP line. The 1/4" nipple I got was galvanized b/c finding 1/4" Sched 80 nipples are like finding Hen's teeth around here

Q. Does the 1/4" nipple HAVE to be black pipe since it is connected to a galvanized Tee? How hot does the burner get after it passes the black burner tube connected to the forge?

Q. Since I am using a Tee to bushings to nipple with gas, does the 1/4" nipple still need a plug with a hole drilled in it to "jet" the gas or does the needle valve do that upsream?

Q. I picked up a Schedule 40 PCV ball valve to control the airflow where I see most people use a Gate valve or Blade valve. I assume that since most parts are galvanized up to this point, I don't have to worry about my PVC overheating? It was available at $16 from TSC for half the price over brass

Thanks

Some people do not do the drilled orifice and get away with it, some regulators have a safety shutoff that will shut them down if there is no backpressure, also I get better adjustability by having a drilled orifice. PVC melts at a lot lower temperature than the temperature that galvanized becomes a problem. I would not use PVC on a forge part. Period.

-Page