Hot enough?

[Mark Knapp]

Hi all, I recently put a blower on my NC forge to get it to welding temperatures faster and for quicker recovery, I built it similar to the plans you can down-load. I also have a pyrometer on it. My goal was to reach 2300 degrees quickly. At a hammer-in (Bronk's, Seatle) the demonstrators rutinely reached those temperatures and squished the metal. The highest I have been able to reach is 2,250. We do not have natural gas available to us here, a friend thought maybe propane just dosen't burn hot enough. Any thoughts? Also, what is a PID and an SSR.
Thanks a lot Mark

 

[David Loukides]

Welcome to Blade Forums Mark.
Propane From a small tank is effected by cold.
I have a hundred gallon tank.
I have never tried to max out my temp but have forged at 2100F with no problems.
Ps, tell Bob I said Hi.

 

[Stacy E. Apelt - Bladesmith]

Mark,
I think you need to do some reading and study up on forges and controllers.

I'm not sure why ( or how) you converted your NC forge to blown, but it should have reached 2300F before the conversion. A blown burner has the advantage of being controllable by adjusting the air and gas flow, thus it lends itself to being controlled by a PID ( Proportional Integral Derivative controller). The SSR ( Solid State Relay) is the electronic on-off switch that the PID controls. The gas is run through a propane solenoid valve which is connected to the SSR, which is connected to the PID. Thus, when the PID sends an ON signal, the gas is on, and conversely, when it shuts off the signal, the gas is off.

Here are some thread links on the subject, and info on my two-stage controller.
http://www.bladeforums.com/forums/showthread.php?t=523845
http://www.bladeforums.com/forums/showthread.php?t=599423&highlight=PID

Post some pictures and descriptions on your conversion. That will help us figure out the heating problems.

Merry Christmas,
Stacy

 

[Will Leavitt]

Do you have ITC 100 on the liner? If not you should pick up some heat through the reflected IR.

 

[Don Hanson III]

My NC easily reaches welding temps but I use a different forge for welding.

 

[CShepherd]

Hey Mark,

Sorry to hijack the thread but this is Charles Shepherd, we worked together on the riverboat. How are you guys doing?

Charlie

 

[sunshadow]

You have to get enough fuel and air in mixed well to supply the necessary heat, have it burn completely in your insulated space, and vent your combustion products out of that space efficiently enough that they do not inhibit combustion all without losing too much heat to the surroundings or monoxide poisoning yourself.

Please photograph your setup so that we can see what you've don and provide more relevant suggestions

-Page

 

[delbert ealy]

Propane gets plenty hot enough, if you have enough of it and air. I've gotten 2700f and that wasn't tapping out the propane or the air in my setup. The main problem with your forge is that it has 2" of brick to heat up and that is a bit much for how much gas you have going in.
Del

 

[jdm61]

+1 on the cold tank syndrome. Even a 100 pounder will choke out a little bit on a venturi forge if it has been running long enough. With that said, my Chile Forge Habanero will get to welding temps easily and fairly quickly. That doesn't mean that I won't be getting a second blown vertical forge for welding, but that is as much an issue of convenience and not wanting to tear up my Chile as is is one of efficiency.

 

[Don Hanson III]

I like my NC but it's a poor choice if one is goin to do a lot of welding.

 

[Mark Knapp]

Mark,
I think you need to do some reading and study up on forges and controllers.

I'm not sure why ( or how) you converted your NC forge to blown, but it should have reached 2300F before the conversion. A blown burner has the advantage of being controllable by adjusting the air and gas flow, thus it lends itself to being controlled by a PID ( Proportional Integral Derivative controller). The SSR ( Solid State Relay) is the electronic on-off switch that the PID controls. The gas is run through a propane solenoid valve which is connected to the SSR, which is connected to the PID. Thus, when the PID sends an ON signal, the gas is on, and conversely, when it shuts off the signal, the gas is off.

Here are some thread links on the subject, and info on my two-stage controller.
http://www.bladeforums.com/forums/showthread.php?t=523845
http://www.bladeforums.com/forums/showthread.php?t=599423&highlight=PID

Post some pictures and descriptions on your conversion. That will help us figure out the heating problems.

Merry Christmas,
Stacy

Before I put the blower on the hottest I could get the forge was 2,200 I was getting some good welding but had inconsistant results, lately I have taken to making much bigger billets, furniture for custom rifles, I have two huge commisioned bowies to make, and I want to do powder metal. I noticed that none of the serious damascus guys I watched at hammer-ins used venturies, in my reading, it became apparent that a blown forge is more economical than a ventury. After consulting some people, it seems that my un-altered forge was having trouble reaching good welding temperatures probably because of the barometric pressure up here. But the main reason I switched, speed man speed, I got work to do.

Insidentally, I would have rather just bought a new blown forge but I was having a lot of trouble getting my order filled.

I would send pictures, it says on the bottom that I "may not NOT post attachments" I paid for a membership a couple of days ago so, I am sure I will be able to do that soon. Thanks for the suggestions.

 

[Mark Knapp]

+1 on the cold tank syndrome. Even a 100 pounder will choke out a little bit on a venturi forge if it has been running long enough. With that said, my Chile Forge Habanero will get to welding temps easily and fairly quickly. That doesn't mean that I won't be getting a second blown vertical forge for welding, but that is as much an issue of convenience and not wanting to tear up my Chile as is is one of efficiency.

The cold tank syndrome seems to have been fixed with the blower, I don't get any more frozen tanks, I did upgrade to a 60# regulator, next I will move to a 100 pound tank, I will have to drill a hole in my brand new forge room wall. Thanks

 

[Mark Knapp]

Propane gets plenty hot enough, if you have enough of it and air. I've gotten 2700f and that wasn't tapping out the propane or the air in my setup. The main problem with your forge is that it has 2" of brick to heat up and that is a bit much for how much gas you have going in.
Del

I dont see any brick in there, only wool, and the consumable tile on the bottom. Thanks again everyone, I will post picture when I can

 

[Phil Dwyer]

Mark,

As I recall, when you upgrade your membership you also have to go into your User CP identify your group membership. Maybe that will enable your photo privileges. If that doesn't work go to the Service & Support forum and ask what's up. Someone will set you right.

I too welcome you! and appreciate your posts. I've still got to respond in the ivory thread you posted in. Thanks!

All the best, Phil

 

[Fletch Helical]

I would send pictures, it says on the bottom that I "may not NOT post attachments" I paid for a membership a couple of days ago so, I am sure I will be able to do that soon. Thanks for the suggestions.

You can always open up a photobucket account and post the IMG code from it in your post to get pics on.

 

[Mark Knapp]

Mark,

As I recall, when you upgrade your membership you also have to go into your User CP identify your group membership. Maybe that will enable your photo privileges. If that doesn't work go to the Service & Support forum and ask what's up. Someone will set you right.

I too welcome you! and appreciate your posts. I've still got to respond in the ivory thread you posted in. Thanks!

All the best, Phil

Looking forward to your post, this place is fun. Forging all day tomorrow, woo hoo

 

[Mark Knapp]

The delay with being able to post photos has to do with my paying with paypal, it is a manual thing for the administrators and after all it is Christmas. I am a patient man (but don't check with my wife on that). Merry Christmas everyone.

 

[Stacy E. Apelt - Bladesmith]

Mark,
Some questions come to mind:
How are you measuring your chamber temp?
Did you modify the existing manifold on the NC forge, or make a completely new burner? How many ports does it have?
Which model NC forge do you have?

There could be many problems with your burner. Too much air, not enough gas ( you didn't put any sort of orifice in it ,did you?), wrong entry angle, etc.

Like we said, a photo or two will clear up many questions. If you aren't able to post them yourself, just email them to me , and i will post them.
Stacy
sapelt@cox.net

 

[Mark Knapp]

Mark,
Some questions come to mind:
How are you measuring your chamber temp?
Did you modify the existing manifold on the NC forge, or make a completely new burner? How many ports does it have?
Which model NC forge do you have?

There could be many problems with your burner. Too much air, not enough gas ( you didn't put any sort of orifice in it ,did you?), wrong entry angle, etc.

Like we said, a photo or two will clear up many questions. If you aren't able to post them yourself, just email them to me , and i will post them.
Stacy
sapelt@cox.net

Frankenforge

I am measuring the chamber temp. with the pyrometer


I started with an original NC K-3, two burner forge, a year or so ago I put two more burners from another K-3 forge in this one to get more heat and get more even heat accross the billet. No more hot spots.

It now has four stock NC burners with original orifices in it, I think they are .035 but I will have to check. I bored out the original mixing tubes from thier original 3/4 inch diameter to 15/16 to get more air through. I built the manifold with 2 inch tubing, added the 50CFM blower, the blower has a damper on it to control air flow. The entry angle is the same as the original. The propane manifol is the same as original except that I added the two new orifices. The second forge box can be attached to the back of the first one for extra long billets and heat treating. It is attached by use of the door hinge pins, and can be removed in just a minute and the back door replaced to reduce the size of the fire box.

Thanks for the offer to post, sending pictures directly

 

[Stacy E. Apelt - Bladesmith]

I received Mark's photos, and here are the pics and my comments. Some of the questions I asked have been answered here, others will still have to be dealt with.
Stacy



Mark,
I've got to hand it to you for ingenuity. That is a neat looking conversion.

If I am seeing the photo right:
The gas line is going to the old manifold, and you have added the blower manifold to the existing burner tubes. Are the old choke plates gone?
I see no needle valve on the gas line, just a ball valve?
Is there any sort of control on the blower to regulate the air volume? - a fan controller, or an intake choke plate?
Did you drill out or otherwise modify the old gas manifold?

Here is what I see as problem areas, and possible solutions ( You may have already done these things):
1) The blower may be delivering way too much air. - Put a choke plate on the blower intake, or use a fan controller to vary the blower speed.
2) The gas may be restricted by the old orifice size - drill out the old orifices jets, and tap the new holes to 1/8" pipe. Install a 2" piece of 1/8" pipe going down the burner tube.
3) The burner tubes are too small for the gas/air volume being delivered - There is not much you can do to deal with this problem. The manifold was designed to allow a certain volume of air and gas go through it. With the forced air, that volume is now larger. It may be creating a much higher manifold pressure than is desired. Adjust the air/gas flow to allow the best burning flame without excess dragons breath, or the chamber being too oxidizing. This is where the needle valve on the gas line , and the fan control is needed. The end result will, however, be about the same as the burner tubes delivered when they were venturi burners. Short of removing the burner tubes and making new ,larger burners, you are pretty much limited to any options here.

If you haven't changed the venturi burners beyond reversal, it might be best to convert back to the way the forge was designed to be run.

You can make a damascus forge ( vertical works best) from 12" round pipe, and use some of the stuff you have. You only need one large blown burner in a damascus forge....1.25" to 1.5" is a good size. The forge chamber should be round.

The real advantage to converting your NC forge to a blown burner is the ability to run it at a lower heat than was possible with the venturi burners. I am sure you had found that the burner would back flash if you cut the gas pressure too low. This makes it hard to try and hold the chamber at temps for heat treatment. With the blown burner, you just throttle back the air and gas to the flame size you wish.

I'll put the photos up on the BF.
Stacy