Need feed back on plan to tune Frosty Burner

[cedarghost]

I built a t-burner today to Frosty's specs with the exception of using a .030 mig tip and I don't have a thread protector. I am running a 0-20 regulator and will be heating around 250 cubic inches. I read a lot of posts from others tuning this style of burner and there was another guy using a .030 tip and Frosty suggested the amount that got cut off would vary from a .035, but it should work.

At first I couldn't get the burner to stay lit outside the forge. I wasn't too concerned as I understand this is normal and it should be tuned in its environment. I slid a piece of bigger pipe over the end and BAM...it would stay lit. That was a great feeling.

Next I stuck the end of it into the forge where it is going to live (without the extra pipe on the end) and I had a hard time lighting it and getting it to stay lit. I had to turn the regulator way open and then adjust it down until the flame started to roar. 

I noticed a coupld of issues. 

1. It is difficult to light. I think a ball valve will help and maybe I just need to light it then adjust the pressure as it heats up.

2. I am getting flame back into the burner tube. It is my understanding that everything behind the burner head should not have flame in it.

I cut off 1/8 " of the mig tip and the problem with the flame was lessened but still there. So tomorrow, my plan of attack is this:

1. go ahead and mount the burner tube as it will be mounted on the forge. I am going to use a floor mount flange like I saw on one of Frosty's forges in his pictures

2. go ahead and line the forge with inswool and create a "flange in the inswool at the burner port

3. Install a ball valve for quick shut off and turn on ability.

4. let the forge heat a little before turning down the regulator to get the roaring flame.

5. cut off another 1/6th to 1/8" on the mig tip I keep getting backdraft (not sure if that's the right term)

try again.

Does this sound like a feasible plan of attack? 

I'm attaching a picture of the backdraft I was seeing in the "T" area

Thanks for any suggestions. In the meantime I will do a lot of research tonight. 

 

 

You know what? I just double-checked the plans, and I used an 8 inch black pipe nipple instead of a 6 inch. Would this make a huge difference?

I think I answered my own question. Seems like I remember reading in the Burners 101 thread that the length needed to be between 8 and 9 times the diameter of the pipe.

That, combined with a smaller jet size wouldn't be able to push the gas down the tube fast enough. Am I right?

[Frosty]

A couple points: :1, the floor flange isn't to mount to the forge it's to keep everything centered will you drill and tap the T and fittings to mount the mig tip. 

A 0.030 mig tip in a 3/4" burner will draw more air per fuel so it'll want to make a lean flame. It'll need to be closer to the throat for a proper fuel air ratio, not farther back. Don't trim it to start and if it needs trimming at all do it 1/32" at a time. I chuck the mig tip in a drill motor and use a fine single cut file, the kind used to sharpen axes, machetes, etc. Then deburr the orifice with torch tip files.

It will ROAR, T's especially are known for being loud.

A smaller jet will require higher psi to supply the same amount of gas per second so it flows faster and draws more air relatively, leaning the ratio. This means the flame will enter the forge at a higher velocity and will be less susceptible to back pressure and outside breezes. 

It'll work just fine once you get it tuned.

Frosty The Lucky.

[cedarghost]

Thank you sir for the reply. I will take this information and put it to use! 

I did use the flange to drill the T and it worked great!

[cedarghost]

Posting results after feedback.

I switched to a 6 inch pipe, put a 6 inch x 1 1/4" pipe as the chimney into the forge and dropped the burner in there and backed it up just a little where it was right to the beginning of the ceramic blanket.

Then I put a uncut .030 mig tip in and fired her up. I don't have a regulator with a gauge, but I think it is running less than 5 psi and roaring like a dragon! 

I soon figured out that my channel locks were too short for this baby and after 2 Peddler's Mall's without finding a set of tongs, I decided to make a set. It heated up the bar stock to white hot just fine and pretty quickly and I soon had a very ugly set of tongs that feel pretty good.

I used it to heat treat two knife blades as well and it made REALLY short work of those, WAY faster than the paint can forge that I was using.

I may still try a .035 tip just to see the difference just as soon as I can find some for less than $10 around here. I'll just have to hit the welding supply store instead of Lowe's.

Thanks again Frosty!

 

[Frosty]

You're welcome.

Did you take any pics of it at heat? It sure sounds like you've got it licked but you want to keep an eye on the steel IN the forge and watch for scaling in the fire. Scaling IN the fire means it's running too lean. However if it's too reducing it's pumping out Carbon Monoxide in prodigious amounts. It'll be making CO regardless but they can be really dangerous CO generators.

Frosty The Lucky.

[cedarghost]

Here are the best pics I have right now. This was during the test burn. I have since relined it to make the interior more even and smooth, but nothing has changed with the burner. I'm not getting scaling in the fire, so that's good.

I'll try to get some video for you as soon as I can if you want to take a look at it.

 

[AdamG]

I'm fairly new, so please take this with a grain of salt, but it looks like that's unlined ceramic wool.  You should really stabilize that stuff or you'll be hacking to death one day.  

I'm just at the point of tuning some T burners too, and it's amazing what a difference the tube length makes.

[cedarghost]

Thanks for the concern. It was unsurfaced wool. I was just building the forge.

It has since been coated with refractory cement. 

I never had to do anything else to this burner. Once I got it in the forge it's pretty danged good.

It will get to welding heat and it heats up stock QUICK. No scale forming inthe forge to speak of and it's pretty good on gas.