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Another tuning question


rburrus44

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So I built my first burner following Frosty's T design and now trying to tune.  I am at 5,000+ feet of elevation so I followed the design and started with a .030 mig tip and was burning rich.  changed to a .023 tip and still rich then trimmed the tip to 9/16 length and it still seems to be rich.  the flame is blue coming out (not as compact looking as a netural or lean flame) but around it is orange and all the rest of the flames in the forge are orange and DB is also orange.  This is all at about 5 psi.

 

Can the .023 tip be to small and not be creating enough vacuum to pull the air in?  go back and trim the .030 tip shorter?

 

Thanks for the help this is my first adventure into gas forges.  I'll try to get some pictures tomorrow before anything gets changed

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What are the other dimensions of the burner? YOu can't give specific answers even to a pretty specific question without a baseline of info.

 

However I can answer the one question though it may not really apply to YOUR burner. The farther back from the throat the jet is the more air it will entrain. So, yes shortening the mig tip jet WILL entrain more air and lean the mix. There might be something else wrong though. We'll get it up and roaring no worries.

 

Frosty The Lucky.

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So I took a video that is being uploaded to the tube now and will post in a little bit.

 

Frosty:  3/4 inch design so the burner tube is 6" length, 1 x 3/4 x 1 (3/4 in middle) T and a .023 tip.

 

timgunn:  I have ran the burner in the forge with and without a rigidizer applied and the same burner performance.  I turned the pressure up to ~10psi and the flame had the same characteristics just larger.

 

Fudd:  I would really like to join just a bit short on time now with full time work, masters degree and two young children haha but plan to join at some point.

 

Thanks for taking the time to help, I know that you all answer these questions often and I have looked through a lot of them and really appreciate the time for another one.

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That is running darned rich, especially for a 0.23" jet. Trimmed to 1/2", from what point is it 1/2"? I can't see the fitting from the fuel line very well or I'd have a better idea from the look.

 

A 3/4" tube with a 1"x3/4"x1" T should be screaming with a 0.035" jet and one of the guys up here is using a 0.045" jet in his. Looking straight through the legs of the T" the end of the mig tip jet should be between 1/4 to 1/2 of the way across the port from the back (fitting) side.

 

Another possible factor might be interference in the flame's flow by the liner. It doesn't "look" like a problem to me but if the fuel air mix is hitting the Kaowool it can cause bad turbulence and hurt the induction.

 

Do you have anything to act as a "flare" on the output end of the tube? I've had good luck using a thread protector, a LOT cheaper than a coupler but the same action.

 

Frosty The Lucky.

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It is 1/2" from the tip to the shoulder on the mig tip that butts to the 1/8 npt fitting.  before I got the kids ready for bed I made a few more cuts down to 3/8" and its running the same.  I am now in between 1/4 and 1/2 way through the T as you described now.

 

I do not have a flare on it, tried to mold it into the liner but think I might have done a poor job at that.  I will try opening the hole in the liner tomorrow and using a steel flare. 

 

This may be a silly question/ thought but could the .023 nozzle be to small and the propane jet not be expanding to fully to meet the burner tube and creating a pseudo "leak" that would be robbing the induction action?

 

Thanks for the suggestions.

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Running as little pressure as you are a 0.023" jet may not be enough to entrain much air. I never turn mine down that low and I run a 0.035" jet. If anything it "should" be running lean with a 0.023" jet. The propane jet doesn't need to expand all the way to the tube walls to induce intake air. However it may not be moving fast enough but the flame in the video looks strong to me so I don't think that's what's happening.

 

I tend to start with what I know works which is 0.035" jet. Did you deburr the jet when you trimmed it? If there's even a little burr in the orifice it WILL screw the gas jet up royally. Anyway, when I start tuning I trim the jet to 9/16" from the shoulder, this is a bit too long but close. I light the burner, read the flame ad dragon's breath and shorten it as necessary. Starting too long is deliberate, that way I don't have to wonder which way to adjust. Just remember to deburr after every trim, I prefer torch tip files they work really well and don't make scars.

 

So lets see, how about trimming your jet by 1/16", deburr and give it a try. While you're at it trim a 0.035" mig tip to 9/16" from the shoulder and deburr it. That will give you two widely different sizes to adjust from . . . in case.

 

Frosty The Lucky.

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Even tho you don't have the time to join SWABA some of us would still be happy to help you get your whole setup working. Let me know if you'd like our help.

 

Making a flare and using it to adjust the flame outside of the forge will make your life a lot easier. If you can't make a flare I probably have an extra that I could give you.

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When I was getting my second degree; I too was working 50 hour weeks and I had two small kids. I also had a 100 year old house always needing maintenance.  I joined SOFA that was a 2 hour drive each way and had meetings every month---carpooled to save gas $$.  It was one of my best decisions!  The time I saved by interacting face to face in a shop with experts was massive and my frustration levels were much lower.

 

Everybody's experience is different; but give a thought about spending a couple of hours every other month...

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Frosty:  I have tried turning the pressure up to almost 15 psi and the general flame characteristics are the same just larger.  I thought I had read someone say to tune at low pressures because the induction curve is pretty linear up to 20 psi or so.  I bought coupler today to act as a flare and ran the burner otherwise unchanged in the forge (but did not have a chance to trim the liner away) and still the same flame maybe slightly better but probably not.  I did try to run it with the flare outside of the forge and could not keep a flame lit by itself but using a lighter could keep it going and saw that the flame looked much much better, probably heavy on the lean side.  this leads me to believe that it may be the liner causing to much back pressure so that is going to be my next step is to open that up so that I know it is not in the way.  I am also going to trim a .030 and .035 tip tomorrow and start playing with those after I have worked on the kaowool.

 

Fudd and TP:  I know your right so I got a birthday coming up and will ask the Mrs. to pay the membership for that

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If you can't keep it running with a flare outside of the forge you need to be aware that you have to move the flare up and down on the tube to find the spot where it will keep running.

If you run the flare too far in either direction the flame will die. 

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Happy New Year,

 

No one has commented on you being at 5,000 ft. That is a mile above the tide, Hairplain Country!!!

Thin air, thin McJet. Don't be afraid to crank some pressure into that poor little jet.

The theory is, small jet will keep back pressure in the Propane = ability to turn up the pressure at  the regulator.

The location of the tip of the nozzle MUST BE IN THE CENTER OF THE PLENUM, POINTED DOWN THE CENTER.

You can adjust the nozzle in and out to figure out the best place to draw Hair. Move the burner in and out. Put doors (bricks) on the end of your forge and see if it works better when the inside insulation start to kick off with heat. Don't be afraid to try things.

Some things can't be figured out when you run to the keyboard instead of trying something else.

 

If the propane bottle is frosting up, put it in a pail/bucket/garbage can of water. the water will act as a heat sink and slow down the freeze, keeping the propane liquid, liquid.

 

There is a reason why, sometimes a person should buy a forge that is already debugged.

You are now the De Bugger!!

 

I know, you have been called worse, by better :) :) :)

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Whoa now! I'm at the same location and you really don't need to crank up the pressure at this elevation! I run my two main forges between 3 and 6lbs of pressure when doing forge work. If I want to 

forge weld (which I rarely do) I will crank the pressure up. Swedefiddle is correct tho about moving the nozzle of the gas jet in and out to get the right burn but the flare must also be move in and out.

 

rburris44 you and I had corresponded when you were looking for an anvil and I gave you Fred Moore's number. (He said you got a nice anvil) . PM me and we can get together and I'll show you how to fix your burner, or you can come to my house and I'll you you some of mine and you can use that info to fix yours. Sometimes its just plain easier to ask for help.

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rburrus- 

The next SWABA meeting is at the Bernilillo County 4-H center 1510 Menaul NW 87107 on Feb 7 and it starts at 9am. 

You don't have to be a member to attend in fact everyone is welcome.. Just come on down! Usually have about 30 to 50 folks.

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Fatfudd, I just may have to come attend myself. Just spoke to the wife and she has given me the blessing to do so but a 4 hour drive one way may be out of the question. Who knows? So far my learning has been through Thomas Powers, and it has been great buti think I'd like to see others at work.

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quick update.  So after trying a few more things with the .023 nozzle I came to the conclusion that it was just to small of a jet.  So I bumped up to an .030 tip and am work with that now.  through progressive trimmings I am at about .5" long and still running a bit rich but it is starting to look way better and beginning to have a few blue flames in the DB. hopefully after a few more trims I will be there

 

Fudd I sent a PM your way

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