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First forge, first post. forge not heating (Taking a long time)


MonkeyForge

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RJS,

I am one of those "heavy hitters," and I want you to know that the idea has HUGE potential. So, please don't underestimate yourself too quick nest time;)

Nest time; really? Let's try "next time" instead.

A century back, snake oil salesmen were becoming a problem; so our society started issuing licenses and degrees to the 'qualified' in an attempt to solve the problem. Today there is more snake oil marketed than ever. Don't be impressed with titles or celebrity; look closer at the ideas being proffered, and judge advice on it own merits.

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Thanks Mikey, I proceeded and started building a burner. I am going to get the right T next time So I don need the adapters. I'll update this thread when I light it. I am a little worried about the seal on the additional fittings, they seem tight though.The T is 3/4 all round the burner tube is 1/2. I am using a .6 mm MIG tip.

For now I need to wait for my day off and get a new propane hose. (The one I got with the tank is old and I don't trust it)

IMG_20160215_190230.thumb.jpg.fef0005194IMG_20160215_190156.thumb.jpg.b81b931ee0

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@rjs Any advice is appreciated, pointing out someone else has a good idea counts. And I agree that the secondary air intake can be useful, The torch seems to perform better when used in this way, less to no blue flame from the front of the forge, quicker heating times.

@Mikey98118 Could not agree more, especially in this online world.

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Paulo,

Since you've already got MIG contact tips:

MIG tips only go down to >023"  call-out size; this is the welding wire size they are meant to feed--not the actual size of the orifice, which is .031". The best orifice size for a 1/2" burner is .028" orifice diameter. You can't get smaller than an .031" diameter orifice using a MIG tip...unless, you add a section of hypodermic needle as an internal sleeve to it. It was this frustration (which being a perfectionist) lead me to start experimenting with capillary tube and dispensing needles, and finally to Luer-lock dispensing needles. I won't pretend to have any idea how available various products are in Portugal, so will assume that hypodermic needles would be the easiest source of capillary tube for you to find. Hypodermic needles are all made from stainless steel, which requires boron modified flux for successful silver brazing; fortunately, all these needles can be bent in a curve, and all of them retain a certain amount of spring afterwards. So by combining the right sized orifice with the closest MIG tip orifice diameter, you can slip such a needle into a MIG tip, and it will stay in place (If you cant find a proper match, carefully drill out the MIG tip with the closest hole diameter to the needle's outside diameter) Afterward you grind off the excess needle, and sand away the inevitable internal burr with some spit and a circular motion on very fine sandpaper (at least #200 grit).

The best gas jet orifice size for a 3/8" burner is .022" but you can reduce that to as little as .019" by shortening the needle length down to about 5/8".

The best gas jet orifice size for a 1/4" burner is .016" but you can reduce that to as little as .014" by shortening the needle length down to about 5/8".

Obviously you're not going to have a lot of success bending a 1/2" to 5/8" long sleeve from a hypodermic needle, so for such a short length, the alternative plan is swaging the copper MIG tip down around the needle, so that it firmly grips it; this is done by drilling a hole in a small block of steel or brass, cutting the block in half, and setting the MIG tip (with needle inserted) in the bottom half, covering the tip with the top half, and hitting the block with a hammer; rotate the tip one quarter turn and hammer the block again.

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Monkey Forge,

It isn't only steel pipe fittings you can use for smaller burners. There are a lot of copper and brass fittings that can be employed for 1/4" and 3/8" burners, by doing a little bit of silver brazing :D Of course copper is no where near so strong as steel; on the other hand, the smaller the burner the less strength is needed, and the "T" fitting can be silver brazed (not soldered) to steel pipe or steel tubing for the mixing tube section of the burner. If you want to strengthen the top of the "T" for the gas jet fitting, a section of steel or brass pipe can be saddle cut and silver brazed in place as a stiffener in that area.

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Mikey,

It appears as though the orifice size for the jet is approximately 0.06 times the inside diameter of the tube used in the burner and the tube length is about 9 times the inside diameter.  Out of curiosity was this discovered through trial and error or was this a specific calculation that you found when working with burners?  If that's a decent way to determine jet orifice size for a given tube then it would be as easy for those using the metric system as it is for those of us using imperial measurements to relate the two without any conversions involved.

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Mikey,

 

I am learning a lot about the different kinds and sizes of fittings and plumbing. In both gas and water both metric and imperial are used for size. Converters from one to the other are quite easy to find in brass and copper. I like iron though which can also be found, though it is kind of tricky and you need to be specific about them being non-galvanized. (also listed as black here) Tomorrow I will to test the burner I showed earlier, then we'll see if the next project is another burner of tweaking this one, or if all is well hammering iron.

All in all an enjoyable effort so far, also because all the input I get here. So thanks again. 

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Buzzkill,

Orifice size to inside diameter size of mixing tube was a matter of trial and error over a three year period, and only applies to linear and jet-ejector burners. Vortex burners have their own set of rules, although these same orifice to inside diameter proportions make a good starting point with them (this is one of the ways that Vortex burners depart from all previous designs).

The nine diameters rule of thumb was already a good bit of advice before I started my experiments. With Mikey burners I found that  the rule was more flexible and could be varied to one inch less than recommended, and up to two inches longer than recommended on 3/4" burners to tweak them for best performance in heating equipment (shorter), or when used as hand torches (longer). This information was never included in the book, because I wanted readers to build the burners in narrower safety margins, rather than pushing the edge of the envelope.

Monkey Forge,

I advise you to disassemble the burner and internally bevel every threaded edge, which faces toward the incoming gas and air; otherwise you will have three obstructive shoulders interfering with laminar flow.

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Ron Reil had the formulae and ran the numbers to calculate the proper size ratios for linear induction devices. Ron's a retired high school science teacher so it's no surprise. I copied the basic ratios from sales brochures a coffee shop friend gave me a couple years before the internet went public. I used trial and error to fine tune mine. It only took about 2 months but I had a head start. Maybe I should say it only took me a couple months to make a burner well enough it worked on industry standard ratios. It was me needed fine tuning, not the devices.

I'm glad you did the simple math and pointed out Mike is hitting at or close to 0.06x tube dia. on his jets. Consider that written down here. ;) Thanks Buzzkill.

Frosty The Lucky.

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57 minutes ago, Mikey98118 said:

Monkey Forge,

I advise you to disassemble the burner and internally bevel every threaded edge, which faces toward the incoming gas and air; otherwise you will have three obstructive shoulders interfering with laminar flow.

I'd just amend this slightly to "if you have significant Dragons Breath"

 

 

 

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1 hour ago, Mikey98118 said:

Monkey Forge,

I advise you to disassemble the burner and internally bevel every threaded edge, which faces toward the incoming gas and air; otherwise you will have three obstructive shoulders interfering with laminar flow.

I'd just amend this slightly to "if you have significant Dragons Breath" internally bevel etc..

Doing the bevelling thing will probably increase the amount of air drawn in for a given gas flow, leaning off the mixture somewhat. 

The probability is very high that you have a rich mixture and increasing the air intake will make it less rich and thereby increase the flame temperature. 

In the unlikely event you have a slightly lean mixture, increasing the airflow would reduce the flame temperature.

If you have DB, you have a rich mixture. 

 

 

 

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Mike, Timgunn, thanks for pointing that out.  I will probably be able to get a a 3/4 to 1/2 to 3/4 inch T when I pick up my propane hose and some other stuff tomorrow. I still have a length of 1/2 nipple left over because I got a long one and cut it off to get the right total length just in case. This means I can test both set-ups :) I'll show you the results.

If I am unable to get the other T I will work with this one and figure something out with what you posted above.

 In my day job we have a pitfall we call "premature optimisation"(do or do not google it).  I am avoiding it now as well more or less. I gather info while I anticipate a potential problem, or am unsure about what potential problems I run into. I build a prototype that works, (with what I know already) figure out what can/should/could be better. (with your help so far :)  ) and fix it. The end goal is always to have something working as good as it can, as good as I can make it.

Any comments on above are welcome. I am, for now still waiting for sleep to set in and for the hardware store tomorrow.

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Progress, the little burner will burn, just not outside the forge. When I light it outside of the forge it blows out as soon as I take away the ignition flame. The regulator I have is set at 1.5 Barr which is around 21 psi which might be to much? Or will it simply not burn outside without a flare? It heats up the forge quickly, at the moment it is a bit bright outside to get a good picture.

Burner now looks like this:

IMG_20160217_135457.thumb.jpg.b24643be01

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Frosty, I learn something new every day on here.  That's what keeps me coming back.  Well, that and I love to see what the next play on words or pun will be.

MonkeyForge, it is normal that the burner will not burn outside of the forge without a flare on it.  There are a lot of factors that go into what the "right" pressure is, but I will say that 21 psi sounds really high to me.  On my 3/4" Frosty T burner I usually forge around 8 psi, but my elevation, humidity, etc. is likely different from yours so don't try to match what works for me or anyone else.  If the burner is functioning correctly, you want it to heat your forge to the desired temperature without blowing a bunch of excess heat out the openings.  My guess is that at the pressure you mentioned you are burning more fuel than is needed, which just costs more money in the long run.

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Buzzkill, I remember reading about burners not working outside of the forge without a flare, just never tried it out since this is the first one I built. Thanks for confirming. Sorry for the bad picture, but this is how it burns now. As you say, a lot of heat coming out of the front and back if I remove the brick.I need to find a better way to mount the burner in the forge, it kind of wobbly now.

IMG_20160217_181838.thumb.jpg.1425d78da8

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I got myself an adjustable regulator, this helps. A lot :) I just gave it a quick test run and I have to figure out how to get some nice pictures of the flame. Also I need to find the right pressure. I do get flame from the front and back, not as much as at 1.5 bar so that's an improvement. I get a pretty even heat across the chamber but I need to experiment with the burner angle. straight in from the side will give me more of a hot spot than the propane torch did so I'll see if I can reintroduce the upward/forward angle.  Some pictures below. I will keep you posted.

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IMG_20160218_180403.thumb.jpg.47d05b1d7d

IMG_20160218_180008.thumb.jpg.4e7bc7bcc8

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While it is raining and I cannot go out and play I was looking into kiln wash (Thanks Mike) Materials (easily) available are zirconium oxide and also zirconium silicate. Chamotte (fire sand/grog according to wikipedia) is also available. Does anyone have experience with these combined? As far as I could find out the zirconium oxide has a higher thermal rating than the silicate.

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For everybody's info, the burner with all the fittings forming the tube huffed and puffed. The one with the single brass ring worked better, just to prove mike's point.The fuel mixing is disturbed  . I still need to do another burn and get a good picture. I have an odd shift this week so if I run the forge it going to be daylight... I applied a coating of 70 % zirconium silicate to 30 - ish % kaolin to the chamber. I let it air dry but now it needs another burn to cure fully. I got lucky and found a pottery warehouse within walking distance from my house. The stuff you find out when forging iron.....

 

And to the credit of @timgunn1962 I used my butane plumbing torch with the inward-funnel to cure most of my coating.

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I wanted to share a picture of the burner flame so I stacked some of the hard bricks I have. As you can see it is still in a small chamber and aimed directly at the wall. Again, the set up is just for the picture and  the burner has been running for a minute. I would like to know what you think. (And I ran out of gas)

IMG_20160224_223716.thumb.jpg.972bc00361

 

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While I Wait for the weekend, and to have my tank refilled I thought I might share some pictures. (thanks ,Mike, for encouraging me to share )

I could only find a 3/4 all around T for some reason. And the reducing fitting I got at first was causing issues while running the burner. (sputtering, disrupted flow/mixing) I found this one that seems to perform better:

IMG_20160226_000432.thumb.jpg.e86bbfd661

that fits like this, with the 1/2 inch nipple almost al the way in:

IMG_20160226_000805.thumb.jpg.3cf89f383d

IMG_20160226_000850.thumb.jpg.5695d21c1e

Entire T burner disassembled:

IMG_20160226_000658.thumb.jpg.3b894bcc35

This produces a steady burn, though I have not tuned it and still need to put it to work properly.

IMG_20160226_000805.jpg

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Do you have a pipe cutter with the burr reamer? If so you will really improve the performance of your burner by flaring the inside of the pipe to the outside edge at the fitting end. The burr there now will cause bad turbulence, a smooth interface between the fitting and the tube will improve things considerably.

Frosty The Lucky.

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Frosty, I do not have a pipe cutter. I can think of a couple of ways to get the same results. Or get a pipe cutter, which I need anyway. Would it make any difference to have flaring on the other end as well? Or would this have a negative effect on the flame? 

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I ground the end of the 1/2 nipple to flare into the fitting (I might grind away the inner thread if needed):

IMG_20160227_234716.thumb.jpg.7100db242f

One test burn for tuning (I still need to figure out the ideal pressure):

IMG_20160227_200519.thumb.jpg.b9cf1f6188

When I run the burner in the 2 brick forge I get a lot of blue/orange flame from the front/back. Turning down the pressure eleviates this somewhat but at some point I start getting less heat. To be continued. Tips welcome, as always :)

 

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