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I Forge Iron

My NARB Is Underway


stockmaker

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I am finally getting started on my new forge and wanted to share with you my progress on the burners.  This forge will employ None Aspirated Ribbon Burner (NARB) burners, (2).   I based the design on Frosty's burner but change the dimensions from the 2X2X7 to 4X4X2.5.  I am using the same number of ports (17), but reduced the size from crayons (3/8") to 1/4" as I will use machine threaded bolts in place of the crayons..  Today I ran a test of the burner using a  wood insert to take the place of refractory.  It fired off nicely, sounds good, and the flame looks ok but I have not turned the MIG tip in the burner yet, I will do that once it is installed into a forge.    I ran the pressure from 3lb to 6lb, the flame did not vary,  after about 45 seconds I shut it down.  The pipe casing you see in the pictures is not the forge body as I do not have the little part yet. 

Tomorrow I will do a test of the burner refractory with a couple of my machine bolts installed.  One with release agent, one without. 

If anyone has comments or concerns I would like to hear them. 

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20170223_142753[1].jpg

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As you can see the flames are jumping off the burner block, meaning the air fuel velocity is almost fail fast. It needs either more ports or larger ones. You want the flames barely in contact with the block, soft and quiet.

Other than a bit fast it looks good, all the flames appear pretty even.

I don't understand how you intend to use machine screws to cast the burner ports. Are you going to make the ports with internal threads? Or you using long lag screws? 

If you make the ports threaded I'll be very interested in the results.

Oh, and not to be picky but it's "Naturally Aspirated" not "Non Aspirated". Aspire means to Breath IN and Aspirated means "breathed in" past tense. Yeah, I know it IS picky but a word means what it means and if we want to know what the other guys is trying to say it's handy to know what the words mean. 

Frosty The Lucky.

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Hi Frosty.  On the ports, yes I am going to make them with internal threads, but hope to file them out a little, we will see..   A hour ago I cast a test block with two 1/4" X 28 bolts installed. Tomorrow, or when the castable looks almost dry I am going  to try to remove the bolts, if that is successful I will than try to ream out the threads with a file or a hand held 1/4" straight reamer.  If none of this works I will probably go with crayons.  I don't recall reading how the lag screw idea for casting burner ports turned out.   Thank you for the tip on the flames jumping off the burner block,  I will address that.  

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OK the screw idea is not going to work out, but no exactly what we thought.  The bolts came out of the test refractory block fine and a 1/4" twist drill bit in a drill cleaned up the remains of the treads in the holes quickly, although the risk of breaking the block is high doing this.  But the big reason I am not going forward with this idea is because the refractory has ceramic fiber in it, when the refractory is disturbed the fibers stick out, so the two holes I drilled are now filed with a fine fuzz from top to bottom.  I Used  kast o lite 3000. 

I too like the straw idea for casting the refractory burners, thank you Neil.  I still think I will use screws to position and hold the straws vertical.  I assume the straws just burn out?  I will cross that bridge when I get there. 

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In regards to the flame jumping off the burner block.

Frosty I did another test of the mock up burner, the one with a wooden block.  I drilled out the 1/4" holes to 5/16", still keep the count at 17, and o boy was that better. See picture, pressure at 3lb. I could not experiment with pressures as the block was starting to burn.  Thank you for those eagle eyes of yours.

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Good Morning,

Drill holes in the lower wood block (the part that is the pattern) they won't move. You can also use a wood block to stabilize the upper ends of the straws. The plastic straws will either come out by twisting or they will magically disappear when the Forge is fired.

K.I.S.S. Don't look for the Hard Weigh!!

Neil

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Good Morning,

It's always morning Somewhere!! Unless you are the Center of .............  LOL

Relax!! It matters Knot. Vancouver Island is only connected to your Island by Water. Some get their knickers in a KNot that YOU are on a Continent, guess what, your Island has wet stuff all around it Tooooo!!!! LOL

Neil

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  • 2 weeks later...
On 3/7/2017 at 6:46 PM, Mikey98118 said:

I see much more satisfactory flames too; valuable information there! Also your idea of using a wooden block was genius.

The wooden block is a Frosty idea, he used it while testing his very first NARB design.  I did come up with an idea that may be of value to some.  I use Modelers Clay to plug ports in the burner block for testing, this has been done both on the wood block and a cast refractory block.  I don't know how long the clay would last in a block, I have got a minutes run out side of a forge with no effect to the clay.  And it removes easily. 

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