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Drilled (no crayon) ribbon burner


Ted Ewert

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I wanted to build a ribbon burner without having to use any crayons or acrylic rods for the holes. What could be simpler than just drilling the holes out? 

I started with a 2-1/2" piece of square tubing, drilled an inlet port, welded on a 2" female fitting, welded a couple pieces of scrap sheet metal on the ends, and cut a big hole in the end opposite the fitting. Pretty standard start.

MjC4JYS.jpg

I then cut some pieces of acrylic sheet and formed them into mold the same size as the manifold. This one was going to be 2-1/2" deep.

I squared the pieces up and used 2 clamps to hold them together. I set these 4 pieces down on another piece of acrylic for the bottom, and filled the thing with cement. Then I set the manifold down on top of that, making sure the cement came up inside to catch the ledge.

4eKqui2.jpg

I don't use any glue for the form because it doesn't need any. A little water will seep out, but that doesn't hurt anything (I put a little extra in to begin with). The cement does not stick to the acrylic, even without release agent, so disassembly takes about 30 seconds. I leave the plastic protective sheet on the acrylic, then just peel it off for quick clean up. Forms can be very simple and easy if you use the right materials. 

24 hours later...I uncrated it and got it set up in the drill press. I had to use two vises because of the fitting (maybe put the fitting on last next time), but I got it squared up. I used a 5/16" masonry bit for the drilling (same diameter as a crayon) and set the speed pretty slow. It took about an hour to drill all the holes. The bit will get gummed up with cement when it gets down a ways. I used a little wire brush to clean it off when it came up. 

DFK5ULI.jpg

The drilling went pretty smooth overall. The cement is still soft enough at this point to machine, yet hard enough to stay together. 

Once the drilling was done. I reamed out tapers for each hole. At this point you could also use a larger drill to create a step up in diameter for the gas to decelerate in. Perhaps a 3/8" or 7/16" bit drilled down 3/4" or so would do the same thing as a taper. I haven't tried it, but Mikey seems to like that method. May even work better, who knows. 

ZUz96OV.jpg

What I am trying to demonstrate here is that there are other ways to build and cast these burners, which may be easier for some guys. My total investment of time from start to finish was about 5 hours, not counting curing time. I just don't see using crayons and painted wood as the most efficient way of casting these things.

Cheers,

 

Ted

 

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Hi Wayne,

I didn't put a baffle in for a couple of reasons. It's a short burner with a large input which takes up 1/3 of the total width. If it was a 1" input a baffle would help a lot. 

I'm also spinning the air as it enters the plenum. Centrifugal force alone will distribute the gas nicely.

Mainly this is just a demo to illustrate the use of alternate materials and methods to achieve the same results. As Frosty said, "What Mike and I are hoping for here Ted is someone who'll take things other folk have done and come up with something better, easier, cheaper, etc." I think this qualifies as easier, maybe even cheaper too. 

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Excellent approach for a short burner. Standard, or long, might necessitate a baffle. 

Thank you for posting with images. That is greatly appreciated. 

And for my edification, since you mentioned spinning the air, is this burner interchangeable with the forge you built from the air canister, or is it merely an example of what could have been used with it (and others)?  Thanks. 

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On 7/7/2018 at 9:33 PM, MikeTausig said:

And for my edification, since you mentioned spinning the air, is this burner interchangeable with the forge you built from the air canister, or is it merely an example of what could have been used with it (and others)?  Thanks. 

It is not interchangeable as it is a different size. I built this one for the other forge I have, which I'll post pictures of once I have it running.

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8 hours ago, jeremy k said:

Cement or castable refractory?

Kast-o-lite 50 refractory. Nevertheless, it sets up and cures just like concrete would. 

This is the forge I'm putting this burner in. I lined the inside with Kast o lite, cut the door off and filled in all the major defects. It's not ideal, but the fact that the chamber is small means it will get nice and hot. 

6hRrbBO.jpg

I still have to put up a ledge for the doors and an extension rest. I ordered all the plumbing for it today, so all I have to do is use the blower and tank from the other forge. 

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I fired it up last night. Here was the test setup:

FnL2A1C.jpg

The burner was sputtering initially, so I knew I didn't have a good mix of air and gas. I used it in the above configuration with the spinner and that smoothed things out. I figure that probably no one is going to bother to make a spinner like I have so I started thinking of different ways to mix the gas and air better. I tried a twisted plate:

hUJBGae.jpg

This worked better than nothing, but the flame was still uneven. So I next tried a mixing tube which sticks out into the flow of air.

ZgZ3bmt.jpg

This worked even better than the spinner. the flame was smooth and I had to turn down both the air pressure and the gas to get the same flame I was getting before. 

I wrote more about the details in the "Burner 101" thread if you're interested.

The burner itself works great.

 

Ted

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  • 2 weeks later...

I wanted to add a note to anyone considering drilling out your holes. I would suggest adding a little extra cement inside the plenum during casting. Drilling does not leave a clean exit hole in this material. There is 1/4"-1/2" of spalling which occurs. This does not effect the performance of the burner, but it's good to have some extra material in the plenum to account for this effect. 

 

Ted

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Ted I like your gas mixer and the drilling approach as an option.

Did you have a backer behind the refractory when it chipped/spalled as the bit exited? If so was it similar in consistency to the material being drilled? Trying to work thru in my mind if that could be controlled/eliminated.

Best

Steve

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I couldn't figure out how to get a backer in there, so I just added an extra inch or so of cement inside the plenum. The surface is a little rough, but the holes are clean and the burner works fine. 

I'm sure someone more clever than me could figure it out. 

The mix is still relatively soft at 24 hours, maybe waiting another day would be better. 

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What kind of drill bits are you using Ted? What you're calling spalling we called blow out. You can  minimize it by backing way off on the down pressure and letting the bit "wear" through rather than "drilling it in." If you're using tungsten carbide masonry bits it's going to be a problem they're intended to chatter in the hole and chip their way through. 

You might find an abrasive impregnated bit you can use to ease your way the last 1/2" and minimize spalling.

Frosty The Lucky.

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9 hours ago, Frosty said:

What kind of drill bits are you using Ted? What you're calling spalling we called blow out. You can  minimize it by backing way off on the down pressure and letting the bit "wear" through rather than "drilling it in." If you're using tungsten carbide masonry bits it's going to be a problem they're intended to chatter in the hole and chip their way through. 

You might find an abrasive impregnated bit you can use to ease your way the last 1/2" and minimize spalling.

I'm using a masonry bit in my drill press, so I can control the pressure. There is no hammering action so the bit cuts smoothly (Regular high speed steel bits don't work well and get dull real fast). There is also an issue with the bit getting gummed up. I drill for a couple of seconds and then raise the bit up and clean it off. I think a lot of this can be cured by waiting and extra day for the cement to harden some more. I'll do a test casting this week and see at which point of curing the drilling works the best. It may work fine when the casting is fully hardened. Kastolite is not very tough. I'll do one hole a day to see what happens.

9 hours ago, Jspool said:

Just a thought.  If you are not casting the holes with crayons and drilling them instead, why not forgo the casting all together and cut a fire brick to size and drill that?

I've tried that but there are a couple of problems involved. Attaching and sealing the brick to the plenum is not easy. You need a good mechanical bond as well as a good seal which is inherent when casting the plenum on the cement. The other issue is the bricks ability to hold up in the forge environment. Refractive bricks are a bit delicate and tend to crumble in spots. Regular clay fire bricks are exceptionally hard and drilling them requires a hammer drill which is no fun at all (not to mention inaccurate). 

 

Ted

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  • 2 weeks later...
On 7/25/2018 at 11:52 AM, Ted Ewert said:

Regular clay fire bricks are exceptionally hard and drilling them requires a hammer drill which is no fun at all (not to mention inaccurate). 

Ted

Ted, what specific kinds of hard fire bricks were you trying to drill? I've been able to drill hard fire bricks using an ordinary carbide-tipped masonry bit in a drill press (i.e., WITHOUT a hammer drill) quite easily. For example, as shown in the image below, I drilled holes through three different kinds of hard fire bricks with the same carbide-tipped masonry bit in a drill press, and I had no problem at all. I got these fire bricks from Sheffield Pottery in Massachusetts, and the terms in quotes are the nomenclature that they used on their website. The bit drilled through the first two types VERY easily, taking less than a minute to drill a 3/8" by 2.5" hole all the way through each brick (these are full-size bricks). I think that the "high heat" brick was a touch softer than the "super duty" brick, but both drilled quite easily. The third (70% alumina) brick was harder than the other two, and it took an extra minute or so to drill the hole through that one. All of these holes are quite smooth inside. After drilling the 70% alumina brick I noticed some erosion on the leading edge of the carbide tips, but I think I could probably drill three or four holes through the 70% alumina brick before having to touch up the bits on a wheel or use a new bit. However, I'm sure that I could drill a lot more holes in the first two brick types without replacing or sharpening the bit.

fire-brick-drilled-three-samples.thumb.jpg.9f9e2dec96fd49e0664ca3e8b8f6b062.jpg

More information about these bricks should be available on the Sheffield Pottery website.

By the way, Ted, I like reading your posts. Keep it up!

Al (Steamboat)

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I must have a batch of really hard bricks then! Nevertheless, clay firebricks are a big heat sink and don't insulate well, and I would not recommend these for gas forges. They could be used as an outer container, followed by a layer of Kaowool and then Kastolite if you wanted. 

Refractory cement, such as Kastolite, is the only thing I would use for a ribbon burner anyway. These burners get very hot on the inside of the forge and you need something that can remain structurally sound at those temperatures. Clay bricks would also transfer a lot of heat back up to the plenum where you really don't want it. 

Ted

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Serious terminology point here, KastOLite-30 il is NOT a cement if that's what you're referring to Ted. Kastolite makes cement products but they have specific designators. Not using the product designations will confuse folks who aren't already familiar. 

No, you don't need to use a hammer drill to make carbide tipped masonry bits work, they were designed to work best under a hammer drill but it's not necessary. Chattering is how they cut they aren't sharp. They rub on the surface and vibrate making thousands of small impacts per revolution and chip through masonry. 

Al: Are those nice clean holes, are they entry or or exits?

I don't CARE how you make the outlets for multiple outlet burner blocks. My only dog in this is discussion what is the most effective technique and how it's done. I'll put ANY tool in MY box so long as it's safe. Heck I have more and larger file folders of unsafe and B-A-D, DO NOT DO THAT! things in my tool box so I can warn folks off and explain why. 

Frosty The Lucky.

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1 hour ago, Frosty said:

Al: Are those nice clean holes, are they entry or or exits?

Frosty, those are the entry holes, but the exit holes really aren't too bad either. Here are both sides of the "high heat" brick:

fire-brick-entry-exit.thumb.jpg.e0370eecffa162f6b04ff1fa342abf69.jpg

I'd say that all but about the first and last 1/16" of the holes are nice and round, straight, and with smooth sides. The 70% alumina brick had a bit more tear-out than the others and seems more granular in nature than the others. The masonry bits that I use have very "crisp" edges on the carbide inserts...almost what I would call "sharp." I can check on the brand, but I usually order them from McMaster-Carr. In any case, they seem to cut smoothly and evenly...at least that's my "physical"perception. At the microscopic level, they could very well be chattering away like mad, as you said.

I've done a lot of stone foundation work and granite splitting with feathers and wedges, so I've drilled hundreds of holes in granite, schist, gneiss, and other stones with hammer drills, and some bits definitely hold up better than others, and some have deeper inserts than others, allowing more resharpening.

I think that if one were to drill a hard fire brick with the brick tightly clamped against a piece of sacrificial hardwood, it might further reduce the tear-out at the exit edge. I'm guessing that a small amount of tear-out would be acceptable, as you might want to put a very small radius on the edge to help stabilize the edge and smooth the gas/air flow into the hole a bit.

Al (Steamboat)

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I spent 20 years drilling myself and know how carbide rock drills work, took classes, even a couple out of state work shops. You may not feel a masonry bit chatter but it's not "cutting."

Your results show your experience, most folk hog the down pressure rather than let the bit do it's job making the entry skate around till it spuds in and the exit blow a crater.  The same operator error causes bits to jam exiting steel. A good judge of drill reaction can tell when the pilot begins breaking through and eases off the down pressure and floats the bit through. 

The entry side shows almost exactly the same chipping as the break out. As the instructor said at the CME drilling seminar while discussing various carbide bit tools. Hmmmmm? 

Honest, I wasn't expressing opinion as to how carbide masonry bits work. 

Frosty The Lucky.

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3 hours ago, Ted Ewert said:

I must have a batch of really hard bricks then! 

Ted, it would be interesting to know what manufacturer and model of hard fire brick you were having difficulty drilling. I've never had an issue with cutting or drilling any of the ones I've used over the years for stoves, fireplaces, a glass furnace, and more recently forges, but I can't claim to have used them all. You might also try drilling it again with a fresh high-quality masonry bit and experiment with drill speed and pressure, as I recall Frosty suggesting. If the speed and pressure aren't close to optimum, the bit won't drill effectively.

As to the material for a ribbon burner head, I wasn't necessarily suggesting hard fire brick (I was just responding to the fire brick drilling issue), although as I have no serious experience with ribbon burners I'm not yet ready to categorically rule it out as a material for the burner head. There are certainly hard fire bricks that can remain structurally sound in temperatures achieved in gas forges, so I don't think that should be an issue. The specification sheets for various hard fire bricks can provide data regarding their performance at different temperatures.

I've used Kast-O-Lite 30 refractory to make a number of castings, and I've discussed Kast-O-Lite esoterica with tech reps, so I'm pretty familiar with it, and I absolutely agree with you that the thermal transfer rates of hard fire bricks are greater than that of Kast-O-Lite 30 refractory, but there are a lot of factors that can affect net thermal transfer.

You could be correct about the unsuitability of hard fire brick for the ribbon burner head, but can you provide some specific data about it making the plenum too hot, either via your own experience or a reference to that of others? Maybe someone else on IFI has tried it and posted it (Frosty?) but if so, in reading about ribbon burners on IFI, it appears that I've either missed that somehow or forgotten it, and a reference would be appreciated to refresh my memory.

Another factor that could be important is the expansion/contraction of the burner head material, especially if it is to remain firmly attached and sealed to a plenum. There are certainly ways that a hard fire brick could be mechanically secured and then sealed to a plenum, but I don't know how the dimensional changes of that material during the heating/cooling cycles would affect the bond to the plenum, or how its dimensional changes would differ from the concurrent dimensional changes of the plenum itself. Would Kast-O-Lite be a better match in that regard? I don't know. Maybe someone has already done that research, but I haven't, and that would be just one of many factors that I would want to explore.

By the way, if you want to see a couple of my Kast-O-Lite castings, I posted the beginning stages of a gas forge project of mine on IFI a while back. I finished that forge some time ago and had intended to post the entire build process, but was sidetracked by other demands that life imposes. Anyway, I'm back at playing with hot metal, and as soon as I complete one small modification to that forge (a removable cast-Mizzou floor) I plan to post the entire construction process on IFI. I also recently built a solid-fuel forge that uses some Kast-O-Lite castings.

Here is the link to the first stages of the gas forge build:

https://www.iforgeiron.com/topic/47889-castable-sleeves-for-gas-forge-openings/

And a  link to the solid-fuel forge that I recently built (scroll down to see the Kast-O-Lite castings):

https://www.iforgeiron.com/topic/58855-oldnew-compact-convertible-solid-fuel-forge-photo-heavy/

I also want to mention that I appreciate your interest in experimenting with materials, designs, etc., as I have the same tendency.

Cheers,

Al (Steamboat)

 

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18 minutes ago, Frosty said:

The entry side shows almost exactly the same chipping as the break out. As the instructor said at the CME drilling seminar while discussing various carbide bit tools. Hmmmmm? 

Frosty, when I drilled that brick, I drilled it with a small piece of sacrificial plywood under it to reduce the "breakthrough" effect and was very careful to apply only the slightest pressure when nearing the bottom side of the brick. That brick drilled quite easily, with very little pressure applied. I believe that I could duplicate that in a video if anyone is interested. The bottom breakout was larger in the 70% alumina brick, but as mentioned, that brick seemed more granular and less homogeneous than the other two.

This is slightly off-topic, but on the subject of drilling with carbide masonry bits, here's a stairway that I built last year, which required quite a lot of drilling (with a hammer drill) and wedging to split off some large granite slabs to make room for the stairway. It was not a comfortable working position, and it was a four-hour drive from my house, so I had to make do with some tree limbs and rocks for a "scaffold." I pre-built the stairway in my driveway, disassembled it, and installed it piece by piece at the location you see. I had to drill more holes in the side of the cliff for anchor bolts for chains to suspend part of the stairway.

http://todacosa.com/campobello/images/side-view-of-stairs-looking-up.jpg

http://todacosa.com/campobello/images/stairway-looking-down-from-top.jpg

http://todacosa.com/campobello/images/a-few-feathers-and-wedges-for-splitting-granite.jpg

Al (Steamboat)

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4 minutes ago, Steamboat said:

I drilled it with a small piece of sacrificial plywood under it to reduce the "breakthrough" effect and was very careful to apply only the slightest pressure when nearing the bottom side of the brick.

Experience shows. You could've backed it with another brick and and clamps, too much pressure would've caused more breakthrough spalling.

I've never worked with feathers and wedges, knowing HOW they work isn't the same as KNOWING how to work them. Do you work many faces like that one? 

Frosty The Lucky.

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Just now, Frosty said:

I've never worked with feathers and wedges, knowing HOW they work isn't the same as KNOWING how to work them. Do you work many faces like that one? 

That's the first time I ever split rock from a cliff face. Most of the splitting that I've done has been for foundation work and for a couple of fireplaces. For example, my wife and I are gradually restoring a house that is more than 200 years old, and we had a huge amount of foundation work to do on it. The original foundation was loose-stacked stones with clay pointing, and previous owners tried to "fix" the broken-down areas with mortar, but did a poor job. We had to remove all of the old mortar, re-stack many of the stones that were out of place, and split dozens of stones to get them to fit correctly, and all this while the house was up on jacks. I did have help jockeying the heavier stones around. We did a "proper" mortar job, as well as a reinforced, out-of-sight, below-ground "battered" wall against the foundation, plus a whole bunch of other foundation and basement stuff too numerous to mention here. Anyway, we managed to maintain the basic original appearance, keep 95% of the original stones, and ended up with a strong and dry basement, and dry basements in old houses in Maine are quite rare. I also did some rock splitting (and 6-inch diamond drilling) on ledge rock when we installed the shore posts for our dock. Also a bit of patio fieldstone work that I had forgotten about until now. Splitting rock is actually quite fun (all except for the drilling). It's amazing how a repeated series of relatively light taps on wedges can split a stone the size of a Volkswagen, although I personally have never split one that large.

Al (Steamboat)

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Nicely split field stone is darned attractive. I've been tempted to make some feathers and wedges if I start doing any fossil hunting again. Last time I went I took a couple speed bars to go with my rock hammer and they worked a treat. 

I've seen videos of a guy splitting marble 40' high 20' thick faces in a quarry with feathers and wedges. One guy walking down a line 100' long with a 2 lb. hammer giving each wedge a tap, walk back and repeat and in an amazingly short time a crack appears then SNAP and it settles away from the face to be further processed. 

What they didn't explain was how they got it to break cleanly along the bottom face but I guess there have to be trade secrets eh?

Have pics of your house? 

Frosty The Lucky.

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