Naturally Aspirated Ribbon Burner. Photo heavy.

[tinkertim]

This looks really cool Dan!
I'm keen to see how well it works at max-heat.  If it will comfortably reach welding heat, then I may modify my NARB setup as well.

I've just done some hunting, and using Ceramic Honeycomb search keywords, managed to find the same ceramic elements as you on Amazon.uk for around £12, so cheap enough to play with.

Good to see you posting again.

All the best matey,

Tink!

[D.Rotblatt]

Failure... I got excited and posted too soon .

The honeycomb melted at high temps... BUT... before it did, I got 130F extra out of it at 5 lbs compared to my NARB - same burner, same forge, etc.  My NARB gets to 2170 at 5 lbs, the honeycomb was sitting at 2300.  So lots of tiny holes work very efficiently.  

Analysis: First I preheated at 5 lbs for 20 minutes or so, everything looked fine.  I turned it up to 12lbs, heating up a canister for welding.  Failure happened only about 5 minutes in, the canister was just turning red.  The a thin line along the edges of the honeycomb, where it was against the mortar, was a lot hotter than the surface - glowing brightly.  The surface is not flat.  It's got dimples with 6 holes in a hexagon around the edge and a center hole in the bottom of each dimple.  It seemed to melt in the center of each hole.  The burner was still working fine when I turned it off.  The inside surface was obviously being kept cool by the moving gasses.

The other thing about this honeycomb, is I'm not sure it was a cordierite ceramic.  This one was not labeled as such but the company offered one other plate that was smaller that was labeled as cordierite - I got this because it was larger.  I noticed that two kinds are sold, one commonly for soldering boards that is rated at 2000F, and the cordierite ceramic that's rated at 1300C (or 2350).  It's sintered at 1400C (around 2550), so it should take quite a high temperature.  

Back to the drawing board...   The fact that this worked so well (before it destructed) gives me some other ideas.  I thought of drilling 1/16 holes in high density ceramic fiber board.  There's some on amazon, .8" thick and 2750F max temp.  That should be enough, and I know the back won't get too hot.

Hey Tink!  Hope all is going well!  Don't buy any yet...looks like I have more experimenting to do.  

 

 

[Goods]

It looks like it melted in the areas with lower gas flow. Would that mean that the size was just too large for the output? Not sure how it the flame would perform with half the size, but maybe the ceramic would hold up.

Any thoughts?

David

[D.Rotblatt]

42 minutes ago, Goods said:

It looks like it melted in the areas with lower gas flow.

Good point, but I'm not sure.  The flames looked pretty even throughout.... but there is definitely a relation to the gas flow and the melted part.  If you look carefully at a zoomed pic, every center hole on the bottom of each dimple is starting to melt. It might be that on the edges the gas is flowing at an angle or more turbulence or something.  

I'm not willing to continue down the line with this material, it failed too quickly and I'm afraid it could fail catastrophically.  It does confirm for me that the small hole concept is a winner, and I'm going to try some other approaches.

Dan

[Goods]

I understand completely. I have been wondering about these burner blocks and I’m a little depressed at the rapid failure.

[D.Rotblatt]

I went ahead and bought a codierite one for $10. It looks a different color than this, so I might have gotten a 2000f one, not a high temp one. Hopefully I can remove the burnt up one and put this in its place. I hope it works!

 

Dan

[tinkertim]

Good to hear from you Dan. Hope all is well with you.

Re. The honeycomb.  That's a real shame, but you've got some pre-failure info which is good.

I remember these sorts of honeycomb on portable gas heaters, where it seemed that the front face would glow orange and appeared to radiate as much as the flame (you could turn off the flame and feel how much heat was still coming off the honeycomb). I agree that if we could find high-temp honeycomb it would be the "Holy Grail" of NARB development!  I'll keep watching your experiments with keen interest.

On another note, I've been getting a few people in the UK trying out your Zircopax/Silica (ZS) slurry for flame-coating of rigidised Ceramic blanket or board. They have reported very positive results, so we have a few more converts to the ZS slurry approach. 

All the best,

Tink!

[Another FrankenBurner]

Well that is a bummer.  Hopefully better luck with the codierite.  

[D.Rotblatt]

Thanks Tink!  Haven’t been pushing the ZS just cause finding the right colloidal in small quantities is nearly impossible here. The one person who was selling it doesn’t anymore. 
 

1 hour ago, Another FrankenBurner said:

Hopefully better luck with the codierite.

Already got the cordierite, it looks the same but we’ll see. BUT, I have another plan...it just requires drilling 500 holes LOL. But that’s what a CNC mill is for. I’ll spill more if it works. 
 

Dan

[tinkertim]

It's Funny Dan,

It's pretty easy to get Colloidal Silica in the UK, but a pain to have to import Kastolite30 from the States, yet you have the problem the other way round!  Ho-Hum!  It's a weird world we live in, and people just have to find out what works for them.

Re. a CNC mill.  This has been on my Tinks-Toys list for so long now!  Very jealous! 

Tink!

[Frosty]

Dan: Have you checked with a fiberglass supply? Colloidal silica is commonly used as a thickener in resin, polyester or epoxy. I could buy it in 55gl drums locally and I live in Alaska. I grew up in the San Fernando Valley, worked in Burbank and we thickened resin for some of the parts we made on a regular basis. There was a big cardboard barrel in the supply room. I didn't know what it was at the time but it was almost certainly silica. We had to wear a mask and turn on the exhaust fan before opening the barrel.

I think you must be looking in the wrong place. You can get ANYTHINNG in L.A.

Frosty The Lucky.

[D.Rotblatt]

On 3/12/2021 at 8:52 AM, Frosty said:

Colloidal silica is commonly used as a thickener in resin, polyester or epoxy.

Sorry to disappear for a bit.  

It's easy to get that kind of colloidal silica, but it's not the same as the colloidal I'm using.  I tested that kind, and it makes the ceramic fiber melt.  What I'm using is a colloidal silica binder for ceramic shell casting.  Look up "Remet colloidal silica" (Remet is a company that makes it).  They don't have what I used to buy, Adbond II, but I think their Remasol is the same type of thing.  I used to buy it in 5 gallon containers.  Don't really see it sold in smaller lots.  It's a completely different animal than the fused colloidal silica we use to rigidize wool - at least in how it works.

I've moved the experiment to using ceramic fiber board that I found on Amazon:  "BXI Ceramic Fiber Thermal Insulation Board (2732F) - Inorganic - Flame Retardant, Heat Resistant (12'' X 8'' X 0.8'')". My first couple of test blocks worked well. It holds up to the heat just fine - I'm going over my pyrometer which tops out at 2400F.  I'm finding that rigidizing it with the colloidal/zircon mix first is working better for drilling, if I don't it rips out since the holes are so close.  I'm playing with different amounts of holes.  My last try used less holes and I got the dreaded organ harmonics that didn't want to go away.  I'm playing with it as I have time, which is less than I'd like.  I'll keep you all up to date as I get any successes.  

The unfortunate part is that while I can drill 500 holes with my CNC, not many people have that (it's still a 45 minute program run).  We'll have to see if it is a working proposition for others to use.  

DanR

On 3/9/2021 at 7:49 PM, Another FrankenBurner said:

Well that is a bummer.  Hopefully better luck with the codierite

Same problem.  I think the first was cordierite as well.  Playing with fiberboard... see post above.

On 3/11/2021 at 1:41 AM, tinkertim said:

It's pretty easy to get Colloidal Silica in the UK, but a pain to have to import Kastolite30 from the States, yet you have the problem the other way round!  Ho-Hum!  It's a weird world we live in, and people just have to find out what works for them.

Easy to get... just not in small quantities.  I used to buy it in 5 gal batches which is the smallest they normally sell.  I stopped doing shell casting, but have a couple of gallons left over from literally a decade or so ago.  

The CNC is fun!  If you were out here, I'd be happy to share  

[pnut]

On 3/12/2021 at 11:52 AM, Frosty said:

Dan: Have you checked with a fiberglass supply? Colloidal silica is commonly used as a thickener in resin, polyester or epoxy. I could buy it in 55gl drums locally and I live in Alaska

Restaurant suppliers too. It's used to thicken food products and as an additive. 

Pnut

[Savlaka]

So I was reading through this thread, and had seen some of the discussion on tapered exit ports and tapered holes. As I was reading it I wondered if anyone had thought of using golf Tee's as the cores for the burner holes?

IIRC they are about 1/8 or 3/16” in diameter along the shaft and flare out near the head to something around 3/8 or 7/16” at the top. Seems to me you could cut them off at whatever exit size you wanted and end up with cast in micro retention nozzles. They come in both wood and plastic types, and with the wood painted they should be easier to grease up to release from the castable used.

[Frosty]

I haven't but I don't think much of tapered outlets as flame retention nozzles. My first reason is, A properly balanced flow prevents the flame from jumping off the nozzlettes and provides cooling to prevent the block overheating to the point the fuel air mix reaches ignition temp in the block and burns back into the plenum.

Reason 2, The expanded shape facing into the forge is subjected to increased IR radiation without the cooling provided by the flow in contact. 

With the wide part of a T facing inward there would be increased contact with fuel air flow for increased cooling. However the outlet narrowing towards the forge increases the flow velocity making it necessary to reduce flow to prevent the flame from jumping off the block.

If you give it a try, please keep us in the loop. I've been wrong so many times I should have a pHD or two, learning from my mistakes. 

Frosty The Lucky. 

[Doc Peepaw]

I've been reading through the text here, lots to read, lots of good information.  I decided to switch over my single port naturally aspirated burner to a ribbon burner.

I've got a big blown ribbon burner that I use for my main forge, works great.  When I travel for work I can't take it with me since it needs electricity.   My travel forge has, er, had a single port naturally aspirated burner made from a 3/4 to 1/2 T reducer with a 0.035 mig tip and a had a 1 inch flare to attempt to slow down the velocity of the gas and lessen the hot spot.  After reading through a bunch of the posts here I decided to give it a go.

I hated drilling out and burning the crayons so I didn't want to go that route this time.   I recently bought a cheap 3d printer on Amazon and have been reading about lost pla casting when I realized I could make a mold for a NARB and it "should" melt out without issue.  

I designed two versions,  one with 41 1/8 inch diameter holes and the other has 41 1/4 inch diameter holes.  After I printed the 1/8 inch holes mold I thought they might be too small so I printed the 1/4" version.  It is 3" x 3" and 1.75" deep.  

I welded up a plenum, don't just my welds, I'm out of argon so I'm practicing my stick welding.  It is 3" x 3" and 2" deep.  I had planned on inserting it 1/4 into the mold but my measurements were slightly off so, fingers crossed it is not going to leak.  I angled some 1/8" A36 steel to keep the cast burner face on the plenum.  If it fails to work I plan of scaling up the mold a bit and reprinting it.  

I did a test burn with a block of wood and 41 1/8" holes and it came out like I wanted so I mixed up the Harbison walker refractory cement I have, it worked well for the other ribbon burner, and packed it down carefully in between the 1/8 inch rods and pressed the plenum up against it as tightly as I could.  I hope it holds but I've got a plan if it doesn't.   Thanks for all the good help here. This is my first post here so if it shows up weird, whoops.

Doc Peepaw

The video didn't work, not sure how to upload them.  Here is a picture of the wood block test at roughly 2 psi.

[JHCC]

Despite many forum software “upgrades”, it’s still really practically impossible to upload a video file. Some of us have YouTube accounts where we upload our videos and then share the links here. 

[swedefiddle]

Merry Christmas Doc,

You will find that your burner will work better with a hair dryer. You have too many holes for your atmospheric. Hold a Hair dryer near your air intake, doesn't have to be direct. You will hear it begin to ROAR!! The burners always work better when in a Forge Body, holding them in a vice is misleading.

Good luck with your learning about Forges. There is not ONE hard and fast rule, there are many. The most important is be SAFE!!! Never fire up your experiments in a confined room/space!!

Neil

[Doc Peepaw]

Good call on the YouTube.  I uploaded both my test fires.  I think the picture of the test fire looked like it was running very rich because it was in wood face and didn't do justice to the actual effect and mixture I'm really getting.  

 

[Doc Peepaw]

I hade some time today while the wife and kids played with their new toys so I fooled around with the NARB.

It seems to be doing well.  It can get my travel forge to almost forge welding temps, just below by my best estimate.  

Initially with the door closed the back of the forge wasn't getting hot, not enough flow in that area I'm guessing.  Opened the door and it did better.  I drilled a 1 inch hole in the door amd it does well, though it might need even more.  

I started with the burner on the side, then tried on top.  It seems to like being on top better than being on the side, I get that *smirk*. I tried 2 psi, 5 psi, 10 psi and 15 psi.  At 15 psi a lot of fuel is being pushed out of the forge before it burns, it is a very small area inside.

The forge does seem slightly overpowered by the burner since lots of flame is escaping out the front and the hole it drilled in the door.

I might need to build a bigger travel forge.  I did try it in the big forge, made from a 20 gallon propane tank. I let it run, holding it in the door for 5 minutes but it is too cavernous for such a small burner.

Even with the burner set at 15 psi running for abour 15-20 minutes the plenum never even got hot.  I was able to hold it in my hand once I shut it down. 

Here are some of the videos I shot.

 

The PLA pulled out of the holes fairly easy at 200⁰F though some broke off and had to be melted out completely at 400⁰F. At 200⁰F they stretched and got narrow.  After pulling and melting out the PLA I reamed the hole with an old drill bit.

I did try blocking off some of the holes with Satanite gasket cement based on the comment that I had too many holes.  It ran way worse, though I didn't get video of it.  I drilled out the satanite and returned to testing with the 41 1/8" diameter holes.  Based on the flame pulling away at the corner holes I wonder if I have enough.

 

 

[Frosty]

Are you still trying to run a 1/2" T burner with a 0.035 mig tip jet? Change it out for a 0.023 mig tip and it'll be close enough to tune properly. 

There are directions for building a T burner pinned in the gas forge section. If a burner requires any kind of forced air it's built wrong. 

The rich flame wasn't because of the wood, the T was too far out of tune to work.

How about posting still pics? videos don't tell much I stopped watching them years ago. A still lets a person focus on the issues without annoying sounds or trying to follow random movements. 

Not saying your videos were like that, I didn't watch any. 

That's too small a forge for that burner and aiming it straight across at a flat wall increases back pressure which inhibits performance of the T. That's often the reason the nozzlets in corners or around the edges are the only ones working well or jumping off the burner block. 

By refractory CEMENT, are you just calling it that or does the package actually say CEMENT? 

Cements have a pretty short lifespan as propane forge liners, the burner block is part of the forge liner. You want to use a 3,000f, "high alumina, castable REFRACTORY. PERIOD. No cement or mortar in the designation at all. 

Cements and mortars are intended to stick things together like a masonry wall. In that use they are shielded from direct contact with a propane flame. In direct contact mortars and cements degrade rapidly. 

A final coating of kiln wash, Plistex 900 being one of the best commonly available puts another layer of armor on the forge liner. It makes a very durable flame face and is a better IR re-emitter.

Frosty The Lucky.

[Doc Peepaw]

I just called it cement, it is refractory from Harbison Walker.  Cement just makes sense in my mind, since it looks like it.  

I thought videos would be better, I'll do a mix of pictures and videos for my next tests.  

Good tip for changing out the tip to a 0.023 tip, I'll give that a go.  

I've already started brainstorming my next build of a smallish forge that I can take with me when I travel.  It is going to be bigger and most likely an arch design with the flame at an angle or even on the bottom/floor aiming up the arch.  I've done the floor burner on my blown forge before and it worked gang busters.

I did coat the inside with some ITC 100, I found some from Mr. Volcano on Amazon that was cheap for ITC 100. 

I did take some pictures from last night as well. Unfortunately I don't remember the pressure I was using at the time.  One it from when it was mounted on the side and the other is mounted at the top.  I tried to get a picture of the flames coming out of the burner face on both but it's a hard angle to get.

I just checked my welding stuff looking to see if I already had a 0.023 tip and found I actually was using a 0.03 not 0.035.  I didn't have a 0.023 though.

[Doc Peepaw]

The refractory I used was Mizzou Castable Refractory from on line, the 55 pound bag said Harbison Walker Monolithic and I couldn't remember what it was off the top of my head.

[Buzzkill]

On 12/26/2021 at 6:28 PM, Doc Peepaw said:

I just checked my welding stuff looking to see if I already had a 0.023 tip and found I actually was using a 0.03 not 0.035.  I didn't have a 0.023 though

Just for reference's sake, the last NARB I made uses a .030 mig tip in a 3/4" Frosty T configuration.  If you are using the same size tip in a 1/2" setup it's pretty much guaranteed to be running way rich.

Based on the apparent size of your forge chamber the 1/2" T is probably the right size, but as Frosty said you need to drop back to a .023 mig tip to get it dialed in. If you're anything like me, once you get that NARB tuned properly you'll never go back to a single port NA burner.  There are just far too many benefits and very few drawbacks imho.

[Doc Peepaw]

I had built my T burner off the design I saw on YouTube, I believe it was Red Beard Ops's video.  

I ran out of welding gas a few weeks ago and have been putting off getting more, providence.  I went today to buy welding gas and seemed as good a time to pick up some 0.023 MIG welding tips. Holy cow, you guys were right.  Thanks Frosty.

Today's tests were positive.

4 psi

5 psi

Burner in open air butbi forget, I think it was around 5 psi. 

if I had to guess, I would say I'm still running slightly rich but I'll wait to fully tune it until the new forge is complete.

Frosty, if you were a guessing man, what cubic inch volume would this size burner power?  Current forge interior is 67 in³.  The forge I've drawn up would be about 280 in³.