I never bought Gibberson's head because it was originally designed for glass work, and had some warnings about fracturing; so, I didn't think they would work out very well in a forge; especially at their price (for which you could buy a complete burner). whether or not he has changed his refractory to be more friendly to fast thermal cycling, I doubt. For a glory hole or day tank, I would choose them in a New York minute.

In the meantime, being able to buy the hardest part of a muilti-hole burner head at the price of these tiles is enough to sucker me down the rabbit hole

Certainly sounds like it is worth investigating.  Even though Dudley now produces burner blocks specifically for small forges (check the Joppa Glassworks site), I agree with Mikey that he is still most likely casting them out of the same high alumina refractory he uses for his normal glassblowing burners.  Of course I did thermal cycle one of those in a glory hole for quite a few years without cracking or failure (where it would run for a couple of hours pretty much full out then be shut off with a trickle of forced air to keep it cool while the glory hole cooled down. 

I think Mike may be correct on the advantage of a thinner face for a multiport burner based on my experience with Dudley's burners.  It makes sense to me that the thermal gradient between the mixture plenum (which ideally should be close to ambient due to the unheated air either forced or entrained and the expansion of fuel gas in the orifice) and the inside face of the forge would be the same regardless of thickness of that face.  With a thinner face there is less surface area in each of the discharge ports that will be up to a pre-ignition temperature and the air/fuel mixture will be in contact with that portion of the discharge port for a shorter period of time.  That is all to the good.

Of course my experience is with forced air, natural gas burner assemblies, and the dynamics may be different for NA burners with propane.  The former is certainly easier to tune.  I expect another factor that should be considered is that as the forge gets up to temperature it becomes more acceptable for the flamefront to lift off the surface of the burner outlet a bit, allowing the air/gas mixture to cool that face as well.

When weather and time permit I plan on casting a new multiport burner for my small forge.  I will do that in Mizzou and use a thinner face more similar to Dudley's following this topic.  Will report back with results when that happens, but it will be quite a while from now.

Thanks for refining my understanding, Latticino. Apparently I over reacted to his warnings about fractures in his ceramic burner heads.

Thanks Latticino, more info is a good thing, especially from someone who uses the things so regularly.

Thin burner blocks next experiment, come spring. 

Frosty The Lucky.

That's used, unfortunately, no longer uses...  I"m back to the corporate world these last 20 years and  only get to be a hobbiest.

 

Mikey:  I think I cracked (2) Joppa burner heads in around 12 years of steady use, and one of them was likely in a move.  Certainly acceptable from my point of view.  Dudley makes an excellent burner.  They still are the standard for most glass blowers I know.

The hobbiest of hobbyists. 

On 2/10/2019 at 8:42 AM, Latticino said:

It makes sense to me that the thermal gradient between the mixture plenum (which ideally should be close to ambient due to the unheated air either forced or entrained and the expansion of fuel gas in the orifice) and the inside face of the forge would be the same regardless of thickness of that face.  With a thinner face there is less surface area in each of the discharge ports that will be up to a pre-ignition temperature and the air/fuel mixture will be in contact with that portion of the discharge port for a shorter period of time.  That is all to the good.

On the same line of thinking. a thick coating of re-emissive material on the plenum chamber side of the of these tiles, before they are installed on the burner head, might also help keep ribbon burners from backfiring as easily?

Well you could certainly try that.  I'd be worried that a thick coat would obstruct the outlets.  If I recall there are a lot of very small ones?  I also believe these tile are used with forced air burners.  You headed over to join me on the dark side?

10 hours ago, Latticino said:

If I recall there are a lot of very small ones? 

I have been out sick, I will recreate the burner and get some pics. i still have the parts. I had to cut one row of 4 off in order to fit in the bag balm plenum.

Any thoughts on a castable like Kasto 30 sticking to this ceramic? expansion issues? 

On first glance looks like they are cast from some kind of high alumina ceramic.  Differential thermal expansion might be something you will have to contend with.  They sure look like they would work well for a burner face.  Will take some creativity to get a good seal while still allowing for thermal expansion.  Dudley uses a similar material, but his joint is much further away from the burner face.

Kastolite might work, it sticks to everything. Don't know how it works as cement though. Might need to sift the aggregate out first.

Frosty The Lucky.

11 hours ago, Latticino said:

You headed over to join me on the dark side?

You mean, am I shifting to being on the fan-blown burner side by that? Been there for the last five years; just using different fans to effect different outcomes. I had no use for the fan-blown versus naturally aspirated burner controversy, which was raging twenty years back. Frosty has it right; it all boils down to how well you build  and tune either kind. Are there cookies on the dark side?

The difference in coefficient of expansion needn't be a problem. I visualized the plate as sitting within a recessed ridge on the burner head. Yes, there would still be a small difference in rate of expansion, but if we coat the inside of the plate , and then place ceramic paper around that edge of the plate, and then coat the ridge face before assembly, wouldn't that allow the tiny amount of movement needed to avoid cracking?

Yeah, I have no dog in the NA vs. Gun burner debate, I got into NA because I couldn't find a decent size blower locally, then Cruz gave me that box of articles and stuff.

I embedded the steel plenum in the refractory block and let it flex. An Udder Balm can is darned thin so just clamping it to the plate should take care of any COE differences. Seriously, you can crush an Udder Balm can in your hand, it's not going to break the burner plate. If you're wondering, I have a can of Udder Balm right next to me, it makes the best darned hand lotion there is. Lanolin RULES!

Frosty The Lucky.

 

On 2/13/2019 at 6:06 PM, Frosty said:

An Udder Balm can is darned thin so just clamping it to the plate should take care of any COE differences.

how could it be clamped? An easy plenum would be nice. The thin walls would probably need to stay away from the heat and the head would have to extend into the forge. the plates are too thin too extend inward unless 2 or 3 three are somehow fused maybe?

Udder balm is king up here in the mountains!

It was just a thought, I didn't think about how I'd clamp the can to the plate but I'd probably start with a long hose or maybe a muffler clamp. A length of strap stock with flanges bent in the ends and a nut and bolt. It'd take some experimentation.

Heat would be a problem though not like stacking a bunch of plates though that might be something to think about. I'd try isolating the plate from the forge a little, say recess it an inch or so back into the liner?

Frosty The Lucky.

14 hours ago, Mikey98118 said:

Are there cookies on the dark side?

Of course, dark chocolate chip tollhouse...

I forgot that you have been experimenting with the whole vortex blower thing.  Thanks for reminding me.

14 hours ago, Mikey98118 said:

then place ceramic paper around that edge of the plate

That sounds difficult to achieve and potentially creating a leak for the fuel/air mixture around the face plate.  It may be that allowing the leakage will be acceptable, and just working with it as another "port" for the burner outlet.  If that is the case some kind of cast slot to slide the perforated face plate into may work.  As I've noted before, Dudley uses  a metal mesh joined to the rear pipe fitting then grouts his plenum/diffuser to this mesh.  This seems to work quite well, but the joint is not close to the flame front.  I think this is going to take some experimentation and look forward to hearing what results folks who are playing with it get.

My own ribbon burner has some metal mesh welded to the plenum and extending into the block, but that's a different kind of thing.

(This was as-welded; I ended up trimming it back before casting the block.)

I've had good luck by casting the plenum into the block as John shows above.

I've been thinking about the plates and think the easy way to connect them to the plenum is cast them in the same manner. A short piece of expanded metal welded to the plenum extending down the side of the plates far enough for a good bond and cast or ram in Kastolite or equivalent. 

While thinking about that last night it occurred to me stacking those plates would make excellent heat isolation. HOW you ask? Buy or make wax cores maybe a touch larger than the existing holes in the plates. Maybe roll balls between your palms, more later. Then you sift the aggregate out of Kastolite, we only want the high temp binder here. Mix it with zircopax at. 80% Z to 20% K. Here's the tricky part I haven't worked out to my liking, I'm basically lazy and this'd be a lot of fiddly work. With the wax cores stuck into the holes in a plate, carefully fill the space with the KZ mix. Press the next plate on and repeat till you have a 3 plate block. Immediately cast the plenum to the stacked block so the KZ and Kastolite bond well. 

About the wax outlet cores being larger than the holes in the plates. Wouldn't that allow more surface area to cool the plates and accelerate the FAM as it passes through the holes? 

I'm just skyballing this here. What do you think?

Frosty The Lucky.

 

As lean as I could get it till it back fires. 5 psi. Ever seen a burner with duct tape?

Also check out this reducer 

Man, you can use Bag Balm for anything.

You sure can, it makes a vinaigrette that really sticks to your salad. Ask the in laws. 

On 2/14/2019 at 8:05 PM, 671jungle said:

Ever seen a burner with duct tape?

I've seen burning duct tape. Why do you have your finger over an air intake, it's burning rich you know. If you can't get it to work below 5psi. then don't run it below 5psi. The purpose isn't to see who uses the least pressure it's about a HOT fire. Set your sights on what counts a reasonably neutral flame.  Hmmmm?

Frosty The Lucky.

A 2" x 1/2"  reducer would make an excellent choice on a linear burner to feed your gas plate.

12 hours ago, Frosty said:

it's burning rich you know

yea, i didnt explore its range as I probably should have to get a better understanding of what needs to be done. It seemed it didnt want to stay lit the more I cranked the psi. I used a 1/2" mikey the last time and it didnt backfire at the same psi if remember correctly. the sound that plenum chamber makes when it flashes reminds me of the soda can cannons i used to make as a kid.

I will give it more pressure and/or increase intake openings to create more induction?.  Im running a .025 mig jet.

That burner is a side arm burner.  The best I have seen for side arm are the modified side arm or the z burner.  Both use a larger fitting then the mix tube size for increased air inlets.  Even still, if you follow the link to the z burner page, you will see a rich flame.  A Frosty T produces a better flame with similar fittings.

You might try an 023 mig tip, it seems trivial but it makes a difference.