Dual IFB ribbon burner gas forge with retractable rear wall

[Lateralus]

Hi everybody,

 

I just found out it has been 10 years since I last logged in to this forum. Time flies. Anyway, I really appreciate it still being very active and full of supportive people. The pages about Frosty's burner really helped me out.

 

I had some problems with forge welding more difficult damascus patterns and I partly blamed my current single venturi burner gas forge. For big billets I had to put the choke sleeve fully open in order to have enough heat, but I guess all the oxygen also contributed to some bad welds. I also had a hot spot in the middle, so I wanted an oven with a more evenly distributed heat and with more control over the air/gas mixture.

 

Here's my design. I wanted to try out the ribbon burner, but figured it might be easier to just drill holes in IFB 3000F instead of pouring it. The square tubes are connected to it with heat resisting silicone kit. I hope the bricks will hold up, if they don't I'll have to make refractory burners.

 

The rear wall is retractable, so I can make use of half the oven for smaller work. The second burner can be shut on or off with the 2" ball valve.

 

There's a safety system with an air pressure sensor (not drawn) which will shut of the gas solenoid in case of blower failure or the power going down.

 

The door has counterweights inside the square tube, both left and right (cables are not in the drawing). I'm guessing the door won't skew when I attach a door opener in the middle. I'd like to open it with my tongs since I'll already need to have tongs in my hands for the forgings to take out.

 

Most of the materials are here, so I can start welding the base frame. 

 

Any critique or ideas are welcome!

 

Kind regards,

 

Johan van Zanten

The Netherlands

[ThomasPowers]

What are the walls made from?

[Frosty]

Good to see you again Johan, don't be such a stranger. 

That is one complicated design! I'm sure it'll work but I don't know how well nor if that much work is worth it.

I like venting the exhaust gasses out of the work space, that's a very good thing.

The air curtain is a plus.

The skirts on the hood will be stopped by the frame of the door. How are you going to open or close the door when the forge is hot? 

Frosty The Lucky.

 

[Lateralus]

On 1/14/2021 at 10:06 AM, ThomasPowers said:

What are the walls made from?

The walls of the forge itself are made from 2800 degrees F insulating fire brick. The small bricks surrounding the forge are regular yellow fire bricks.

On 1/14/2021 at 10:08 AM, Frosty said:

That is one complicated design! I'm sure it'll work but I don't know how well nor if that much work is worth it.

I like venting the exhaust gasses out of the work space, that's a very good thing.  The air curtain is a plus.

The skirts on the hood will be stopped by the frame of the door. How are you going to open or close the door when the forge is hot?

Yes I always end up making complicated designs  I wanted a forge that will last and is easy to rebuild and easy to move to my next workshop. No hoods taking of the wall for instance. The hood can be taken of the frame so the frame will fit under the doorway of my shop. 

I will test the door sliding mechanism fist, the amount of skew will determine what kind of door opener stud I will weld on it, possibly a 5 inch rod that can be gripped with tongs.

When I need a bigger interior, it will be easy to lay the bricks in a different configuration. Relining (changing bricks for new ones) is also easy. I once read your comment about one forge to rule them all, you said it doesn't exist, I'll agree with that, but nevertheless tried to make a forge as good as I could imagine.

I hope the second burner will burn as good as the first one, no weird gas mixture problems etc.

[Frosty]

1 minute ago, Lateralus said:

I once read your comment about one forge the rule them all, you said it doesnt' exsist, I'll agree with that, but never the less tried to make a forge as good as I could imagine.

It's a craft hazard, we all do it. My last forge is too large of course. The next one should be more of a universal do all. It'll be easier to dust too. 

I get the brick pile forge, I like them for all the reasons you list. Don't have a question there.

Good luck with a door that shape my intuition says it's going to be difficult to move as long as it is. The telescoping tubing guides are going to wrack and jam at the least excuse.

Frosty The Lucky.

[Lateralus]

Yes the door is tricky. But did you notice that both inner tubes have big steel counter weights (not shown in the drawing because it sits inside the tube), one left and one right, in total the same weight as the whole door, and the connection with the cable and pulley (also not drawn)? The opening stud will be mounted in the center (left-right-center) of the door.

[Frosty]

Yes, counter balanced is implied. Unless you install a screw lift or some other mechanical lift that guide will only need to be off maybe a cm. to jam. The hood has the same issue.

I'd go with a double swing arm system like a WATT linkage. They counter balance easily and don't wrack. 

Frosty The Lucky.

[Lateralus]

Frosty you are right, thanks, I searched up a bit on skewing and it turns out it is independent of the forces added by the counterweight, it depends only on the angles and the length/width ratio of the slider.

I'll need to come up with a new door system

In the formula, d will give the minimum length needed for skewing, so it can also show the minimum length for a, which in my case will be 732mm which is way more than I have designed right now  

[Mikey98118]

I am heavily into micro-burners in mini-forges--at present. But don't intend to move on, without doing this same kind of forge. It is simply part of the complete story

[Lateralus]

I don't really understand, do you mean you also want to built a brick pile forge?

What do you use your mini-forges for?

[Mikey98118]

It won't be my first. Also, buy starting from an up facing burner in a brick top table, you will be able to do more than you imagine at present. I built a very similar system to yours for Gas Burners for forges,Furnaces,

A brick pile forge on a brick lined table; these are good examples of 'universal' tools. I share Frost's view of the inbuilt problems in such equipment. It boils down to "nothin's for nothin." That said a brick pile forge is a universal tool

AND, so is a table top forge. Together, what they can do is even more universal type stuff

But, not without penalties.

They aren't my mini-forges; several better men than I have pioneered their use. What they do is save fuel, shop space, and heat gain in your shop in hot whether.

[Lateralus]

Ah cool, do you have pics from the similar forge?

Yeah, I agree, I suppose the brick pile forge will be very universal, though I doubt how often I will place the bricks in another configuration haha. I do think I'll replace the back wall often together with the use of one or two burners.

What do you mean by the inbuilt problems?

I designed another door system. Thanks Frosty for convincing me. I hope this one will work OK.

Edited January 16, 2021 by Mod30
Remove excessive quote.

[Mikey98118]

12 hours ago, Lateralus said:

What do you mean by the inbuilt problems?

Nothing sinister; all gas forges have inbuilt problems. Brick forges are square or rectangular by nature. Tunnel forges are cylindrical by nature. Neither design is flawed, but both are limited by their nature. Tunnel, "D," and oval forges have their shapes "set in stone." Brick pile forges (and casting furnaces) are variable. On the other hand, shaped forges seal up much better than brick piles, and are generally more fuel efficient. A certain amount of added space is needed to store sufficient bricks to meet occasional needs while lessor amounts are normally used. And of course the worst problem of all is dreaming up projects that will absolutely require its use

[Lateralus]

So far, so good. It is burning beautifully even. Very happy about that, I forge thin blade's and the last forging step is a pass through the rolling mill, so an even heat over 40cm length is very nice for an even thickness in the end.

So today was test firing. Runs smooth. Made a mistake by shutting of the air whilst still running gas, gave me a backfire and this blew my burner brick up. I'll see if I can glue it together.

Here you can see the oven with the double ribbon burners

[Mikey98118]

Impresssive build. What refractory brick did you choose?

[Lateralus]

2600F, for the bottom, because there was not enough 2800F left in the store, the rest is 2800F and the burners are 3000F insulating fire brick. Unfortunately they break very easily. Maybe they are low quality...?

I'm thinking of getting the walls together with mortar for extra strength.

This is what the backfire explosion did with the burner:

[twigg]

Lateralus, thank you for sharing a really cool build! Rookie question here. What is that sealant you used to seal the ribbon burner bricks to the steel manifolds? It looks like it did its job and then some surviving the temperatures and the backfire. Thanks!

[Lateralus]

Commercial link removed per TOS.

Here it is, Seal-It 211 Silicon HT, it goes to 300 degrees Celsius. It makes a very good glue bond between the brick and the steel. I had the oven running for 45 minutes, and during the run the silicone kit never got hot because of the cooling effect of the gas/air stream. When I shut it off, it did get warm, but not above 75 degrees C. So I guess it will be fine after hours of running, but that will still need to be proved.

Edited January 27, 2021 by Mod30
Remove commercial link.

[Lateralus]

I fixed the burners, and decided to mason the bricks together. Did a little painting job and bought another blower. The bigger one uses 200 watt 3 phase, the new blower is from a boiler, 24v DC 2A, 48 watt and still has more than enough power. It is quieter too. By the way, these ribbon burners are very silent! I'm very happy with that, keeping in mind the loud roar from the venturi burners I'm used to. 

Today I checked the lowest possible air setting for the gate valve (photo), I'll make a little stopper in the valve so I won't have backfires anymore. The next thing is wiring.

[Mikey98118]

Very nice flames

[tinkertim]

Are you sure they're not photoshopped? 

[Frosty]

On 1/26/2021 at 6:01 AM, Lateralus said:

Made a mistake by shutting of the air whilst still running gas,

That's a pretty universal no NO! Most commercial gas burning appliances have sensors that prevent gas flow if the air is not running. Your flames are beautiful and the forge appears to be evenly heated as far as I can see. You should leave the blower running after shut down to help cool it down. There is no good reason to allow the heat to soak more deeply into the brick and especially the burner blocks than you have to.

The rapid degradation of the 3,000f brick you're using for the burner blocks may be due to rapid thermal cycling. For the most part IFBs aren't designed to go from room temp to yellow heat in a few minutes and IFBs heat up FAST by their nature. Perhaps a kiln wash would help protect them.

It's a beautiful dedicated use, forge, I like this door mechanism a lot better, it addresses my concerns nicely. So long as they don't swing past the sides of the openings I'd call them good as they are. 

Even if I wanted to build a forge this size and shape for the same purposes, this is not how I'd do it. That's no matter though, if the end product suits your needs she's a beauty. I have different resources available and my forge construction reflects it.

Well done.

Frosty The Lucky.

[Lateralus]

 

11 hours ago, tinkertim said:

Are you sure they're not photoshopped? 

hahaha yes it does look so!

 

Frosty  yes, the air mistake was a real no no. Today I got my pressure sensor, Monday I'll make the safety system.

OK, so you suggest leaving the air on after shutdown, I was thinking about that, I was afraid the cool air might make the burner block crack earlier, but your argument is also valid, hmmms, I'd have to think about what's best.

I still don't really understand the difference between a kiln wash and a refractory cement. I do have INTOVAL T 85 SP 10 REPA (as in the attachment) laying here (refractory), but I guess a kiln wash is from different composition and maybe thinner and easier to apply with a brush in thin layers?

Do you mean you built a certain forge depending on the materials you got on hand? What is your latest and most usable forge? Would be great to see some pictures. I have to say, I don't do regular smith work, only bladesmithing and maybe heat treating.

INTOVAL T 85 SP 10 REPA

INTOVAL T 85 SP 10 REPA(1).pdf

[Frosty]

If leaving the blower on after shut down causes damage stop doing it. There is a world of things I don't k now and different IFBs are different so my experience may not apply.

A kiln wash is a last layer of protection in furnaces with hostile environments or special requirements. For example ITC-100 is a kiln wash that was formulated to prevent molten materials from sticking to the interior of the furnace. Pottery glazes to the inside of pottery kilns for example. It's not particularly good in a propane forge, it doesn't fire hard so it rubs off.

Kiln washes are called washes because they are usually thin like latex paint and can be brushed or sprayed on. They do a number of things in general they fire hard like a tea cup and resist mechanical abrasion, they are non-porous preventing the extremely chemically active propane combustion products from penetrating the refractory, lastly good kiln washes have very high temperature ranges and are poor thermal conductors. They absorb energy but don't conduct it very well leaving radiation the only outlet. They re-radiate IR back into the forge, further improving the forge effectiveness.

There is a BIG difference between between "refractory" and "refractory CEMENT." Refractory CEMENTS and MORTARS are intended to cement bricks together, they are NOT suitable for lining a furnace. They have a short life in direct flame contact.

The product you linked appears to be a: high quality, water setting, refractory. It should make a darned good propane forge liner even without the insulating properties of Kastolite 30. I believe from my limited ability to read the PDF data sheet that it is probably considerably tougher and more chemically robust. I'd like to have some to experiment with.

No, what I meant is I build a forge the way I do because of the refractories and other materials I have available. I could build a forge with a very similar shape and size as yours but it wouldn't be made from IFBs, it would be: rigidized Kaowool, insulating outer liner with a Kastolite 30 water setting hard refractory inner liner, flame face and a final Plistex kiln wash. Or perhaps if I did some experimenting and found it suitable maybe a 97% Zircopax, 3%bentonite /veegum kiln wash.

Plistex does not contain zirconium and I don't have enough to experiment with adding it and testing the results. It MIGHT work though. 

Below is my latest too large forge. I won't go into the mistakes I made on this one. It works okay is all I can say but it's not what I wanted. Pic below. The excessive orange flame isn't really "dragon's breath," it's the calcites in the refractory inner liner oxidizing. It's made as described above. The biggest mistake was not making a wide enough porch to support IFBs for thermal baffle doors.

Frosty The Lucky.

 

[Mikey98118]

What finish coat do you plan to use inside the forge? I would suggest Plistex to protect your bricks.