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Welcome to the forum, Kreuzmant.  Sounds as if you might not have taken the time to read completely through this entire Forge 101 thread before ordering a bunch of materials.  So much to learn here and you could have saved yourself many mistakes because others have already made them and learned from them.  I'm assuming your split brick is hard brick.  ???  If so, be aware that hard brick sucks heat away from the forge's cavity where the heat needs to remain.  Soft, K-26 insulating brick under a layer of KOL-30 is far more useful inside the forge. 

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  • 3 weeks later...

If you already have the ITC 100, than you might as well use it. I would still suggest using Plistex first; it costs very little and does very much more than just acting as a re-emission agent. When the Plistex is fired, then use the ITC 100; after the first coat of it is fired, separate some in a clear glass container, and add water to the mud, until all of a sudden it separates, with the coarse particles dropping out of solution. Then paint the resulting colloidal mixture over the first ITC 100 coating and fire it. This is how to get the best use out of a bad previous decision. The result will turn your frown into a smile--which is always better than a kick in the rear, yes? :)

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  • 2 weeks later...

There are forges that are set up to be used both in vertical and horizontal positions, BUT most (not all) of them are used as casting furnaces when in the vertical position; in this case a drain hole at its bottom end is advisable, in case of crucible failure.

A drain hole for melted metal needs to be about 1" minimum diameter in order to work properly.

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Hello and thank you every body for putting up with me.

 

Well I did it. It’s a frankenForge but I didn’t rush the build.  

The shell is an old stainless brewers pot that I cut down to size.

First a layer of 1” ceramic wool, rigidized and coated with KOL-30 and left to cure before another layer of 1” wool rigidized followed by the last layer of KOL-30. The kastolite is pretty thin maybe 1/4” a bit thicker around the ports and the floor. But I used less then 10 pounds of KOL30.

i used Metrikote over the kastolite and I put it on kinda thick.

if I did the math right I have just over 350cu inches for my 3/4” burner.

I think the opening should have been bigger but it should work

my main issue is the burner in relation to the port. Placement and how close it should be.

i currently have it inserted about 3/8” into the shell. The port being about 2” thick and flaring slightly

I thought it needed an air gap between the burner flare and the forge wall. 

 

Test fired it it for the first time tonight but the nozzle was getting a lot hotter then it did firing the burner by itself.

I know it looks crude but is the burner in a bad position?

 

 

 

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4 hours ago, Euphorious said:

Test fired it it for the first time tonight but the nozzle was getting a lot hotter then it did firing the burner by itself.

I know it looks crude but is the burner in a bad position?

That is completely normal. You should put it deeper into the forge, leaving only about 1'' inside of its inner wall (hot face). It should then become yellow hot.

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12 hours ago, Euphorious said:

First a layer of 1” ceramic wool, rigidized and coated with KOL-30 and left to cure before another layer of 1” wool rigidized followed by the last layer of KOL-30. The kastolite is pretty thin maybe 1/4” a bit thicker around the ports and the floor.

This is a variation from what we recommend.  I would not tear it apart and rebuild at this point, but there is little to no value to a layer of KOL-30 between 2 layers of fiber blanket.  The purpose of the insulation is to hold the heat and the purpose of the kastolite is to protect the insulation from us ham-handed smiths poking it with hot metal, so putting kastolite between the layers of blanket is unnecessary at the very least.

This isn't intended to pick on you so much as clarify for anyone who may be reading this thread later.

As Mikey has said it is normal for the last bit of a flare to get hot enough to glow.  However, if your mixing tube would get that hot (and it doesn't look like it is),  that would indicate a problem.  Chances are that inserting your flare a little deeper and maybe some final tweaking will have you bashing hot steel in short order.  If you need help doing the final tweaks on your burner then some pictures of the flame in the forge shortly after startup will help us help you.

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Cold spot in forge and dragons breath. Possibly debris. Will check when home.  Nice video of swirl from bottom mounted burners. Once the shop is up, I will make a larger forge with either 4 1/4” or 2 3/4”  bottom mounted burners. 

 

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Wow; that is excellent swirl going on in your forge. The color is just into the orange range. I have not seen a gas forge that can get beyond red, that has intractable problems. I don't think that forge has either. Next thing is to put a baffle wall in front of the opening and see how much hotter the forge will get :)

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Thanks Mike. It gets yellow hot without the obstruction and without a baffle door, but only the inner 3/4 of the forge. If it had a door, I’m sure it would get “screaming hot”. The big brother will have a shelf and baffle door. 

 

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  • 2 weeks later...

Not sure if this is a burner, narb or forge question....

 

any suggestions on how to mount the ribbon burner to the forge?  Planning on L brackets attached to Ribbon burner and then it sits on forge.   Any suggestions for filling a gap between burner and forge kaowool/kastolite 30?

 

on Narb, any thoughts on using a slip on mount to plenum instead of screw on?  Seems like it would be nice to pull burner tube out of burner when you want to avoid chimney affects.  Obvious concern is that the joint might leak, causing an issue.

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This is one of those questions that're hard to answer for someone else, so much depends on your variables. One thing I can say for sure is don't do what I did and weld it to the shell. I knew better and did it anyway, the plenums have angle iron welded to them so all I needed to do was drill a couple holes and screw it on. Stupid mistake, I could be experimenting with them in different forges but . . . <sigh>

Just screwing the burner to the forge has advantages in a couple ways. It's easier to seal them in, I found mine burn almost exactly the same in or out of the forge so allowing additional combustion air access around the burner isn't a factor. It's fast and easy. I'm sure there are more but those are what's coming to mind right now.

Using a sleeve with set screws has it's own advantages: You can adjust the depth of the burner, even while running. The set screws allow you to change the orientation and adjust flame flow patterns, vortex, flame shadows, etc. 

If the burner is well tuned a gap between sleeve and burner won't matter much to the flame itself but it could alter the atmosphere in the forge to oxidizing (lean).

Chimney effect didn't show to and degree when I was running the T inducers vertically, I think maybe all the holes in the burner block and the plenum before it reaches the mixing tube disrupts much if any convection. There was pretty warm air coming out of the Ts but not a real flow so I don't think it's a factor. It might work out differently for you though, that happens all the time.

Frosty The Lucky.

 

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Cool, gonna go with the sleeve.  Can always cut it off and put a coupler if it leaks out the sleeve.

I’m going with the L brackets/angle so I can shim it up if it’s below the face of the forge.

 

thanks.  Hope to get it cast tomorrow.  Hurry up and wait!

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Can someone validate this is the proper process/timing for kaowool/kastolite 30/plistix?  This is what I’ve gathered from this thread and several others, mostly in piecemeal, so please correct me if I got something wrong or can improve.

 

1.  Layout 1” layer of kaowool in shell.  Wet with silica rigidizer 30/70% ratio.   Use torch to dry wool/melt silica.  Torch time is ~15-20 minutes.  Ensure entire wool insulation is rigid, otherwise repeat for that area.

2.  Apply second layer, repeat above process.

3.  Mix Kastolite 30 to thick peanut butter consistency.  Butter wool with plain water.  Trowel mix onto kaowool 1/2” thick. 25 min working time.   Put in garbage bag, spritz some water in bag to maintain 100% humidity.  Let cure 2-7 days.  Remove from bag.

4.  Bake in oven for a few hours or all day from 200-500 degrees.  OR. Run torch on low to remove moisture for a couple hours.  OR leave out of humid bag for a couple days and then run torch on low for a couple hours.  When all done, run torch on high for 30 minutes.

5.  Mix Plistix to sour cream/latex paint consistency.  Brush on to Kastolite in thin paint like thickness.  Let dry to hard coating which is about 1 day.  

6.  fire up forge/use it.

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Hots spots

A common worry about choosing a square forge design is if it will have a tendency to develop hot spots.

Technically the answer is yes. But the qualifier is in the word "tend." The other side of the coin is how well the forge is designed, and how sanely it is run. Two different builders have registered temperatures of 2750 F, in forges using my burner design. While very satisfying personally, who the devil needs to run a forge that Hard?!?!? The higher a forge's temperature gets the harder its burner(s) must run to reach it. The harder burners are run the more likely hot spots are to to matter. So, are we building dragsters or practical tools?

Both of those very hot forges were tunnel deigns. Tunnel, "D", and oval forges circulate internal atmospheres better than "box" (square) forges possibly can; that doesn't make them superior to box forges, because every advantage in forge design comes at the cost of some other factor; in this case it is maximum available space. When added to the many advantages of using brick materials in manufacture, possible hots spots are merely a aspect of design; not some major bugaboo.

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MIke: I don't think you need 15 - 20 minutes torch time to set up the rigidizer. I don't think it'll hurt though.

Mix the Kastolite to a consistency you CAN trowel, the crushed aggregate makes peanut butter consistency hard to imagine in my dented head.  Being broken the aggregate will key together and not slide so it's hard to trowel if at all stiff. We don't need maximum compressive strength or temperature rating so we can get away with mixing it wetter than factory recommendation. 

Kastolite sets and then cures just like Portland cement concrete does and those procedures work just fine. Once it sets, seal it up with a wet towel or in a tub with a couple inches of standing water. I have a plastic tub just the right size. 7 days is the factory recommendation for max strength but over a night or two is plenty of cure time for our uses.

Kiln washing with Plistex or Matrikote is as simple as painting. MIX enough water to make it like latex paint. You'll need to stir it regularly or it'll settle. Brush, roll or spray it on. Many thin coats with time to dry between works best. A thick coat will likely flake and peal as it dries or in use. Oh, butter with plain water before you apply it. 

Does this help Mike? Don't overthink it, this you aren't painting a cathedral you know. :)

Frosty The Lucky.

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Burner positioning

Burner designs have improved over the years, and are continuing to develop. Refractory product improvements are advancing even faster than burners. Both changes are shifting the ground rules for forge design. Top-down facing burners were the practical choice in the past, for good reason; mainly, it integrated well with the limits of reasonably priced refractory wall materials, by permitting flames to impinge on forge floors, which needed to be made of tougher materials anyway.

    But while new materials (including Morgan’s K26 bricks), can simply be used to improve performance of standard forge designs, they are even better when combined with greater distance between flame tip(s) and work, to ensure complete combustion; and therefore a reduction in scale formation by pointing burners up and away from the work pieces in tunnel, "D," and oval forges; or high on a side wall of box forges.

    A neutral flame is not only hotter than a reducing flame, but it is much better for your health; employing lightly reducing flames used to be standard practice for blacksmiths, in order to reduce scale from heating the work in a gas forge. Increasing the distance between flame tips and parts is the cleaner choice.

    Top facing burners have no problems with heating from the chimney effect after shutdown; this position also permits lose fitting refractory flame retention nozzles to sit on a flat washer that is placed on a burner's mixing tube; avoiding the need for a complicated steel to ceramic joint.

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