Tuyere question....

Here is the chimney liner in place and the first of two layer of wool in place. I am going to get some SS wire to loop through the tig wire pegs and the will use Sodium silicate to glue the second layer of wool. Or should I use Satanite as the glue?

 

That lid looks similar to the one I made.
How thick is your wool? I used four layers of 1/2" wool and ran the wire on top of all the layers. With the Satanite coating over it, I haven't had any problems.
On the lid, just two layers of Satanite or gravity will pull it loose over time.
I've never tried gluing wool together, so can't help there.
The side walls won't need reinforcement, the Satanite forms a shell to hold the wool in place.

 

Here is the first 1” layer sewn into place. Then next layer of 1” will be placed on top of it and glued. Based on my first oven used to melt iron I am not confident that exposed wire will hold up.

I have zero experience with Satanite. Do you (or anyone who can chime in) think the Satanite would form a durable bond between layer one and layer two?

 

I am using Morgan Cerachem 2600 degree ceramic wool. I am pretty sure the wire and hanger wires protected by a 1" layer of wool will be fine. I just need to glue the inner layer to the outer. I originally planned to use Sod Silicate but now am wondering if Satanite might be better. I have a test piece glued up and cooking in my kiln right now. Will take it up to 2000F and that should set the Satanite. What I am wondering is if the Satanite will flake and fret over time and thus allow delamination.

Denis

 

Following. Going to do something similar later on.

 

The way to handle inserting photos is like this:

Method #1:
Insert all of your text, and put spaces between the stuff that goes with each photo.
Attach all of the photos at the same time.
Pick the area of the screen under the first line of text, and hit the "full image" button that is next to the photo you want to insert.

Pick the screen under the second section of text.
Hit the "full image" button next to the second image.

Etc. for each photo.

Method #2:

Start a post, but before you insert any text, attach all of your photos.
Pick the screen, and hit the "full image" button that is at the top, next to the "Insert All" label.
This will insert all the images at once.

Pick the screen on the left side of the first photo.
Hit the left arrow, followed by a couple of returns (returns are the "enter" button on the keyboard).

Hit the left arrow again, and again a few returns.
Do this until you get to the bottom of all your photos.
This will put all of your pictures in a vertical column with a couple of spaces between each photo.

Then go back and pick the screen above each picture and add your text above each photo.

 

Good suggestions, Pat. Those are methods I’ve used in the past. But, somehow the code for that post must have gotten corrupted as what was showing in the edit post box refused several times to translate to the editted post. I finally gave up.

Denis

 

That post was created solely on THF on my phone. But then I tried editing on my PC. Maybe there is some code incompatibility when attempting that sequence between IOS and DOS/PC language. It was somewhat surreal.

Denis

 

First, Sorry for intruding on this thread.

But some follow up to the above: I pulled the test pieces of ceramic wool from the kiln this morning. It looks like the Satanite does a great job of gluing one layer to another. Perhaps that should not be surprising given that Satanite is a high-temp mortar. I had mixed some up to the consistency of honey more or less and applied a thin coat to both pieces and then lightly pressed them together. The mortar is thick enough that the pieces had no tendency to then pull apart. I put the sandwich in the kiln and cooked it to 1850F for a couple hours. The resulting sandwich showed solid adhesion of the two layers to the limit of the strength of the wool itself. I also noted pretty good bending rigidity caused by the set Satanite. My limited experience with Sod Silicate under similar circumstances suggests the Satanite bond will be stronger and probably less subject to breakdown due to repeat heating and cooling. So, Satanite it is for bonding the two layers of the lid and sides of the kiln.

Despite Bonz reassurance that no wire stitching should be needed on the kiln sides, I think I will do a more limited stitching scheme there too as my hoisting gear system is likely to occasionally snag the sides. I suspect he is indeed correct that this step is not needed. But it will only take an hour or so to tack in the studs and pull wire between them.

Denis

 

Above: Assembled form box as seen from outside furnace end. Burner tube absent.


Above: Burner tube in place with flared plug in end of burner seen from inside the furnace end.

I have cast the tuyere in (stone, well almost) concrete. I suspect that attached photos may be challenging to sort out. Patience! Tomorrow I will pull the Kastolite30 out of the mold and more will be revealed.

The first photo shows the 4 sides of the form box. (I now see the little clip blocks were not in place when the photo was taken.) It is intended that the outside of the tuyere neck down as it crosses the furnace shell. Then I can use clips to hold it in place pressed against the outside steel furnace wall. Wool will be used as a gasket.

The last photo shows burner tube centered in the tuyere with a flared wood plug which will form the flaring tuyere mouth.

The small rectangular plugs will form recessed for the tuyere retention clips.

Prior to assembly I “painted” the inside surface of the box pieces with polyester resin to reduce water absorption and I sprayed on some silicone mold release.

Denis.

 

I pulled the cast tuyere from the mold this AM. Now it needs to fully set---only partially
set right now.



Denis

 

I will add one note that I think is potentially useful whether casting a tuyere, chimney opening, hard face, or whatever. I found that my impact driver used to sink drywall screws in the form for the tuyere provided a desirable amount of vibration and was oh so handy. No special tool to be fabricated or dug out of the locker. I simply applied the impact driver lightly to a drywall screw and it did a nice job of vibrating the relatively dry castable so that it self-leveled in only a few seconds of vibrating. FWIW.

Denis

 

Still responding to this post. Here are a few pics of the cast tuyere held in place by the retention clips. They provide a good solid grip on it. And if/when the tuyere starts to deteriorate, it will be easy to remove it and cast a new one. I have two cast right now and will save the forms. Kastolite 30 is a breeze to cast. For scale, the studs are 1/4-20 SS.



Denis

 

@ Denis. Thanks for the details and pics, that's a nice piece of work there.

I'm currently drawing full scale the furnace wall w/ tangent at 9-10" bore (15.5" keg diameter) for tuyere fitment. Good to see the shoulder/ burner tube abutment as cast in your pics. I was concerned about casting that shoulder but it appears not to be an issue from your details (I'm using Kastolite 30 also).

Current thought is 9" bore (3.25" castable wall void of Inswool in that area) and 1" burner tube in Schedule 40 or 80. Current test mule burner is 3/4" pipe but was going to build new anyway.

It's still a work in progress.

 

Fasted58,

I notice on my most recent tuyere casting a few small cracks on the outboard end and extending an inch or two. I think they will not matter functionally. But I wish they were not there. I am wondering if the sharp square edges may contribute to their formation. So, I plan to cast a spare tuyere and make moderate chamfers on the corners. The cracks did not occur during the dry-out phase but did happen when I fired it to 1500F. Since I have a programmable electric kiln for firing the castable parts, I was able and did follow exactly the manufacturer's schedule for dry-out and heating. I used the same schedule on the chimney liner rings and had no cracks. But they have no similar square edges and are thinner in section. So, we shall see. Since dry-out and firing take nearly 48 hours, I'll have nothing to report for at least two days and maybe longer as there is some family travel late in the week.

I also have some denser refractory concrete that I may use to try casting a tuyere. I did use a silicone mold release on the form for the tuyere and that allowed easy and clean form stripping.

A few questions about your design. You are planning to use what size crucible and to melt what metals?

A comment: It seems like your walls will be unusually thick. I think most furnaces (may be wrong on this) have had something around 2 to 2.5" walls. Seems like such thick walls will cramp your bore size
but I am not sure they will gain you much in terms of efficiency. How thick will the castable be? On my first furnace I feel the castable sucks up a lot of heat as the furnace warms up.

Denis

 

One other comment: If you can make your tuyere as a modular replaceable unit rather than a just an extended portion of the overall hard-face casting, I think that is better. The tuyere obviously gets a lot more "abuse" than the rest of the hard face and thus may break down sooner and your burner tube design ideas may evolve with actual use of your furnace. So, being able to change out your tuyere while leaving the rest of the hard face intact may be a plus.

Denis

 

Related to the hairline cracks I saw in the outboard end of the tuyere casting, I am adding chamfers to the corners of the outboard end. There were n cracks on the shoulders or mouth of the inboard end, so, I added no chamfers on that end. They are about 1/4" on a side. I'll cast later today.