speaking of G-holes

[Brent Hickenbotham]

Has anybody had a bad or negative experience with cast glory holes?

If so, what refractory was it? and what was the problem?

I don't have any experience with them so I was just curious.

And John thanks for your input already.

[James Ennis]

I know of one that had the back wall
cast, on the first fire up, when it finaly
got hot, something like a steam bubble
burst and shot part of the back wall
across the shop and almost hit my
frend in the head! the guys that bult it said they used "old" castable.

[Rick Sherbert]

I have a cast glory, 12" interior , 3" walls with 4" fiber backing. Cast-o-lite30. Drill holes in your drum to let steam escape, something on the floor to catch glass droppings. But you know all that. It takes a little longer to heat up than IFB, but once it's hot it stays hot even with the doors open. I use it every day and I really like it.

Rick

[Steve Stadelman]

I have built several with really good results.

[Pete VanderLaan]

I think they need to be at least three inches thick or they sag.

[Brice Turnbull]

I'm using about a 3" thick rough 'tube' cast inside of an old electric kiln. I ground off the part of the soft bricks that held the elements, then cast directly inside the body of the kiln.

Only used it for a year and a half now, but I see no wear in the castable. I love it! Takes 2 to 2 1/2 hours to get hot, versus the 40 minutes of the frax lined holes I built and used for 5 years before this one. Once hot, it stays hot, which I really like.

I'm using a 3000 degree castable, but it is not castolite. The bag says "Versaflow 57A", and is a Harbison-Walker bag.

[Jordan Kube]

Takes 2 to 2 1/2 hours to get hot

That sounds a bit excessive and probably unacceptable to most production shops.

[TC Robertson]

I have been using cast G-holes for many years with good results. Last winter we converted an old brick lined remnant into a 20"x16" cast unit. Open though the middle, with bit warmer and pipewarmer on either side. There is always some initial cracking, but it is generally not a prob. We didn't support one section of the floor and it dropped 1/2". Packed it with plastic and all good to go. Warm-up on the big guy is about 1.25 hrs, faster if it's still warm.
Kruzite is my fav for the castable. We did the doors out of K-30 and I will replace them with kruzite when needed. Hugh J.'s recomendations on insulation look good. Watch where the holes go thru for ribbon burners, it can cause a real weak area.
I will post some pics someday, hope this helps. Later, TC ;)

[Scott Novota]

What is the largest glory hole you would use the standard gibberson burner on and get it up to a temp. I guess having it rebound fast enough is also a point of contention as well.

I have two of them(burners) in the garage but I was just wondering how large you could go with just one.


Scott.
.