Big kiln, hot flash waaaahhmbulance

[Cher]

So now that I got the big evenheat 2541 x13 of my dreams, it intimidates me to pieces. First, to crash cool, it's top load, so do I:
1. rig a cable and hoist thing? If yes, how what and where do i get the stuff?
2. do, as some in the archieves sugguest, and not crash cool? hard to beleive I'd never do that again. But if you insist....
3. Get all the welding gear instead of hoisting, and hold it open, or prop?

Second issue: my studio is rather on the small side, never noticed how small until I got this kiln With a close ceiling is all of that released heat gonna cause "spontainious combustion"? I know wood combusts at around 700 degrees, but I haven't checked the temp above the kiln when crashin. Before I get too crazy, thought I'd ask.
If any of this sounds overly cautious, I did try to check out the archives first, but didn't find much, except it did make me want to try combing real soon! Thanks for any assist, YO

[Barbara Muth]

Yo,
I never crash cool. Besides being hard on you, there is plenty in the archives that suggests it is hard on your kiln.

Just cool afap to the next process temperature. If you work with small jewelry pieces I recommend a lot of tests in your kiln to determine what temp to go to. You will find that the temp in your big kiln will not be as high as in the baby kiln when you get to process temperatures.

Have fun!!!!

Barbara

[Phil Hoppes]

Why are you crash cooling? You don't really need to and you will cause problems with your kiln. In particular if it has a brick top, you will accelerated the degredation of the bricks and they will start to rain particles on your work. Just program your controller to go AFAP or FULL from your peak to your anneal temp.

I would not locate your kiln right up against any wall, keep at least a 2' to 3' distance. No NOT store any flamable materials in the same room, ie paints, varnish, solvents. Anything that fumes is not good to have in the same location. Don't use your kiln as storage for things (don't laugh, others have done it and burned their house down) Your kiln will be hot to touch at it's peak temp but not so hot as to cause a fire. Since it is a commercial kiln I'm guessing it is UL approved to as long as you follow the guidelines published by the manufacturer you should be safe. Use common sense and you will be fine.

Phil

[rosanna gusler]

i do not crash any more but i still love to peek at the top shelf. i rigged up a pulley. securely bolted to a ceiling timber. put it behind the front of the kiln for ease of opening. you know, pulling back at an angle instead of strait up. use chain or wire cable for the first couple of feet. there is enough heat escaping to damage rope. i have a big shark hook to catch the handle with, and a cleat on the wall for the rope. no more burnt sleeves for me. rosanna

[Chip]

Yo! Yo, (I just had to do that),
For my kiln, the top is really heavy too, so I went to Home Depot, bought a length of chain and a large "S" hook, and then attached one end of the chain to the ceiling. I put the "S" hook on the chain depending on my needs (1/2 open, 1/4, etc) and then the top handle hooks on the chain.

I also do not "flash vent" or "crash cool" after reading the archives. The chain and "S" hook are merely for convenience when I don't need to put the top all the way up for loading/unloading.

[Tony Serviente]

As others have posted, crashing with brick is problamatic, but fiber kilns do fine with it. Only reason I crash, and pretty regularly, is to increase production throughput. I've done it enough to know what I can get away with, both with the glass and the kilns, but I would not recommend it as a technique for non production folks. Now venting is another story, but I'd define venting as accelerating the cool down to annealing to minimize devit, then going as slow as you need to. Crashing, for me, is quickly cooling to room temp once you've passed the strain point. Another take on way to keep kiln lid up is to use a steel bar as long as the kilns lid is off the floor, and mount it to the lid on a hinge. Notch it at strategic points, depending on how much you want the lid to open. On the body of the kiln would be a steel "tooth", meant to fit into the notches. Everything has to be done so that the bar wants to seat more firmly with downward pressure, but it's easy to get that right. I've used both the chain, and the bar, and I like the bar more. On the kilns heat, rule of thumb I use is the surface of any combustible near the kiln should be touchable. If I can't lay my hand on it while the kiln has been on, and count to three, it's too hot and I have to deal with it somehow.

[Paul Tarlow]

In addition to the info above, the other reason to crash cool is to "freeze" a slump. The most common place I've seen this done is with drop rings.

-Paul

[Marty]

I've got that kiln and the lid is heavy. Make sure the kiln can't move (mine's on wheels but they're blocked) and hang 2 pulleys from hooks screwed or bolted into the cieling. Two S-hooks on the handles, garage-door cable attached to the S-hooks, run through the pulleys to a counterweight (sand-filled containers, scrap metal, anything heavy). Adjust the weights until you can open the kiln with one hand. Your hardware store will have everything, cheap.

[Cynthia]

There is such a huge volume of heat in this kiln that I wanna make sure you know to not be in the path of that heat as it escapes when you lift the lid or to look over the kiln when you open that lid. I tried to crash my Denver (60" x 30" interior dimension) by opening the lid while looking in, just like I could with my little jen-ken ...I was fortunate that only my eyelashes, eyebrows and bangs were singed off. Could have been a very serious burn, but instead I just looked rather funny for several weeks.

If you can fire with a schedule that doesn't require you to crash, I'd recommend that. I don't crash my kilns anymore (fiber or brick), but still have the need to peek at full process temps or to help the venting along since they cool so slowly. I make sure I peek from a distance these days.

[watershed]

Counterweights. The easiest is lengths of 4" PVXC pipe with glued on caps, drill a hole across the top, and put in a bolt. Hang this from the cable. If you use sand, then they are adjustable by dumping.

Crashing: I would recommend Real Kevlar gloves, cotton (not 50/50) clothing, and a cheap face shield. Make the face shield one with replaceable visors, you'll need to.

If you are casting, crashing MAY be encouraged due to the length of time it takes to get from 1500degf to 900degF. And 1200degF is your de-vit zone.

Greg

[Cher]

Thanks for everybodies input. Barb, I agree it looks like crashing is
bad for my health! When I do drop rings like Paul mentions, I'll
stick to using my Mama sized Paragon (Does "Mama kiln" make it sound
big? ) I would imagine that I'll do most of the jewelry cabs in
the baby kiln or mama when I'm felling "productive".

Watershed, Do you use special arm protectors? Thinking about combing
or casting. Replaceable visor makes sense, I wouldn't have thought
to ask.

Marty, Chip and Tony, thanks for the opening device advice. Don't
want to make more health problems and like to work this stuff out,
and with all of your help, I've been able to get with the program,
but it'll be a while before I get to that point where I know what I
can get away with!


Phil, you ask why do I crash cool and I guess I'd have to answer "out
of sheer ignorance". I've used kilns for 6-7 years now with no
controller til now and I had understood that to be the way its done.
Never questioned it 'til now, and only because the lid is so heavy
and I have tennis elbow slowing me down and was looking for a better
way to crash AND lift the lid.

Like Rosanna, I'll probably always be a peeker, and I know it blows
out a vast amount of heat when opened.

Soon as I have these lifting issues worked out,I will undoubtedly
have fun!!! This has already freed up my head. I thought about going
to a Marina for a cranking type of hoist, but Chips', Rosannas' and
Tonys' ideas make MUCH more sense.

Tony, like your 3 second idea a lot too.!

Thanks all! I'm saving this thread for constant referance, and I
appreciate all of the responses. YoDuh

Oh yes, in keeping with the season and the reason for fun with ma
name,
Yo Ho Ho !!!!

[watershed]

I invested in the longsleeved gloves, and have never looked back. Also I wear a sweat shirt (too often 50/50 gets kind of crunchy). SO with the gloves, I'm covered to the elbow, the sweatshirt takes care of the rest.

Greg

[Paul Bush]

Another simple and cheap counterweight idea: get used lead wheel weights from your local tire shop, put them in an empty can that has a handle (such as a clean 1-gal paint can), attach the cable to the handle by making a loop in the end of the cable and securing with a cable clamp (any good hardware store has them). I used this for my raku kiln for years, when I had to open the kiln fast, and it had to stay open while I pulled the red hot pieces out.

Paul

[David_S]

Hi Everyone!

I'm new to this board, and have been doing a lot of reading tonight. Have learned quite a bit - even though I've been fusing and abusing kilns for quite a few years now.

I have always flash cooled - mainly because I have always used a "manual" approach (no rampmaster - just a darn good pyrometer and habitually prying eyes!)

Lately we've been doing production dichroics in our Olympic. Inside size is 20 X 24 H I think. I say I think - because I'm at work and I can never remember the sizes of the kilns without measuring them. We have 4 of them that we use for different things - being both ceramic and glass. One is an "antique" from 1971 when I first started this craft - go figure.

Once soaked at full fuse, I usually flash cool down to around 1000 before closing her back up. I do a second - and even a 3rd vent - but shorter - until the closed temp stays at just below 1000 for the anneal - then let it cool naturally to room temp overnight.


Frankly in all these years I have never had any devit problems - nada - on either large or small pieces. Never had any kiln degradation problems either.

Granted - that heat blast deserves respect - and your undivided attention when opening!

Anyway - guess what I'm getting at here is - am I missing something here? I've been doing this for over 30 years now and it's worked for me - but I read alot of ambiguity into the previous posts. What are the current thoughts on this - outside of the obvious dangers? Is there now a better way? Have looked thru the archives - but being new - I'm still having a bit of a time navigating here.

BTW - Thanks so much for this board - and all you folks that regularly post here! Don't know why I didn't find this WAAAAY sooner than I did! I intend to be a "regular" here and learn from all you glass pros! One thing about this craft - you never stop learning!

David

[Tony Serviente]

David, what you're doing may be the reason you have had no devit troubles, or you might have had none anyway! Only big advantage I can see to the flash cooling you are doing is that you get to opening temp sooner. As mentioned before, I virtually never crack my kilns above 1000, and do not have devit troubles that aren't addressable through other means. If you have been doing it that way for 30 years, and your glass is good, and you like doing it, then keep at it. I used to like to mess with my kilns cuz it felt like I was doing something, not passively waiting for thermodynamics to work its magic, but now I'm lazy and let them be(mostly).