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How do you handle a HAZ?
How do you guys handle working with a HAZ on plate? Heat Affected
Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
On Sun, 02 Apr 2006 00:52:32 GMT, Gunner wrote:
How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Suggest you read posts other than yours & winger BS in alt.machines.cnc. HTH -- Cliff |
How do you handle a HAZ?
Since you hardened the edge of the 4130 the only way is to soften it. I
would try "very slowly " run your cutting torch along the edge... I am guessing at an inch every thirty seconds ( 1/4 plate?). The thicker the plate the worse will be the quenching effect so you may have to even move more slowly. If that doesn't work it is time to anneal in a furnace and cool slowly as possible. I hate to say it but flame cutting was the problem. The only way to cut the stuff without having a HAZ is to saw or water jet cut it. Randy "Gunner" wrote in message ... How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
On Sun, 02 Apr 2006 01:06:15 GMT, "R. Zimmerman"
wrote: Since you hardened the edge of the 4130 the only way is to soften it. I would try "very slowly " run your cutting torch along the edge... I am guessing at an inch every thirty seconds ( 1/4 plate?). The thicker the plate the worse will be the quenching effect so you may have to even move more slowly. If that doesn't work it is time to anneal in a furnace and cool slowly as possible. I hate to say it but flame cutting was the problem. The only way to cut the stuff without having a HAZ is to saw or water jet cut it. Randy I got the stuff as drops from a mold making and welding shop. So I didnt have much choice in how it was cut. the stuff is 1.260 thick plate..hot rolled making it even worse. Im just making fingers for a finger break. The faces were easy to flatten out..its the sides that are the bitch Gunner "Gunner" wrote in message .. . How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
Gunner wrote:
On Sun, 02 Apr 2006 01:06:15 GMT, "R. Zimmerman" wrote: I got the stuff as drops from a mold making and welding shop. So I didnt have much choice in how it was cut. the stuff is 1.260 thick plate..hot rolled making it even worse. Im just making fingers for a finger break. The faces were easy to flatten out..its the sides that are the bitch If you get well under the HAZ and conventional cut it, an end mill will work just fine. 4130 crystalizes. Very nasty. -- John R. Carroll Machining Solution Software, Inc. Los Angeles San Francisco www.machiningsolution.com |
How do you handle a HAZ?
Gunner wrote: How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner: Is there enough material to bandsaw off? If so, you could use a die grinder to grind a place for the bandsaw blade to start and cut through, then keep the blade in the unhardened stock. If milling is the only option, conventional milling (not climb milling), often lets you get under the worst of the hardened scale. It's going to beat up your tooling no matter what so using inserted tooling is probably going to be cheaper than burning up high dollar end mills. All in all, your shaper may be the cheapest way to go. -- BottleBob http://home.earthlink.net/~bottlbob |
How do you handle a HAZ?
Gunner wrote: Im doing it now...on a shaper..simply because it was killing my endmills Shaper? What the hell is a shaper? Kidding. Sort of. "How do you guys handle working with a HAZ on plate?" I have some old end mills that are "used up" on the first .100" but are sharp above that. I save these for this kind of thing. I'd cut it with the side, not the end. Conventional type milling deeper than the worst of the HAZ. I might use an old junk 1/2" carbide at 500 RPM at 5 IPM with flood coolant. I know, that's moving really slow, but that's how I do it. The worst HAZ I've ever seen was some very thick plate that was cut with a carbon arc. I took a grinder to the bad areas first. |
How do you handle a HAZ?
On Sun, 02 Apr 2006 01:14:58 GMT, Gunner
wrote: I got the stuff as drops from a mold making and welding shop. So I didnt have much choice in how it was cut. the stuff is 1.260 thick plate..hot rolled making it even worse. Im just making fingers for a finger break. The faces were easy to flatten out..its the sides that are the bitch 3 You might have to grind through the hard stuff. With the shaper maybe you can "get behind" the hard edge with the point of your tool and peel off the hard stuff? -- Randy Replogle |
How do you handle a HAZ?
On 1 Apr 2006 17:26:51 -0800, "Polymer Man"
wrote: Gunner wrote: Im doing it now...on a shaper..simply because it was killing my endmills Shaper? What the hell is a shaper? Kidding. Sort of. Actually..for the home guy not in a hurry..there is nothing you cant do on a shaper that you cant do on a horizontal miller, except drill holes and pocket. I use mine mostly for cutting dovetails and the like. But..its slower than a mill of course. But it doesnt leave any machining marks either..nearly glass smooth. I put a 36" Smith-Hall into a aerospace shop a couple years ago. He fixtures up a ****load of small parts, places the fixture in the shaper, and lets it run. In 30 minutes..he has all 300 parts faced, cut to length and glass smooth, without needing an operator. Just someone to load the fixture. Plus a shaper makes inside square holes and such with true square corners, keyways and such really nice without needing any broaches. They have a place in some shops. Id like to have a bigger one. Mine is a Logan 8"...but with a vise..its about 5.75 max height "How do you guys handle working with a HAZ on plate?" I have some old end mills that are "used up" on the first .100" but are sharp above that. I save these for this kind of thing. I'd cut it with the side, not the end. Conventional type milling deeper than the worst of the HAZ. I might use an old junk 1/2" carbide at 500 RPM at 5 IPM with flood coolant. I know, that's moving really slow, but that's how I do it. The worst HAZ I've ever seen was some very thick plate that was cut with a carbon arc. I took a grinder to the bad areas first. The HAZ is about .09 thick..which is pretty small..but not small enough. I may have to trepan down into the material with a trepanning tool in the shaper, and try to peel it away as Randy said. I roughed em out .375 bigger in all dimensions just in case..but this has been kicking my ass. I need either a bigger shaper..or a K&T #2 for this..my little Clausing horizontal isnt beefy enough to run a slab mill on this stuff..and I dont have a power feed on the Gorton MasterMill.... Thanks for the suggestions. No matter what I do..this is gonna be a bitch on anything smaller than a Viper..sigh I might try recutting them with the bandsaw..which really isnt a bad idea at all. I might be able to slide down just inside the HAZ. My 7x12 Emerson bandsaw cuts pretty straight. I think Ill try that first. Thanks guys. Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
I have an old ceramics kiln that I use to anneal flame cut steel. So
far the normal cool down in the sealed kiln is slow enough. It's probably more of a normalization that a true anneal but it's good enough. Kelley On Sun, 02 Apr 2006 00:52:32 GMT, Gunner wrote: How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
On Sat, 01 Apr 2006 20:39:34 -0800, Kelley Mascher
wrote: I have an old ceramics kiln that I use to anneal flame cut steel. So far the normal cool down in the sealed kiln is slow enough. It's probably more of a normalization that a true anneal but it's good enough. Kelley Interesting. What temps should I run up to? I have a furnace. Gunner On Sun, 02 Apr 2006 00:52:32 GMT, Gunner wrote: How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
"Gunner" wrote in message ... Im doing it now...on a shaper..simply because it was killing my endmills Have you tried a indexable facemill? I never use an endmill for squaring blocks - only facemills. With hardened stuff, I find carbide works well as long as you slow it down. You're good if you've got one that takes cheap inserts. I was thinking along the lines of Karl with the disc grinder, but .09" is a lot of material and it's very labour intensive to hog material for a long time. Regards, Robin |
How do you handle a HAZ?
"R. Zimmerman" wrote in message news:bsFXf.212105$H%4.85152@pd7tw2no... Since you hardened the edge of the 4130 the only way is to soften it. I would try "very slowly " run your cutting torch along the edge... I am guessing at an inch every thirty seconds ( 1/4 plate?). The thicker the plate the worse will be the quenching effect so you may have to even move more slowly. If that doesn't work it is time to anneal in a furnace and cool slowly as possible. I hate to say it but flame cutting was the problem. The only way to cut the stuff without having a HAZ is to saw or water jet cut it. Randy "Gunner" wrote in message ... How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Just throw the whole chunk into the woodstove or burn pile--and let it cool down back down with the ashes, pick it out the next day. -- SVL |
How do you handle a HAZ?
"Gunner" wrote Interesting. What temps should I run up to? I have a furnace. My Tempil Basic Guide to Ferrous Metalurgy shows a normalizing temp of about 1600 F. for steel with 30 points of carbon. 4130 normalizes in still air, very still air, don't let the cat wag his tail near the cooling piece and don't fart. A full anneal can be had by very slow cooling in the furnace. The stuff will cut like butter then and will need to be re-hardened after machining. Good luck. -- Tom Wait Barton Rifle Shop 1805 Barton Ave Suite #9 West Bend, Wisconsin 53090 (262) 306-RIFL (7435) |
How do you handle a HAZ?
On Sun, 2 Apr 2006 10:19:25 -0400, "Robin S."
wrote: "Gunner" wrote in message .. . Im doing it now...on a shaper..simply because it was killing my endmills Have you tried a indexable facemill? I never use an endmill for squaring blocks - only facemills. With hardened stuff, I find carbide works well as long as you slow it down. You're good if you've got one that takes cheap inserts. Actually..no..I dont have such a facemill. I havent been able to scrounge up one and a supply of inserts. A fair and dimenishing number of carbide facemills that are cemented..and no way to resharpen them. And with material like this...I dont want to use any more up. I was thinking along the lines of Karl with the disc grinder, but .09" is a lot of material and it's very labour intensive to hog material for a long time. Regards, Robin Yup. Thanks for the advise Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
On Sun, 2 Apr 2006 09:34:56 -0700, "PrecisionMechanical"
wrote: "R. Zimmerman" wrote in message news:bsFXf.212105$H%4.85152@pd7tw2no... Since you hardened the edge of the 4130 the only way is to soften it. I would try "very slowly " run your cutting torch along the edge... I am guessing at an inch every thirty seconds ( 1/4 plate?). The thicker the plate the worse will be the quenching effect so you may have to even move more slowly. If that doesn't work it is time to anneal in a furnace and cool slowly as possible. I hate to say it but flame cutting was the problem. The only way to cut the stuff without having a HAZ is to saw or water jet cut it. Randy "Gunner" wrote in message ... How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Just throw the whole chunk into the woodstove or burn pile--and let it cool down back down with the ashes, pick it out the next day. Wish I had a woodstove. But this is Central California desert. I do have a kiln though..small one..big enough for heat treating. What temp should I get it up to? Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
On Sun, 02 Apr 2006 17:14:26 GMT, "Tom Wait"
wrote: "Gunner" wrote Interesting. What temps should I run up to? I have a furnace. My Tempil Basic Guide to Ferrous Metalurgy shows a normalizing temp of about 1600 F. for steel with 30 points of carbon. 4130 normalizes in still air, very still air, don't let the cat wag his tail near the cooling piece and don't fart. A full anneal can be had by very slow cooling in the furnace. The stuff will cut like butter then and will need to be re-hardened after machining. Good luck. So if I stack em up, and hold em at 1600 for a couple hours..then turn off the juice and leave em in the oven..it may anneal them. Thanks, Ill try that as my second option Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
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How do you handle a HAZ?
On Sun, 02 Apr 2006 21:49:34 GMT, Gunner
wrote: Wish I had a woodstove. But this is Central California desert. I do have a kiln though..small one..big enough for heat treating. What temp should I get it up to? Gunner Bonfire? -- Randy Replogle |
How do you handle a HAZ?
Gunner wrote: On Sun, 2 Apr 2006 09:34:56 -0700, "PrecisionMechanical" wrote: Just throw the whole chunk into the woodstove or burn pile--and let it cool down back down with the ashes, pick it out the next day. Wish I had a woodstove. But this is Central California desert. I do have a kiln though..small one..big enough for heat treating. What temp should I get it up to? Gunner: ================================================== ======== http://www.suppliersonline.com/propertypages/4130.asp Annealing 4130 (and most of the other low alloy steels) may be annealed at 1550 F for a time long enough to allow thorough heating of the section size. It should then be cooled in the furnace at a rate of less than 50 F per hour down to 900 F, followed by air cooling from 900 F. ================================================== ======== -- BottleBob http://home.earthlink.net/~bottlbob |
How do you handle a HAZ?
On Sun, 2 Apr 2006 09:34:56 -0700, "PrecisionMechanical"
wrote: Just throw the whole chunk into the woodstove or burn pile Yep. Get better stock. -- Cliff |
How do you handle a HAZ?
Try these endmills
http://www.wttool.com/c/09420005p they are very cheap and I have used the 1" double ended in my horizontal mill to clean off torch cut edges. I bought them for that reason. I think they were $2.00 each at the time, thats $1.00 per end and they hold up good, not the smoothest cut but they have cleaned up my torch cutting. I by no means an a good torch cutter. Let me know what size can fit you mill I have a few extra 15/16. I have used the 2, 3 and 4 flutes. "Gunner" wrote in message ... How do you guys handle working with a HAZ on plate? Heat Affected Zone..on flame cut plate. Its driving me nuts trying to square up some rectangles of flame cut 4130 Im doing it now...on a shaper..simply because it was killing my endmills Gunner "A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3 |
How do you handle a HAZ?
On Sun, 02 Apr 2006 00:52:32 GMT, Gunner
wrote: Im doing it now...on a shaper..simply because it was killing my endmills What type of endmills were you using? |
How do you handle a HAZ?
Just throw the whole chunk into the woodstove or burn pile--and let it
cool down back down with the ashes, pick it out the next day. Wish I had a woodstove. But this is Central California desert. I do have a kiln though..small one..big enough for heat treating. What temp should I get it up to? Go to www.mcmaster.com and put 3460 in the search box to go to that page, then click the link at the top for additional info. This gives composition and physical properties for most common steels, and heat treating data on the tool steels (but not 4014, big sigh ;-)). Then put 3464 in the search box and repeat to get data on stainless steels. Again, they give annealing data for most alloys but not for 17-4 and 17-5 PH, again, big sigh. Anyway, a useful grab for the future. Hold times at temperature seem to be 1 hour per inch of thickness. This assumes good heat circulation and if you stack your plates directly on each other they will look like one really thick plate. Put some little spacers in between each plate so the air can circulate. -- Regards, Carl Ijames carl.ijames at verizon.net |
How do you handle a HAZ?
On Tue, 04 Apr 2006 00:00:08 GMT, "Carl Ijames"
wrote: Just throw the whole chunk into the woodstove or burn pile--and let it cool down back down with the ashes, pick it out the next day. Wish I had a woodstove. But this is Central California desert. I do have a kiln though..small one..big enough for heat treating. What temp should I get it up to? Go to www.mcmaster.com and put 3460 in the search box to go to that page, then click the link at the top for additional info. This gives composition and physical properties for most common steels, and heat treating data on the tool steels (but not 4014, big sigh ;-)). Then put 3464 in the search box and repeat to get data on stainless steels. Again, they give annealing data for most alloys but not for 17-4 and 17-5 PH, again, big sigh. Anyway, a useful grab for the future. Hold times at temperature seem to be 1 hour per inch of thickness. This assumes good heat circulation and if you stack your plates directly on each other they will look like one really thick plate. Put some little spacers in between each plate so the air can circulate. I ah..ahum....put them in the kiln last night. Its a Cress ceramic kiln..with no ramping control....simply a temp gage and a hotter/cooler pot. And I promptly forgot about them. This morning..I walked by the kiln..and noticed it was warm..then remembered. The thermometer showed 2100F Opening it up...was not pretty. they had sagged somewhat..or at least it appeared that they had... So I fiddled around and got the temps down to 1500 F..and held it there for a couple hours. then ramped it down to 1000F over another couple hours..then opened the hatch and let em air cool They are still hot..and the one closed to the hatch has a thick layer of something black on the outside..and a gentle tap broke much of it loose..and it looks like a gravel road underneith it. All bumps and whatnot. I think this is some sort of scale.....cringe... I think..before I try this again anytime soon..maybe I can trade someone here Stuff to make me a temperature controller with times etc etc... sigh....well..it was a nice idea. Ill take em out in the morning before I head south..but suspect they are literally..toast. Gunner "I think this is because of your belief in biological Marxism. As a genetic communist you feel that noticing behavioural patterns relating to race would cause a conflict with your belief in biological Marxism." Big Pete, famous Usenet Racist |
How do you handle a HAZ?
On Tue, 04 Apr 2006 09:20:30 GMT, Gunner
wrote: I ah..ahum....put them in the kiln last night. Its a Cress ceramic kiln..with no ramping control....simply a temp gage and a hotter/cooler pot. And I promptly forgot about them. You have to use aids to avoid big attacks of 'Can't Remember Sh*t' like that. Do you have any programmable timers or an old Lux wind-up kitchen timer around? Or use a good old (loud) alarm clock that will not quit till you turn it off... If you figure it's going to need looking at in an hour, set the alarm for an hour. And set up a second alarm at two hours in case you miss the first. If you figure it needs looking at before you go to bed, put something big and heavy on the bed - when you go to move it, you'll remember. (And tell the wife/roommate/kids why you are setting the alarm, so they know not to just turn off the alarm without finding you.) And in the end... It was already scrap material when you started. So what did you lose, except some electricity running the kiln? ;-) If they did warp into interesting shapes, you can always weld them into a sculpture, let your muse loose. -- Bruce -- -- Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop Electrician for Westend Electric - CA726700 5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545 Spamtrapped address: Remove the python and the invalid, and use a net. |
How do you handle a HAZ?
On Tue, 04 Apr 2006 15:55:33 GMT, Bruce L. Bergman
wrote: On Tue, 04 Apr 2006 09:20:30 GMT, Gunner wrote: If you figure it needs looking at before you go to bed, put something big and heavy on the bed - when you go to move it, you'll remember. (And tell the wife/roommate/kids why you are setting the alarm, so they know not to just turn off the alarm without finding you.) -- Bruce -- I try putting things in conspicuous places to remember things to do and my wife puts them away. A couple of weeks later I'll remember (maybe). -- Randy Replogle I've found that relationships are like a bell curve. You love a few, hate a few, but most you're just indifferent to. -- Randall Replogle 2006 |
How do you handle a HAZ?
On Tue, 04 Apr 2006 15:01:52 -0400, Randy Replogle
wrote: I try putting things in conspicuous places to remember things to do and my wife puts them away. Lucky, lucky you sigh. -- Cliff |
How do you handle a HAZ?
On Tue, 04 Apr 2006 15:55:33 GMT, Bruce L. Bergman
wrote: On Tue, 04 Apr 2006 09:20:30 GMT, Gunner wrote: I ah..ahum....put them in the kiln last night. Its a Cress ceramic kiln..with no ramping control....simply a temp gage and a hotter/cooler pot. And I promptly forgot about them. You have to use aids to avoid big attacks of 'Can't Remember Sh*t' like that. Do you have any programmable timers or an old Lux wind-up kitchen timer around? Or use a good old (loud) alarm clock that will not quit till you turn it off... If you figure it's going to need looking at in an hour, set the alarm for an hour. And set up a second alarm at two hours in case you miss the first. If you figure it needs looking at before you go to bed, put something big and heavy on the bed - when you go to move it, you'll remember. (And tell the wife/roommate/kids why you are setting the alarm, so they know not to just turn off the alarm without finding you.) And in the end... It was already scrap material when you started. So what did you lose, except some electricity running the kiln? ;-) If they did warp into interesting shapes, you can always weld them into a sculpture, let your muse loose. -- Bruce -- I think next time..Ill fire the oven up without anything in it..fiddle around until its the proper temperature..THEN load it. It will sag of course..then slowly return to the proper temp..and I can go from there Still ****ed me off. Gunner "The importance of morality is that people behave themselves even if nobody's watching. There are not enough cops and laws to replace personal morality as a means to produce a civilized society. Indeed, the police and criminal justice system are the last desperate line of defense for a civilized society. Unfortunately, too many of us see police, laws and the criminal justice system as society's first line of defense." --Walter Williams |
How do you handle a HAZ?
On Wed, 05 Apr 2006 15:18:52 GMT, Gunner wrote:
It will sag of course sigh That's why (usually ceramic) standoffs or firebricks are used to support what's being heated. -- Cliff |
How do you handle a HAZ?
On Wed, 05 Apr 2006 15:18:52 GMT, Gunner wrote:
I think next time..Ill fire the oven up without anything in it..fiddle around until its the proper temperature..THEN load it. It will sag of course..then slowly return to the proper temp..and I can go from there That's just going to take longer, not halt distortion. -- Cliff |
How do you handle a HAZ?
On Wed, 05 Apr 2006 17:01:24 -0400, Cliff wrote:
On Wed, 05 Apr 2006 15:18:52 GMT, Gunner wrote: It will sag of course sigh That's why (usually ceramic) standoffs or firebricks are used to support what's being heated. I think he means the temperature, not the piece(s) being heated. |
How do you handle a HAZ?
"Gunner" wrote in message ... They are still hot..and the one closed to the hatch has a thick layer of something black on the outside..and a gentle tap broke much of it loose..and it looks like a gravel road underneith it. All bumps and whatnot. I think this is some sort of scale.....cringe... Maybe wrap em in copper or stainless foil first.....IIRC this helps keep all the carbon from outgassing to the surface..... g -- SVL |
How do you handle a HAZ?
On Wed, 5 Apr 2006 22:18:50 -0700, "PrecisionMechanical"
wrote: "Gunner" wrote in message .. . They are still hot..and the one closed to the hatch has a thick layer of something black on the outside..and a gentle tap broke much of it loose..and it looks like a gravel road underneith it. All bumps and whatnot. I think this is some sort of scale.....cringe... Maybe wrap em in copper or stainless foil first.....IIRC this helps keep all the carbon from outgassing to the surface..... LOL ... or an inert atmosphere ... Beware a reducing one except for specially designed heating devices (now I wonder how Michael's slip-cast-in-silicone-rubber clay is drying ...) -- Cliff |
How do you handle a HAZ?
"Cliff" wrote in message ... On Wed, 5 Apr 2006 22:18:50 -0700, "PrecisionMechanical" wrote: "Gunner" wrote in message .. . They are still hot..and the one closed to the hatch has a thick layer of something black on the outside..and a gentle tap broke much of it loose..and it looks like a gravel road underneith it. All bumps and whatnot. I think this is some sort of scale.....cringe... Maybe wrap em in copper or stainless foil first.....IIRC this helps keep all the carbon from outgassing to the surface..... LOL ... or an inert atmosphere ... Beware a reducing one except for specially designed heating devices (now I wonder how Michael's slip-cast-in-silicone-rubber clay is drying ....) ****. I never suggested that he should put it into an electric furnace, then "promptly forget about it" --as it is, the "woodstove suggestion" was...err...questionable... A pretty good way to end up with "low carbon steel" in either case though... Spose he might a learned anything from this all ??? G -- SVL |
How do you handle a HAZ?
"Gunner" wrote in message ... On Tue, 04 Apr 2006 15:55:33 GMT, Bruce L. Bergman wrote: On Tue, 04 Apr 2006 09:20:30 GMT, Gunner wrote: I ah..ahum....put them in the kiln last night. Its a Cress ceramic kiln..with no ramping control....simply a temp gage and a hotter/cooler pot. And I promptly forgot about them. You have to use aids to avoid big attacks of 'Can't Remember Sh*t' like that. Do you have any programmable timers or an old Lux wind-up kitchen timer around? Or use a good old (loud) alarm clock that will not quit till you turn it off... If you figure it's going to need looking at in an hour, set the alarm for an hour. And set up a second alarm at two hours in case you miss the first. If you figure it needs looking at before you go to bed, put something big and heavy on the bed - when you go to move it, you'll remember. (And tell the wife/roommate/kids why you are setting the alarm, so they know not to just turn off the alarm without finding you.) And in the end... It was already scrap material when you started. So what did you lose, except some electricity running the kiln? ;-) If they did warp into interesting shapes, you can always weld them into a sculpture, let your muse loose. -- Bruce -- I think next time..Ill fire the oven up without anything in it..fiddle around until its the proper temperature..THEN load it. It will sag of course..then slowly return to the proper temp..and I can go from there Still ****ed me off. Wrap them else also add some charcoal. -- SVL |
How do you handle a HAZ?
On Wed, 5 Apr 2006 23:18:09 -0700, "PrecisionMechanical"
wrote: "Cliff" wrote in message .. . On Wed, 5 Apr 2006 22:18:50 -0700, "PrecisionMechanical" wrote: "Gunner" wrote in message .. . They are still hot..and the one closed to the hatch has a thick layer of something black on the outside..and a gentle tap broke much of it loose..and it looks like a gravel road underneith it. All bumps and whatnot. I think this is some sort of scale.....cringe... Maybe wrap em in copper or stainless foil first.....IIRC this helps keep all the carbon from outgassing to the surface..... LOL ... or an inert atmosphere ... Beware a reducing one except for specially designed heating devices (now I wonder how Michael's slip-cast-in-silicone-rubber clay is drying ...) ****. I never suggested that he should put it into an electric furnace, then "promptly forget about it" --as it is, the "woodstove suggestion" was...err...questionable... A pretty good way to end up with "low carbon steel" in either case though... Reverse carburization? I'm not so certain as the Carbon is more soluable in Iron as it gets hotter. Not my field though. Spose he might a learned anything from this all ??? Spend less time posting winger-propaganda & more time watching the free eggs? G G. -- Cliff |
How do you handle a HAZ?
On Wed, 5 Apr 2006 23:24:37 -0700, "PrecisionMechanical"
wrote: Wrap them else also add some charcoal. IIRC That sounded like softening/drooping + oxidation scale .... -- Cliff |
How do you handle a HAZ?
"Cliff" wrote in message ... On Wed, 5 Apr 2006 23:24:37 -0700, "PrecisionMechanical" wrote: Wrap them else also add some charcoal. IIRC That sounded like softening/drooping + oxidation scale .... IIRC ~1500 ~1700 or so as being critical--NOT 2100 deg. Almost hadda compleat meltdown, would appear. -- SVL |
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