how to argon seal my thermolyne muffle furnace? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: August 16, 2025, 09:32:58 pm
content: I want to get rid of the white stuff that is forming on my silver paste experiments. I believe it might be possible to seal up my kiln so it uses a reasonable amount of argon gas, which may prevent the formation of silver oxide on my ceramic electronic devices.The kiln body is a metal cube, with an attachable back panel.Sealing points:1) back panel (4 screws) (sheet metal screws). There is a substantial gap here2) where thermocouple goes into hole3) 4 screw holes on bottom to attach the electronics housing (sheet metal screws)4) nichrome element holes5) loader doorThe screws are pretty far away from the action. I thought silicone might work.The back panel needs some kind of large gasket with a thickness of a mm or so. I thought a soft silicone might work, I just need to measure temperature back there too see if its viable.The front panel is a big unknown. This part will get very hot.https://cdn11.bigcommerce.com/s-zgzol/images/stencil/original/products/9322/236671/thermo-scientific-thermolyne-fb1315m-benchtop-muffle-furnace-max-temp-2012f-1.3l-120v__15295.1751137997.jpg?c=2What kind of measures can I take to try to do this out so its reasonable on argon consumption? I suspect it will billow out the front door.I know it won't be gas tight but I was thinking with some modifications maybe it will be 'reasonable' to run inert.I think a viton sheet gasket can seal the back thing. 600F caulk on any seams. 1mm ceramic paper bonded with a bit of ceramabond might make the front tighter. 7mm multibore alumina tube for gas inlet.Made a viton seal. Found a big gap in the back, I will stuff it with insulation and it will need 1 bead of glue on the panel. Hard to drill all that crap.it's looking good everywhere but the front. It kind of feels like I sealed everything but the problem. I thought about making a bent wire thing that is threaded through insulation braid, so I close the front and stuff in the 'seal' wire.Hmm, I added the argon port, and did a test. While the overshoot before was 1 degree C at 900C setpoint, with the argon, when set to 851 to kiln got all the way to 871 before I turned it off. I guess you need to retune it. I did a experiment to heat a bit of brass and some kind of carpenter's bracket (nickel plated steel, supposedly) in there to see if it works, even with a messed up door.

author: coppercone2
author_rank: Super Contributor
timestamp: August 24, 2025, 04:33:59 am
content: omfg even without a great seal it seems to work. I set it to 800C and with a very low flow (barely see the flow meter move), I tossed some parts in there and heated it up.I let it sit there for a while and took em out after it got down to maybe 450 and they looked a little grey (steel) and .. strange (brass).Anyway I disconnected the argon line and put the parts back in there (I blew in the furnace a few times to clear out the argon) , got it back to 850. When I took the parts out there was dust all over the brass, and the steel bit was like.... flaking and turning blue and stuff.So it looks like the crappy door seal is at least.. functional. I will buy a proper flow meter in ml/min.Can't believe it works. I thought it would have to be like hermetic lolI did a small touch up on the front using furance cement, which I will re-coat with ITC, to make the door a little more complete. I got a 0-250ml / hour flow gauge that will be used to regulate argon flow.and a tip, if you get any of that refractory stuff/glue/etc on your hands, that makes them feel slick, vinegar will instantly neutralize it and get rid of the basic compounds that are making your hand slippery (hard to 'wash' it off). I use balsamic vinegar while rinsing my hands after things like furnace cement, etc, if there was a ripped glove etcalso works for oven cleaner, oxygen bleach, etc

author: coppercone2
author_rank: Super Contributor
timestamp: September 01, 2025, 07:15:59 am
content: well I Have been doing experiments on copper pipe, and even with 300ml flow rate, at 900C copper gets a scale on it that pops off when you put it in water. There is one more small hole to fix that might be letting O2 in (other then the front). I imagine it might be hard to keep copper from oxidizing, but at least steel seems alot better, though in general I think it might be very difficult to get the O2 out of that brick and stuff, and that it would need to be purged for hours, even with a tight sealWhat is kind of cool is that the copper oxide in the flake form (reddish color) almost looks metallic from the cross section on where it cracks off the pipe. It has some shine to it, like a metal.

author: JimboJack
author_rank: Regular Contributor
timestamp: September 06, 2025, 02:08:32 am
content: that device is very small, just get a large vacumn chamber, place the device inside turn it , remote wire the controls out, and vacumn pump it, should purge any mosture out, then when you ready, heat it up with vacumn should drive any mosture out, same again what ever you want to heat up as well. no need for argon if it a vacumn. or you can add argon later if you want just keep the top clamped down whilst on.

author: coppercone2
author_rank: Super Contributor
timestamp: September 06, 2025, 03:39:19 am
content: how would you build a vacuum chamber that large?I got these 1mm ceramic fiber blankets, I was going to try to jam one in a door and try a copper heating cycle to see how it looks, even though its non robust

author: JimboJack
author_rank: Regular Contributor
timestamp: September 06, 2025, 11:12:43 am
content: seperate the device in two, there are plenty of vacuum chambers that fit the heating body online. , if not check for larger industrial vacuum steralization chambers if you not want to seperate the device in two.

author: coppercone2
author_rank: Super Contributor
timestamp: September 06, 2025, 07:00:57 pm
content: i wish I can find that meme of the saucer separation going wrong for picardunless, you can permanently seat a vacuum chamber on top of the control section of the box, kind of like a 'big head' mod. its completely insane but it would work.do you have a part that could work, something that would fit the cubic heater box, have a front loading door? I measured the surface skin of the kiln to be at 200C when its at maximum setting (max, in most places its maybe 150ish. I assume this vacuum box would need... at least an inch bigger then the cube kiln to separate the walls of the heater from the chamber surfaces.The idea would be to make.. clamps.. like the ones you have on a wooden barrel, to attach the vacuum chamber to the base with the controller in it. (like pipe straps)And I would need some kind of feedthrough, one for the thermocouple wire, and one for the heating element.And how would you fix the kiln cube to the vacuum chamber box? I could put it on a plate with 4 standoffs, but how to attach the plate. Some kind of bolts that have a vacuum seal on them? Like rubber washers?inspired by a tesseract, sitting on a cube?I don't know what car the thermolyne kiln equivalent is (it aint cheap), but to me this is like getting to a doc brown level of modification.like a USPS mail truck being modified for interdimensional travel

author: coppercone2
author_rank: Super Contributor
timestamp: September 06, 2025, 07:25:30 pm
content: if the wall of the 6 inch cube gets maybe 150-200c (especially on the back), how much distance would I need in a vacuum to the back of the vacuum chamber to prevent over heating? And could there be a problem.. if it was operated without a vacuum in the vacuum box?I see some appealing plexiglass boxes, but I don't think they could take it. Would I be restricted to only metal enclosures?

author: JimboJack
author_rank: Regular Contributor
timestamp: September 07, 2025, 11:47:17 am
content: in a vacuum , infrared is via radiation only, no convection, but your mini is convection, i think, so vacuum it never work.that silver oxide is probably from your paste cook it longer and higher maybe