Sciencemadness Discussion Board - So I Have a Microwave.

So I Have a Microwave.

KesterDraconis - 8-5-2016 at 12:21

The title says it all basically. I recently acquired a broken microwave oven. When I cracked it open this afternoon, there was a bit of melted rubber and a lot of black charred mess all around the secondary coil of the transformer. I also got out the powerful capacitor inside and the magnetron. Both seem fine. I have the main circuit board as well for all the controls and things.

So my main question is, what all can I do with these things? Particularly when it comes to applying these things to chemistry projects? I know that on Youtube the Grant Thompson has some videos with projects that are possible, but I'm looking for new ideas to add on to these sorts of things, and more chemistry related stuff particularly.

I will also say that I'm not terribly well educated in physics and electronics, but I am certainly willing to learn and read up where I have to.

aga - 8-5-2016 at 13:07

Not a lot. That coil is pretty much required to get the magnetron to work.

ISTR there's some nasty stuff you can try to get off the magnetron, not sure it's worth the effort.

Jstuyfzand - 8-5-2016 at 14:21

you could give a go at a birkeland eyde reactor

KesterDraconis - 8-5-2016 at 15:12

Quote: Originally posted by aga

Not a lot. That coil is pretty much required to get the magnetron to work.

ISTR there's some nasty stuff you can try to get off the magnetron, not sure it's worth the effort.

Yeah, I actually decided just to go ahead and take the magnetron apart to play with the magnets. I'm not prepared to deal with many things that would result of the projects I could use that for.

Jstuyfzand, that sounds like a pretty good idea. I've got about all the pieces I would need, so it would be low cost and rather fun. I couldn't imagine building something as good as this though, https://www.youtube.com/watch?v=2RRqIv4SoLg

[Edited on 9-5-2016 by KesterDraconis]

m1tanker78 - 8-5-2016 at 17:58

If the transformer primary is intact, you could take a hacksaw and apply some elbow grease to remove the secondary. Rewind to make a high current, low voltage AC source.

Save the switches, power cord, light socket and bulb, diode, capacitor, and any other goodies. I can't think of any way to directly apply any of this to chemistry projects. With some modification and additional investment, you can construct a small furnace..?

Jstuyfzand - 9-5-2016 at 03:51

Quote: Originally posted by KesterDraconis

Quote: Originally posted by aga

Not a lot. That coil is pretty much required to get the magnetron to work.

ISTR there's some nasty stuff you can try to get off the magnetron, not sure it's worth the effort.

It would be a nice and fun way to make some acid, and a reactor like that would be nice but 2 nails and a fish tank could do the same!

KesterDraconis - 12-5-2016 at 21:18

Quote: Originally posted by m1tanker78

If the transformer primary is intact, you could take a hacksaw and apply some elbow grease to remove the secondary. Rewind to make a high current, low voltage AC source.

Save the switches, power cord, light socket and bulb, diode, capacitor, and any other goodies. I can't think of any way to directly apply any of this to chemistry projects. With some modification and additional investment, you can construct a small furnace..?

I did in fact take a hacksaw to it and have rewound the secondary It amazes me how powerful the thing is. (and I am EXTREMELY wary. I don't want to get shocked to death in an instant.)

I've taken all the other goodies, and likewise don't see much chemistry application, but meh, may come in handy some day for something.

BTW, how should I dispose of the leftover magnetron parts? You know, the insulators containing beryllium oxide?

Fegie - 13-5-2016 at 06:04

Quote: Originally posted by KesterDraconis

Quote: Originally posted by m1tanker78

Dont worry, if your voltage is below 60 Vac in the secondary you shouldnt get shocked, 60 volts is the safety limit for AC and 120 for DC around here.
Like, you dont get shocked by a car battery if you grab the positive and negative bits....

But id keep the voltage close to 2-4 volts for such a device.

Mailinmypocket - 13-5-2016 at 06:15

Be careful with the ceramic-type insulator material on the magnetrons "gun". From what I remember it contains beryllium which is hella bad to breathe if you crush it up.

KesterDraconis - 13-5-2016 at 08:04

Quote: Originally posted by Fegie

I know, I'm just trying to be very, very careful. While I have fairly good physics knowledge on electricity and basic electronics knowledge, I've not had a terrible amount of experience with this sorts of things, and the power is really impressive to me, which demands an extreme amount of care.

The only thing I am really worried about right now though is the magnetron gun insulators. Can I just throw this in the trash, or should I dispose of it in a more proper way? Like I said, I don't like carcinogens or things which could cause chronic illness with a really good whiff.

Fegie - 16-5-2016 at 04:13

Quote: Originally posted by KesterDraconis

Quote: Originally posted by Fegie

Yeah, if i recall the magnetrons contained stuff that was a real hazard for your health if you accidentally broke it and inhaled the dust.
I think it was Beryllium that was inside, last time i dismantled a microwave i just wrapped some plastic wrap around it and then ducttaped it shut and put it into my shed.

AdamAlden - 26-6-2016 at 19:16

The magnatron can be used to heat your distillation or reaction flasks. I personally have never tried this but I plan to in the future. From what I have read using microwaves to heat your material doesn't cause any unwanted reactions which is why we are allowed to use microwaves to heat our food. The added benefit of using a microwave to heat the distillation flask is that it isn't actually heating the flask its heating the material inside of the flask which means an even distribution of heat throughout the material. I'm sure that this using microwaves is superior to the standard heating mantle.

[Edited on 27-6-2016 by AdamAlden]

zed - 28-6-2016 at 17:27

Monkeying with the innards of microwave ovens can be touchy business.

Some of the fellers on youtube suggest that there may be life-neutralizing electrical charges lurking in the shadows. So.... I'd visit some videos, and pick up a few pointers on what not to touch or point at, on account of high voltage electrically charged capacitors, have been known to point back..... Zzzzzt.

[Edited on 29-6-2016 by zed]

AdamAlden - 28-6-2016 at 17:45

Quote: Originally posted by zed

Monkeying with the innards of microwave ovens can be touchy business.

Some of the fellers on youtube suggest that there may be life-neutralizing electrical charges lurking in the shadows. So.... I'd visit some videos, and pick up a few pointers on what not to touch or point at, on account of high voltage electrically charged capacitors, have been known to point back..... Zzzzzt.

In other words... You might die if you are shocked by the microwaves electrical components or someone else could die if you managed to make a home made capacitor out of a role of aluminum foil, charge it with the microwave, and then attach it to the end of a broom stick.

blogfast25 - 28-6-2016 at 18:23

Quote: Originally posted by AdamAlden

From what I have read using microwaves to heat your material doesn't cause any unwanted reactions which is why we are allowed to use microwaves to heat our food.

The added benefit of using a microwave to heat the distillation flask is that it isn't actually heating the flask its heating the material inside of the flask which means an even distribution of heat throughout the material. I'm sure that this using microwaves is superior to the standard heating mantle.

Are you sure about that first part? Since as it's advice from 'socially engineered' people? You know, who believe in evidence and all those tedious sciency bits?

The second part is nonsense. Glass absorbs microwaves very well. Stick a piece of boroglass in your micro and find out yourself. Microwave heating has a place in labs but has serious drawbacks too, which is why it is used relatively rarely in lab heating.

Again, you're 'sure' about something you clearly don't know much about...

[Edited on 29-6-2016 by blogfast25]

zed - 30-6-2016 at 14:00

An interesting point Blogfast. I microwave food in "soft" glass containers all of the time. The glass itself doesn't heat up much. But, Boro-silicate glass might be quite different in its response. Sometimes glass is just glass, and sometimes it isn't.

wg48 - 1-7-2016 at 09:56

Most glasses including borosilicate glass have very low absorption of oven microwaves compared to water.

For example many microwave ovens have glass turntables or glass windows, pyrex cookware is considered safe for use in a microwave oven. My first microwave oven had a magnetron with glass insulation even around the output stub.

aga - 1-7-2016 at 11:19

Magnetite is interesting with microwaves.

I think it's called a 'susceptor'.

It absorbs the microwave energy and re-emits it as heat (i.e. changes wavelength).

ISTR it has been used in making a microwave furnace.

Edit:

Found it : https://www.youtube.com/watch?v=ZJvCuGmRWL8

[Edited on 1-7-2016 by aga]

NEMO-Chemistry - 1-7-2016 at 13:09

I want to alter my microwave for extractions, but it has a fan inside thats in the way!! Still looking to find out if its safe to ditch the fan etc. Loads of papers around indicating microwave extraction for plant material is the way to go, but most show part of the distillation outside the oven.

The coward in me prevents me from messing with it, with my luck i would toast my eye balls

zed - 2-7-2016 at 14:58

wg48, "Pyrex" ovenware is a deceptive term. Pyrex ovenware is NOT made of borosilicate glass. Very disappointing that. Were it Borosilicate glass, I could buy massive "Pyrex" cassarole bowls at garage sales, and have my friendly neighborhood glassblower, craft them into massive (inexpensive) reaction vessels. Alas, that is never to be. Sigh.

I correct myself. Contemporary Pyrex ovenware manufactured in the U.S. is not made with Borosilicate glass. Other places, it might be.

[Edited on 2-7-2016 by zed]

[Edited on 2-7-2016 by zed]

mayko - 2-7-2016 at 20:39

Glass can conduct electricity and absorb microwaves if it gets hot enough for its ions to get mobile! This causes a runaway meltdown effect. You sometimes see this if you microwave a dead lightbulb, and a bit of hot wire gets throw against the glass bulb and creates a hotspot. You can also do it with a blowtorch:

https://www.youtube.com/watch?v=cskB5c0mJ58

Actually, Bill Beatty has a really awesome website and in particular a long list of terrible things to do once you have a (functional, for now :cool:

) $5 microwave you're not too attached to:

http://amasci.com/weird/microexp.html

[Edited on 3-7-2016 by mayko]

blogfast25 - 3-7-2016 at 08:20

Quote: Originally posted by zed

An interesting point Blogfast. I microwave food in "soft" glass containers all of the time. The glass itself doesn't heat up much. But, Boro-silicate glass might be quite different in its response. Sometimes glass is just glass, and sometimes it isn't.

How long is a piece of string, zed? I've used glass too for heating up food, no problems. But the glass heats up considerably in a MW. Borosil will make no appreciable difference (borosil contains only a few % of boron oxide).

Very few things don't heat up in a MW, in fact.

I use my 850 W MW to heat up dinner plates (china). 1 minute for two on full power and they're basically already too hot to touch!

[Edited on 3-7-2016 by blogfast25]

arkoma - 3-7-2016 at 08:49

Quote: Originally posted by AdamAlden

You Sir, are a JackAss. You are engaging in the same schoolyard behavior that you feel so "victimized" about.

wg48 - 3-7-2016 at 15:46

Quote: Originally posted by zed

wg48, "Pyrex" ovenware is a deceptive term. Pyrex ovenware is NOT made of borosilicate glass. Very disappointing that. Were it Borosilicate glass, I could buy massive "Pyrex" cassarole bowls at garage sales, and have my friendly neighborhood glassblower, craft them into massive (inexpensive) reaction vessels. Alas, that is never to be. Sigh.

I correct myself. Contemporary Pyrex ovenware manufactured in the U.S. is not made with Borosilicate glass. Other places, it might be.

[Edited on 2-7-2016 by zed]

[Edited on 2-7-2016 by zed]

Sorry I should have remembered Pyrex can be tempered none borosilicate glass but in the UK Pyrex is borosilicate glass.

camerican - 9-7-2016 at 20:40

You can find several threads in Energetic Materials on the topic of exploding bridge wire detonators. That would be a good use for your capacitor!
I have purchased several secondhand microwaves just for their capacitors in the past, so you're way ahead of me in thinking about alternate uses.
https://www.sciencemadness.org/whisper/viewthread.php?tid=23...

Remember to be very careful around microwave capacitors. Many of the more interesting applications will require that you remove the internal resistor in order to reduce the discharge time. Doing this will also allow the capacitor to retain a potentially lethal charge for a significant period of time. Keep the leads tied together until the moment you use the capacitor, and actuate any devices attached to the capacitor with an insulated tool.