CORONA Quick-UVC-Face-Mask-Irradiation-Disinfection-Chamber Station, Box Something….

Since this is a very useful tool during this pandemic and used every day in our household, here it is….

Since I’m in the IT market, I had no lock-down or other time with my hands tied, but am aching under the additional work-load that the increase in the demand in the digitalization of processes produced. And thus, I simply had no time to indulge in writing another Instructable until I was recently fired with still unknown cause - but that is another story….

Due to the rampant pandemic, most of us have had a quite bad past year with worries, and fears for ourselves, for our jobs and worst of all our loved ones.

Beyond IT, my background is in science - a previous life…. - which demanded from the onset of the infections in China, that I immediately set out to find ways to protect those important to me, should it (the now pandemic) reach us in Germany.
It did so, all too quickly, but by then we were at least already prepared with home-made poly-filter masks, as well as some single-use FFP2 and FFP3 masks.

There was an early and great Instructable for it, on which I elaborated, but that would be another Instructable….

Here’s the link to the Instructable I started from:

https://www.instructables.com/DIY-Cloth-Face-Mask/

They did a great job and also collected lots of sensible and valuable research, so I won’t repeat it here.

Suffice to say, that masks are simple Physics, Chemistry and Biology, which tell you, that the smaller the particle, the thicker the filter, or the smaller the pores need to be. In addition, if a particle is lipophilic - like SARS - a filter material that likes oil is better. Organic particles like Bacteria and Viri (or Viruses) don’t deal well with salts and tend to be of slight positive charge, that tends to make metallic fibers a danger for them, Silver agents are good to purify questionable water out in the wilds….which gives you several approaches to further modify and impregnate your masks....

There actually is a Silver-Spay currently available on Aldi-Süd (Germany), which works with Silver and helps at using single-use masks more than once:

https://www.aldi-sued.de/de/p.vitalia-masken-hygie...

As so many in the country at the beginning of March 2020, we had also stocked up on toilet-paper, which strangely rapidly became one of the most scarce commodities.

Another article that disappeared over night from most shelves of supermarkets and hardware stores, was simple rubbing alcohol! When I went to the local „Bauhaus“, I was told that just in the morning, a person had bought up their complete stock all in one go.

It seems that someone had read the WHO recipe for hand-disinfectants, which is essentially alcohol+glycerine, and had decided hat there was a great business opportunity, as official disinfectants were at the time no longer available in stores.

Since single-use masks were no longer available at acceptable prices, if at all, washing face masks after each use seemed impractical and would require a huge number of them - we have a 4 person household - and soaking the masks each time in alcohol might get the kids drunk, I decided to take a different approach to disinfecting our masks. My wife and daughter are both teachers, so Masks are THE most important safety-factor they have!

This, especially since politicians are insisting on opening day-care centers and schools - even though there are strong indications that children cary the same viral loads as adults, though without symptoms - but that is another story….

Another reason was that the few FFP2,3 masks that we had then were not washable, single-use - as they are mostly today - which makes for a quite large energy footprint.

We have a tiny (500l) pond behind the house with a huge family (14) of little goldfish. To keep them visible I installed a UVC clearer when I built the pond, to reduce the algae from time to time.

CAUTION: UVC is a high energy radiation that destroys organic material and causes DNA defects.

So PLEASE, don’t play with it!!!!

An active UVC-bulb looks cool, because it gives off this strange light-bluish glow in the visible spectrum, but the invisible UVC radiation will also cause serious damage to the eyes, as well as it can damage DNA and cause cancers in exposed skin. Normal UV from the sun will burn your skin and may lead to skin cancer. UCV is more energetic, but doesn’t normally reach the ground, which is why life is possible on earth.

Even the small 5W rated bulbs for clearing pond water are powerful enough to clear the water of a good sized pond if you run them from time to time - and don’t put them directly in the pond, because that will kill your fish too!

Another note of CAUTION: UVC bulbs run at a power around 35V, but the transformer uses your mains power of 110/220V, and that may kill you!

Playing with electricity is fun, but every caution should be taken when dealing with it. Turn off Power, unplug, don’t touch life wires, check everything you wire up 10 times, before you turn on the power. If you’re not careful, the least might be a fried construct, but you could also start a fire or stop your heart!

That said, I decided to simply take a couple of UVC-Bulbs and put them in a small cabinet to make a CORONA Quick-UVC-Face-Mask-Irradiation-Disinfection-Chamber station, box something….

The Materials are few and easy to acquire, the built is simple and can be done in a couple of hours. Emphasis was also on spending al little as possible - of course. It took me about 3 h after I had everything together, to assemble it. Altogether, I spent about 50€ on the whole thing.

It took me longer than that to write up this Instructable….

Materials:

• A box to hold the lights and masks (30 x 20 x 14 cm, Pine) (7€)

https://www.bauhaus.info/holzkisten/zeller-presen...

• 4 5W UVC bulbs (a 9€)

https://www.ebay.de/itm/153877094764

• 4 G23 Sockets (a 1€)

https://www.ebay.de/itm/370744707931

• 2 Transformers min 10W (a 16€)

https://www.ebay.de/itm/193311118099

• Some Wiring (e.g. 2,5€)

https://www.bauhaus.info/kunststoffschlauchleitung...

• Some cable connectors (1€)

https://www.bauhaus.info/verbinden-isolieren/luest...

• 1 push button switch (don’t know where I got it - 2 €)

https://de.rs-online.com/web/p/mikroschalter/80739...

• 8 small screws
• 1 Angle, or hook + screws (from IKEA shelf)
• Glue
• Aluminum foil
• Hot glue sticks

Tools:

• Electrical screw driver
• Knife to remove insulation
• Wire cutter
• Brush to spread glue
• Hot glue gun

I decided to dimension the irradiation chamber to simply hold one Mask at a time to make sure that it gets dosed from all angles. I had bought a couple from wooden boxes at a local hardware store (Bauhaus) some time ago with hinged lids, which were still in use, so I got another.

To allow for good reflectivity inside the box, it needs to be coated with reflective material. this is also needed, so that the radiation is not simply absorbed by the walls - in this case wood.

Cheap and available and simple is the Aluminum foil that most of us have somewhere in the kitchen. To stick it to the wood, pretty much any glue will do, since the foil will have no further strain after in place.

I simply took pieces from the role, that roughly fit down one side of the box across the bottom and up the other, covered one side of the box with glue, stuck the first part of the foil-piece in place, covered the bottom in glue, stuck down the next part and then up the other side.

To make the final cover seamless, I made sure that the pieces of foil were all a bit too wide, so as to extend across to the other sides. The width of the role was a perfect fit for the size of the box. Then simply cut two pieces for the ends of the box and glue them in.

Then do the same with the lid.

The surplus foil of the pieces can easily be trimmed with a sharp knife.

I didn’t fill up the handholds of the box, because I used the „bottom“ one as an exit for the wiring and the top one, because I covered it with the aluminum foil anyway. If I get around to it, I’ll fill them both more permanently though.

General Considerations

When I started out with wanting to build this project, I thought the UVC bulbs ran on mains current, so I simply ordered 4 side-mountable sockets and planned to simply wire everything together - BANG! LIGHTS OUT!

NO, well, luckily I remembered, that the pond clearer had come with a separate power supply. So I decided to buy two separate power supplies with high enough rating to drive two of the small 5W bulbs. Of course, you can just take one, with enough rating, or take just two 11 W bulbs, or whichever way you like it….

My reasoning was that 4 bulbs placed on opposite sides on the long sides of the box and +/- in the middle of the depth of the box - look at the pictures - would provide the best radiation coverage for objects placed in the center of the box.

Also, with 2 bulbs on two separate lines, might be better in case one of the bulbs should fail.

There is no permanent On/Off button and no timer in my design. Instead, you activate the setup by pushing the door/lid of the box closed, losing the circuit via a push-button type switch. Exposing easily flammable materials like gauze and paper filters to strong radiation and light bulbs that can get excitingly hot, has never been a good idea, unless you want to start a fire. So coming home and throwing a mask into a heater while you drop the keys, the Paper, the daily mail, take off your shoes, your jacket, go wash hands - you get the idea….

Activation and use, happens by a spring resisting switch and is quite secure. You push the door closed, wait until the bulbs have started up - the pinging stops - and count to 15-20 (sec) depending on the literature, that you have read, let go of the door and it opens, while automatically turning off the lights.

When you remove the mask, you’ll notice the Ozone-Smell that is caused by the strong UVC radiation.

PLEASE, don’t place the box where children kann reach it!!!

It might be considered great to hide toys in, gives off funny pinging noises and a cool blue glow, but,

IT IS NO TOY!

The wiring is pretty simple.

I cut the leads of both power supplies, because they were both designed for outdoor use and therefore too unwieldy and, of course, far too long. Please make sure to mark them beforehand on which go to the mains and which to the bulbs, because in my case they look identical. I took a power cable, I had left over from some under-cupboard kitchen lights and connected the blue line with a row of cable connectors to a piece of cable to the switch and the brown line directly to the brown wires from both power supplies.

The brown wire coming back from the switch was connected to the blue lines of both power supplies. This way the power supplies are only on, if you close the door/switch.

The lines to the light bulbs I kept separate for each power supply, so that one connects to the left-side bulb sockets and the other to the right-side sockets. The wire colors are not really relevant there, but i connected blue-blue, brown-brown nonetheless.

The wires to the switch I ran through a hole in the back of the box to the inside upper outer corner and glued in place with a dab of hot glue, so that is would activate when the door was completely closed. In the lid/door I glued a small piece of wood in the corresponding corner that would push the switch closed, when the door/lid closes.

All Cables are glued in place with hot glue.

To keep the box from wobbling due to the cables and to keep the door from scraping on the table-surface where we keep it, I stuck some foam pads on the bottom of the box.

Since it simply sits there and doesn’t complain, I never got around to finishing the outside of the box.

However, it has become one of the most used gadgets in our household, since the beginning of the pandemic.

Also, since it lets us reuse all single-use FFP2/3 masks, it has also saved us a lot of money.

Of course, we have also used it for other Items, such as phones, keys…. as long as it fits in the box. Always keep in mind though, that the high energy radiation may also damage materials and displays.

I hope you enjoyed my Instructable and that it might help you make things a little safer for you and your loved ones.

No small parts, but KEEP AWAY FROM CHILDREN!!!!

Our cat isn’t interested, but kids will be!

And that blue glow is simply cool…

Stay healthy, and always stay fascinated!

Greetings from Heidelberg, Germany

Nils