How to Make a UV Box

How to Make a UV Box

What you need to cure 3D resin prints

So, you’ve bought a 3D resin printer? Or were thinking about it. One of the major differences between the 3D resin printers (SLA - stereolithography) and the plastic-printing kind (FDM - fused deposition modeling) is the post-print process.

With the resin prints, however, UV light is what turns them from goop into a solid object. Sure, you can use the sun to cure them. But you risk uneven exposure to your print, causing discoloration (the clear resins are especially prone to this). Plus, an indoor UV box means that you don’t have to wait for sunny, no-rain days.*

  • Acquire the Box
  • You might have some cardboard boxes lying around. Boxes you got from packages, moving boxes, or office boxes that hold paper or store files work quite nicely. You could also try asking the stocker at your local grocery store if they have any cardboard boxes that you could take off their hands. That’s one less box going to the dumpster or recycling center - reusing/upcycling extends the life of the object.

    There’s fancier UV light boxes that are out there made for this sort of thing, but this is a DIY project (and it will be cheaper). If you want a fancy setup then you can buy this and forget the rest of the article:

    Or the cheaper light box:

  • Line it with Aluminum Foil
  • You probably have some aluminum foil around the house. It’s not totally necessary to have it for your UV curing box, but it does add some reflectivity for the light to bounce around into all the nooks and crannies of your prints. Plus it’s shiny.

    You may shape the foil into the box and tape it down, but adding a few lines of hot glue will help ensure it sticks to the inside walls of the box. Go ahead and line the top of the box, too, so that light bouncing upwards can reflect down to your 3D print.

  • Set up UV Light
  • Would any old LED light work? Nope. Make sure it hits the 405 nm wavelength or very close to it when looking at the specifications. It needs to be UV (ultra-violet) light. Below are some UV lighting options. We think the LED strip is the best way to go, but feel free to compare it to the other methods.

  • LED strip:
  • This 6 ft. (1.8 m) long LED strip is the perfect amount to line the inside of the box, yet be a few feet away from the wall (power source). It’s power comes from a USB plug, so this can plug into USB wall outlets or power bricks. Installation is easy too since you can peel off the thin paper backing to use the sticky back of the LED strip.

  • Flashlight:
  • Getting a flashlight allows portability. But, UV light is a drain on batteries, and not the best option for a 3D printing assembly line. On the other hand, if 3D printing turns out to not be the hobby you wanted, then a UV flashlight comes in handy for spotting pet stains, scorpions, or sanitizing objects for example.

  • Flood Lamp with Stand:
  • A short UV lamp that can stand on its own and fit in a box. It’s also waterproof, and has a 6 ft. (1.8 m) long cord. Just feed the cord through the box’s handle, or cut a hole with a box cutter.

  • UV Bulb:
  • In case you want to convert a closet or small room into your UV room. Like a modern day dark room for photographs. Using lightbulbs is unconventional, but then that room doubles as a party room!

  • Put a Display Stand Inside
  • Solar-powered rotating display stand:

    It works on solar power, or AA batteries. You can choose to set it outside, on the windowsill, or inside your UV box and let the UV light power it.

    Don’t Forget the Cleanup Process

    Resin for 3D printing is toxic! You don’t want to be huffing it or letting it sit on your skin. Think of it like paint: wear gloves and have enough ventilation when using. It needs to be handled properly.

    Some resins can be rinsed off your 3D print with rubbing alcohol, and other kinds are water washable (which saves you money from not buying the alcohol because you’re using tap water instead). Either way, you can’t rinse off your prints and have all of that uncured resin going down the drain. It must be cured with UV light first. So, follow these simple steps:

  • Rinse off excess resin in a container.
  • This could be a pickle jar, plastic tub, anything that can hold liquids and fit what sized prints you’ll be making. Be sure to label it as toxic/yucky so kids and adults won’t be drinking it, pouring it down the drain, or reusing it to store food; keep it stored up high and out of reach from kids and pets. This pickle jar should do it if you can’t find a good container:

  • Cure the 3D print and the alcohol/water with UV light.
  • Now that you have your UV box, you can fit both the print and the jar of alcohol or water solution in there. You don’t have to cure the solution in the jar after every print, but if you’re going to be leaving it alone for a few days then go ahead and cure the solution. Remember: stagnant water grows bacteria and mold. Gross.

  • Filter out the hardened resin leftover in the solution.
  • Carefully pour your alcohol or water bath through a strainer. The strainer will catch the resin bits, letting the solution pass through. The alcohol can be strained into a bottle and get some more uses out of it. If using water, and it’s been fully cured, then it can be poured through the strainer and down the drain (but please check your local laws if they have preferred disposal solutions).

    A disposable strainer could work, but why not opt for the sturdiness and reusability of a metal strainer?:

    That’s it! Most of the UV box is probably lying around your home right now - it just doesn’t know it yet. Add some UV light, and you’re ready to finish off your 3D prints.


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    Feature photo by Matthew Henry from Burst

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