UV for post-curing

So I have been doing some reading about UV tonight, and it turns out the 405nm (blu-ray) wavelength that our Form1’s use is not UV at all. It is totally in the visible spectrum. Check out the picture I found that sums it up. It also appears that UV sterilizers emit way over in the actual UV area. So UV sterilizing cabinets and UV curing lamps are not ideal at all.
Aside from slow curing, I imagine real UV devices risk damaging your eyes without knowing it. Not to mention sunburn/yellow your prints.

You’re right Josh. a 405nm laser isn’t a UV laser! Officially it’s called a Violet laser or sometimes a near-ultraviolet laser (which is exactly what it is). However, most people refer to it as a UV laser. Because a lot of people don’t care to understand how the whole process works, they just repeat what others say, The majority just say it’s a UV laser as that is what they heard and that is what sounds plausible.

But you’re absolutely right!

UV-A does, however, help with curing the parts as it has a shorter wavelength than 405nm. This will just reduce the curing time and won’t be harmful for the print.

And yes, UV devices can be harmful for your eyes, but the cabinet is supposed to cure your print, not your eyes, so if you use it properly, it shouldn’t be an issue. Furthermore, a steriliizing cabinet has a uv-blocking coating.
The yellowing of prints will happen with slow curing as well. Luckily they found a solution to that for the clear resin. I’m sure it’ll be just a matter of time when they find a similar solution for the white resin.

I bought one of the UV sterilizers someone mentioned on the forum earlier this year. I returned it shortly after getting it because it was not curing the prints. It even came with a warning that UV light would produce O3 gas and that was dangerous. I decided hell with it when I smelled the pungent gas. What do you use?

You could be right. Some UV sterilizers aren’t powerful enough and need a stonger bulb in order for the print to cure.

I made my own curing-cabinet with this face tanner as the lamp: Bought it at a 2nd hand shop for a few euros.

This together with an aquarium with aluminium sheets on the inside works like a charm. All I do is plug in the face tanner and put it on top of the aquarium. The cabinet itself looks terrible, but it does the job perfectly!

Neat. You must have had the aquarium already? I can’t find a cheap one.

Nope. Bought it at the same 2nd hand shop. €5 is all they wanted for it. The aluminium sheets I already had lying around.

But you can use any box as you’ll be glueing Alu sheets on the inside anyway!

Huh, that’s a good second-hand shop. I guess I have some time and a few clever ideas. I will start playing.

I had a small fluorescent tube black light my wife bought at the pet store to use to find pet “oopsies”. If it was $10 I’d be surprised. The tube is maybe 1/2" diameter by 14" long. I can’t imagine it’s more than a couple of watts, I’m powering it with some random wallwart 12V transformer I grabbed from my parts bin. I have no idea what the tube’s frequency is, though most similar items on the web appear to be in the 395-410nm range which is exactly right. So I grabbed a large empty cigar box (I smoke cigars) and lined it with Aluminum foil, all crinkly, not smooth. I put my slightly soft/sticky/greasy part in the box and lay the lamp across the top and let it sit overnight. I was surprised at how much light coverage I got. The foil really effectively scattered the light pretty much everywhere. I think crinkly foil might be a better choice than something more mirror-like. The part looked like it was being illuminated from every direction. It was really “lit up”. In the AM the part was unquestionably fully cured, the surface was dry and hard and not the least bit tacky.

The setup is a little too “ghetto” so I’ll be making a more elegant curing box with some LEDs at some point. But it appears you can get very effective results with only the most minimum of investment. Any any box much larger than the largest part you can print is IMO overkill. A decent sized cigar box works great.

I had a good experience with the UV cabinet, still using it.

Do you know the wavelength Oemer?

@JoshK: 200-275nm
if you can build by yourself a better adjustable UV light, then its a better solution.
But for me this solution is better then nothing.

Huh. Cool.
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I bought a relatively cheap UV sterilizer off amazon, and it works absolutely great for curing prints.

This is the one I bought. All it did was try to kill me :frowning:

I have that one too, but I changed the bulb with a black-light bulb. It works better for some reason.

Hey Monger_Designs do you have a link or info to which black-light bulb you got to replace the one that came with the unit.

Here it is

However I’m thinking of getting a more powerful one. This works well for the black resin, the grey, etc., but not so well for the castable resin. Nothing beats the sunlight for that so far for me.

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Thanks for the link