Thinking about buying one of those “Sterilizer” ovens, but I’d like to drastically reduce the 2hr cure time mentioned above. According to the description on Amazon.com, it comes with a 2-pin, 12" long, G8T5 bulb. G = germicide, 8 = wattage, T5 = 5/8" diameter.
The closest thing I found to 405nm in that form factor and wattage is this:
It has a peak wavelength of 368nm, so I suspect it emits a lot more light around the 400nm spectrum than the stock 254nm bulb the oven ships with.
Price of the substitute bulb is only $4 + shipping. I’m hoping someone who already owns one of these ovens can give it a shot and report back here!
EDIT: I ordered the oven and the bulbs linked here, and the 368nm bulb fit perfectly.
EDIT: For other Canadians who want the oven but can’t get it from Amazon (because that seller doesn’t ship to Canada), you can find the same product on eBay: www.ebay.ca/itm/221474551527
The two-hour suggestion is based on a webinar FormLabs did with Robert Vignore (check out his *AMAZING *website, Mold3D TV: https://www.youtube.com/channel/UCYlDRd5eYjT54xG-BD6-V9g) Here’s the link to the webinar and at 00:19:44 he talks about the UV Sterelizer and the curing times:
I’ve had my first three pieces “cure” in a half-hour, so my suggestion would be to first buy the Sterilizer, try different curing times and if needed, buy the more stronger lamp. Just a suggestion!
I placed a small amount of Formlabs Grey Resin on a piece of clear plastic inside the cabinet for 1 hour using the 254nm UV bulb that came with the Sterilizer and found that no curing had taken place, the resin was still completely liquid.
Then I replaced the bulb with one purchased online from Topbulb a 368nm bulb http://www.topbulb.com/8w-t5-fluorescent-blacklight-blue-miniature-bipin-base
After less than 1 hour the same amount of resin was fully cured!
I highly recommend getting the UV Sterilizer Cabinet and replacing the bulb with the 368nm bulb from Topbulb.
Just FYI. I bought the sterilization cabinet and it seemed to speed curing somewhat so I bought a bulb that was closer to the 405nm curing of the epoxy. Really did not see any improvement with the new light which really had me puzzled. If anything it seemed worse. I could cure raw epoxy with the new bulb but it did not make the part feel less gooey. At this point, it occurred to me that perhaps it wasn’t a curing issue but rather an evaporative issue. I printed a new part and placed it in front of a small desk fan and less than an hour later, it was tack-free.
@Paul_Valente, have you tried submerging them in water while curing them in your sterilization cabinet. According to @RocusHalbasch, it’s a neat trick which helps speed up the cure time and eliminates sticky parts!
@Alex_Vermeer@Paul_Valente@RocusHalbasch The water+UV light curing trick works incredibly well but be careful! If the part is not washed thoroughly with IPA extra uncured resin on the surface of the part combined with the water and UV light will lead to a whitish, powdery looking surface. You can always buff or sand it out but it can be a pain. Just a heads up.
@RocusHalbasch, @Clark_Anthony, I think I see what you mean. I just rapid cured this clear print which was mostly filled with water, except for the clear bubble you can now see on the photo. The rest is indeed a whitish haze!.. Perhaps rapid curing should only be done with pigmented resins :).
I’ll just let them sit to see what happens to them…
The haze will not go away. You can sand it off. If you start curing with the part submerged in IPA instead of water you will get better results. I’m trying to find a method that results in rapid cure with as little exposure to IPA as possible as IPA causes warping. I’ve had good luck with 2min agitation in “dirty” IPA. A quick rinse in “clean” IPA. 2mins of UV submerged in IPA. And finish with extra time in UV submerged in water if not fully cured.
This results in only about 4min of exposure to IPA. And the 2mins of UV in IPA has prevented hazing so far but I’ve only done it a couple times.
If anyone has good results with this or comes up with a better method let me know.
If you have a big part, what you can do is stand it up (with the opening down), remove the bottom plate and put the part in front of it. If you have 2 of them, you can sandwich them together and have the part cure from both sides at the same time.
So, my UV sterilizer cabinet stopped working today. The main power switch still illuminates when turned on, but the UV bulb doesn’t, and there’s no violet/blue light visible through the little inspection window anymore. Tried three different bulbs all with the same result. The door close switch sounds like it’s operating properly, and the main fuse is good.
I noticed there’s a cylindrical component inside, near the top right corner of the back wall. I removed it and opened it up - looks like some kind of bulb or fuse, and it looks burnt out:
My guess is it’s a little 4W lamp to reduce power going to the main bulb. Anyone know where I can get something to replace it? Or what the socket type is?
With all the smart people here I figure someone might recognize this thing and be able to shed some light :-).
EDIT: After some research I think I answered by own question. It’s a fluorescent tube lamp starter, I think 4W. Folks in the US are luckier than me and can get replacements for around $2 at Home Depot.
In europe you can get one as cheap as €1,- (conrad). Not including the shipping costs of course. but if you order over €20,- you don’t have any shipping costs. Luckily they have a lot, so I never end up below €20,-
I stopped curing my prints. After building a UV light cabinet and using that to cure the prints I felt they were too brittle, cutting the supports off sometimes resulted in broken edgges and sanding the support nubs took a lot of work. So, I stopped doing it.
I now, after draining the parts from the last IPA bath, I dry them with a paper towel and Q-tips then let them air dry. I find the sand much better after sitting for a day and the edges aren’t as brittle. When I cut off the supports I don’t get breakage like I use to. After sitting around for a day or two the parts are nice and hard with have a dull finish to them. I’m much happier with the results.