I like your grandma.
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Here is some sample emission spectrum of a common 405 nm UV LED. Note the peak width.
Here is a sample absorption spectrum of a random photoinitiator (this one does not match the UV LED used, needs other source, but good for a rough idea.)
From here: Molecules | Free Full-Text | Recent Developments of Versatile Photoinitiating Systems for Cationic Ring Opening Polymerization Operating at Any Wavelengths and under Low Light Intensity Sources
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I have to admit, I made up that homily, but she did come out with some good common-sense wisdom, such as the fact that modern weather is due to space rockets making holes in the atmosphere.
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Admittedly it was something like 9 lbs of it. Mmmm butter.
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When someone asks me âhow much do you know about photochemistryâ I assume that they need to know what level of explanation I will require in order to understand something complex that they would like to share with me.
If I say âI have a PhD in that field and have worked in it for 30 yearsâ the conversation will proceed differently from the way it would if I said âI have completed one semester of college biochemâ or âI know nothing about it at allâ.
It seems like youâve assumed that if someone asks you what you know about something, itâs some sort of personal attack. Thatâs a strange reading, and unwarranted in my opinion, and your own subsequent posts read as passive-aggressive insults, which again seems unwarranted.
Donât want to join the conversation other than to point this out to you, just in case you didnât intend to give the impression that youâre insulting someone for asking you questions.
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Graphs! Pretty!
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I can see your point. However, the question comes off a bit differently, when Iâve already explicitly stated that I was just relaying what the manufacturer states as fact, and that if someone disagrees with it, the manufacturer is the one they need to take it up with.
shaddack didnât explain it very well, but he canât be wrong about this.
What the manufacturer decides to state as fact doesnât change physical laws.
Even daylight would work, it would just take all day, or several. Years maybe.
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Which the manufacture freely admits on its website. Thatâs why the gel is stored in a black, UV opaque tube, and then the whole thing is stored in a metal box. The question is, will it fully cure in 5 seconds, as it does with the supplied UV light? If youâll look back at the original claims, he said it should work with a UV laser that operates at some specific wavelength that I donât recall, and donât care enough to look up. And I said that the manufacturer states that it only works (and by âworksâ, I mean that it cures completely in 5 seconds) at a particular wavelength, meaning you canât necessarily just use any UV light you happen to have (which personal experimentation has shown to be correct).
Assuming the supplied UV light is a cheap UV LED (therefore the 400 or 405 nm one) with a CR2032 battery, we know the wavelength. Given the power density of the 404 nm violet laser being way higher than of a puny LED, it should cure way faster.
And I stay behind that claim. Most UV-curable products that use LED light rely on these cheap LEDs, being it a glue or a nail gel. Therefore I have a pretty high probability of being right.
The vendor made an oversimplified statement, and, in corporate user-nonfriendliness, omitted the absorption curve, even the wavelength. These days you have to guess to get any technical data.
You canât take vendor statements as a gospel. (Even gospels themselves arenât advisable to take as a gospel.) There will be an inaccuracy, omission, oversimplification (like here), and as anybody who relied on chip datasheets for too long can confirm, even outright errors (google âdatasheet errataâ - and thatâs way more important information to be correct than a luser-level blurb on a consumer-grade website).
If physics disagrees with a vendorâs statement, I know where Iâll place my bet.
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You lost this one, by a fairly wide margin. Unless you have a last-ditch bomb in the form of actual wavelengths the vendor uses that disagree with my estimate, and, preferably, a spectrum that shows an absorption band of the photoinitiator narrow enough to be considered a single-wavelength line (say, 50%-width being say 5 nm).
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I havenât âlostâ anything. I donât have a stake in this. As youâve been told before, these are not my claims. Iâm just passing on what the manufacturer says on their website. If you have a problem with their statement, email them.
To quote John Fugelsang - 'Youâre trying to score points in a game no one else is playing."
Yup. A person who doesnât spend hours a week looking for non-existent data in a data sheet doesnât have the pain invested to care about an argument on that subject.
I, on the other hand, could go on for days about missing data in data sheets.
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The vague MSDSs are even worse. If you can get one, often it is more than difficult to find what the thing actually is. One has to guess and second-guess, sometimes even try to divine the information from patentsâŚ
We need $100 GC-MS rigs. Because fuck secret compositions. We have the right to know what we are using, down to every molecule.
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And my claim proved to be correct.
405nm laser was successfully tested on Bondic and Acrifix192:
A LED torch suitable for Bondic and with wavelength of 380-400 nm is here:
http://www.ebay.com/itm/UV-Pocket-torch-1-Led-for-Adhesive-suitable-also-to-Bondic-SOLIQ-Ber-Fix-/252060145215
It can also cure fast with a 365nm LED.
Looks like the absorption peak is wide as a barn door.
From the vendorâs FAQ:
What wavelength does the fluid cure at?
Thanks for asking but sometimes the chef doesnât tell you the secrets of their recipes!
Fuck you and your secrets, Mr. Vendor, they are just a google away. Itâs UV-A range, with anything from 365 to 405 nm.
âŚAnybody with the gear to bother measuring the actual absorption spectrum? (Or, better, find cheaper alternatives from less-secretive, less-asshole vendors?)
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I hope they didnât try patenting their formula with that kind of shitty attitude. If they want to have trade secrets they donât get the benefit of patent at all.
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Itâs no rocket science, too. The tech of UV-curable polymers is quite well-documented and quite mature, there are recipes all around. If only the standalone chemicals were easier to buy in small amounts for a mere mortal without an institution behindâŚ
Edit: Basically the same principles are behind this goo, other UV-curable adhesives and resins, photolithography goops, dental resins, UV-cured printing inks and conformal coatings⌠Pretty fascinating chemistry, with wide range of uses.
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In many countries, depending on the filling size/location, they offer mercury free ceramic and gold options, which outlast the mercury amalgam without mercury. Mercury fillings often arenât an issue, unless they fail, or are in a bite strike zone. They can be an issue in those cases though.
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Been on Amazon looking at BondTec and all the similar knockoffs.
It occurred to me that this is a ghetto (by that I mean makeshift/re-purposed) super duper, 3D Doodler, without the heat gun pen. you can build up âsculpturesâ in a similar manner by curing as you go.
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