I folded a small container from tinfoil filled it with some thinner, placed it on my hotplate, and put some leds in mounted on a ledboard. I soon found out that you want to be outside when doing that (headache now :person_facepalming: ). I checked a XM-L2, a 3rd gen Oslon Square, and a Nichia 219B.
Once the thinner was hot, the XM-L2 dome floated off in 3 minutes. Not all the silicone was removed after 25 minutes but the die was nice and clean.
When after 20 minutes (yes, I was impatient and curious) the other 2 domes did not spontaneously fell off (they did look far gone though) I gave them a gentle push and there they went.
The Oslon dome came off together with a clump of phosfor while in other places still silicon was on the die (probable cause: phosfor mixed in the silicone), dedoming without removing phosfor will not work like this (and likely never). The picture looks better than in reality: the remaining phosfor layer was of uneven thickness, the silicone broke off in a random way inside the phosfor area.
The Nichia dome came off with a clear layer of silicon left on the die.
When trying to pry off remaining silicon it became clear to me something that I did not realise before: also the Nichia phosfor is mixed with silicone but during production the phosfor-silicone mix is applied in a die-cavity first, filling it up, then the clear silicone dome is added.
So with these Nichia’s you end up with damaged phosfor or with a film of silicone on the phosfor. This is not different from a shaved dome.
In my case: damaged phosfor:
Conclusion:this is a very potent method (thanks l.i.), XM-L’s dedoming is peanuts, and with Nichia’s it worked way better than ever before with petrol. But it will not magically dedome leds that have the phosfor mixed in the silicone.
I think you don’t really have good paint thinner there…
Don’t get me wrong but your results are terrible with this method.
You should have ultra clear results with this method especially for XM-L2 and after only 15 minutes…
So it ain’t good… It aint good for now Hope next one will be better.
Edit:
Nitro thinner should not cost more than 2-3$ per liter!
This is proper result of my method:
My conclusion:
I see that Djozz had only 100ml of mentioned expensive paint thinner… That is not enough! During cooking process (boiling hot - not just hot) thinner evaporates very quickly.
I use about 300 ml of boiling hot thinner in a pot that is just slightly larger in diameter than regular glass. In that pot I put around 4-5 emitters. After 15 minutes I have it less than 100ml. So it evaporates quickly.
So when doing this method it all depends on size of your pot. You got to have plenty of nitro thinner inside your pot and that should not be problem since it is dirt cheap.
- Nitro paint thinner does not have to be Italian Buying over ebay is waste of money. It can be from any manufacturer on the world. I even did not used that one that I linked in posts before. I used cheap 2$ one from my local hardware store.
I will write even more detailed instructions since some of you guys seems to have problem with it. You are all adults so I will not take any responsibility if something bad happens:
- Don’t use diy pots out of aluminum foil and similar stuff. Use real “open pots” smaller or larger one like this:
Use plenty of nitro thinner in such pot cause it will evaporate quickly! For example in my small(little larger than regular glass) pot I use 300ml for 5 emitters.
- Boiling hot thinner! So as I said boiling hot so you can see boiling bubbles.
- Boiling time: Emitters like XP or XML should be boiled for 15 minutes from the point when thinner starts boiling(from the point where you’ll start to see boiling bubbles). Other hardcore emitters? I don’t use others but if XHP 50.2 can be de domed with this method so can other ones… If needed you can safely boil them even longer but make sure you have plenty of boiling nitro in your pot! If nitro evaporates from pot you’ll fry your emitters!
- Don’t look, don’t touch, don’t smell before it is done. Do it outside if you can but if you are doing that in your kitchen(like myself) open the window or kitchen hood,
- After it is done use tweezers carefully and put them out one by one in a isopropryl alcohol bath (another small dish full of isopropryl alcohol) and leave them for few minutes. Remember Isopropyl alcohol. Don’t use other ones.
- After that take them carefully out of bath in a hand, turn it over to - side so it is leveled with your eyes and use air compressor pistol or compressed air to fully blow silicone remaining over those tiny + wires. I do that in a single compressor blow and voila! Mirror clean emitter is there.
If you’ll get results like Djozz in above pictures that means that you did not follow procedure well or you don’t have proper solvent, or you did whole method in a wrong way. I’ll give Djozz D - since he managed to de dome XM-L2 but unsuccessfully since it is very dirty and not ultra clean as it should be. Khas did that for A+
Hmm, I’m a bit reluctant letting large quantities of paint thinner evaporate into the environment so if you don’t mind I will stick to smaller containers.
Yes, my stuff may be wrong after all, even though it worked better than the gasoline that I used before. But I doubt that those leds with no clear boundary between phosfor layer and silicon will ever properly dedome.
luminarium iaculator and fellows in general, please be aware you don't need to keep evaporating the paint thinner. Once the pot solution starts to boil (thinner reaches boiling point), lower the pot heat until evaporation is reduced to a minimum. High heat doesn't makes the solution hotter, though it increases evaporation rate (for higher solution temperature, higher atmospheric pressure is required).
Please don’t stick to small containers or you will never de dome properly cause it will evaporate quickly and then you’ll fry the led on a steam like you did on your pictures. Use at least glass size pot and at least 300ml of thinner.
The most important thing is that it is the most perfect method for XP and XML emitters and I am pretty confident that I would de dome even that hardcore ones. If you want you can send them to me. I don’t use nichia or that osram since they are not suitable for my builds.
And thinner is skin friendly. It is stuff for cleaning yourself after messing with paint. So don’t worry for environment
Toluene, which seems to be a major ingredient of these thinners, are on the EPA’s hit list of 187 HAPs (hazardous air pollutants). A few of the other typical ingredients are probably on the list as well.
What we are doing have no impact compared to some big industries, but for yourself and those around you please be careful when boiling off these chemicals.
Well said DEL! I always use a gas mask when dealing with thinner or other dangerous chemicals. Thinner is a especially nasty chemical. I would never think of washing my hands in it after painting.
It’s always wise to read the safety data sheet beforehand, so that you’re sure that you have the right protection when using it.
Guys everything is dangerous and cancerous this days… Even barbecue, normal cigs E cigs… Smokers are greater pollutants than de domers
Have you ever did coloring of metal surfaces like fences and similar stuff using regular paint brush? There is like 99% of chance that you will get dirty after that. Here in X part of the world(Balkan) people would laugh at you to see you wearing gas mask while working with paint thinner To me this is hilarious even when I imagine that
Of course you will not wash your hands with it when you cleaning yourself with it. You will put small amount of that on some cotton or small sponge and then you will dissolve dirty places on skin and then you’ll wash all that with soap.
There are so many chemicals that can harm us more than mentioned thinner.
But of course… We all should be very careful when de doming cause Mr. Devil never sleeps.
That’s not how I used to do it. Oh well, safety is everything nowadays… Yes, I would just wash my hands with it as if it was a liquid soap. I don’t paint stuff for the living, so I somehow survived the score of hand washings that I did in my life.
Yes your method is pretty common in X part of the world also cause people are not afraid of that. There are no house without paint thinner. It is in top 5 used solvents. I see you are from Poland We love your tractors Ursus 330 335 :+1:
I fill the glass to about half full, then with the lid almost closed I put it in a pot of just boiling water, wait five minutes it’s normally enough but if it need a bit more I change the water with some freshly boiled water from the kettle. When I am happy with the result I gently blow it clean with compressed air. I two LED’s in the jar I find it works best that way.
Regarding safety : I do it outside of the house, I don’t have a gas-mask but I normally make sure I have a lit cigarette in my mouth I can breath through just to filter out any fumes
“The OSHA 8-hour time-weighted exposure limit for paint thinner (as Stoddard Solvent) is 500 parts per million (ppm). This is half the OSHA limit for exposure to acetone (nail polish remover), so paint thinners are not terribly hazardous. But, it has to be remembered that paint thinner vapors can irritate the eyes, nose and throat, in spite of their fairly pleasant odor, and can make one dizzy and/or nauseous if the vapors are inhaled in high enough levels over a long enough time period.”
So yes everybody beware when cooking with it. I also warned about that. But you would not really want to try second bolded section(inhalation of vapors)?
Edit: Put it on cooker. Stopwatch at 15minutes when it starts boiling and get out of there on beer or something When you return clog your nose and turn off cooker… Then go to another beer until all vapors evaporates
How to say… On our Balkan market thinner is as regular thing as some dish washing fluid. Even some grocery shops carry that on hardware section. You can’t do anything without it (painting, cleaning, de doming )
Hope next one will be better.
but if XHP 50.2 can be de domed with this method so can other ones… If needed you can safely boil them even longer but make sure you have plenty of boiling nitro in your pot! If nitro evaporates from pot you’ll fry your emitters!
When you return clog your nose and turn off cooker… Then go to another beer until all vapors evaporates