Hi
kindly can anyone please link to me video or a topic for the best way to dedome a cree XM-L2 led
De-doming with gasoline.
Pics by Old-Lumens
car fuel ? 
soaking fr how long ? and will the silicon Decays by itself ? or there is a procedure i will do ?
What should you use to glue back the emitter to the host? Would construction glue work?
Yup. Just regular car fuel in a glass jar. It doesn’t take much. I use a mini mason jar or an old baby food jar because they seal well and no gas fumes escape.
THe only thing special I do is put a few shallow cuts in the top of the dome to allow the gas to penetrate quicker. Drop the star with the emitter on it into the gas and let it sit overnight. Every now and then I swish the gas around in the jar before going to bed and in the morning the dome is gone and the emitter perfectly clean. I pluck out the star with tweezers then rinse it off in a shot glass with clear rubbing alcohol to remove any petrol smell. Set the star down on a paper towel until the alcohol evaporates. That's all there is to it. 8)
Ken, never use construction adhesive or regular glue. You need to use an adhesive that is thermally conductive. The most common used are Fujik and Arctic Alumina. It takes very little to properly adhere the star to the pill/host and the less you use the better it is. You want only a super thin film to be between the two metal surfaces so that maximum thermal transfer from the emitter MCPCB (star) and the host.
Gasoline works perfect, but after some dedoming I need to filter my gasoline because every time I shake it gets milky… :bigsmile:
I also use a very small jar with maybe 0.1litre gas and I wonder every time someone posts a picture of a gallon gasoline, things in America seem to be always bigger.
I solder a scrapwire on the star before putting it in so it can be fished out more easily with the tweezers. I poke it with a knife and then I let it fall in the jar, let it resting on the ground, I don’t hang it in upside down or so. After some hours a shake is enough to separate the dome.
Don’t try to peel the remaining goo between the golden wires, these are super soft and break easyly so a bit of stabilizing is good.
Where can I pick up the Fujik and Arctic Alumina?
Fujik comes in a big tube and is cheap, available from The standard Chinese sellers e.g: DX and fastech. It is like a standard glue just plain white and stays a bit rubber like after hardening.
AA is a lot better in terms of thermal conductivity and is usually available from computer and electronic stores, just check your local internet dealers. AA is a 2 component glue which gets quite hard.
There is also thermal grease out there which don’t glues, I think there is even a non glueing Fujik out there. These can be used if the LeD star is pressed down by a retaining ring, screws or similiar.
Curious, just found my relatively old tube of Arctic Silver 5 Thermal Compound I used for my cpu heatsink some time ago; would this work under the star?
AS5, as we call it, I think is the best (differing opinions of course). Think I was buying from newegg here: http://www.newegg.com/Product/Product.aspx?Item=N82E16835100007, but check around - may find it cheaper, maybe.