de-doming with the emitter still in the light ?

Have you ever de-domed a light with the emitter still attached by hanging the star into gas by it's wires ?


Have you ever de-domed a light by just placing the light face down into a gas soaked rag ?

I've done both ...

The first one I think I unsoldered one wire .... and hung the star into a small shot glass of gas

this last one I just took a paper napkin soaked it in gas and tore off another piece , formed a ball a bit smaller than the size of the star. So the emitter was the only thing touching the paper towel soaked it in gas.I figured the gas would wick up to the emitter just like a wick on an oil lamp . I used a double shot shot glass with the paper towel in the bottom ..tall enough to support the light too .Cleaned up with alcohol and it's probably one of my best de-domes to date ..1.99 zoomies so not risking much .

Anyone else try de-doming with the emitter still in the light ?

I have done it twice , just suspended the emitter until it was just covered , and left it overnight .

Worked great .

Far easier to use the emitters own heat and pop the dome with the light running. Richard told me about doing this and I tried it, works well but works best with a hotter light as a moderately run light may not generate enough heat to allow the dome to come clean of the bond wires.

I’ve used a scalpel to trace/cut around the base of the dome first, then using a welders glass to view the process I turn the light on Turbo and apply a bit of lift with the point of the scalpel, not trying to force it just a gentle bit of pressue and hold that. Within about 30 seconds you can see the bond between the dome and die separate and the dome begins to lift off. It’s important to allow it to release, not rush it. The entire process takes less than 2 minutes from the start of the cut to having perfectly intact dome in your hand. Screw on the bezel and your done.

The only failure I had was with a light that was running around 3A and I rushed it as the dome peeled away at the bond wires.

hm…. so the best dedome you got is using small amout of gasoline by soaking paper towel and use it to cover just the dome ? Then connect to a ‘pond’ of gasoline to continuous supply ?

Never thought of that, I might just try that. But by imagination I can say its a clean dedome, also without messing other area (base plate, other portion of the light) just cleaning with alcohol will do ?

I’ve tried the heat dedoming method (heating the LED and lift the dome off) but I didn’t get any success. I watched and followed Vinh’s tutorial video and I think the main problem is I don’t really know how hot should the LED be before lifting the dome off.

In the heat de-dome I don’t lift it off by force, simply apply light upward pressure so that when it releases I’ve got it coming up off the die. It’s a gentle, by touch, kind of thing. At first there’s no movement, but keeping that gentle lift on it after a few seconds you can actually see the separation between the die and the dome as the bond breaks. This separation starts around 30 seconds in when running in the 6A range on a copper star. The one light I broke bond wires was at much lower power level and I got hurried when it started lifting, I felt that it was taking more lift to get it off but forced it anyway…and the bond wire/wires broke…light went out. This is why it’s important to start on the side opposite the bond wires, in theory the area near the wires will be hottest so if there is release on the other side then the area around the wires should be amply hot.

I’ve damaged em in gasoline too, neither method is completely without fault. And then you still have to manage to get the reflector/centering ring in the light without cause similar damage, as the wires are now unprotected.

I usually hang my led up side down, on a piece of wire inside transparent glass. It takes about 20mins for dome to fall off by itself with thinner. I then clean up the residues with 20x Nikon nature scope. I prefer to leave some material attached to bond wire for extra protection.

Someone (maybe you) posted this the other week and I tried it a few times now, its definitely my new method, works great.

One question, do you cut in (horizontal) towards the die level with the base or do you cut down (vertical) in a circle around the dome pushing onto the square base? Do you remove the excess silicone at the corners or leave it?

It can be hard to cut horizontal if its down in a light but I have a 90* pick I sharpened up just for this so just seeing if you cut down maybe making the sharpened 90* pick was a waste of time?

I cut 90º down trimming at the base of the circular dome. After it’s done there’s a neat circle of bare substrate with the de-domed emitter in it and a scratch showing that I did cut through the dome. I have left the corners on in some lights that were difficult to access, removed it when it was easy to do so.

Using the welders glass makes it neat, you can see the emitter lit up green through the glass and easily watch it separate. Pretty cool.

Edit: I’m using a #11 Hardened Glass Gold Filter Plate 4 1/2” x 5 1/4”, this one is Anchor Brand number FS-3H-11

Guys make sure your using true welders goggles or a dark lens, not an auto darkening helmet, the LED light can usually trigger the helmet when its first switched on but after that it doesnt keep it engaged even shining directly at the sensor and in the rare occurrence it does manage to keep it dark when you cast a shadow on the sensor (with your finger or a tool) it WILL turn off and you will be blinded and have to stop work while your eyes recover. For your own good please make sure your using actual welders goggles/a full helmet or a lens, not an auto darkening helmet. Ask me how I know lol.

Richard told me about this method a week or two ago, but he was doing it at the time of re-flowing onto the star. I tried it in the light and it worked so well I’ve done about 8 of my lights now. Quick and easy, but you do have to be gentle and patient, let the heat do the work.

I should also reiterate that it’s more likely to damage the emitter if the current level is not high enough. 5+Amps to 6A and over it works very well.

Thanks for the heads up. My auto darkening helmet was the first thing I thought of using. Luckily I also have a regular welders helmet and a pair of goggles with my torch set. My eyes thank you in advance, sir.