A Perfect Dedome?

Like many others, I struggled doing a successful dedome -

  • first attempt at cutting: only partial removal, ugly, improved throw but not doubling

  • went at it more seriously - tried the hot iron method: ok, dome softened up, tried the cuts around as shown in the viffer video, got the dome off - going good, then left with the gooey stuff, ok, removed the goo and the wires, hhmm. Tried again: saved the wires, but tearing off yellow phosphor - ok, I did my research, this means game over, blue flame beams, done. Try again.. Same thing, yellow goo!

  • acetone, Yes! This will work! Going chemical! Let the chemicals do it's thing, works for athletes, right? 40 minute bath, dome is real soft, comes off easy, but here we go again with the goo. Goo is still a bit hard, pullling it off - wait, what's that yellow stuff in the pulled off goo? Crap!! Try again, maybe less phosphor removed, try it - Ok - throw went from 19 kcd (stock U2) to 36 kcd (dedomed T6). Ok, but what is the deal with the multi-color beam? Oh, 3/4 nice tint, 1/4 blue, yes -just what everyone said... Try again - yellow goo, same old, giving up on the acetone...

  • Gasoline, a much better chemical! This time, an overnight bath, latest dedoming craze fresh from Germany (where we know all the high tech stuff is going on). Everything dissolves, just disappears right off the emitter, so they say (maybe Coca Cola would do the same thing?). Got a jar with a U2 on a star sitting overnight, check in the morning - the dome is sitting next to the star on the bottom of the jar! Wow! That was easy. I'll give it all day, then when I get home from work, all should be gone (hope the LED will still be there).... Ok, pulled out the emitter/star - hhmm, goo! Wait get the 10x glass for a closer look - goo! Crap! Carefully pulled it off the emitter (dejavu), but wait, this time it really is soft and just peeling off easy. Ok, cleared the emitter - don't dare touch those wires! Leaving the goo around the wires. Carefully dripped some isopropyl on this, let dry, take pics of this miracle birth, pop it in to the test light, beam looks really nice, lux reading comes out to 39 kcd - ok! We got a winner!! But can this be done again? And again?

Last acetone attempt:

Gasoline, I'm on fire! Here's my new born:

Update Dec 24th, 2015:

MEM wrote up a really nice post on gas de-doming in djozz's thread. Please find his detailed post #131 here: https://budgetlightforum.com/t/-/32252.

I'm thinking some may disagree, to each his own, but I have trust in MEM.

now that’s what I call perseverance!

I could try it, I guess. Good Solvent…

I still think Coke may do it . Just good I had a bunch of extra T6's laying around from upgrades. Got into modding just before th U3's came out, so I ordered a few U2's and before they arrived, the U3's became available, so never ended up using all the U2's.

I'm gonna stick with the gasoline for now - I can live with this method, just hoping the LED lasts a while...

I tried a T6 today, cutting. Tomorrow it goes in the juice to get the rest off. I’ll be putting it on copper and into an HD2010. I want to see if it can take out my XM-L2 HD2010 at 81kcd.

The gasoline xml looks great!

When slicing off the dome isn’t leaving a thin layer (goo?) good to keep air off the phosphor & prevent burning / discoloring?

Cool I will have to give this a try. Thanks.

If you have a small ultrasonic cleaner, you might want to try that (at least as a final rinse sort of thing). When I put flammable liquids in my cleaner it is always in a small (like 30cc) cup that is floating in the tank filled with water. The cleaner that I do that in is a small Harbor Freight jewelry sized cleaner. You might need to do a couple of runs with fresh solvent each time.

If its a silicone dome would some kind of silicone spray dissolve it? What dissolves silicone anyways, that is less harsh then gasoline?
I’ve wondered what kind of light output you would get from a concave dome instead of a convex one

Don't know about the phosphor exposure issues - NightCrawl brought up the gas method here: https://budgetlightforum.com/t/-/16982, but didn't mention anything about exposure issues.

Heating works fine for me. You need to have the correct temperature and the results may vary..

i never expected somoene to try it that pricey pcb

Anybody still use Led Seal after dedoming?

I think it's the best thing since sliced domes.

I haven't done a before/after lux measurement yet...I'll put it on the schedule. :)

Thanks for the testing, thusfar I just went ahead with a forceps with various results, I have some leds underway that are going to be dedomed, I'll give a few of these methods a try , including the gasoline one (here in Europe I will use petrol instead, hope that works too ).

No, petrol only works in great britain. ;)

_the_ - that's a great dedome. Was thinking of trying a different approach for a heat method, viffer750 made it look so easy and I think he quotes a 100% success record, but the success I had with gas, I'll probably stick with it, only go to a high octane - NightCrawl mentioned their gas is 95 octane he used.

I cant remember which worked better, but I also dedomed one using a mixture of gasoline and acetone. Pretty much trial and error, but I never touched the dome or the glue with anything because I didnt want to kill the bond wires.

acetone works great, you just need to be much more patient than 40 minutes

also, goes faster if you take the silicone off the flat edge around the dome with a razor before soaking

don’t pull it off…it will float off

I have to ask. Whats led seal?