100% Perfect dedome method

I really don’t know, but the type i used specifies that is is cellulose based, i guess that means some other types exist.

I have been really pleased with dedoming with thinner, i absolutely hate the gas stinkness the led+star gets when i have used gas before.

After the dedome in thinner, i wash it by placing it in a jar of 80% strength foodgrade ethanol, it is basically crazy strong vodka J), to get it clean from any thinner residue.

No smell on the star or led, good tint, clean & fast dedome :slight_smile:

The only thing i wonder is how long i can leave it & if it will get damaged if i accidentally forget it in thinner, i know Mitko said that when he left led’s for to long in acetone they got damaged, and i wonder if thinner could do the same.

Use common sense with any kind of Flammable solvent. Always use in a well ventilated area, Gasoline is fairly nasty also, as it contains benzene. I started using MEK to solvent weld Plexiglas, and it works very well. I haven’t tried it but I can imagine lacquer thinner would work fairly well for de-doming. My major issue with gasoline is the smell, as it is persistent.

I tried the heat method last night on one of my FF 102's. I warmed it up with my reflow gun until it got hot enough to pull the led off the sinkpad which was also soldered to the brass pill. Let it cool for 5-8 seconds the started lightly lifting the edge farthest from the bond wires. Then suddenly a chunk came off at a slight angle from the bottom at the phospor to just above the bond wires. Not what I was hoping for. Had to slightly trim down the high spot above the bond wires. I'll use gas or some other chemical next time or stay with the slicing method.

What is the point of dedoming? More light?

More throw. More powerful and longer reaching hotspot.

Alright so I’m trying my first dedome today after reading all of your guys’ comments. I decided to try the paint thinner method as I’ve heard that it takes a lot less time compared to waiting overnight. Some say as little as 2 hours for the dome to fall off. Well, I rigged up a hanging system for it and let it sit for 2 hours; no changes. 3 hours; no changes. I decided to see how “gooey” the dome felt, so I used my fingernail to scrape the top, and managed to get a little bit off, but not all that easily (I figured it would feel like soft butter but it still had a jelly consistency). I bought the paint thinner today from Home Depot, so I know its pretty fresh… should I let it sit overnight or am I doing something wrong?
Here is my setup


Not all paint thinners are created equal apparently. I left mine in for 2 days and nothing happened. I think we need to find out what the right type of thinner is to get.

I always slice of the dome with a new very sharp razor blade, about half off before i place it in thinner & most of the dome is usually off by 1 hour.

Does yours say cellulose based thinner on the can somewhere, because that is what i use & so far the only successfully quick dedomes i have read about here, using thinner have been of the cellulose based version, there are several, and not all work for dedoming leds.

Mine is mineral based, and can not find “cellulose” anywhere on the can. Here is what I purchased: 1-pt. Paint Thinner I guess I need to find one with cellulose…

Ok that explains it.

I read up on this cellulose thinners just now, it is NOT based on like i said, but a solvent that can dissolve cellulose.

I have tried finding this kind of thinner in the US for you, and it looks to not really be sold anywhere :~ I don’t think you guys use it at all.

In the UK & Europe you can find it anywhere & in Sweden of course it is readily available, but in US it doesn’t seem to be sold, strange.

If i where you i would just use some Gas, it works just fine it takes a bit longer & it is a bit harder to get rid of the residual gas smell afterwards.

I’ve been reading up on it as well. Short of getting a degree in chemistry, it is pretty difficult to find something exactly the same as what you have. I’ve been trying to read the Material Safety Data Sheet to figure out if Lacquer Thinner or Acetone are similar, but I’m no scientist.

I’d much rather find the correct solvent that would dedome my led within a timely manner, but I may have to do the gas method after all.

Anyone want a free can of half used paint thinner? :Sp

If you do what i did, slice of a part of the dome, a gas dedome goes quicker than if you do not.

One solvent i have seen previously recommended here, that sounds good & i think is a part of the chemicals that is in cellulose thinner is MEK.

It is unavailable here in Sweden, but it is readily available in the US
http://www.homedepot.com/p/Klean-Strip-32-oz-Methyl-Ethyl-Ketone-MEK-Solvent-QME71/100210976

It may even be that MEK is the active ingredient in cellulose thinner & the only reason we use the old cellulose thinner is because MEK is illegal here, it is some EU rule that makes it so.

The thinner/paint solvent I used is “industrial grade” and very cheap, about $3 for 1 litre. It is local store branded and doesn’t have much specs on it other than safety warnings…

It gets rid of all the dome in less than 3 hours and the remain are so soft that with a single blow from compressed air it removes almost all of the residue. Dedomed 3 XM-L2s with very good results so far (hanging upside down). I tired the razor method but I’m not delicate and patient enough, made the led go blue and burn after 10 seconds.

I will dedome a XP-L tomorrow with thinner method and post some pictures.

MEK does work very well and quickly. There is also a solvent called “MEK Substitute” sold in Hardware stores in the US. If all else fails, I imagine Acetone will work, I know it is great for dissolving Epoxy and Superglue. It is easily available, also known as Fingernail Polish Remover (don’t tell your wives I told you). Also just a tip; you can use a Qtip soaked in MEK directly on the exposed Phosphor without it rubbing off if you are gentle.

I just went out and bought a quart of MEK from Home Depot. It’s about 3 times the price of regular paint thinner (of which I have no need for either of them other than dedoming flashlights) so let’s hope it works! :party:

Spare a cup?

Let us know how well it works..

Well the MEK worked like a charm! Dome fell off within the first 45 minutes! Now at the 2 hour mark, and there is still a little left around the edges, so I’m going to let it sit a little longer.

Will post pictures tonight.

HD here I come!

Correct, all thinners are not alike not even close. You need to go to a Automotive/Industrial Supply or Painters Supply to get the GOOD stuff. Urethane thinner is unlike Lacquer thinner unlike Enamel (Imron) thinner ect. You can get it in Pints, Quarts, Gallon and 55 gallon drum. It cost more but its worth it, because it’s more refined and cleaner. Just ask anybody that paints cars if they buy their thinner at Home Depot? Heck they might let you have a cup just for the laugh??? Hmmm never thought of that?

Which one do I get?

Urethane thinner, Lacquer thinner, Enamel (Imron) thinner...