all's well that ends well. if i ever have to do another one of these for some reason, i'm sure it will go much faster and smoother. but it wasn't bad honestly.
i used a knipex pliers-wrench with a rubberband as a board clamp because i have nothing else available:
i wasn't getting fast enough heat transfer with a dry (but tinned ofc) iron tip (used a 45° flat chisel type for good contact area). i didn't want to use solder because i wanted to leave the nice gold plating alone, and i wanted it to stay as flat as possible.
instead, i used hot air on the block from below. i left the potting on the underside of the board intact and used it as thermal insulation. aimed the air away from the switch and towards the potted components. worked fine, but i didn't perfectly center the emitter. only noticed after reassembling and seeing that it wasn't perfectly centered in the reflector. oh well. not worth it to redo it.
i dedomed the 519A sm353 (3500K) with a double edge safety razor blade. just did it freehand after reflowing. i gently sliced it off in about 3 slices. i did slice cutting instead of push cutting. tried to minimize stress on the emitter package while doing so, particularly normal stress. tried to make it mostly shear stress. i got the emitter from @azhu btw if anyone's looking for some.
i used noctua nt-h2 paste because i was impatient and didn't want to wait for shipping, but arctic mx-4 or Innovation Cooling Diamond might be be better choices (might last longer without drying out).
i removed the solder on the VCC pad and GND pads (by the screws). i diluted it with some eutectic Pb-Sn to lower the melting point and make cleanup easier, and then i pulled it with wick. then i added fresh Pb-Sn. this made it a little easier to re-solder the supply (especially the screws) at the very end.
new emitter installed and dedomed:
before reassembly, i chamfered the edges of the potting so it would slip into the milled recess more easily since it has to rotate into place.
i used a parallel clamp to press the bezel. worked well and gave me decent control:
beam shot:
left to right:
- sc64w hi (high cri 4000K 90+ XHP35 HI, bob)
- sc64c le (Nichia 219B R9080 sw35 3500K, bob)
- sc64c le (Nichia 519A R9080 sm353 3500K M400 L5 dedomed, me)
- d4v2 (Nichia 519A R9080 sm353 3500K dedomed, stock from hank)