Case for multi XM-L2 DIY lighthead and heat handling

Hi,

I'm new in Candlepowerforums and in Dive lightning but have a lot experience on other lightling + electronics.

I'm looking to do DIY light for up to 40m dives and looking good openable lighthead. Looking something to hold e.g. 7pcs Cree XM-L2 U3 leds with 16mm aluminium base. Would use some of them with reflectors + lens but some without just to get a lot of flood light.

Looking something where I could glue glass on other side and have openable O ring sealed on other side to be able to change after dives. Just for light head, batteries would hold in separate canister.

I'm looking something general and cheap <50USD/EUR container in Finland. Like easily available that could be modified, from plumbing store. I have tried to look from FAQ and other but have not found yet enough info for this.

Also on heat dissipation, I've seen big aluminum blocks in DIY builds, will that be problem? I'm targeting something like 70W on my light and leds should handle 85deg celsius. Only underwater use.

Any help would be appreciated, if I get there I will post build pictures with heat camera info while testing + underwater pictures + video in next 4 months.

--
VP

Yes, 70W in a small light head is a HUGE issue when working with LEDs. You will have to have proper heatsinking, and I would recommend thermal overload protection in case it's turned on out of the water. I've heard of people burning up their cars when a light got turned on in the trunk.

Tnx for info, those things are probably all true you pointed out. I still somehow would like to plan/do it so that not to overdo the heatsink as in water there should not be problems. I haven't build anything that big so far, and it really is good to have also some kind of protection for overheating.

This is bit off topic, but this below 500W watercooled bike light shows that even small amount of water cools it well.
https://www.youtube.com/watch?v=hYxrpHTEEEQ

Any good hints or pointers how to easily have half ready lighthead? I don't have lathe that easily in use but it is possible. That is the thing I have found hardest to find info.