Three options for heatsinking. The center one already has a drilled and tapped hole and screw. The other two - I can drill and tap them too. Which do you think is sufficient and which would you choose?
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The Black one has more surface area would be best.

 

The Black one has more surface area would be best.

Thanks. Do you think it will be a problem inside a sealed container?

 

A heatsink must be in "open" air for it to conduct its heat into the air that moves away then cooler air comes.

 

Been a long day but found time to bodge together the CC supply. Working great on the bench. Next phase is to put this package into a weather proof container and wire the LED's into the old fluorescent housing. CC output is 163.7mW at 19.4V. Regulator not showing signs of heating up on the bench but the LED sure got warm. Like a cup of coffee. I'll be busy for the next few days - helping in-laws this weekend. Tree stuff - you know.

A heatsink must be in "open" air for it to conduct its heat into the air that moves away then cooler air comes.

Will have to use PVC (white) and make the housing tall enough to allow for some convection. There's going to be some heat transfer between the inside air and the outside - I'd imagine.

 

"Have to use PVC"? Aluminum tubing would act as a heat sink easily enough. Circuit could easily be isolated or even insulated from the pipe. A flat spot near the end could be the interface internally to the LM317 and if necessary, a soldered nut on it's heatsink, but easier is if it's near an end of the pipe allowing builder to hold the nut as the screw is inserted. Than silicon is used to prevent moisture intrusion. End caps can be made water resistant, as can the holes for the wiring.

So the Aluminum tube becomes the heatsink, made the length needed. Many years for corrosion to ruin it. Even in open air.

Just thinking out loud.

 

Neighbor has some fence posts cut down scraps. Maybe I could use some of their cut-offs. Weld a cap at the top and plug up the bottom. Good thoughts. Thanks.