New SSRs! Trying to find a good heat sink, Can I mount both to one heat sink?

Well I got one set closer today to my eBrewery, as I purchased two DC triggered 45amp SSRs. They are mande by Opto 22 and I got two for $20 shipped so I couldn't pass up the deal. I realize that a 4500watt element only needs 21A, but that would give me room to grow, possibly 20+ gallon system in the future running two elements per relay.

Relay Product Page

My concern is the heat sink used, as they are rated for 45amp, does that mean if only using 50% of it's rating 21amp, would I not need as large of a heat sink? Also would it be possible to mount both relays on the same heat sink if it was large enough?


Squeeky

If it's a large enough heatsink. I would just mount each SSR to its own, just to be safe. I have a couple Heatsinks from old computers that I plan on using. I'm going to mount them similar to this guy with my SSRs on the inside of the box, and the heatsinks hanging off the back. That way I get plenty of open airflow without the need for fans.