Heat guns work great. I hope you don't take offense but there is a better way to do it, and I'll explain why.
The glue and braze used on Sun Sparks is nasty stuff to burn, and breath.
A heat gun vaporizes some of this material, so doing it in a well ventilated area would be highly advisable, but you can also use a fume extractor, the type that are used in soldering stations, which would do the same thing. When you heat up the braze, it melts and releases the heat spreader because you vaporizing some of the chemicals that allow the glue to work, you are also vaporizing small amounts of lead which you then run the risk of breathing. With a heat gun you have to apply heat for a long time, usually, before the heat spreader is released.
If you use a small torch, like the type sold in most hardware stores that screws on to the top of the small tank they use, you might be better served. You still have to do this in a well ventilated area, but with no chord to concern yourself about it works out better. Also, the open flame acts in a similar way as an after burner does in an incinerator. You are burning off most of the bad fumes/gases as you heat the heat spreader up hot enough to release from the CPU. Not only that, but it's much faster. It takes about 10 seconds of direct flame, which means less fumes, and less work/time. Hold the CPU with a pair of pliers, I would suggest something with a long handle so it doesn't heat up. Wear leather gloves because sometimes the braze splatters and will burn you quick, eye goggles, and an apron. Hold the CPU with the pliers, apply the torch flame to the corners of the heat sink and move around the outside, not the center. If you heat the center before the sides the entire thing sometimes will pop off and fly across the room. The sides is where it is brazed. Then lightly tap it against cement or maybe a cast iron pan, I used a length of railroad track.
In any case, removing the kovar heat spreader is smart smart smart and will allow you to command a higher price than otherwise.
Scott
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