I've actually never used a preheater, mainly because of cost and the fact you need to have a rather large one to better ensure you can preheat just about any motherboard you will need to work on.
I actually saw a "hot plate" in a video by @Branchus, and bought one, but it came crushed (from the factory!), so I filed a claim, got my money back, and didn't risk buying another. Sad too because Bruce showed how the hot plate can be made hot enough to even remove components!
But I would agree that preheating a PCB and then using hot air would be the best approach. That's perhaps most important on vintage boards like the SE/30 where too much heat can cause delamination (bubbling where the layers start to come apart). Not sure if preheating prior to using hot air would prevent that in light of the age of the board, but it very well could prevent it.
Just checked out the JBC website and my eyes glazed over when I saw their larger sized pre-heater units were over $3,000. Yikes!
I actually saw a "hot plate" in a video by @Branchus, and bought one, but it came crushed (from the factory!), so I filed a claim, got my money back, and didn't risk buying another. Sad too because Bruce showed how the hot plate can be made hot enough to even remove components!
But I would agree that preheating a PCB and then using hot air would be the best approach. That's perhaps most important on vintage boards like the SE/30 where too much heat can cause delamination (bubbling where the layers start to come apart). Not sure if preheating prior to using hot air would prevent that in light of the age of the board, but it very well could prevent it.
Just checked out the JBC website and my eyes glazed over when I saw their larger sized pre-heater units were over $3,000. Yikes!