Kabelsalat
- Jul 5, 2011
- 198
- Joined
- Jul 5, 2011
- Messages
- 198
So today was a nice day, 10 degrees and a little windy. If it was a little warmer, the condition for de-soldering using heat gun would be perfect.
Ok, so this is about method for mass-disconnecting most or all components on a pcb board. Still testing out for finding best methods (today about preserving plastic sockets at the edge of pcb).
While standing with the heatgun in my hand working on a socked that simply refused to get off, I started to have a taught. Using a heat gun this way is less than ideal because it often isn't able to transfer heat fast enough, and when poor conditions it may take too long time for the solder to melt, causing the pcb to crack/smoke and the component itself accumulate more heat than it can withstand.
So I was thinking - what if, instead of using pure air flow, use super-heated steam? Steam (thus water) in comparison to air have much better capability to transfer heat. Of course, I don't have the tools nor the skills to create a boiler and pipe for releasing/spraying hot steam on a little area, at least in a safe matter.
Of course, safety must be the biggest concern of design. But if assuming that al safety problems are solved, you think such a method can be useful (i.e. more effective than heat gun) for mass-desoldering of components ?
Another concern I have is environment, because if using steam, then if working outdoor then the steam/water may drip into the ground causing some pollution. But, a heat gun will also provide some smoke going to the air from burning pcb board - so not sure what is worse. What do you think on this?
Anyway - compared to using solder iron, desoldering using heat gun have following advantages/disadvantages in my opinion:
Ok, so this is about method for mass-disconnecting most or all components on a pcb board. Still testing out for finding best methods (today about preserving plastic sockets at the edge of pcb).
While standing with the heatgun in my hand working on a socked that simply refused to get off, I started to have a taught. Using a heat gun this way is less than ideal because it often isn't able to transfer heat fast enough, and when poor conditions it may take too long time for the solder to melt, causing the pcb to crack/smoke and the component itself accumulate more heat than it can withstand.
So I was thinking - what if, instead of using pure air flow, use super-heated steam? Steam (thus water) in comparison to air have much better capability to transfer heat. Of course, I don't have the tools nor the skills to create a boiler and pipe for releasing/spraying hot steam on a little area, at least in a safe matter.
Of course, safety must be the biggest concern of design. But if assuming that al safety problems are solved, you think such a method can be useful (i.e. more effective than heat gun) for mass-desoldering of components ?
Another concern I have is environment, because if using steam, then if working outdoor then the steam/water may drip into the ground causing some pollution. But, a heat gun will also provide some smoke going to the air from burning pcb board - so not sure what is worse. What do you think on this?
Anyway - compared to using solder iron, desoldering using heat gun have following advantages/disadvantages in my opinion:
Pros:
- Easy to mass-remove components from PCB boards.
- Very easy to remove components with many pins from pcb, such as IC's and connectors.
- Very easy to mass remove smd components of any form or size from pcb.
- Doesn't "eat" solder iron tips nor pose wear and tear on soldering equipment.
Cons:
- 10 degrees Celsius is the lower practical limit. If lower temperature, the heat loss on other side of PCB cause it to take much longer time for the heat to melt soldering on both sides. The consequence is often burnt pcb (and thus a lot of smoke), pcb being very soft, pcb bulging out causing heat transfer to practically stop - and of course this means the component supposed to remove gets overheated.
- Very dependent on the pcb ability to transfer heat from one side to another. Two similar pcb with same component may behave completely different. One pcb board may be "nice" and make it easy to pull the component out while the other completely deny heat to transfer causing the solder to not melting (implies overheat, lot of smoke and to give up because by then the component are probably dead).
- Due to excessive amount of smoke and gasses, this has to be done outdoor, and it have to be some wind to ventilate the fumes.
- Components composed mostly of plastic are very prone to start melting before the solder is fully melted. Typical for wire terminal blocks, other connectors and relays.
- Easy to mass-remove components from PCB boards.
- Very easy to remove components with many pins from pcb, such as IC's and connectors.
- Very easy to mass remove smd components of any form or size from pcb.
- Doesn't "eat" solder iron tips nor pose wear and tear on soldering equipment.
Cons:
- 10 degrees Celsius is the lower practical limit. If lower temperature, the heat loss on other side of PCB cause it to take much longer time for the heat to melt soldering on both sides. The consequence is often burnt pcb (and thus a lot of smoke), pcb being very soft, pcb bulging out causing heat transfer to practically stop - and of course this means the component supposed to remove gets overheated.
- Very dependent on the pcb ability to transfer heat from one side to another. Two similar pcb with same component may behave completely different. One pcb board may be "nice" and make it easy to pull the component out while the other completely deny heat to transfer causing the solder to not melting (implies overheat, lot of smoke and to give up because by then the component are probably dead).
- Due to excessive amount of smoke and gasses, this has to be done outdoor, and it have to be some wind to ventilate the fumes.
- Components composed mostly of plastic are very prone to start melting before the solder is fully melted. Typical for wire terminal blocks, other connectors and relays.
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