Wow don't let your kids search on vacuum pump on eBay.

 

This is the one I have that I like the most, though it's not the most durable:

I have one of those radio shack ones with the red squeeze bulb too, and the idea is good but it doesn't seem to have the same heat capacity as the one I linked above. So it doesn't work well for me for anything that has a lot of copper in it, or for desoldering multiple pins in a row. It just doesn't stay hot. It could be a problem with my specific unit as I haven't tried a different one.

 

it doesn't seem to have the same heat capacity as the one I linked above. So it doesn't work well for me for anything that has a lot of copper in it, or for desoldering multiple pins in a row. It just doesn't stay hot. It could be a problem with my specific unit as I haven't tried a different one.

Everyone seems to be diss'ing the RS one, mine must be a different version as I am certainly not seeing the same results!
Max.

 

don't let your kids search on vacuum pump on eBay

Why not? I searched it and found all kinds of vacuum pumps. Nothing untoward there. Maybe my browsing history is different from yours ? ? ?

 

I really like the my Radio Shack manual vacuum pump, does a really good job.
I see you can still get them, ebay etc.
Max.

View attachment 170322

That is the one I use, Max. The problem is that those tips wear away far too rapidly. And I no longer have machine shop access to make more of them.

 

Why not? I searched it and found all kinds of vacuum pumps. Nothing untoward there. Maybe my browsing history is different from yours ? ? ?

Sort by lowest to highest price.

 

I have these (which have been mentioned)


and they work, sort of, but I would like to have the power of one of these:

in a small form like these

and could you design it so that it can be built it for $20

 

I have these (which have been mentioned)
View attachment 170354





in a small form like these

and could you design it so that it can be built it for $20

This is a good ideae but you would have to replace the tip somehow.

 

and they work, sort of, but I would like to have the power of one of these:

in a small form like these

and could you design it so that it can be built it for $20

Anyone have an idea of how powerful a pump you would need?

 

Don't know, but I have seen a number of conversions of small aquarium pumps to vacuums https://www.instructables.com/id/Vacuum-Pump-from-Aquarium-Air-Pump/, but they don't specify the pump power and they stress picking up SMT parts more than solder.

This one, https://hackaday.io/project/45998-p1-aquarium-to-vacuum-pump-conversion however, does, but it specified in millibars which I am too tired to figure out from whatever I know about barometric pressure. Also, he is not enthusiastic about the results (again, more appropriate for picking up SMT components than solder), but was optimistic that a more powerful one would work better.

The big pumps, like pictured give cubic feet per min CFM.

 

Don't know, but I have seen a number of conversions of small aquarium pumps to vacuums https://www.instructables.com/id/Vacuum-Pump-from-Aquarium-Air-Pump/, but they don't specify the pump power and they stress picking up SMT parts more than solder.

This one, https://hackaday.io/project/45998-p1-aquarium-to-vacuum-pump-conversion however, does, but it specified in millibars which I am too tired to figure out from whatever I know about barometric pressure. Also, he is not enthusiastic about the results (again, more appropriate for picking up SMT components than solder), but was optimistic that a more powerful one would work better.

The big pumps, like pictured give cubic feet per min CFM.

Yeah and the big ones are expensive. The cheapest at Harbor Freight is $95. They have a version to evacuate AC for around $20 but it looks really bulky.

 

One source of vacuum pumps that is cheap is in used medical appliances. In many cases even the ones delivering pressure have a pump that has an accessible suction port. I have recovered two like that, one is indeed quite bulky, the other is fairly small. The challenge with solder sucking is that the flow rate needs to be quite large, and the flow must start quickly when wanted. So medium diameter hoses and valves located close to the point of use.

 

A compressor from a refrigerator or small window A/C is free.
Maybe a half gallon in size.
It will pull a vacuum of 30" mercury or better.
I planned on using the small air blower nozzle as a valve so it has time to accumulate vacuum and only used a little bit at a time or the air flow would cool the desoldering tip.

 

A compressor from a refrigerator or small window A/C is free.
Maybe a half gallon in size.
It will pull a vacuum of 30" mercury or better.
I planned on using the small air blower nozzle as a valve so it has time to accumulate vacuum and only used a little bit at a time or the air flow would cool the desoldering tip.

Assuming one has an old refrigerator or AC laying around.

 

Assuming one has an old refrigerator or AC laying around.

In my area they are often available, and don't forget dehumidifiers as a source of compressors, also ice maker machines. Of course there are a lot of places where any sort of free-lance recycling is forbidden by all sorts of laws. Avoid those biggoted areas, they are toxic

 

Vacuum pump:

https://www.kr4.us/vacuum-pump-12v.html

 

Vacuum pump:

https://www.kr4.us/vacuum-pump-12v.html

That pump could produce enough vacuum but it will need a tank to provide enough flow to remove solder. The whole secret of solder sucking is a fast rise in flow rate and the high flow rate itself. That is because the solder has to move while in the fluid state.

 

I wonder, and am just thinking out loud...you really only need to move the solder a few mm in the liquid state. Would it be possible, in principle, to combine the vacuum pump idea with the solder braid idea? We have probably all used that braid before. Something like sucking the liquid solder into the braid? Again, just thinking out loud.

 

I wonder, and am just thinking out loud...you really only need to move the solder a few mm in the liquid state. Would it be possible, in principle, to combine the vacuum pump idea with the solder braid idea? We have probably all used that braid before. Something like sucking the liquid solder into the braid? Again, just thinking out loud.

That would solve the need for a tank.

 

Again, I think it would be a lot more simple to just hook it to a household vacuum cleaner. I have one of those canister vacs that is pretty quiet. The only issue I see is you might want it running most of the time but I guess you could have a foot switch to turn it on and off.