Make vs Buy Hot air tool

[GamerAndds]

Well to start off this post I would like to own a Hot air rework tool. My mind always thinks big however and I also want something like a hot tip solder sucker aswell.  O0

Now based on the forms from what Ive seen and read, a fan is the way to do the rework tool. People say a diaphram pump is too much air pressure. This is not much of a problem to get and access.

One of my minor questions is how is the sucking power for a fan vs diaphram?
Although the fan works good for a rework system how does it compare for a sucking type device. If the fan does not suck well, is it worth it to have a fan and diaphram? One for sucking the other for pushing air?

I have read many posts on homemade ones like this one;
http://www.dansworkshop.com/2008/03/smt-hot-air-pencil/
The problem with that one is I couldent use it for sucking the solder up as the tip is farr away. I need a way to heat up a tip and get it hot enough to melt solder then suck it up. Here is my plan right now.

In the base unit I would have all my power regulation (all the electronics) and blowing/sucking units within a sound isolating case. A solinoid would be in there to choose between a sucking/blowing through the single tube to the hand tip. A final fine filter and low pressure chamber would be included before the solinoid to prevent stray sneaky solder going into it and gunking it up.

The cable between the station and hand piece would consist of a highly flexible tube (somewhere around 1/4"?) probally silicone, and 3 wires- Heater, Temperature and common. Im thinking to use four wires instead because of resistance and problems- but I will see when the time comes.

The tip/handpiece would be the hardest part to make and design. I like the feel of my Hakko pencil tip and pretty much hate anything else. After hours of using the hakko hand piece my hand still feels good. But a few things MUST go in the hand piece. One of the major issues is a place to collect the molten solder before it cools. So a container has to go within the handpiece to hold the solder. This has to be able to be cleaned and emptied easily. Most devices use a spring to actually collect the hot solder and I guess it holds within this. Another filter is a must here to prevent anything from going in the tube and clogging it up. The thing is this also has to be able to push air out the tip.

The tip requires a section of its own. This is my biggest stumper, how to make a tip? I have old hakko tips that I can modify to maby make a tip, and I also have a small tip from a hot glue gun. The problem is how to heat these things. Do I say buy a hakko ceramic iron tip and modify it? Should I just get some nichrome wire and run it red hot wrapped around a copper tube? Any suggestions on this would help get this project started!

During typing this another Idea came up in my mind. The thought of housing the main unit on the ground and having a panel mounted on my desk to control this.

And of coarse theres the main question, is it all worth it. I love to design and make things- so unless its hundreds of dollars diffrent then I really dont care. Remember that not only will this be a rework tool but this will also be a solder sucker.

So yes this is 80$ http://www.ebay.ca/itm/New-YiHUA-852D-2in1-Rework-Solder-Station-Tool-Kit-with-Hot-Air-Gun-Iron-Stand-/331663427861?hash=item4d38ae4915:g:MdwAAOSw-jhULkxz

Nad this is 125$ http://www.ebay.ca/itm/S-993A-Electric-Vacuum-Desoldering-Pump-Solder-Sucker-Gun-110V-90W-/361490193277?hash=item542a7e9b7d:g:yNQAAOxyGStRq4Xq

So as long as I dont go over 300$ Im happy with it. In other words my budget is 300$. Another good thing about this is that its less space on my desk! Its really small and can hardly hold my old 20+ year old Ocilliscope and a project board.


Thanks for reading and hopefully commenting ideas below!   
                           Andre.

Youtube: TrainMasterMan

[KL27x]

A diaphragm isn't going to move enough air for sucking solder. You probably want a vacuum pump/motor. I made one with a 12V 1A vacuum pump that was rated for 16Hg, and it worked pretty well. It worked better when run at 24V, until I burned it out.

I never heard that a diaphragm moves too much air for a hot air tool. Mine goes down to almost nothing. The advantage of a fan is you can put it right in the handpiece, so you have a more flexible cord. The advantage of a diaphragm pump is that you can have a smaller handpiece. I guess a diaphragm can sustain higher pressure through a long hose... but a reasonably sized diaphragm pump won't move much volume of air.

[uncle_bob]

Hi

Fans (and even blowers) drop off quite fast when there is any back pressure. If you have a hose running to your tool, you have back pressure.

A hot air tool that is better than any you could build from scratch is $100 brand new. One that has a pretty good industrial pedigree (and may need a rebuild) is in the same vicinity used.

The one thing you get with a "pre made" approach is stuff like a range of tips and the like. You simply can't make those for any rational price. They wear out to fast ....

Bob

[GamerAndds]

Thanks Uncle_Bob and KL27x for your input.

A diaphragm isn't going to move enough air for sucking solder. You probably want a vacuum pump/motor. I made one with a 12V 1A vacuum pump that was rated for 16Hg, and it worked pretty well. It worked better when run at 24V, until I burned it out.

I never heard that a diaphragm moves too much air for a hot air tool. Mine goes down to almost nothing. The advantage of a fan is you can put it right in the handpiece, so you have a more flexible cord. The advantage of a diaphragm pump is that you can have a smaller handpiece. I guess a diaphragm can sustain higher pressure through a long hose... but a reasonably sized diaphragm pump won't move much volume of air.

Thanks for the input on your vacumm pump. I actually just got an old tire compressor that uses 12 volts. It also has a larger diaphram pump. Ill do some experimenting with these but I think as you said im going to go with the compressor and use a pvc tank. That should be able to store the negative pressure untill I push the button.

Do you think this pump could be used for a hot air system aswell? I will post a picture a little later!

Hi

Fans (and even blowers) drop off quite fast when there is any back pressure. If you have a hose running to your tool, you have back pressure.

A hot air tool that is better than any you could build from scratch is $100 brand new. One that has a pretty good industrial pedigree (and may need a rebuild) is in the same vicinity used.

The one thing you get with a "pre made" approach is stuff like a range of tips and the like. You simply can't make those for any rational price. They wear out to fast ....

Bob

So based on your comment a diaphram pump would be more appropiate?

I was lookng at some tips on ebay and found this.

http://www.ebay.ca/itm/A1003-Replace-Desoldering-Gun-Leader-Free-Solder-Tip-F-Hakko-817-809-808-807-802-/261328169134?hash=item3cd85f68ae:g:JRUAAOxygj5Sges~

I was thinking on making a mount and use them. Easy to obtain and change the tips then...

[uncle_bob]

Hi

A diaphragm pump is about the only affordable pump you can find for something like this.

As long as you are duplicating the Hako mounts, I'd also duplicate their hand piece and feed tube as well. The hand piece fits pretty well in your hand. The rubber stuff is reasonably immune to solder heat. The structure will hold a Hako heater which also works well.

Bob

[MickM]

Hi;
  I bought a BK5000 rework station then later a BK4000 desolder station from these guys:
https://www.circuitspecialists.com/soldering-equipment

They also sell spare parts, so you could start there.

Mick M.

[GamerAndds]

Hi

A diaphragm pump is about the only affordable pump you can find for something like this.

As long as you are duplicating the Hako mounts, I'd also duplicate their hand piece and feed tube as well. The hand piece fits pretty well in your hand. The rubber stuff is reasonably immune to solder heat. The structure will hold a Hako heater which also works well.

Bob

Thanks Uncle_Bob.

Hi;
  I bought a BK5000 rework station then later a BK4000 desolder station from these guys:
https://www.circuitspecialists.com/soldering-equipment

They also sell spare parts, so you could start there.

Mick M.

And thank you Mick M.

Thanks again for the input. I looked at the site you showed me Mick and I almost instantly ordered the heater and tip! I stopped myself though and put it on the list of things for my project.

https://www.circuitspecialists.com/c005a.html
https://www.circuitspecialists.com/302092.html

Its so cheap and there but Ill hold off till I price everything else.

I have some pictures here of the diaphram and compressor pump i have here. I was thinking on having two tanks- one for pressure and one for vacuum. Basically a solinoid valve would change between suction or vacuum, then in the main unit or hand piece another valve would turn it on or off. What to you think about the pumps? My figer shows the head size of the cylinder.


Thanks!

[GamerAndds]

Here is the diaphram I have... The one way valves are shot though.

[uncle_bob]

Hi

A diaphragm pump is about the only affordable pump you can find for something like this.

As long as you are duplicating the Hako mounts, I'd also duplicate their hand piece and feed tube as well. The hand piece fits pretty well in your hand. The rubber stuff is reasonably immune to solder heat. The structure will hold a Hako heater which also works well.

Bob

Thanks Uncle_Bob.

Hi;
  I bought a BK5000 rework station then later a BK4000 desolder station from these guys:
https://www.circuitspecialists.com/soldering-equipment

They also sell spare parts, so you could start there.

Mick M.

And thank you Mick M.

Thanks again for the input. I looked at the site you showed me Mick and I almost instantly ordered the heater and tip! I stopped myself though and put it on the list of things for my project.

https://www.circuitspecialists.com/c005a.html
https://www.circuitspecialists.com/302092.html

Its so cheap and there but Ill hold off till I price everything else.

I have some pictures here of the diaphram and compressor pump i have here. I was thinking on having two tanks- one for pressure and one for vacuum. Basically a solinoid valve would change between suction or vacuum, then in the main unit or hand piece another valve would turn it on or off. What to you think about the pumps? My figer shows the head size of the cylinder.


Thanks!

Hi

With a diaphragm pump, you don't need a tank for pressure. It just runs all the time. The normal way to switch is with ... err .. a switch. Turn the knob and the hose hooks to the other side of the pump.

Bob

[KL27x]

I suppose he's interested in the vacuum tank in order to increase the burst air flow for the desoldering iron part of the project.

A diaphragm pump is like a worm gear motor. Lots of torque but low rpm.

[promacjoe]

my hot air desoldering station uses a diaphragm pump, and a pressure tank. This tank is used like a capacitor, it smooths out the pressure going to the hot air gun.

unfortunately, most diaphragm pumps are Designed for pressure. And are not suited for vacuum applications. In fact, depending on the type of diaphragm pump you have, using it as a vacuum pump could destroy it, or at least shorten its life. you need a vacuum pump. Not a diaphragm pump. And it needs to pull between 18 and 22 inches of vacuum to work correctly. a higher vacuum will also work but should not be needed.

A vacuum tank also works like a capacitor. It smooths out the vacuum, so a strong steady vacuum is applied. vacuum tanks are easy to find. although it has gotten to be rare, Pretty much every Car/Truck that uses vacuum actuators for the air-conditioning/heating system has a vacuum tank.

[GamerAndds]

I suppose he's interested in the vacuum tank in order to increase the burst air flow for the desoldering iron part of the project.

A diaphragm pump is like a worm gear motor. Lots of torque but low rpm.

Yes, im intending to use the tank as storage. I plan to have a switch on the unit. When I switch it to vacuum mode the pump will come on and pull a vacuum in the tank, then trip out. Maybe I could get a couple sucks out of it before the pump comes back on? I mean the sucks are just short bursts. I dont really know if this would be possible.

my hot air desoldering station uses a diaphragm pump, and a pressure tank. This tank is used like a capacitor, it smooths out the pressure going to the hot air gun.

unfortunately, most diaphragm pumps are Designed for pressure. And are not suited for vacuum applications. In fact, depending on the type of diaphragm pump you have, using it as a vacuum pump could destroy it, or at least shorten its life. you need a vacuum pump. Not a diaphragm pump. And it needs to pull between 18 and 22 inches of vacuum to work correctly. a higher vacuum will also work but should not be needed.

A vacuum tank also works like a capacitor. It smooths out the vacuum, so a strong steady vacuum is applied. vacuum tanks are easy to find. although it has gotten to be rare, Pretty much every Car/Truck that uses vacuum actuators for the air-conditioning/heating system has a vacuum tank.

What is your station called? You said it does hot air AND desoldering?
I added a Picture of a small tire compressor- would this be suatiible to form a strong enogh vacuum? I was thinking about using this to be used as the vacuum.

Here is what I was thinking- excuse me for the crudity of the diagram...

[promacjoe]

Sorry, I misspoke. it's a hot air reworkstation. Not a desoldering station. It is made by GQ electronics, Model 5200. It uses a diaphragm pump for the hot air. And will not produce enough vacuum to use as a desoldering  station.

A diaphragm pump is normally designed to produce pressure. Not a vacuum.
it is designed to pull atmospheric pressure in, A very low vacuum, and compress that air to a high pressure normally up to about 100 psi.
 only specially designed diaphragm pumps can produce a vacuum without destroying themselves.

think of it like a rope. A rope is design to be able to pull tight. It cannot push. a diaphragm pump is designed to compress air. It is designed to push, And there is a plate that supports the diaphragm when it is pushing. When you try to use it as a vacuum pump this support plate no longer works. The diaphragm is normally connected to the center of this plate. When pulling a vacuum, this connection point is stressed, and eventually, beyond its normal ability to function, and can prematurely fail.

you need a pump design to pull 18 to 22 inches of vacuum. and it needs to be able to do so, quickly and reliably. Most diaphragm pumps cannot do it. And unless you want to destroy your soldering station, I don't recommend it.

you're better off with a piston or rotary vane pump. avoid using diaphragm pumps unless they are specially designed to be used as a vacuum pump.

[chris_leyson]

Have a couple of PACE ST-75s and they have either a piston or rotary pump, I don't know I can't tell by taking it apart. It's designed to be used either as a desolder pump or as a hot air rework station. Needless to say the pump makes enough noise to wake the dead so they don't get used at home, my house mates would lynch me. I'm considering using a small diaphragm pump from a hobby paint spray for the hot air rework.

[uncle_bob]

I suppose he's interested in the vacuum tank in order to increase the burst air flow for the desoldering iron part of the project.

A diaphragm pump is like a worm gear motor. Lots of torque but low rpm.

Yes, im intending to use the tank as storage. I plan to have a switch on the unit. When I switch it to vacuum mode the pump will come on and pull a vacuum in the tank, then trip out. Maybe I could get a couple sucks out of it before the pump comes back on? I mean the sucks are just short bursts. I dont really know if this would be possible.

Hi

Plan on having a couple of gallon tanks to get any real use out of them. Also consider that your valves need to be low leakage to make it work ... It's a lot of bulk for very little gain. A diaphragm pump (properly done) can be pretty quiet. They are dirt cheap so the cost of the tanks will buy you several new pumps.

Bob

[GamerAndds]

Have a couple of PACE ST-75s and they have either a piston or rotary pump, I don't know I can't tell by taking it apart. It's designed to be used either as a desolder pump or as a hot air rework station. Needless to say the pump makes enough noise to wake the dead so they don't get used at home, my house mates would lynch me. I'm considering using a small diaphragm pump from a hobby paint spray for the hot air rework.

Thanks for the info. Im thinking of mounting them in a box to mask some sound. The pump would be isolated from the box and the box from the frame. Hope fully it will be quiet as im usually the first one up....

I suppose he's interested in the vacuum tank in order to increase the burst air flow for the desoldering iron part of the project.

A diaphragm pump is like a worm gear motor. Lots of torque but low rpm.

Yes, im intending to use the tank as storage. I plan to have a switch on the unit. When I switch it to vacuum mode the pump will come on and pull a vacuum in the tank, then trip out. Maybe I could get a couple sucks out of it before the pump comes back on? I mean the sucks are just short bursts. I dont really know if this would be possible.

Hi

Plan on having a couple of gallon tanks to get any real use out of them. Also consider that your valves need to be low leakage to make it work ... It's a lot of bulk for very little gain. A diaphragm pump (properly done) can be pretty quiet. They are dirt cheap so the cost of the tanks will buy you several new pumps.

Bob

Thanks again for your responces to this thread of mine! I was thinking on using something like a 1- 1/2" PVC drain tube for my vacuum tank. THis would be equipt with a balloon (or similar substance) on the end. As negative pressure would form the balloon would get sucked into the pipe. This would hopefully () keep a relativly strong vacuum for most of its travel. (Like the picture below)

Sorry, I misspoke. it's a hot air reworkstation. Not a desoldering station. It is made by GQ electronics, Model 5200. It uses a diaphragm pump for the hot air. And will not produce enough vacuum to use as a desoldering  station.

A diaphragm pump is normally designed to produce pressure. Not a vacuum.
it is designed to pull atmospheric pressure in, A very low vacuum, and compress that air to a high pressure normally up to about 100 psi.
 only specially designed diaphragm pumps can produce a vacuum without destroying themselves.

think of it like a rope. A rope is design to be able to pull tight. It cannot push. a diaphragm pump is designed to compress air. It is designed to push, And there is a plate that supports the diaphragm when it is pushing. When you try to use it as a vacuum pump this support plate no longer works. The diaphragm is normally connected to the center of this plate. When pulling a vacuum, this connection point is stressed, and eventually, beyond its normal ability to function, and can prematurely fail.

you need a pump design to pull 18 to 22 inches of vacuum. and it needs to be able to do so, quickly and reliably. Most diaphragm pumps cannot do it. And unless you want to destroy your soldering station, I don't recommend it.

you're better off with a piston or rotary vane pump. avoid using diaphragm pumps unless they are specially designed to be used as a vacuum pump.

Thanks again Promac- I am planning on retrofitting an old piston pump to be used as the vacuum side. The diaphram will operate the hot air! I need to get new valves for it though- or just make them. THe same motor can run both of these devices on the same crank.

[uncle_bob]

Hi

Let's back up ... why are you putting the tanks into the mix in the first place? I've seen dozens of different designs for this stuff. None of them needed to go for tanks? It's more space and more stuff to clean / break / repair.

Bob

[promacjoe]

Diaphragm tanks have been used for well water systems for over 50 years. They help maintain the  water pressure. The problem is you have to have air pressure on one side of the tank diaphragm, and water on the other side. The air pressure is normally supplied by a bicycle pump. You pump it up to the pressure you need. The reason this is necessary is water does not compress. They're not much good for air pressure or a vacuum, Since air does compress. if you need a vacuum tank don't waste your time with a diaphragm/balloon. You will still have the same air volume in the tank, with or without the diaphragm/balloon.

[MickM]

Hi;
   This is the desolder station that I bought.
https://www.circuitspecialists.com/bk4000.html

This is the "Gun" from it:
https://www.circuitspecialists.com/b1002a.html

The gun comes apart for cleaning, and you have to wet the sponge in there before use.
The nozzle inside diameter grows with age.
It also gets worn down from jamming into component leads, and cleaning

I have no connection with them, just been buying from then for years.
Great on handling returns/orders.

I think for the price it's a good deal.
It is however large, and the front panel has areas for the better models.
(blank display plate, connector for an iron?)
For some reason the online users manual is heavily redacted.

The BK5000 hot air rework station is discontinued:
https://www.circuitspecialists.com/bk5000.html
Seems they still sell it in Europe:
http://www.circuitspecialists.eu/soldering/desoldering-hot-air-rework/bk-5000-blackjack-solderwerks-hot-air-station-soldering-iron/

It's the same size as the BK4000, but slightly wider.
This seems to replace it:
https://www.circuitspecialists.com/hot-air-rework-soldering-station-csi900+.html
It's $94.50, digital - and cheaper too.

Oh and they have a free gift if you spend over $50.00:
https://www.circuitspecialists.com/free-gifts.html

Lastly the main page has a "Great Deals" link.
Sign up for the email specials.

That's how I bought mine, something like $50 off the 4000, plus the dvm gift.
(they charge postage for the weight of the gift at checkout).

Mick M

[GamerAndds]

Sorry for the late responce- I`m working on a tube amp that need to get out....

Hi

Let's back up ... why are you putting the tanks into the mix in the first place? I've seen dozens of different designs for this stuff. None of them needed to go for tanks? It's more space and more stuff to clean / break / repair.

Bob

Diaphragm tanks have been used for well water systems for over 50 years. They help maintain the  water pressure. The problem is you have to have air pressure on one side of the tank diaphragm, and water on the other side. The air pressure is normally supplied by a bicycle pump. You pump it up to the pressure you need. The reason this is necessary is water does not compress. They're not much good for air pressure or a vacuum, Since air does compress. if you need a vacuum tank don't waste your time with a diaphragm/balloon. You will still have the same air volume in the tank, with or without the diaphragm/balloon.

Thanks Bob and Promac- Ill stay away from the tanks. My original thinking was using it to store a vacuum for a few sucks before the pump would have to come back on to replenish the tank (around 6 sucks then the pump would trip in.). I thought this would reduce the overall noise that was generated by it- not having to come on everytime I use it. Even should the tank have a little leak the tank would just not do as many.

Hi;
   This is the desolder station that I bought.
https://www.circuitspecialists.com/bk4000.html

This is the "Gun" from it:
https://www.circuitspecialists.com/b1002a.html

The gun comes apart for cleaning, and you have to wet the sponge in there before use.
The nozzle inside diameter grows with age.
It also gets worn down from jamming into component leads, and cleaning

I have no connection with them, just been buying from then for years.
Great on handling returns/orders.

I think for the price it's a good deal.
It is however large, and the front panel has areas for the better models.
(blank display plate, connector for an iron?)
For some reason the online users manual is heavily redacted.

The BK5000 hot air rework station is discontinued:
https://www.circuitspecialists.com/bk5000.html
Seems they still sell it in Europe:
http://www.circuitspecialists.eu/soldering/desoldering-hot-air-rework/bk-5000-blackjack-solderwerks-hot-air-station-soldering-iron/

It's the same size as the BK4000, but slightly wider.
This seems to replace it:
https://www.circuitspecialists.com/hot-air-rework-soldering-station-csi900+.html
It's $94.50, digital - and cheaper too.

Oh and they have a free gift if you spend over $50.00:
https://www.circuitspecialists.com/free-gifts.html

Lastly the main page has a "Great Deals" link.
Sign up for the email specials.

That's how I bought mine, something like $50 off the 4000, plus the dvm gift.
(they charge postage for the weight of the gift at checkout).

Mick M

Thanks Mick-
Once again I was tempted to buy that right away. The only thing is I think im going to hate that kind of hand piece-

Just a sub questoin- how does the desoldering gun work with boards that have the leads bent all the way over?

[MickM]

"Just a sub questoin- how does the desoldering gun work with boards that have the leads bent all the way over?

Not well.
They usually do not have enough solder on them to get a good flow.
I add some to the side of the tip, then raise it and trigger the suction.
Wiggle the tip and jam it in,and keep the suction going.
This of course is stupid as it wears out the tip fast.

You can just heat it and wiggle an exacto knife blade under it first to bend the leads up.

The thing works great for regular 1/16 fr4.
DIPs come right out, or with a gentle twist of the xacto.

I am not sure if I mentioned this, but the pump is not continuous.
The gun has a button for the vacuum.
That's good because it is loud.

I have had both for a couple of years now, no complaints.

Mick M.

[KL27x]

My original thinking was using it to store a vacuum for a few sucks before the pump would have to come back on to replenish the tank (around 6 sucks then the pump would trip in.). I thought this would reduce the overall noise that was generated by it- not having to come on everytime I use it.

I figure the benefit would be to get higher peak air flow. Just because a portable tire compressor can achieve 250psi doesn't mean it can move a lot of air.

A desoldering station uses a vacuum motor with a high flow rate but it can't achieve much pressure. A portable 12V tire compressor is optimized to achieve high pressure at the expense of flow rate.

Electrical analogy: if a desoldering station vacuum motor is the equivalent of a 10V 1A current source, a portable tire compressor is a 100V 100mA current source. With a load (nozzle restriction to 1ATM) of 10R, the vacuum motor will produce 10W of power when you turn it on; 1A at 10V. It doesn't matter if there's a capacitor or not, because the output impedance matches load impedance. With same load, the tire compressor will produce about 1/10th that. (Because load is not matched, you can't utilize the entire 100V. Current output is fixed. So you get 100mA @ 10V).

But if you add a capacitor, the tire compressor would be able to achieve peak current of 10A @ 100V, for peak energy of 1000W, which is 100x more (peak) power than the vacuum motor can ever achieve for this specific load, and 1000x more power than the air compressor is able to achieve without the capacitor.

A 3mm nozzle open to atmospheric pressure is a severe load mismatch to a portable tire compressor. It will not be particularly effective. This would be sorta like using a 2000 psi hand pump to fan your face. A folded over sheet of paper would do this much more efficiently.

That said, I don't know how well a tire compressor will work to created a vacuum. Other posters have suggested that it might not work.

Blowing positive pressure air could also be effective to a degree. This blows solder all over the place, so it's probably only practical for salvaging parts or for simple boards. Or maybe to reclaim proto/stripboards. But you wouldn't need to buy/make a desoldering iron with a hole in the tip for pulling the solder. You would just need a little air tube to point near the end of a soldering iron and a foot pedal to open a valve. When lacking access to proper equipment, I have cleared large thru holes just by heating them with an iron and then quickly holding the board near my face to blow out the solder. With 60+ psi, this would probably work better than a vacuum desoldering iron, not considering the mess. At least you wouldn't have to clean the iron .

[uncle_bob]

My original thinking was using it to store a vacuum for a few sucks before the pump would have to come back on to replenish the tank (around 6 sucks then the pump would trip in.). I thought this would reduce the overall noise that was generated by it- not having to come on everytime I use it.

I figure the benefit would be to get higher peak air flow. Just because a portable tire compressor can achieve 250psi doesn't mean it can move a lot of air.

A desoldering station uses a vacuum motor with a high flow rate but it can't achieve much pressure. A portable 12V tire compressor is optimized to achieve high pressure at the expense of flow rate.

Electrical analogy: if a desoldering station vacuum motor is the equivalent of a 10V 1A current source, a portable tire compressor is a 100V 100mA current source. With a load (nozzle restriction to 1ATM) of 10R, the vacuum motor will produce 10W of power when you turn it on; 1A at 10V. It doesn't matter if there's a capacitor or not, because the output impedance matches load impedance. With same load, the tire compressor will produce about 1/10th that. (Because load is not matched, you can't utilize the entire 100V. Current output is fixed. So you get 100mA @ 10V).

But if you add a capacitor, the tire compressor would be able to achieve peak current of 10A @ 100V, for peak energy of 1000W, which is 100x more (peak) power than the vacuum motor can ever achieve for this specific load, and 1000x more power than the air compressor is able to achieve without the capacitor.

A 3mm nozzle open to atmospheric pressure is a severe load mismatch to a portable tire compressor. It will not be particularly effective. This would be sorta like using a 2000 psi hand pump to fan your face. A folded over sheet of paper would do this much more efficiently.

That said, I don't know how well a tire compressor will work to created a vacuum. Other posters have suggested that it might not work.

Blowing positive pressure air could also be effective to a degree. This blows solder all over the place, so it's probably only practical for salvaging parts or for simple boards. Or maybe to reclaim proto/stripboards. But you wouldn't need to buy/make a desoldering iron with a hole in the tip for pulling the solder. You would just need a little air tube to point near the end of a soldering iron and a foot pedal to open a valve. When lacking access to proper equipment, I have cleared large thru holes just by heating them with an iron and then quickly holding the board near my face to blow out the solder. With 60+ psi, this would probably work better than a vacuum desoldering iron, not considering the mess. At least you wouldn't have to clean the iron .

Hi

Your vacuum is limited by the pump technology and by the 15 psi max pressure the atmosphere provides. You don't need / want 0 psi vacuum in this case (stuff caves in).

On the pressure side, the diaphragm pump only goes just so high. Just as with vacuum, it has a pretty shallow curve of pressure vs volume. It does not "build up" pressure in the tank any more than it provides the same pressure to a properly sized / nice and long tube. A 250 PSI solder blow off is *not* at all what you want. The many KW to heat that stream don't make sense and a few PSI are all you need to get the job done.

Bob

[promacjoe]

It is never a good idea, To heat up a blob of solder, and then blow it Where ever it wants to go.  trust me, it will go everywhere that it can. Including any openings in electronic equipment. Which can cause a short. More than likely, this Hot solder will land on something important and damage it. It may not happen the first few times, but it will happen. With a vacuum, your containing the hot solder Using a filter. And It's much easier to clean up.

this same rule applies to metalworking and woodworking. You never blow the chips off your machine. You vacuum them off.

Remember, the item must be safe as well as functional.

Using the vacuum remove the solder =

using air pressure to blow it  anywhere and everywhere =

[GamerAndds]

Well I guess I shouldent have blown those metal chips off my drill press bed, eh promacjoe? 

Thanks Micky for info on that. It never dawned on me before. Right now im using a "solderpault" -the big blue suckers with a yellow cap but it broke (still operational but major speed/time disadvantage) and I just want to know if I sould invest in a new one or make this...

Now when you talk about vacuum pump do you mean high speed with impeller like devices?
How does the tube resistance come into play with this?

Bob- you bring up an interesting point- What is the requirements for vacuum in a tube? Will I need to get vacuum tube?
Say there is verry little nozzle restriction can I use any old tube- say like silicone fish tank tube?