Ghetto Hakko 808

[jdcarpe]

Probably going to try this one out soon. Just an idea I had while browsing eBay for a Hakko 808 desoldering gun.

What if I am able to reverse the air flow on a small aquarium pump, so that instead of blowing air, it sucks air as a vacuum pump. Connect that using standard aquarium air hose tubing to my Radio Shack 45W desoldering iron (the bulb one), by removing the bulb and connecting the air hose to the metal tube. Add a momentary switch (foot switch?), so I can control the suction. Heat the solder joint with the iron, then actuate the switch to start the vacuum, thereby sucking the solder from the joint.

Think it will work?

[Leslieann]

I had the exact same idea for my RS iron too, I just haven't had a chance to dig out my pump.

As for the pump, most pumps aren't setup to suck, only pumpn and will lack the necessary fittings. I do know of one though, the Aqualifter.
http://www.amazon.com/Aquarium-Lifter-3-5gph-inches-height/dp/B001BOD9JI
These are meant to suck and pump both air and water, though not at a very high rate, which could be an issue.

Obviously, be sure and build a trap or you can/will destroy the pump.

[jdcarpe]

I saw a video on YouTube showing how to convert an aquarium pump into a vacuum, but that Aqua Lifter may be the one I want. Thanks for the tip!

Edit: Also just found this small shopvac from Home Depot. I bet this thing has some suction! Need to find a brass valve to step it down to the size of aquariumm hose, and to restrict some of the air flow. Built in trap! Also, I could use the pump setting to have a ghetto hot air rework air gun.

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100021998&categoryID=524502

[Michael]

For as much time you will invest in soldering, paying $175 for the 808 is worth it, I believe.

[jdcarpe]

Yeah, you're probably right. Might as well spring for the real deal.

[WhiteFireDragon]

I see a few problems with this. First, I think pumps are really designed to work only in one polarity to be efficient. When you reverse the flow, it might not work at all, or inefficient, similar to reversing the spin of a fan. Second, you'll have to find some way to add a filter system that will allow you to occasionally change out the filter. If you don't have filters, the solder dust will eventually wreck the pump. Even the 808 have small filters that you have to occasionally replace. Lastly, you'll have to get the proper tubing, otherwise attaching the ones that are come with the aquarium air pump will be melted when you attach it on your desoldering iron. You'd want something like silicone tubing, and those aren't the cheapest things. And you might have to figure out how to get fittings on there to attached the tubings.

Sounds like a lot of trouble at every step, but if you're up for the challenge, go for it!

[rknize]

The 808 is a V2.    It has two diaphragms driven by the crankshaft and the motor generates a lot of torque in order to drive them fast.  You need both volume and pressure (vacuum in this case) to make an effective solder pump.  Solder is heavy and likes to wick.  The RoHS stuff is even more stubborn.

The 808 is really effective for the price.  I desoldered over 50 caps out of thick, multi layer motherboards with it.  I have been very impressed.

[Leslieann]

I see a few problems with this. First, I think pumps are really designed to work only in one polarity to be efficient. When you reverse the flow, it might not work at all, or inefficient, similar to reversing the spin of a fan. Second, you'll have to find some way to add a filter system that will allow you to occasionally change out the filter. If you don't have filters, the solder dust will eventually wreck the pump. Even the 808 have small filters that you have to occasionally replace. Lastly, you'll have to get the proper tubing, otherwise attaching the ones that are come with the aquarium air pump will be melted when you attach it on your desoldering iron. You'd want something like silicone tubing, and those aren't the cheapest things. And you might have to figure out how to get fittings on there to attached the tubings.

Sounds like a lot of trouble at every step, but if you're up for the challenge, go for it!

Most of it's actually not a big deal.
For me, I already have the iron and the pump and most of the tubing needed. It's just a matter of (finding and) connecting the pump to the iron. As for the filter, a small canister could serve as a trap, but would slow down the initial syphon. A common inline aquarium air filter would work, just a matter of how long.

Another alternative though is using the pump to power a small vacuum chamber, and have valve to the iron.... yeah, getting overly complex now. LOL


I know I could easily build something that would work for well under $100, even if I had to pay for everything, but it would be clunky, and for as often as I need it, the bulb actually works fine.

[dorkvader]

I see a few problems with this. First, I think pumps are really designed to work only in one polarity to be efficient. When you reverse the flow, it might not work at all, or inefficient, similar to reversing the spin of a fan. Second, you'll have to find some way to add a filter system that will allow you to occasionally change out the filter. If you don't have filters, the solder dust will eventually wreck the pump. Even the 808 have small filters that you have to occasionally replace. Lastly, you'll have to get the proper tubing, otherwise attaching the ones that are come with the aquarium air pump will be melted when you attach it on your desoldering iron. You'd want something like silicone tubing, and those aren't the cheapest things. And you might have to figure out how to get fittings on there to attached the tubings.

Sounds like a lot of trouble at every step, but if you're up for the challenge, go for it!

Most of it's actually not a big deal.
For me, I already have the iron and the pump and most of the tubing needed. It's just a matter of (finding and) connecting the pump to the iron. As for the filter, a small canister could serve as a trap, but would slow down the initial syphon. A common inline aquarium air filter would work, just a matter of how long.

Another alternative though is using the pump to power a small vacuum chamber, and have valve to the iron.... yeah, getting overly complex now. LOL


I know I could easily build something that would work for well under $100, even if I had to pay for everything, but it would be clunky, and for as often as I need it, the bulb actually works fine.

Actually, having a pump/vacuum chamber might be the only workable "ghetto 808" design. One of the reasons for this (other than the ones WFD pointed out) is that most fans lack the static pressure necessary to move the required solder around (or even to make a vacuum.) It's not always in the datasheet, but look at the pressure graph for a normal fan. As the pressure mounts, it'll become less and less efficient, as it is operating outside its design and air will start to flow "around" the blades. Fans (radial or axial) are out of the question. (I ran into similar issues when I wanted to design a high velocity wind tunnel in my dorm room)

Now having a pump might actually work, as they're designed for pressure, but you still need to make sure there's "enough" pressure.

Another thing to consider for the grate or filter. This is important, and you can probably get away with metal, mainly because I imagine the solder will start to turn into a spray or aerosol. Such grates are used in some types of machines designed to make metal particles for powder injection molding (and rarely, ceramic powders too)

I don't know about the cost, but higher temperature plastics should work for the tube, at least up to the "grate". It's not the most flexible, but teflon would probably work if you can find it in the necessary diameter.

To address leslieann's case: Make sure that solder won't melt the tubing you have. Also make sure it won't melt (or worse: burn) the air filter.


Now I'm all for designing something cool like this (especially designing things out of spare parts that work!) but there are always hurdles.