I can't take it anymore. This is 2007 and I am still trying to make do in a surface-mount world with the same type of soldering iron I used 30+ years ago, with the same crummy solder wick braid, with the same lousy results. No, strike that, WORSE results as now PCB pads are so small that the least little mistake with a soldering iron can destroy pads. I recently discovered the joys of using a $20 electric skillet from Target as an "electric reflow skillet" to ease in soldering boards full of SMT components, but there are times when this approach won't work, such as when dealing with thru-hole parts. Why in the hell would someone need hot air to solder thru-hole parts? Appearance! My boards full of SMT stuff look awesome because all the solder joints are shiny and perfect with no assymetry or discoloration, but all my thru-hole stuff is has splotches of carbon trapped in the solder, the joints are not always shiny (friggin' cold joints!) and there is usually a ton of sticky flux all over it. "Clean" solders have not helped much, so I experimented with SMT solder paste that I heated with an iron; not bad, but still imperfect. I have a project that is almost entirely SMT except for three display boards with 48 thru-hole LEDs, and I decided I needed to get a hot air station so that I could cleanly solder the LEDs so they would look as good as the rest of the board. I also occasionally need to remove SMT components non-destructively, either to reuse the part or reuse the pads it was sitting on, and as I said my experience with a soldering iron was poor. So, it was time to buy my first hot air station!
O... MAI... GAWD!! THE COST!! Even a n00b tool like me knows that Hakko is the name for hot air stations, but the average selling price is around $200! I found that the guys at Sparkfun were selling a Hakko clone for only $175 or so... not bad for a nice air kit and a decent soldering iron, but I started to think about the iron as less of a benefit and more of a way to drive up the cost needlessly. I have really nice irons that cost a lot and I have crappy irons I will carve plastic with, and this kind of iron isn't really going to fit in with either of those roles. So, I started looking for a station with ONLY air, no iron. I found that the only decent place to buy one was eBay, with at least 3-4 storefront shops always selling Hakko clones, so I began to shop around their wares.I settled on a Aoyue 850A for only $85 plus $16 for shipping. I Paypal'd my 101 bucks, waited a week or so, and got the goods. Notice the considerable similarity between that Hakko 850 in the upper left and my Aoyue 850++ on eBay? Astonishing, how great minds can think so alike. ;)
Out of the shipping box we were off to a modest start; the inner "retail" box was your typical nondescript Asian OEM special, just a step up from a white box. At least it spoke to some desire to be taken seriously, and was simple and factual. The unit was pretty well packaged inside the retail box, nested inside a well-fitting cardboard "eggcrate" that floated the whole thing a couple inches all the way around. The accessories were nestled in compartments in the top eggcrate, which easily lifted out to reveal the main unit and wand assembly, which itself was easily lifted out of the box using the nice solid handle on top. It isn't too often you find something that is well-protected yet easy to open, but this is yet another example of how some clever Asian OEM spent some time thinking about the most efficient design possible. With this much thought put in to the utility of the packaging I had reasonable hopes for the hot air station itself.
I connected the power cord to the back of the unit and plugged it in to the wall, and at this point by all rights I should have just turned on the power as that is my customary way of dealing with new devices... but something said "hmm... look around". I have no idea why I even thought to check, but on the bottom of the unit was a big screw that had its head painted red, and it didn't look like any of the screws holding the case together. I checked the instructions, and lost quite a bit of that utility respect for the Asian OEM that I discussed earlier; the docs were among the very worst "Japgrish" I have ever seen. I guess they spent more time on the eggcrate packaging than translation! They seemed to indicate that there was a retaining screw that needed to be removed, but it wasn't clear to me. I started to remove the screw but just as it was coming free it suddenly bound up sideways!! I removed the screw and I visibly saw through the screw hole that the INNARDS were shifting so I panicked and put the screw back! I checked the net quickly and found no similar screw on any Hakko. I then decided the only way to know for sure what was coming loose in there, and whether or not that was a good thing, was to open the case.
The unit seems to be well made and very cleanly thought out. While it was not a feature I was seeking out I am pleased to see this is something well within my capability to service when the day comes that something critical stops working. Most components are thru-hole, but often this is of necessity in order to handle the power that the pump and heater draw. I was somewhat surprised at the arrangement for moving air through the pump, what with the clear "fish tank" tubing running all over the top, but it all seemed to make sense so I moved on to the real project... finding out if there was a screw that needed to be removed, or was I badly messing up and unscrewing the motor from the housing? As you can see it is pretty easy to follow the big red screw, which is shown here in a backlit profile.
So, this screw DOESN'T hold the thing in place per se, so it MUST be that vaguely referred to screw in the farsically-named "documentation"! w00t! Interestingly, what seems to hold the pump in place is white nylon bands that run around the whole thing. OK, put the case back together again and let's move on.Once I got it all reassembled I thought about flipping the power on real quick, but again thought it through and decided I better have a place to put the blazing hot wand. A brief scan of the "manual" gave me the lowdown on installing the wand holder on the side, and with a Philips screwdriver, a few twists of the wrist and about 60 seconds I had a little wire rack installed. There are mounting holes on either side of the unit, but in my installation I wanted the wire rack on the left so that is what you see here.
... gawd, what I tool I can be! Well, nice to have confirmation of what I now already know, and it was fun to look around inside.
I attached the largest of the included nozzles (which I failed to show here, this is just the wand with no attachement), set the air and heat for 3.5 (don't know why, just seemed a good place on a rather odd scale of 0-8), and turned on the power. It purrs nicely! I have a friend with a desoldering iron like a jackhammer, so I was pleased this was so tolerable. I think I could put up with this for hours with no real complaint. I noticed the "heat" light was solid when I flipped the power on, and after maybe 15 seconds it started to dim and flicker, which I took to mean it was ready to go. No, I didn't read that in the manual... I gave up on the friggin' manual. From here on out it is all theory, anecdote and testing!I selected an old PCB from a CD-ROM drive for testing. I placed the board in my "electric reflow skillet" to confine the heat and avoid burning anything and proceeded to try to remove some of the smaller ICs. First one was a very small 14pin chip, then a similar sized 8pin chip. Both came up with very little effort, I just heated the area for about 20 seconds and was able to tweezer it away. The pads were left in perfect shape, with pretty much all the solder still on the pads.
I then tried what I figured would be quite a torture test; a very small plastic connector used to join flat flex cables (shown to the left). Much to my surprise it came off quickly and with virtually no melting of the housing! Again, the pads were perfect.I moved on to a semi-challenging quad package. I moved the nozzle around in a small circular pattern, and after 30-40 seconds I was able to pull it up with tweezers. Again, nice pads were left behind (shown here to the right). I keep saying that because my experience desoldering is typically using a soldering iron and braid... never EVER works quite right. This is amazing.
Next up was a quad socket for an EEPROM. I popped the EEPROM out, slowly orbited the nozzle over it, and after 45-60 seconds it came loose. This one concerned me, as I felt like I was smelling melting plastic the whole time, so I was tugging at it to try to get it up ASAP. As it turned out my concern was excessive, and the socket came off with very little damage. It is definitely resuable.Then I just went nuts and started pulling up pretty much every surface-mount chip and connector on the board! I have an art project I want to do that requires vast amounts of ICs as tiny tiles, so this was a good chance to get a bunch. In this image you will see a fairly meaty chip by itself along the right side of the skillet. This is (likely) a big motor controller, and had big heatsinky "pins" on it. This required a lot more time and heat, but it came up.
I have put about 3 hours on this thing, mostly removing parts but just to prove to myself that I could do it I also put a few down with some paste. All in all this thing is great! It remains to be seen if it withstands the test of time as well as a Hakko, but I can buy THREE of these for the cost of ONE Hakko! That's not quite "disposable" but damn close. It is solidly built, as I discovered when I needlessly disassembled it, and even servicable if you know what you are doing. Since the nozzles are Hakko compatible there is no shortage of tip styles or sources you can buy them from. I strongly recommend this tool for its price/performance.
(C) 2007 Don Stratton
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