Written by Kiriakos A. Triantafillou, Industrial maintenance electrician, Hellas.
YIHUA 8508D+ Hot air rework station review.
By Kiriakos Triantafillou ©2014 19/1/2014
What we have here is one of the latest rework hot-air stations which belong to the reasonably priced entry level category.
This actual model is one product which attracted my personal attention for personal use, by looking those pictures and specifications I did get the impression that this is right one for me.
Today this product review is going strip down the bolt impressions and to revel the absolute truth.
This station it does come with all the main features which I needed to have as:
Digital LED temperature meter
Ball type, air flow meter
Auto/manual (handle switch)
Automatic cooling down / shutdown function
This YIHUA 8508D+ is actually offered to ITTSB by BaumTronics that is a relatively new e-shop based in Estonia and is an authorized reseller of YIHUA.
Regarding this product review, the YIHUA brand is informed too, and the direct communication with them in China is relatively easy, what is difficult for them due their small size as business, is to actually offer directly any spare parts due the high transportation cost due their location in China.
Today by setting this 8508D+ under the microscope, what I am looking to discover is the all around built quality and how sincere is those specifications’.
For getting true credible measurements regarding L/Min I had to purchase a professional grade Air Flow meter, with this instrument at hand, now I am truly prepared for this review.
The supplied accessories are three air nozzles and one IC popper.
More specifically the supplied nozzles diameter is 10 mm, 8 mm, 5 mm.
The specific selection of sizes it did displease me, especially regarding the smallest nozzle.
It is well known that the 3 mm nozzle have the highest popularity because is a key tool for replacing electrolytic capacitors in multi layer PCB, and in my case I did purchased two of them separately from eBay.
Regarding additional pictures of the YIHUA 8508D+ and it carton packaging you may found them here.
YIHUA feels pride about using this new Samsung microcomputer processor PID with programmable temperature control technology.
Their precision software PID in cooperation with the hardware (temperature sensor) is capable for temperature monitoring and temperature corrections every 20 ms (microseconds).
Therefore this combination is capable to offer a significant benefit regarding temperature stability.
YIHUA on the 8508D+ did also another step ahead from the previews model 8508D, by using SMD technology in their printed circuitry boards.
This change it is supposed to offer an even greater life cycle to it.
One significant amount of pictures at the end of this review it does verify that in YIHUA assembly line they do a proper job.
Even me as electrician I could not find anything irregular, other than those soldered cables directly on the mains switch instead using proper electrical clips.
Regarding the aesthetics and the metallic housing, the over all quality is very good.
But I did spot light scratches over the acrylic windows of the air flow meter and the temperature meter.
I did remove those light scratches by using special scratch remover cream, but honestly this finding it did take away some of my enthusiasm about this product.
YIHUA received my note about this detail by a positive manner.
Therefore I am expecting in 2014 this to not be an issue any more.
In this part of my review we will actually talk about expectations.
My personal needs are limited at making:
a) High quality Heat shrink tubing
b) Removal of electrolytic capacitors from multi layer PCB
c) Reflow of common type IC’s with exposed leads
d) Large parts soldering / de-soldering, examples: replacing carbon brushes from power tools.
e) Soldering of large clips over cables which are serving in high current applications.
Therefore this review comes to answer in the question of how useful this YIHUA 8508D+ it can be found in the hands of an electrician.
With the default supplied nozzles, the heat shrink tubing is served well.
The adjustable temperature is the most valuable feature, which helps even inexperienced people to create properly made heat shrink tubing over cables.
The only requirement is to set up-front the suggested temperature for your heat shrink tube that you plan to work with.
By operating the YIHUA 8508D+ over PCB with the 3 mm nozzle I did get the feeling that the air pressure even in the lowest setting it is still somewhat strong.
I did talk to a local friend about that, who is a sales partner of expensive Rework-Reflow systems, and he did confirm my saying, and pointed out that he is now interested finding less powerful in L/Min stations, because they are more practical solutions for micro electronics.
What looks as totally undocumented by all manufacturers is the correct nozzle placement over the heating element?
By using plain logic it seems that you have two choices regarding nozzle placement.
a) All the way in: The heating element is fully covered and all Air flow passes thru by the nozzle.
b) Half way in: The nozzle by design has above the mounting point a 180 degrees opening, logically by leaving this opening uncovered it is expected the pressure in the end of the nozzle to drop further down.
Temperature is actually energy, and all electricians are aware of that and of how dangerous it is.
Therefore when you blast thermal energy over a surface, you have to do that by working slow, and giving time to this thermal energy so to make it job.
Lack of patience when working with multi layer PCB it can ruin them in several ways.
The sudden temperature change it can destroy thin printed circuit pads over printed circuit board, and even to cause PCB layers separation, which it looks like as the PCB it starts forming an air bubble.
Therefore my advice when you buy such a tools for delicate applications, is to also have a time clock and a K type thermocouple as supplementary equipment.
By testing the 8508D+ over a dead motherboard, it did a great job about parts removal and even about removing solder stacked in thru-hole pads.
Large parts soldering
I did not have any such project running in this two months that I reviewed the station, but by confirming that 8508D+ is capable to eject (with out a nozzle attached) a blast of air at 490 Celsius in the distance of two centimetre away, I got convinced that it does the job.
Possibly I am the first reviewer of out times who wanted passionately to discover all truth regarding that Diaphragm Pump.
The 8508D+ is marketed as 560W, 28 L/ Min.
When a marketing team uses a specification as key feature so to gain a market share, in this case I feel even eager to act as myth buster.
I did purchased a bright new Air flow meter which originally is to be mounted over machinery housing which it comes with small in diameter input/output points which is 100% compatible in diameter with the size of the silicon tubes which transferring the air from the pump.
Below there is images which any one can see and verify that I did everything properly, therefore today I am standing behind my findings by be 100% convinced that my measurement procedure is very accurate.
By connecting directly my flow meter over the pump, and by having the mechanical air flow valve all the way open with out been connected with the handle tube, the pump of the YIHUA 8508D+ managed to deliver just 14 L/Min instead of 28 L/Min according it specification.
The test was performed in a room temperature of 17 Celsius.
When questioned YIHUA ( before running this test) I did receive the reinsurance that YIHUA engineers they do run tests, and that their pumps is capable for 28L but they were unable to offer any documentation as data about the actual performance curve (Min to Max, L/Min) about this product.
8508D+ testing with the handle attached
Below are my actual measurements by setting the air speed knob in those eight positions of it total range.
Knob position … L/Min Flow meter … YIHUA Air flow meter
Position 1 = 9.5 L/Min …2.5
Position 2 = 10.0 L/Min …3.0
Position 3 = 10.5 L/Min …3.5
Position 4 = 11.0 L/Min …4.5
Position 5 = 11.7 L/Min …5.0
Position 6 = 12.8 L/Min …6.0
Position 7 = 13.5 L/Min …over range
Position 8 = 14.0 L/Min …over range
Those measurements have been taken by having the external air flow meter connected in circuit instead of the YIHUA Air flow meter.
After evaluating all those measurements I can only come down in very specific conclusions.
a) This YIHUA 8508D+ it is unable to deliver 28 L/min
b) Hakko suggests as minimum air flow for such systems the 3.5 L/Min, therefore the true 9.5 L/Min of the 8508D+ is far higher than that, and it is possible to displease the users who expect very low flow rate at the lowest air speed setting.
c) The end of the road with those 14.0 L/Min as maximum performance it can shown as enough (or not enough) only when someone will buy and use the very large nozzle parts which are coming shaped according large in diameter IC’s.
d) From a consumer point of view, it is unethical all those manufacturers of those hot-air stations to announce such untrue specifications, especially when there is just two or three manufactures in China for those pumps. Therefore I will have to currently stick to my personal experiences which are saying that there are no supreme pumps out there.
e) In the positive side of things, the pump which the 8508D+ comes with, it does run smoothly by making a very low noise, and by those observations I get the confidence that is not going to fail prematurely, that is even after the first year which the product is under warranty.
By this very simple test I wanted to verify that the temperature sensor in the handle of the 8508D+ it is acceptably calibrated.
By using my FLUKE thermocouple positioned stably two centimetre away from the heat element, and by using the FLUKE 28II multimeter as recorder, I did manage to record the below temperatures chart.
8508D+ / FLUKE 28II
200C / 220C
300C / 310C
400C / 410C
500C / 490C
Automatic power of at 103C (specification 100C)
Yes those are good results for my taste, from the other hand when YIHUA specifies +/- 1C stability I think that I am not capable to confirm that.
I did my tests with the air flow at max, my setup with the thermocouple shown the best stability to be somewhere between +/- 6C
Naturally the users guide it does mention in rough English that the thermal stability comes by fine adjusting temperature in combination with air flow, and you will have to wait until both parameters are met, before using it for a job.
Personally I did give to this system an 10 minutes run before taking my measurements, therefore I came as close as possible about making another one properly made measurement.
Every first-time owner of a low priced hot-air station has to face the same annoyances which in the end you have to accept and live with them.
The first problem is the unstable operation of the magnetic switch (inside the handle).
Usually it works normally the first time in setting the hot air station in operation, and after that this function works unstably or not at all.
Here it comes handy the auto/manual switch which isolates the magnetic switch and removes this annoyance from the equation.
The implementation of this magnetic switch design is rather poor, mainly because the parts behind it they are two simple bare metal pins which are facing its other in a close distance, as soon the handle gets warm or if the micro controller accepts constant triggering by those contact pins, their existence in the circuitry gets ignored by the micro controller.
One second annoyance caused by this lightweight handle, even with the weight of the silicon tube it is still extremely lightweight, you need to place the hot air station in such a position in which the gravity will pull down the silicon tube, and because of that the handle it will stay in place too (on the cradle).
The third annoyance could be the lack of having this external spring which protects the silicon tube from getting folded, which translates that the airflow stops and your heating element gets in danger.
Regarding this issue I made accidentally the discovery that the spring in those 3$ handheld de-soldering pumps have the perfect dimension so to be added at the top of the silicon tube (just by folding the spring over the silicon tube), and by adding it over the exit point of this silicon tube (metal housing) it really works great, and it does prevent it from getting folded.
In the positive side of things, the specific 8508D+ even by bringing along all those annoyances which most hot air stations have, it does come with small innovations too.
A good example could be the top handle which is made by rubber, and it is easy to completely remove in case that you need to place something at the top of it.
Or even the fact that the holes about mounting the cradle at the left or ride side, they are correct made regarding proper inclination.
Regarding safety, YIHUA writes in the user manual that this hot air station offer electronic protection against all faults.
a) Over temperature
b) Short circuit
c) Open circuit
d) Over voltage
And all those conditions are reported by a unique fault code on the display.
But they do not mention any details other than the code S-E which indicates thermal sensor damage.
The addition of real temperature switch about reading the true temperature of the handle, it is an also good to have and important feature.
By testing the temperature range with an external thermocouple and my Fluke 28II, this 8508D+ found as very honest, it did delivered 505 Celsius as Peak when the temperature were set to 500C which is the top of it capabilities.
Even in the beginning of 2014 this 8508D+ it does deserve the title of the most complete hot-air rework station regarding features at list on paper.
I am from the people who have the belief that analog controls are much preferable over digital, and also that a ball type flow meter is by far more trustful compared to digital ones.
I was researching the market of those items for over a year, and externally alike to 8508D+ there is only one model by another vendor.
Therefore I was had only two options to choose from by excluding the significant price difference among the two.
Mostly because my main consideration when shopping for tools is to buy quality.
The air flow measurement with the flow meter, it did load me with negative energy, mostly because this specification about the 28 L/Min it did influence my choice about selecting the unknown.
It is true that YIHUA is actually a small company and a new comer in this product range, therefore I was hoping that every offered specification is 100% honest, so this new comer brand to gain a wider popularity over other vendors.
From the other hand is not fair to through my darts yet with out measuring first the true performance of pumps coming from other vendors too, and this is my plan for the future.
After inspecting and testing this 8508D+ from hair to toes, it does gain the recommendation of ITTSB as entry level hot-air rework station.
And even the price point of 65.81 EUR (that is currently offered by BaumTronics), it is a true bargain price which justifies to spend even a bit more and buy also and a complete hot-air handle for the 8508D+ as spare part too.
It is a fact that a complete hot-air handle gets out of the factory in a lesser price than 10$, therefore the expectations for perfect operation of the magnetic switch they should follow the reality as is.
The heating element seems properly designed but I feel that is too soon to judge it build quality, for now I will stick to my tests results which confirmed that it does deliver the heating energy according to specification.
Regarding the 3 mm nozzle which is a true must have, BaumTronics informed me that it would be also included as standard from now and on.
I like to thanks Mr. Tarmo for his cooperation with ITTSB and about sponsoring this product review.
Estonia is part of the European Union and therefore at the top of the retail price there is only the additional shipping cost and no worries regarding customs clearance.
Suggestions by Kiriakos
YIHUA 8508D+ internals
YIHUA 8508D+ Air Flow tests
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