Soldering iron that won't melt? - Page 1
Forum section: electronics / beginners

author: Jookia
author_rank: Contributor
timestamp: August 30, 2019, 11:14:38 am
content: I bought my first soldering iron (a Duratech TS-1620) in 2017, and I've been using it to practice soldering now and then since.Today it's handle melted as I left it it on its stand for a few minutes while I tried to place a through-hole resistor.I'm not exactly sure why this happened. Maybe the stand got too hot. I've attached some photos if anyone's interested.But evidently the soldering iron was not able to cope with this task.Is there any other soldering irons in Australia suitable for a beginner that can be left on in its stand while placing components?Am I doing something wrong? It's a little annoying to have to wait a while for it to heat back up.

author: Ian.M
author_rank: Super Contributor
timestamp: August 30, 2019, 11:34:05 am
content: The Duratech TS-1620 is advertised as being temperature controlled so what probably happened is the temperature controller failed shorted leaving the element on 100% of the time.Lets see a picture of the stand it was in at the time to eliminate the possibility that you had done something stupid to it or used an inappropriate one.If you got the iron from an Australian supplier, I'd contact them and see what they can do as I'm sure they don't want theAcccall over them calling for a compulsory recall.If you imported it yourself you are probably S.O.L.

author: Jookia
author_rank: Contributor
timestamp: August 30, 2019, 12:03:11 pm
content: It's likely that it's my fault then if it's a defect: I burned off some of the insulation of the cable between the station and soldering iron in 2017 and wrapped it with electrical tape then thought nothing of it since everything worked. I think I also had some power draw issues once when I used a sketchy power board too. I'm surprised it would melt itself at its own temperature, unless it decided to draw as much current as possible.I just wasn't sure if this was normal or something I was supposed to do when soldering. Here's a picture of the stand, it seems fine still.

author: Ice-Tea
author_rank: Super Contributor
timestamp: August 30, 2019, 12:12:01 pm
content: Just to keep its temperature, the iron will turn the element way down. Maybe 10-20% or so. So I'd say its fairly normal it would 'melt itself' if left @100%.

author: magic
author_rank: Super Contributor
timestamp: August 30, 2019, 12:12:30 pm
content: Nothing to do with cables or mains outlets unless you connect it to wrong voltage (like a 110V unit at 240V).

author: Ice-Tea
author_rank: Super Contributor
timestamp: August 30, 2019, 12:17:29 pm
content: ... but he mentioned the cable between station and iron. You know, the one that carries the temp sensor information..

author: Zero999
author_rank: Super Contributor
timestamp: August 30, 2019, 12:40:41 pm
content: It looks suspiciously like an open loop phase controlled soldering iron, i.e. just a lamp dimmer connected to a heating element. If so, it will have no feedback, so will cool down or heat up a lot, depending on what it is soldering i.e. how much heat is being sunk.Does the brightness of the LED change, as the knob is adjusted by any chance? If so, it's definitely phase controlled.I have one. It's fine for soldering small components, but not much else. Set the temperature so it just starts to melt the solder and not much more.In the long term, I recommend getting a proper temperature controlled iron.

author: Jookia
author_rank: Contributor
timestamp: August 30, 2019, 12:55:20 pm
content: Someone else did a bit of a tear down of the station itself but there's no pictures:https://www.eevblog.com/forum/beginners/duratech-ts-1620-soldering-station/It may be an older revision however.The brightness of the LED does change as the knob is adjusted, but it's very bright to begin with and I didn't notice until I looked just now.Would it even be possible or a good idea for the iron to report its temperature back given it only has a positive and negative wire to it?What proper temperature controlled iron would you recommend? Is there a list somewhere?It would also be nice to have one that doesn't have exposed wiring inside like that.

author: Rerouter
author_rank: Super Contributor
timestamp: August 30, 2019, 01:01:41 pm
content: Had one of those at my work when I started, they are very painful to use compared to even the plug in irons, as at least those tend to hold a somewhat consistent temperature due to the thermal mass.A Hakko 936 clone would be the next step in the right direction, with an actual Hakko 888 as being the norm for me these days. but the clone of the earlier model is a lot cheaper for a beginner.

author: Ian.M
author_rank: Super Contributor
timestamp: August 30, 2019, 01:04:35 pm
content: The stand looks OK and original although as there have been several stand design changes, I cant be certain.Also, I couldn't find any internal photos of the base unit. Please open it and take some, as it would be interesting to know for certain if the iron is an isolated low voltage one with a transformer or SMPSU in the base unit, or if its got a mains voltage element, in which case making the handle out of a thermoplastic would be a critical safety flaw as any overheat would risk leaving live conductors exposed.If its confirmed that it isn't a proper temperature controlled iron, I would be unhappy if the supplier offered an exchange - hold out for a refund or if they have a better model, or other stuff you want, store credit.@Jookia: Thanks for that link.

author: Jookia
author_rank: Contributor
timestamp: August 30, 2019, 01:25:37 pm
content: Here's a photo of inside. Yes, there was a large unconnected piece of metal to make it feel heavy.Edit: Uh, does this mean I had mains voltage isolated by just electrical tape?

author: Zero999
author_rank: Super Contributor
timestamp: August 30, 2019, 02:27:40 pm
content: Yes, it's just a lamp dimmer. If you looked at the other side of the PCB and reverse engineered it, you'll find it's a standard lamp dimmer circuit, consisting of a TRIAC, DIAC, potentiometer and a couple of resistors and capacitors.The weight is essential to stop it from tipping over, when the soldering iron is in the stand.The soldering iron itself runs off the mains voltage, so insulating the cable with electrical tape is a bad idea. The entire cable should be replaced, preferably with a heat resistant one. Indeed the first thing I did with mine was replace the crappy PVC cable, with silicone one, before I got the chance to burn it.

author: Ian.M
author_rank: Super Contributor
timestamp: August 30, 2019, 02:48:41 pm
content: Quote from: Zero999 on August 30, 2019, 02:27:40 pmBit late for that now.The handle should *NEVER* have melted like that, exposing live connections, as that's a major electrical safety fail. It should either be made of a thermoset plastic that can't remelt, or there should be a thermal fuse on the back of the mounting flange that blows before it reaches the handle melting point, or the connections should be touch proof even with the handle missing. Therefore I believe you have a good case that the device was potentially unsafe and therefore 'not fit for purpose' at the date of purchase.N.B. IANAL nor qualified to do electrical inspections, especially not in Australia.

author: ArthurDent
author_rank: Super Contributor
timestamp: August 30, 2019, 03:53:19 pm
content: There are a lot of similar irons and lots of rebranding so the name and model doesn't mean that much. Here is a photo of my base that has the same blue plastic case but a different dimmer circuit board and a connector so the iron itself can be unplugged from the base.I have turned mine up to 100% to heat some solder joints that were probably too massive for this size iron and left the iron at full for some time with no problem. If your iron got hot enough to do the damage shown I would guess that there was some shorted sections in the heater and that allowed the iron to get far hotter than it could if set to 100% and working normally. This problem could also occur if you had a 120 volt iron like I do and ran it from 220 volts.In my photo you can see that the 3 wires coming from the iron are ground/earth, 120 volt low, and 120 volt high through the dimmer circuit, there is no sensor on either mine or yours. In my photo you can see a small heat sink on the TO-220 triac on the side of the dimmer board. Even if you had damaged the dimmer circuit when you melted through the wires and the board shorted the iron would only see the line voltage and should be o.k. at 100% power.If it makes you feel any better I'd bet it was a problem with the iron and you had nothing to do with the problem.

author: Audioguru again
author_rank: Regular Contributor
timestamp: August 30, 2019, 04:02:52 pm
content: The soldering iron is cheap, Chinese and maybe was never certified to be safe. If it caused a fire then your insurance company would laugh that you bought a cheap Chinese soldering iron. Claim denied!

author: Audioguru again
author_rank: Regular Contributor
timestamp: August 30, 2019, 04:06:53 pm
content: I forgot to say that my electrical utility company gave free compact fluorescent light bulbs to show consumers how to reduce electrical wattage. But reports came in that some dripped burning plastic. They were all recalled and replaced. They found that the Chinese manufacturer stole the safety certificate number from a competitor so these cheap ones were never certified to be safe.

author: Jookia
author_rank: Contributor
timestamp: September 01, 2019, 06:38:15 am
content: I'm going to ask for a refund from Jaycar, who sells these on their website and in the physical store I bought it at.There's no photos of the other side of the PCB, so here's one. I the flipped underside to match.I'm not sure which iron to buy next, but that might be a topic for another thread. An EEVblog episode comparing a Hakko and Weller soldering iron did a burn test on the cables showing how the iron can't burn through them. Is that a common safety feature?Though, with some Weller stations not having fuses it's a bit concerning how safe these things are.

author: Rerouter
author_rank: Super Contributor
timestamp: September 01, 2019, 06:47:30 am
content: your going to be more happy with the hakko, if cost is really a concern, an older hakko clone will still beat out the iron you currently have.

author: amyk
author_rank: Super Contributor
timestamp: September 01, 2019, 07:27:30 am
content: Quote from: Jookia on August 30, 2019, 01:25:37 pmThat is what electrical tape is meant to do, so not really a problem...You'll find even a 936 clones to be a significant upgrade from that iron. There are several cases where the triac failed shorted and the tip will glow red, but I don't recall anyone saying they melted the handle that way. For a cord that won't melt through, find one with a silicone cord.

author: Zero999
author_rank: Super Contributor
timestamp: September 01, 2019, 08:10:51 am
content: Quote from: Ian.M on August 30, 2019, 02:48:41 pmI agree. I think there's a fault in the element causing it to get too hot. A thermal fuse is a must, since any case material, be it thermoset or not, will present a fire/burn hazard once it gets past a certain temperature.Quote from: Jookia on September 01, 2019, 06:38:15 amYes, it's a lamp dimmer. The TO-92 package is a TRIAC and the little blue cylindrical component with axial leads is a DIAC. One of the capacitors will be for timing when the TRIAC fires, depending on the potentiometer setting, another capacitor might be as a ballast for the LED and the rest will be for RFI filtering. The inductors and transformer-like component, which is a common mode choke, again will be for RFI filtering, as phase controllers are noisy and can interfere with radio reception.Of course they should give you a refund. They should also stop selling such a dangerous PoS. Tell them they should investigate this further, before it burns someone's house down.I've had a good experience with Hakko. I have the US model and run it from a 110V transformer and it works fine, even though it's 50Hz where I live and it's designed for 60Hz.Quote from: amyk on September 01, 2019, 07:27:30 amNot really. It's never a good idea to insulate something with electrical tape. It's not so much of a problem if there's something else already providing protection against shock, such as a plastic or earthed metal enclosure or device is run at a non-hazardous voltage, but is completely unacceptable otherwise. Electrical tape peels far too easily. The adhesive is nowhere near reliable enough for anything safety critical. Just replace the whole cable, rather than splicing it.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 01, 2019, 10:31:01 am
content: I turns out to have the same internal "guts" as the one I bought from Jaycar some years back to use while I was fixing my Weller WTCP.That one had a base a bit like the older Wellers , but quite small.As soon as I saw the uncalibrated knob, I knew it wasn't really temperature controlled.I suppose you could use "weasel words" & say,"Well, you can control the temp with the knob", but that is seriously sleazy.In my case, I thought "It is what it is" & would probably be useable, was cheap, so bought it on the "like a fuse" basis that you buy most stuff these days-----If it dies, you throw it away & get a new one!Well, it was lousy, though I did a few jobs with it-------too hot for really small jobs, not hot enough for average work, only about one third of the control rotation gave enough heat to solder.It felt heavy, as if it had a transformer, which could maybe be salvaged, so I decided to pop it open, only to find my "transformer" was a weight, & the same cruddy little lamp dimmer as in the OP's one was inside.I would advise the OP to buy an old WTCP, but if they do, make sure it cycles on & off, as sometimes the Magnastat switch gets old & becomes stuck "on" making the iron run "full on" continuously.I've never seen a Weller melt its handle though!

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 01, 2019, 06:02:46 pm
content: Quote from: Audioguru again on August 30, 2019, 04:02:52 pmThis is just plain wrong. As consumers, our insurance companies cannot hold us responsible for evaluating the integrity or safety of products we buy. To deny a claim, an insurance company would have to prove you did something willfully negligent. Depending on the laws in your country they can sue the maker, distributor, dealer, etc.. Even a half-assed repair to the cord like the OP admits to would likely not get them off the hook. Not being pompous, I have wrapped more than my share of electrical cords with cheap tape or worse.

author: Audioguru again
author_rank: Regular Contributor
timestamp: September 01, 2019, 08:31:32 pm
content: I suspect that the manufacturer of that cheap soldering iron that gets too hot has no quality control and never tested it. They probably make 120V and 240V ones and got the heaters mixed up.

author: Jwillis
author_rank: Super Contributor
timestamp: September 01, 2019, 10:45:47 pm
content: Did you check the thermistor in the handle.They do fail over time .Although thermistors fail open circuit more often , there is a chance that they can fail closed circuit. Drift in the resistance value is the second most likely failure.Maybe check for possible short in the control circuit.

author: ArthurDent
author_rank: Super Contributor
timestamp: September 02, 2019, 12:18:32 am
content: Quote from: Jwillis on September 01, 2019, 10:45:47 pmThere is no thermistor in this iron. It is just a 'dimmer' circuit and there is no feedback to regulate temperature.

author: Jwillis
author_rank: Super Contributor
timestamp: September 02, 2019, 11:26:14 am
content: Quote from: ArthurDent on September 02, 2019, 12:18:32 amOh Ok thanks ArthurDent.So that black blob is just more melted plastic.

author: Jookia
author_rank: Contributor
timestamp: September 02, 2019, 11:30:06 am
content: I've been researching irons and it looks like I'm either going with a Hakko FX-888D or a generic 937D from eBay.What are the biggest differences between a generic soldering station like that and a genuine Hakko station?I'm still learning soldering, would I even notice the differences at this stage?Also yes, melted plastic.

author: Rerouter
author_rank: Super Contributor
timestamp: September 02, 2019, 11:35:54 am
content: Both will get you far, the 888's parts will last a fair bit longer in general, however my reference point is 20-100 connections soldered a day,For reference the 888 is still in pristine state after 3 years with this kind of workload, the clone needed a new tip every 4 or so months, and a new heater about once every year.

author: KL27x
author_rank: Super Contributor
timestamp: September 02, 2019, 09:09:30 pm
content: Jookia: ^+1 to that. I'll add some points from my own experience.Real 888 has a true 26VAC transformer, no sag at all under load, no matter the duty cycle, 24/7. This was a bump from 24VAC of the 936. Many of the clones might even be a bit less than 24VAC under load once the transformer heats up.Plastics are also not the same. China can clone the electronics very easily. If they want to make a handpiece that is as good as a Hakko, they have to buy the materials from Japan. They don't do that.Heater is another point. The generic clone heaters are not made the same way. The genuine Hakko uses a foil heater. The clones are wound wire under the ceramic shell. The genuine Hakko heater is made to tighter tolerance for a better fit and is made to last a lifetime, designed to remain completely sealed from outside atmosphere, indefintely.The genuine Hakko will probably last a lifetime with zero maintenance. The generic clones, you can expect 2-4 years of hard use before parts start failing. Heater will go. The entire handpiece can eventually just snap in half from heat cycling of the plastic. You can also expect the handpiece of most clones to become significantly hotter than the genuine during use.There are high quality chinese stations that are hakko compatible. Xytronics comes to mind.I have 3 888's and have been using them since 2008 or 9? I have had 1 X-tronics clone (not even close to the same as Xytronics!!), one eBay generic 936 clone, and a couple T12 clones. The genuine 888 outperforms them all. Even with just limited use, the X-tronics handpiece broke in half. The generic handpiece got really hot during use and I only used it once or twice before giving it away. The T12 clones are not half bad, but the 888 outperforms them in most ways in actual use, and in just everything except warm up speed from cold and maybe speed/ease of hotswapping tips. There is one main advantage of the cartridge tips, though. When doing a lot of high thermal joints in succession, the T12 cartridge clones can truck along without the handle warming up in the least.The cheapo clones serve a purpose. They are way better than an unregulated mains stick. You get a huge variety of useful tip shapes, either cheap clone or genuine Hakko T18/900M. And for a hobbyist, they can last longer than one's duration of interest, anyway. If the price is right and you don't solder a lot, then you can sacrifice some performance and comfort. But if you live in the USA, the genuine Hakko 888 is dirty cheap and is a really good deal, IMO. Having used cheap irons for many many years, one of the first things I used to look at when buying a station is the cost of replacement parts. Hakko replacement parts are expensive as hell, which was a bit of a pill to swallow. But under normal use, you will probably never have to buy a replacement part! The relatively inexpensive upfront cost (to US consumers, anyhow) is not an "inkjet printer marketing scheme" to get you to buy expensive parts. The 888 is actually built to last a lifetime.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 11, 2019, 08:45:28 am
content: Quote from: vk6zgo on September 01, 2019, 10:31:01 amI lied!------I found the thing "tucked away" yesteday, & it isexactlylike the OP's one!

author: Jookia
author_rank: Contributor
timestamp: September 18, 2019, 12:35:12 pm
content: Well getting a refund for the now taken apart and possibly broken more soldering iron without a receipt wasn't going to work. So I got the 937D+ from eBay for $46 AUD. I took it apart to make sure it wasn't going to melt, and it didn't look too bad.The joint between the ring connector that connects to the transformer, the primary side earth and secondary side earth cables looked a bit too sketchy for my tastes since the secondary side seemed to have only half of its strands soldered in (aside from not being crimped). So I bought a Hakko RED 20W soldering pencil for $32 and figured having some kind of branded iron that won't break is a good idea anyway. I used that to re-do the secondary side and joint with the primary side and ring connector.The Hakko RED has been working really well and not melting. It takes a few minutes to get hot, but that's not too big of a deal.I've left it in a stand and it hasn't melted which is great.I haven't used the 937D+ much, but it heats up fast which is nice. It has a big transformer and an input fuse too. Lots of tips too.I'm not too sure how accurate or well the temperature sensor or control on it is yet.Both have burnable cables, but it takes some effort and at this point I think I'm aware enough now to just not burn them.I don't think the 937D+ is going to melt being left in a stand. But I also have no way to check the actual temperature and compare it to what it says. Ideas on how to do this would be welcome.

author: KL27x
author_rank: Super Contributor
timestamp: September 20, 2019, 09:03:45 pm
content: Hakko makes a tip temperature tester. I believe it's called Hakko FG-100. It costs more than all your soldering irons combined.But there are many clones of this device that cost 10-20 dollars, and you will find them if you search "FG-100."

author: Jwillis
author_rank: Super Contributor
timestamp: November 21, 2019, 06:54:03 pm
content: Quote from: KL27x on September 20, 2019, 09:03:45 pmHave you or anyone used these Hakko clones? I want to get one but not sure as to how accurate they may be .Or should I just bit the bullet and get the original for around 200 bucks.

author: rrinker
author_rank: Super Contributor
timestamp: November 21, 2019, 07:10:51 pm
content: There's a cheap Weller like this, the give away is that the handle has a 3 prong plug that plugs in to the side of the base - ie, at least in the US, you could use it as a standalone uncontrolled iron. It's the same thing - just a dimmer switch. The price gives it away too, although for what most places ask for this model, I got my Xytronic which is a real controlled unit. And yes, even though my model (I got it some 12 years ago) was discontinued at least 6 or 7 years ago, parts are still available. Anyway, no idea if they sell in Australia. But there should be some decently put together options that don't cost an arm and a leg.

author: KL27x
author_rank: Super Contributor
timestamp: November 23, 2019, 07:16:36 am
content: Jwillis:I have a cheap temp tester. The reading is precise, steady, and repeatable. I.e., it is a good tool.Absolute accuracy/calibration? I dunno, and I don't care. I mean it's definitely in the right neighborhood. But I can't vouch for it beyond that, because I don't have anything to certify it against.added:Some readings are coming back to me. But take them with a grain of salt.I recall measuring 3x Hakko 888's at maybe 300C, and they all agreed to within maybe +-5C of the measured temp (at least when pairing the original iron that came with each station).I recall measuring the temp of my T12 clones to be a bit hotter than they were set to, by maybe15-20C ish.It's coming back to me, now... the Bakon was just about exactly 10C hotter than it was set to on its display. But the manual said to expect exactly this. So it was dead on. The other clone measured a tad hot, too, but I can't remember. Not much.That's not a lot of data points, I'm afraid. Also I don't know how sensitive the reading is to changes in temp of the housing or whatnot.My method of selecting was to find the cheapest one with shipping. It must have been $12-15, delivered.

author: SL4P
author_rank: Super Contributor
timestamp: November 23, 2019, 10:04:42 pm
content: That photo of Arthur Dent’s controller is nasty...The output connector to the iron certainly isn’t rated for mains voltage / isolation.