There’s an outdated saying about one thing being a “drop within the ocean.” That’s how I felt confronted with the prospect of changing a 12 V heated mattress on my printer with a brand new 24 V one. The outdated mattress had a pleasant connector assembled from the manufacturing unit, though I had changed the cable way back resulting from heating points with that individual printer. The brand new mattress, nevertheless, simply had naked copper pads.
I’m no soldering novice: I made my first solder joint someday within the early Nineteen Seventies. So I felt as much as the problem, however I additionally knew I wouldn’t have the ability to use my regular Edsyn iron for a job like this. Because the heated mattress is actually a large heatsink for these pads, I knew it might require the large weapons. I dug out my outdated — and I imply tremendous outdated — Weller 140 W soldering gun. Absolutely, that will do the trick, proper?
Properly, the Weller…
Clearly, it didn’t, otherwise you wouldn’t be studying this proper now. It might be it simply wanted a brand new tip — the factor is severely outdated, however it simply wouldn’t get the pads scorching sufficient for solder to really circulate. I did lastly get the wires to stay, however the solder joints have been so dangerous I couldn’t think about they’d maintain as much as fixed flexing.
I considered making an attempt a scorching air gun, however I made a decision I’d attempt one thing even totally different: flame. You may get butane soldering irons and torches from quite a lot of locations at many various value factors. Being low-cost, I picked up a Schneider-branded iron from Harbor Freight. The deal with has three attachments that nest. One collar simply shoots flame like a torch. A bit tube that matches the collar retains the flame away and also you get scorching air out the tip. That tube also can take a soldering iron tip.
We expect the promotional image on the Harbor Freight web site (see adjoining) is perhaps a bit optimistic. We don’t suggest this iron for doing floor mount work on a PCB. Nevertheless, I wanted a whole lot of warmth and, because the video beneath discusses, the factor places out nearly an excessive amount of flame. You’ll be able to mod it like [marshkid1] does within the video to make it put out much less, however that wasn’t my downside.
Seems, it isn’t as straightforward to get butane because it was once. In addition to that, you actually need butane made for this kind of software so it doesn’t clog. I settled on simply utilizing lighter refill butane and took my probabilities. Thus far, so good.
There was just one downside. Regardless of the vigorous flame, the solder simply wouldn’t actually soften sufficient to circulate. The tinning on the wire would soften and somewhat of the highest floor of the pads, however with your complete floor space of the PCB resistance to sink warmth, it was inconceivable to get a very good joint.
What to Do?
I contemplated heating the entire board up in an oven or with a scorching plate. I even considered soldering below an IR lamp. Ultimately, I used a two-pronged strategy. I eliminated the soldering tip from the iron and let it jet scorching gasoline over the connections. Then I used the Weller and I did lastly get moderately good solder circulate. The recent air alone, nevertheless, was not enough.
The joints aren’t the best-looking ones I’ve ever carried out, however it appears to be holding even below use. After all, I soaked every thing with rosin, tinned every thing, and made positive every thing was clear. There was simply an excessive amount of warmth capability.
I’ll but attempt once more, although it’s working properly sufficient for now. Possibly I want a kind of enormous automotive soldering irons. Or perhaps I ought to use the SMD warmth gun to preheat the joints. I’m positive I’ll get some issues to attempt within the feedback.