Soldron SL-938 review

I very recently purchased the Soldron SL-938 and this post contains all of what I experienced initially. The Soldron SL-938 specifications can be found on the Soldron website. You may consider it as more of a “first impressions” post than a complete review. I will definitely post more updates and probably a complete Soldron SL-938 review in the future.

As this was the first session, I did not quite try to push my soldering skills too hard. It takes some getting used to when it comes to using tools. So I set off trying to solder some usual 0.1″ pitch DIP headers on to a module so that it can be inserted into a standard breadboard. Also, I soldered an ESP-12 F module to its breakout board. The ESP-12 is not tough to solder but it is good enough to tell you if your soldering iron is decent enough for basic surface mount component soldering or retouching.

SL-938 Soldron digital temperature controlled soldering station review
SL-938 Soldron digital temperature controlled soldering station setup

The soldering station was packaged really well by the seller I purchased this from. I received it with a Soldron conical tip mounted. I put on a Hakko chisel tip and it fit in just fine. Not that the Soldron tip was bad, the issue with conical tips is that you need it only for components that are small in size (by small, I mean lead sizes of less than 0.5 mm). But since I had larger stuff to solder, chisel tip was just fine for the job.

What the usual 25W mains irons do

Just for your reference, here are some images of what actually happens when you use one of the cheapo 25W uncontrolled little irons working directly off the mains. I tried to solder some bulky DIP headers to a multi-layer board, the heat spreads out fast on those and sometimes solder just solidifies way too fast. The result? Absolutely unacceptable solder joints! Take a look:

Bad solder joint from cheap 25W mains soldering iron

Well, what you see above is an absolutely useless soldering job. The solder did not flow properly and got accumulated up on the top. Clearly, it was too thick to be able to enter the plated hole, which means the iron was unable to provide enough heat. The bottom side reveals an equally unfortunate condition:

Due to cold solder, solder did not flow to bottom layer

This will simply render your design defective and unable to work properly.

Soldering with the SL-938

However, on a similar board with multiple layers and good thermal dissipation, the Soldron SL-938 did a really good job. The fillets were precisely formed and the solder flowed right through very easily. The reason being that the SL-938 was really good at maintaining the temperature at the tip and prevent cooling of the solder before complete and free reflow. Here is what the joints looked like when soldered at 320 deg Celsius:

1mm spacing surface mount connector soldered with Soldron SL-938
The solder flowed uniformly and the joint turned out really good for the first attempt with the iron. I’m sure it will improve as I get used to the new iron and tip. And to compare with the above photo of DIP header, here is what a 0.1″ standard DIP header soldered with the Soldron SL-938 looked like:

DIP header soldered with the Soldron SL-938

As you can see here, the 0.1″ headers have a perfect conical shape of solder around them. This means that the solder cooled off properly and flowed really well around the pad and into the cavity. This is what you would expect from a good soldering setup.

So far, everything was good with the iron. The cleaning sponge is probably manufactured by Soldron itself and it was of good quality too. Same with the holder for the iron. Some other positives that I immediately noticed are:

  • Smooth temperature control knob
  • Good build quality of equipment
  • Fast initial heating
  • Responsive temperature compensation and powerful iron
  • Flexible cable that makes it easy to maneuver the iron freely

And the negatives I noticed are:

  • Slight heating of the iron handle after 30 min of usage
    Not a big deal but may be uncomfortable if you use it often and for long sessions.
  • No instruction of safety manual included.
  • No chisel tip !!!

That is all I have to share as the first impression or initial review of the iron. I like it so far and would definitely recommend it if you plan to work with components of about 1mm pin pitch. I have not tried smaller SMD components, but I will definitely post one more article along with photos of the work done.

Do leave your questions in comments below if you have any! 🙂

5 Responses

    • pratik

      Going over the surface of the 938, the plastic actually builds up static charge. So I guess the plastic is not really all that ESD-safe. You can have damage when you operate the machine and handle your sensitive chips.

  1. Debraj Deb

    I have the same soldering station, but the tip has blackened. Never ran it for longer time or above 310 deg C. Some website suggest that tap water may spoil the tip. What is your suggestion? Also, do you know of any source to procure a new tip (other than e-bay/ amazon)?

    • pratik

      Ohh, do not use the tips supplied with this iron. They don’t seem to work well at all. Use genuine Hakko brand tips. They will cost a lot, almost Rs. 500-1200 usually. The one I have has been working well for over a year (soldering every second day for 20-30 min at 310 C usually). Sponge and tap water for cleaning… but it is as good as new.
      I’ll add this in the article, recommended tips, etc. 🙂

  2. Ashutosh

    Nice review. I am a novice and finally found (at least till now) a professional review rather than the amazon customer ‘reviews’ or superficial videos! I was hoping you will have more reviews about irons or other tools here.
    I will write to you personally but wanted to post publicly for ithers too.

    For a once in a while basic use, which soldering iron can you recommend that is not expensive but is of decent quality and durability with replacebale tip? I will have general soldering and a rare SMD solder for a small fet timer circuit (but that would need a different tip).
    Also which multimeter for similar basic use?

    Do consider doing a post with product links for beginners about good soldering irons and multimeters available in India (or other tools). Amazon has Stanley and Amicikart currently as most popular items and Mastech multimeter, but the reviews are of no help with quite a few telling they are trash and others just singing praises. It becomes impossible to decide and one feels that if these are also likely to be bad, then why not buy local ones.

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