Wonderway Sn42/Bi58 T4 Lead Free Solder Paste No Clean, 138℃ Melting Point (20g)

The low 138C melting point is genuinely useful for soldering heat-sensitive components. I have used this on several PCB rework jobs where I could not risk overheating nearby parts. The paste flows cleanly and produces bright, shiny joints without much residue. The no-clean formula means you can leave it in place without worrying about corrosion. The T4 grind is a good size for most SMD work. One tip: replace the plunger cap after each use to keep the paste from drying out. Overall a quality solder paste at a fair price.

Soldering is not something I am an expert at. This made repairing a ring quite simple. I found if remove the plunger and need and place the caps back on the syringe after use, the solder does not dry out. I have used it several times over the past month and it is still workable. The solder is quite versatile and a good product for the money.

This solder worked really well for my projects. It melts smoothly and flowed nicely, which made my joints clean and easy to solder. I also like that it’s lead-free — it gives me extra peace of mind when working in shared spaces. The thickness (Sn42/Bi58) felt just right for both small and medium-sized connections. Overall, I’m very happy with this solder and would buy it again.

Excellent stuff, good value as not very much is needed and pretty easy to use or clean up. I bought this to assist with removing solder on controller pcb's so that I could do stick swaps. I do not use this for the solder to hold the new sticks in place I use 63-37. What I use this for is to add a little to the globs of factory solder to help reduce the melting point as most use non leaded these days. If you are doing it for this purpose you do not need very much a small dot and you are good. Then just a touch of heat to melt the solders together and then remove, very easy and works great.

Imagine not having to have 4 hands and a fume hood. So easy to use. I took off 1 star just because it's not exactly "no clean". More like easier to clean.

I use a heat blowing device for melting my solder for custom circuit boards. I had an old brand of solder paste but it reached end of life where it became hard so I needed to get some other new one. This product worked great as a replacement for my old. There isn't much in terms of residue or issues with the solder sticking to the pins. A little flux and this paste and I am able to solder most things with my device. It has a lower melting point which is also nice. I think it's a great product and would recommend it.

Great repair kit. Avoided tossing an LED dog collar.

Works just ok

Worked great, the low melt temp really makes it easy to work with using hot air. Got some excellent solder joints with low effort on even the smallest SMD components i was testing with. It is fumes and mess free for zero cleanup and you don't need much at all to get a good solder joint. Very impressed and glad i went with this one.

Much of the new electronics now ships with lead free solder which works great but is less forgiving to thermal expansion and contractions over time and may require reflowing a component. This is perfect for the task as it makes the hobbyist capable of almost pro like repairs. The paste solder flux applies very easily with the syringe (make sure you recap it tightly) and is best flowed with a hot air solder gun. It will make clean repairs (maybe as not as easy as the video's), it is always good to keep a little bit of solder wick on hand for a clean job if you get too carried away. Do a bit of practice on scrap boards with components until you get the knack! I highly recommend this with a tube of 37 tin 63 lead and you are set for most repairs.

Dos the job

Help to avoid soldering bridge. Good

The demo video looked impressive, but one always wonders if the reality will be as good. I'm happy to say I had a very difficult SMD repair job and this soldering product solved my problem perfectly. Being able to low temp solder a big board full of devices like the example in the video wasn't my problem. In my case, keeping solder bridges out of some very close spaces at already damaged traces was the issue and on that score Wonderway performed excellently.