XINHONGXIN XHX QY-309Bi SnBi solder paste - real!

Flashlight Modding and DIY Parts
1

After buying 2 “Sn42Bi58” wires (Mechanic, UYUE) which turned out to be fake I tried again. There was no other wire, so I bought a paste.

I run an experiment:
On the tip of my iron I put 2 blobs of solder paste, Mechanic SnPb and Auchans SnBi. I turned the iron on with the lowest temperature setting - 200 C.
Expected result:
Once the tip is heated both pastes are melted. Auchans is melted way quicker.
Actual result:
Once the iron stops heating neither paste is melted.
But if I keep waiting, Auchans melts.
If I wait much longer - Mechanic melts as well.

So really thermal control of my iron is quite bad.
I have no idea what was the melting temperature of Auchans. But it was clearly lower than that of Mechanic.

What else can I do to check if I got the real stuff?

ADDED:
I bought a TM-902C thermocouple.
After I set my iron to 180C I checked temperature - a bit lower than set, 171 C. Depending on the touched part of the tip, 171 was the hottest, ~150 coolest.
The iron has melted the paste with ease.

2

Use a stove top and IR temp gun instead as if you were going to reflow it?

I cant really answer your question but that should get you much closer to an accurate temp

3

heat up a bigger copper part like an MCPCB with iron
check temperature with IR thermometer when you see the Paste starts to melt

make sure the IR thermometer does not see reflective metal parts of the MCPCB, like using some tape or other stuff to cover it

4

Argo, product link?

5

I bought from
https://www.aliexpress.com/item/60g-Sn42Bi58-QY-309Bi-Low-Temperature-Lead-free-Solder-Paste/32805170614.html

That was the cheapest at the time. Though expensive compared to the fakes I bought before.

6

Thanks for this heads-up. May have to try soon, and my iron can go much lower in output temperature setting.

Had to find alternative seller links:

7

Good product, pricey but if the quality is high it shouldn’t matter too much.

8

tastes real to me

9

Suggestion for Agro: I prefer to properly name stuff and of course I believe it can be of a lot of help for related searches. I'd edit the title to include the actual product brand and name: (XINHONGXIN) XHX QY-309Bi.

10

You’re right, fixed

11

I bought a TM-902C thermocouple.
After I set my iron to 180C I checked tip temperature - a bit lower than set, 171 C. Depending on the touched part of the tip, 171 was the hottest, ~150 coolest.
The iron has melted the paste with ease.