Solder that won't solder

[ACharnley]

About 5 months ago I purchased 500g of solder on aliexpress, this stuff. It has lots of positive reviews.

1.8% flux.

**broken link removed**

I've come to use it today and it won't flow at all. I added Kingbo RMA-218 flux (which has always worked with other solder I've used) and still it won't flow.

The iron I've turned up to 220c, I can go higher but it might burn the coil out. The solder melts around the 180c.

What gives?

 

[tvtech]

About 5 months ago I purchased 500g of solder on aliexpress, this stuff. It has lots of positive reviews.

1.8% flux.

**broken link removed**

I've come to use it today and it won't flow at all. I added Kingbo RMA-218 flux (which has always worked with other solder I've used) and still it won't flow.

The iron I've turned up to 220c, I can go higher but it might burn the coil out. The solder melts around the 180c.

What gives?

I run my iron at 350 degrees C. Have for 30 years or so. Soldering never a problem.

 

[Ylli]

220°C is awfully low for soldering. It might be hot enough to melt the solder on the iron tip, but it is not hot enough to transfer any heat to a joint to be soldered. You will need that soldering iron at least 330°C, preferable closer to 370°C.

 

[Visitor]

I have some crap solder purchased from one of the Chinese sellers. It is horrible. Somehow, the alloy mix is inconsistent. An inch or two might seem good, and then the next section won't even melt at normal iron temperatures.

 

[ACharnley]

My fault for not saying, 220c is at the tip. The iron is on 345c for the good solder. I took it up to 400c on a re-try and admittedly the crap solder was better but as soon as it touched the PCB the heat dissipated slightly and I was back to square one.

I started going through the reviews and a few have said the same, it's a high temperature solder. Not 183c as said on the packaging. Buy cheap buy twice!

 

[Visitor]

Kester all the way.

 

[Ian Rogers]

My iron sits at 350°c all day.. Never had a problem.. Tips don't burn out.. For low leaded solder, crank it up past 400°C do the job, then put it back to 350°C

 

[Nigel Goodwin]

I usually run mine at 325c, and increase it for unleaded - but MUCH prefer leaded solder.

 

[narkeleptk]

I switch between 350-450c with a chisel or knife tip . Only work with lead free tho.

 

[Ylli]

I set mine to 700°F and leave it there. If you are going to increase it for lead free, you better have a stock of new tips on hand as the higher temp along with the lead free erodes the tip quite quickly.

 

[dr pepper]

I have mine at 385 C, works fine.

 

[gophert]

There are some crappy discount soles out there - some ball up and never "wet-out" the copper or tin-plated pad. Some won leave our soldering iron tip.

Make sure you have a clean tip that is not eroded. Use good solder. The Kester only comes in fairly large rolls. MG Chemical all solder in small rolls (they used to re-roll Kester solder into smaller rolls (4oz and 8oz rolls). The last spool I bought was 1/32" MG chemical 4oz (lead/tin) and it worked perfectly fine. The second-to-last roll I bought was a no-name brand rom Amazon and it just wouldn't wet-out onto the pcb.

 

[Ylli]

I'm not a big user of solder, so this is what I keep in stock:

Kester 44 Solder Wire, 63/37 0.031-in, RMA Rosin, 1-ounce Tube - - Amazon.com

Kester 44 Solder Wire, 63/37 0.031-in, RMA Rosin, 1-ounce Tube - - Amazon.com

www.amazon.com

 

[dr pepper]

Here in the Uk multicore savbit was the go to solder at one time, it contained a little copper so didnt eat the bit too quick.
You can still get it, but they dont seem to keen to say whether it contains lead or not, it doesnt seem as good as it was, maybe thats my eyesight.

 

[Ylli]

MC337 | SOLDER WIRE SAVBIT 6 366 5C 0.91mm 200g - RMS Components

Multicore Savbit Solder is produced especially to overcome the problem of ordinary tin/lead solders dissolving copper. It is an alloy to which a precise amount of copper has been added

rmscomponents.com.au

SKU: MC337 Categories: Multicore, Solder Wire, Solder Wire - Tin/Lead

Type	General soldering use
Alloy	Savbit 6 60% Tin 38% Lead 2.0% Copper

 

[dr pepper]

So you can still buy it then.

 

[ACharnley]

I've just replaced it with Savbit equiv from RS (2% copper) and all is fine. I'd have got on to the aliexpress seller if I hadn't left it so late.