Solder flux - important to remove?

Tornadoboy

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Another one for the "dumb question" KLOV collection:

Is it important to remove the solder flux after doing PCB rework? I just got done rebuilding the power supply boards of a turbo and there's quite a bit of solder flux underneath, although if I don't have to worry about it corroding things in the long term then I don't care.
 
Another one for the "dumb question" KLOV collection:

Is it important to remove the solder flux after doing PCB rework? I just got done rebuilding the power supply boards of a turbo and there's quite a bit of solder flux underneath, although if I don't have to worry about it corroding things in the long term then I don't care.

Not a dumb question, definitely clean it off.
 
what does solder flux look like? im getting ready to cap and install a lv2000 on my 6100 and want to make sure i do everything correctly
 
It is built into the solder and liquifies when you heat it up. You can also buy it seperately in a small round metal can. It is the dark yellowish brown residue that you see when you are done soldering. If you use the right size solder, you don't get much residue to clean off.
 
It is built into the solder and liquifies when you heat it up. You can also buy it seperately in a small round metal can. It is the dark yellowish brown residue that you see when you are done soldering. If you use the right size solder, you don't get much residue to clean off.

what size solder should i use, i have heard 63/37 64/something but which one its very confusing
 
The 63/37 number or the number that you see like that are the ratio of materials that make up the solder. If you look around you'll see that you can get a few different types. I don't think the actual makeup of it that important. Although, the newer RHOS compliant stuff is harder to work with and you get as nice of a joint when you are done. You want to use Rosin Core solder and not the Acid Core, the Acid Core solder is for soldering pipes and if you use it on a circuit board it will damage the traces.

The sizes are usually a number like .62 or .08 or something like that. It's the diameter of the solder. I guess you could find a chart with recommended sizes for what kind of work but it isn't really that critical. But if you use the thicker stuff for board work, it's easy to create bridges across the pins and you end up with a pool of hardened flux around the joints. On the other hand I don't think there is any downsides of using too small of a size.
 
The 63/37 number or the number that you see like that are the ratio of materials that make up the solder. If you look around you'll see that you can get a few different types. I don't think the actual makeup of it that important. Although, the newer RHOS compliant stuff is harder to work with and you get as nice of a joint when you are done. You want to use Rosin Core solder and not the Acid Core, the Acid Core solder is for soldering pipes and if you use it on a circuit board it will damage the traces.

The sizes are usually a number like .62 or .08 or something like that. It's the diameter of the solder. I guess you could find a chart with recommended sizes for what kind of work but it isn't really that critical. But if you use the thicker stuff for board work, it's easy to create bridges across the pins and you end up with a pool of hardened flux around the joints. On the other hand I don't think there is any downsides of using too small of a size.

thanks for that, only thing i can get locally is lead solder :( dont wanna die young but ohwell :p but thats alot of good enough im going to be tearing down the monitor soon and recapping it
 
a big bottle of pure acetone and a toothbrush works great. can get form hardware store or salon place

Just make sure that you keep sparks away as its very very flammable
 
a big bottle of pure acetone and a toothbrush works great. can get form hardware store or salon place

Just make sure that you keep sparks away as its very very flammable

I read in another thread that acetone is bad and can damage the parts
 
I use 91% isopropyl alchohol. It is cheap and you can get a large bottle for a couple of bucks. It also works great to clean up the dusty greasy gunk on the topsides of monitor boards. It also doesn't flame up as quickly as some other solvents.

ken
 
I think I'm going to go with the 90% alcohol, it's cheap and I can use a normal toothbrush without it melting. I picked up a can of Ratshack PCB cleaner and the crap is so expensive ($10+) I'm going to save it for the connectors.
 
Is this the stuff?

http://www.radioshack.com/product/index.jsp?productId=2102868#

And how big a sin is it to not clean off the flux? Major sin as in you'll pay for it for sure, minor sin as in you may pay for it later, or "it's just a good idea"?

Whoa, no it is definately NOT that stuff! lol :D That literally eats copper, it's for etching your own PCBs!

It was this crapola:

http://www.radioshack.com/product/index.jsp?productId=2102649

One thing I've notice change in recent years about RS cleaning products is that they no longer can be used sparingly, the spray valves are either completely closed or all the way open, so in other words you can only spray it full bore like a fire hose or not at all. Who's willing to bet that's on purpose in order to make you waste as much as possible to make you buy more?

Grrrrrrrr..... Ratshack.... and I say all this as a former employee.
 
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We used to call it "Radio-Shaft"



Yeah no kidding, try asking them what a potentiometer is, it's like trying to ask a hamster about quantum physics.

Oh I know... Sometimes they know them as pots better. Usually not. But the pots are so expensive there that they are not worth buying.
 
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