So ive soldered a few pads on a f4 05 aio and theres flux around the outside and i want to clean it so it doesnt bridge or short anything but afraid to to use some kind of cleaner like rubbing alcohol, dont know if it will hurt anything on the board? Also is it ok to use the rubbing alcohol or should i buy actual flux cleaner? Oh and im using good 60 40 solder with %2.2 flux n says ra flux on it, hope these arent dumb questions n thats why i havent been able to jus google this
Need advice about soldering FC
- Thread starter Rex3906
- Start date
ArmyVet
Well-Known Member
Use 63/37 solder. It has a lower melting point and gives you some room for error. Bit more money. but worth it. Amazon has tons of it.
RMA flux should leave behind less residue and still be non-corrosive.
I use some R for the low impedance characteristics and a good bit of RA but it is pretty messy.
There are desirable and required characteristics for your solder, RA would only give you some desired properties so here is no real reason to buy something else if that is what you already have though.
Thankz alot for all your advice, i desoldered the small solder pads to clean the flux off but i cant get all the stickyness off so is that ok is it conductive at all? I dont know alot about soldering i know how to thats easy for me but the pads being so close to each other. I tried to scratch some of it off went through paint real small not touching any pad itz right in the middle. Im gonna cover it with epoxy so thats y i need to know how conductive the flux is?
Jackson
USA member at large
Why?
ArmyVet
Well-Known Member
Rule number one was always make a good physical connection. Not always possible anymore.
Rule number two was if your solder joints are shiny. They are probably good.
Yours loook Shiny!
Have fun
Bill
Gyro Doctor
Electronics Tech for over 45 years
... Not too bad of a soldering job for a newb at it ... lol ... that should work just fine. 
Words of advise on future soldering work though:
Solder is NOT melted upon the wire or the pad as was obviously the case by looking at two of your solder pads.
The tip of the soldering iron should contact the place where the wire meets the pad in such a way that BOTH the solder pad AND the wire are heated simultaneously
to the point at which they melt the solder when it's touched to THEM (not to the tip of the iron). The solder will then flow over the entire pad uniformly and create a "fillet"
which rises from the edges of the pad up to and around the wire.
If the pad is not hot enough it will look like "a drop" of solder sitting atop the pad (like your "S4 pos and neg" connections) but all the other connections look really good.
In fact, the connections I'm critical of are good enough too, so I wouldn't mess with them again. If the pad is hot enough but the wire is not, then the pad will be covered
well but the solder will "pucker" around the wire rather than flowing up onto it. The connection being "shiny" is proof that the solder was clean (no contaminants or slag)
and that the solder was not overheated.
Words of advise on future soldering work though:
Solder is NOT melted upon the wire or the pad as was obviously the case by looking at two of your solder pads.
The tip of the soldering iron should contact the place where the wire meets the pad in such a way that BOTH the solder pad AND the wire are heated simultaneously
to the point at which they melt the solder when it's touched to THEM (not to the tip of the iron). The solder will then flow over the entire pad uniformly and create a "fillet"
which rises from the edges of the pad up to and around the wire.
If the pad is not hot enough it will look like "a drop" of solder sitting atop the pad (like your "S4 pos and neg" connections) but all the other connections look really good.
In fact, the connections I'm critical of are good enough too, so I wouldn't mess with them again. If the pad is hot enough but the wire is not, then the pad will be covered
well but the solder will "pucker" around the wire rather than flowing up onto it. The connection being "shiny" is proof that the solder was clean (no contaminants or slag)
and that the solder was not overheated.
Ya when im soldering the wire to the pad im gonna make sure its melted n on whole pad. I cant change temp on soldering iron n its 400f it doesnt like alot of solder one pad had too much n wont melt n now i gotta desolder n redo.
And i got another question my vtx that i got from another quad is 5v i cant find docs on it, can i put the cam 5v n vtx 5v on same pad?
And i got another question my vtx that i got from another quad is 5v i cant find docs on it, can i put the cam 5v n vtx 5v on same pad?
Gyro Doctor
Electronics Tech for over 45 years
Usually yes, but you want to check that the PDB you're using can handle it before trying.
The total current drawn by the cam and the VTX added together should be less than the rating
for that connection on the PDB, otherwise you'll fry the voltage regulator on the PDB.
Gyro Doctor
Electronics Tech for over 45 years
That's pretty low temp for an iron unless it's used for soldering the actual parts (tiny parts) onto circuit boards.
Do yourself a favor and buy an iron that's at least 600-700 degrees because soldering is best done quickly , otherwise you risk having the pads
lifting off of the board from being too hot for too long (not hot enough to melt the solder but still hot enough to delaminate from the board).
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