Mosfet hole cleaning solder out

[whatever]

Might seem pretty obvioius to some, but here is my method for cleaning out the holes in circuit boards that are filled with solder when replacing mosfets. I just get a safety pin which is approx same diameter of the hole, just a little bit smaller.

Put the pointy end of safety pin on the hole filled with solder then touch the solder trying to remove with hot soldering iron with a little bit of solder on it ( sometimes easier to go from top or sometimes bottom of board).
I always put the safety pin such a way that it wont push any contact metal on board out, so if contact is on top of board push down from top.
So you wiggle the safety pin a little while applying the iron, it will go through the hole as soon as solder gets liquid, it will take the solder with it. To withdraw the safety pin is usually necessary to scrap off the solder on the pin with knife or similar.
Its extremely quick and effective method.
Before puting new mosfet in place, work the safety pin around the hole just to make sure its big enough for the mosfet to push in,
its usually a nice snug fit.

 

[DogDipstick]

Solder wick works wonders, you know.

If you dont know, get some, and you will throw the safety pin AWAY. It is amazing. Will leave that pcb bare.

https://www.google.com/search?q=solder+wick&client=firefox-b-1-d&sxsrf=ALiCzsaBXSWawI5G1qwloDhjC8AfOeD-6Q:1666185374088&source=lnms&tbm=isch&sa=X&ved=2ahUKEwieteiasOz6AhX3hYkEHXHvAT0Q_AUoA3oECAEQBQ&biw=1920&bih=937&dpr=1

 

[red]

You can also use bare stranded wire, with a little flux, to remove old solder from a circuit board. The commercial product for this job is usually called Solder Wick, or some variation of that term. The commercial versions come in all sizes, thin to thick; it is finely stranded braided wires, with dry flux in it.

When used, the last inch of Solder Wick will be stiff with solder. Bend it where the solder stiffness stops, and apply the soldering iron in this bent corner to the hole to be cleaned. Use the soldering iron to touch the Solder Wick to the hole to be cleaned. When the old solder is absorbed by the Solder Wick, take away the Solder Wick and soldering iron. Pull the Solder Wick straight, let it cool, and make the bend for the next use of the Solder Wick. Repeat if necessary.

It is also very helpful for any soldering if you have a high-quality flux on the job. This non-acid La-Co flux paste washes away with plain water; no need for solvents and chemicals. None better for electronics work. This stuff make you look like an ace in soldering. Acid flux destroys copper circuits in time. Rosin flux is lame, by comparison to La-Co flux. Never leave any flux on a finished job; it can cause problems later. HTH.

https://markal.com/collections/soldering-fluxes/products/regular-flux-paste?variant=9204786921519

 

[Comrade]

It is also very helpful for any soldering if you have a high-quality flux on the job. This non-acid La-Co flux paste washes away with plain water; no need for solvents and chemicals. None better for electronics work. This stuff make you look like an ace in soldering. Acid flux destroys copper circuits in time.

Blanket statements like non-acid flux is none better is absurd. There is a right tool for each job.

Acid flux doesn't destroy copper circuits. The point of flux is to deoxidize surfaces. In the context of a bike controller I'd take a good solder joint with acid flux vs. some theoretical copper damage from acid flux 50 years down the line. The controller will long be in the trash by then.

 

[marty]

It is also very helpful for any soldering if you have a high-quality flux on the job. This non-acid La-Co flux paste washes away with plain water; no need for solvents and chemicals. None better for electronics work. This stuff make you look like an ace in soldering. Acid flux destroys copper circuits in time.

Blanket statements like non-acid flux is none better is absurd. There is a right tool for each job.

Acid flux doesn't destroy copper circuits. The point of flux is to deoxidize surfaces. In the context of a bike controller I'd take a good solder joint with acid flux vs. some theoretical copper damage from acid flux 50 years down the line. The controller will long be in the trash by then.

When I went to solder school 1970s. Teacher told us. Rosin core solder for anything to do with electricity. Acid core solder for every thing else.

We built a little tool tote tray from galvanized sheet metal. All folded and soldered together. Handle was about 1/8" x 1/2" steel bar riveted to sheet metal box. I still got tool box somewhere. It's painted blue.

Now i see the world is changing.
https://en.wikipedia.org/wiki/Solder#Flux
Due to concerns over atmospheric pollution and hazardous waste disposal, the electronics industry has been gradually shifting from rosin flux to water-soluble flux,

Flux
Electrical solder with an integrated rosin core, visible as a dark spot in the cut end of the solder wire.
Main article: Flux (metallurgy)

Flux is a reducing agent designed to help reduce (return oxidized metals to their metallic state) metal oxides at the points of contact to improve the electrical connection and mechanical strength. The two principal types of flux are acid flux (sometimes called "active flux"), containing strong acids, used for metal mending and plumbing, and rosin flux (sometimes called "passive flux"), used in electronics. Rosin flux comes in a variety of "activities", corresponding roughly to the speed and effectiveness of the organic acid components of the rosin in dissolving metallic surface oxides, and consequently the corrosiveness of the flux residue.

Due to concerns over atmospheric pollution and hazardous waste disposal, the electronics industry has been gradually shifting from rosin flux to water-soluble flux, which can be removed with deionized water and detergent, instead of hydrocarbon solvents. Water soluble fluxes are generally more conductive than traditionally used electrical / electronic fluxes and so have more potential for electrically interacting with a circuit; in general it is important to remove their traces after soldering. Some rosin type flux traces likewise should be removed, and for the same reason.

In contrast to using traditional bars or coiled wires of all-metal solder and manually applying flux to the parts being joined, much hand soldering since the mid-20th century has used flux-core solder. This is manufactured as a coiled wire of solder, with one or more continuous bodies of inorganic acid or rosin flux embedded lengthwise inside it. As the solder melts onto the joint, it frees the flux and releases that on it as well.

For the amount of soldering I do. I have no concerns "over atmospheric pollution and hazardous waste disposal"

 

[red]

For the amount of soldering I do. I have no concerns "over atmospheric pollution and hazardous waste disposal"

Marty,

Prolly so, but I might still bet that you like the La-Co flux better than rosin, as your go-to flux.
With La-Co flux, there is no need for alcohol to wash away flux after soldering; use plain water.
There is a good list of metals that you can easily solder together with La-Co flux,
where rosin would be very little help. It's really good for soldering on copper.
My US$ .02 worth . . .