Guy swore solder paste was good enough for through-hole jobs

Had a dude on here tell me to stop using regular solder for through-hole repairs and just use paste with a hot air gun. Said it was faster and stronger. Tried it on a power supply board last Tuesday. three joints looked fine but one never wetted right and cracked after 20 minutes of runtime. Had to redo the whole thing with my iron and got it done right on the second try. Anyone else get bad advice from these forums that cost them time or parts?

3 comments

3 Comments

emma_garcia3d ago

Toss the paste for through-hole and stick with a decent 63/37 rosin core. Hot air is fine for surface mount but you need that mechanical bonding plus the wetting action from a hot iron on leads.

nathankim3d ago

Yeah you're right, I used to think paste was fine for everything but this makes sense.

wendy_henderson213d ago

Hmm, idk, I gotta push back a little on that, @nathankim. Paste can actually work fine for through-hole if you're careful with your technique. I've done plenty of joints where I just tack a lead with a bit of paste and hit it with the iron, gets a solid flow without needing separate flux. Maybe it's just me but I've had more luck with paste on tight pads where rosin core feels like it dries out before the joint wets fully. You just gotta watch your heat and not let it cook.