What is a mechanical solder sucker?

[stj]

Re: What is a mechanical solder sucker?

i use 3in1 or some Singer machine oil - whatever is closest.
teflon loaded oil would be best, but i'm out of it.

[johnnyh55]

Re: What is a mechanical solder sucker?

I just use a bit of petroleum jelly (vaseline).

Ok. I was told never to use petroleum based lubricants on rubber O-rings as they will dry and crack overtime. I'll get some silicone grease and try that.

[SteveNielsen]

Re: What is a mechanical solder sucker?

It is not the petrol-based oils that cause damage to synthetic rubbers and plastics but additives to them which are solvents. Basic petroleum jelly doesn't have them. Mineral oil doesn't either, which is basically what 3in1 and Singer are with some perfumes added. Baby oil too but it has a lot more perfume, which doesn't hurt anything.

Regardless, the solder sucker is gonna wear out or get broken long before the o-ring would be damaged by using a basic petroleum lubricant. Use whatever you have short of maybe bacon grease. It's not really a big deal.

[johnnyh55]

Re: What is a mechanical solder sucker?

Ok, thanks for the help. Here is a picture of the capacitors I am trying to solder in. I squared the area of the one that I think has a lifted pad.

[stj]

Re: What is a mechanical solder sucker?

you lifted the surface-pad, but the sleeve is still in the board,
you can flow solder down the leg of the cap into the sleeve.

btw, get some damned IPA and clean the board!

[johnnyh55]

Re: What is a mechanical solder sucker?

I was thinking that my 1.2mm solder might be too thick? If I purchase 0.8mm solder, should I use lead free solder or buy leaded solder? I know lead free is harder to work with but is there less chance of having a cold solder joint if the board uses lead free solder?

[SteveNielsen]

Re: What is a mechanical solder sucker?

Smaller dia solder might help in some cases but if your pics are an indication of your skill then you need to practice a lot. Lead free is not harder to work with provided you know how to work with it, and there again that takes practice. For you I say stick with leaded rosin core and not complicate things. 60/40 is ok but 63/37 is better.

[johnnyh55]

Re: What is a mechanical solder sucker?

Smaller dia solder might help in some cases but if your pics are an indication of your skill then you need to practice a lot. Lead free is not harder to work with provided you know how to work with it, and there again that takes practice. For you I say stick with leaded rosin core and not complicate things. 60/40 is ok but 63/37 is better.

Ya I probably do. I've done dozens of capacitors on single sided pcb boards with an el cheapo 25w iron but I didn't think the motherboard would be this hard with a good iron. I tried using a safety pin to clear the vias but solder seem to sitck to the pin, so it's not working as I was hoping for. Maybe the ones I got from the dollar store aren't made from stainless steel.

[SteveNielsen]

Re: What is a mechanical solder sucker?

A brass safety pin will bond to the solder. A steel one won't because it requires much higher temp and a more a acidic flux than rosin.

[johnnyh55]

Re: What is a mechanical solder sucker?

A brass safety pin will bond to the solder. A steel one won't because it requires much higher temp and a more a acidic flux than rosin.

Actually the ones I got are silver so I assume they are steel? Maybe the solder is not sticking to it but the pin gets stuck inside the vias?

[SteveNielsen]

Re: What is a mechanical solder sucker?

A steel pin may stick but you should be able to turn it out. Multi-layer boards present more difficulty. You have to get the spot hot enough and fast enough to not damage the board and still work. It's about temperature and timing. Remember, these boards were soldered quickly by a machine. They may have been pre-heated before soldering as well. They were not made with component level repairs in mind.

[stj]

Re: What is a mechanical solder sucker?

you can use leadfree solder just fine with a programable temp iron like yours.
it's only a probem for people with $10 irons!

i use 0.7mm myself.
---
if you want to buy some solder, let use select it for you so it has good flux in it.

[johnnyh55]

Re: What is a mechanical solder sucker?

you can use leadfree solder just fine with a programable temp iron like yours.
it's only a probem for people with $10 irons!

i use 0.7mm myself.
---
if you want o buy some solder, let use select it for you so it has good flux in it.

Do you think it will bond better or probably not?

[SteveNielsen]

Re: What is a mechanical solder sucker?

Lead free solder is stronger but requires higher temperatures. How well it bonds in a solder joint depends on your soldering skills. You still have to be mindful of temperature and timing or you'll get a crappy joint or damage the board with either. For a beginner the higher heat requirement may pose a greater threat of overheating the work.

[stj]

Re: What is a mechanical solder sucker?

soldering a pcb, you can use any flux, but if it's too agressive you need to clean up the mess after.

where flux becomes important is if you need to solder brass, aluminum or something "dirty"
then the different chemical formula's make all the difference.

[johnnyh55]

Re: What is a mechanical solder sucker?

Well thanks for all your help, I figured out a technique where I apply flux to the solder on top of the vias to be clean and then I align my safety pin and I apply heat with the iron. The the pin goes through almost like butter and I then wiggle it and pull it out and it clears the hole.

Now some of my caps are the right capacitance but too big physically for the ones they are replacing(1800uf 35v instead of 6.3v) or they hit each other side by side, if they don't touch the board does it matter if they don't interfere with other components on the board?

Oh by the way, nothing is soldered yet.

Here is a pick below

[johnnyh55]

Re: What is a mechanical solder sucker?

Now that I think of it I think these caps will be in the way of the heatsink so I will order some new ones 8mmx8mm. If I replace polyester caps with aluminum caps would that be ok? The only ones that would work from digikey are aluminum caps 680uf 6.3v and they are 8x8mm.

[stj]

Re: What is a mechanical solder sucker?

no
polyester caps arent polarised, electrolytics are.

unless you mean polymer

[SteveNielsen]

Re: What is a mechanical solder sucker?

I would not replace polys with aluminum electrolytics. They have some different properties and the designers of the board decided to use polys for a reason, otherwise they'd have gone with less expensive aluminum caps.

[johnnyh55]

Re: What is a mechanical solder sucker?

no
polyester caps arent polarised, electrolytics are.

unless you mean polymer

Sorry I meant polymer.

I would not replace polys with aluminum electrolytics. They have some different properties and the designers of the board decided to use polys for a reason, otherwise they'd have gone with less expensive aluminum caps.

Actually it's the other way around. Right now I have aluminum electrolytic and I'd like to replace them with aluminum polymer capacitors, would that be ok? I can't find 680uf 4v caps in aluminum electrolytic only in aluminum polymer. I can find 680uf in higher voltage like the ones I have now but the dimensions are usually too big and I don't think they would fit.