Desoldering tool. Completely clears holes?

[Faringdon]

Hi,
Do you think the following desoldering gun will completely remove solder from 1mm PTHs on a 1oz  copper PCB which is 1.6mm thick?

https://www.aliexpress.com/item/1005001804146055.html?spm=a2g0o.productlist.0.0.7bcc1ccc4P6pow&algo_pvid=c9954131-a05c-43e0-8cf4-acbeb4646efc&algo_exp_id=c9954131-a05c-43e0-8cf4-acbeb4646efc-10&pdp_ext_f=%7B%22sku_id%22%3A%2212000029869443811%22%7D&pdp_npi=2%40dis%21GBP%2142.88%2123.58%21%21%21%21%21%400b0a0ae216630568980487213e76ba%2112000029869443811%21sea&curPageLogUid=0XvJk3MhO5Zp

We need to re-insert de-soldered 20 way, 2.54mm pitch  pin headers...
https://uk.farnell.com/harwin/m20-9990246/header-straight-2-54mm-1row-2way/dp/1022247?MER=TARG-MER-PLP-RECO-STM71233-0

The PTH is 1mm diam and the pin header pin is 0.65mm diam, so even the slightest trace of uncleared solder prevents re-insertion of a fresh pin header into the holes.

[AndyBeez]

Depends how much solder is left plating the PTH and pins. Is this lead or lead free solder? It's a tight tollerance.

Sucking clean PTH holes is a pain but can be achieved with practice. Don't overheat or the pad sucks right off too. Provided everything else is within spec, and the pins are straight, they should go together. Just. Liquid flux can act as a 'lubricant' on the pins. Just try it out on a scrap board if you're concerned. * A hot air gun might just save the day.*

Regardless of the hardware, I ask who is doing the rework? A skilled practitioner who understands how to use desolder equipment, someone with the necessary attention to detail? Or a bench monkey of average ability (on minimum wage) who'll make parts fit, even if they don't? Reworking boards is a skill in its own right.

[jpanhalt]

If suck doesn't work for you, try blowing.  That's what I used to do.  You can get a pretty good blast in a small area.  It's a little messier.  You can also try flicking the board on a trash can.  That is probably not practical given the board size you have. 

Today, I use a fine solderdick with a conical SMD tip.  You can poke a little bit of the braid in the hole and it clears just fine.  Multiple holes will be a pain regardless. 

[jc101]

If the connector isn't there and you just need to clean up the holes, one of these may do the job...

https://www.rapidonline.com/anvil-av-dsp-desoldering-pump-85-0601

It can help to add solder before using suction too. 

Is it just the one connector, or many?  There are a number of companies who could re-work them for you too.  I've done similar over the years.

[eugene]

I agree with jpanhalt that blowing air often works better than sucking. I keep a can of 'air' on the bench that I use to blow solder out of holes as well as from under chips, etc. Good for ll sorts of things, really. They sell cans at most office supply stores intended for cleaning keyboards, etc.

[edpalmer42]

I wouldn't touch that desoldering tool.  There's nothing to suggest that the tip is temperature-controlled.  It will likely get too hot.  Add to that the fact that 30W is marginal at best for a desoldering tool.  Without enough power, it takes a long time to melt the solder.  That cooks the adhesive holding down the traces and burns the board.  And, WTH is 'electromagnetic power'?  It has a 30W heater.  Period.

Do a search for "S-993A desoldering".  It's widely available on ebay, Aliexpress, Amazon, etc.  Variable temperature, 90W, 3 different size tips, reasonable availability of spare parts, reasonable price (US$100 - 150).  There are multiple video reviews on Youtube.  Be sure to watch more than one.  I've found that some people are really clueless about soldering and desoldering.

Ed

[Circlotron]

I wouldn't touch that desoldering tool.

I think this says it all.

[Kean]

I wouldn't touch that desoldering tool.  There's nothing to suggest that the tip is temperature-controlled.  It will likely get too hot.  Add to that the fact that 30W is marginal at best for a desoldering tool.  Without enough power, it takes a long time to melt the solder.  That cooks the adhesive holding down the traces and burns the board.  And, WTH is 'electromagnetic power'?  It has a 30W heater.  Period.

Do a search for "S-993A desoldering".  It's widely available on ebay, Aliexpress, Amazon, etc.  Variable temperature, 90W, 3 different size tips, reasonable availability of spare parts, reasonable price (US$100 - 150).  There are multiple video reviews on Youtube.  Be sure to watch more than one.  I've found that some people are really clueless about soldering and desoldering.

Ed

Agreed,  that looks like rubbish.

Although I now have a JBC desoldering tool, I've used the S-993A style desoldering guns in the past and they are OK.  They do tend to clog up a bit too often requiring a time consuming tear down and clean.

A cheaper and quite effective solution is to first remove the part (cut it away or use a big solder blob to heat all the pins at once), and then use stainless desoldering needles to clear the holes.  Do a search on Ebay/AliExpress/etc for "desoldering needle"  to grab some to try out.  They are always handy to have and less messy/trouble/dangerous than compressed air.

[chilternview]

I would also avoid that desoldering tool.

I use a Hakko FR301. Costs an order of magnitude more, but it's worked on everything I've needed to desolder up to 40 pin MCUs. Sometimes a plated thru hole needs a bit of solder wick to clean up the hole after, or a little levering of the pin with a fine screwdriver to 'unstick' it.

[tooki]

We need to re-insert de-soldered 20 way, 2.54mm pitch  pin headers...
https://uk.farnell.com/harwin/m20-9990246/header-straight-2-54mm-1row-2way/dp/1022247?MER=TARG-MER-PLP-RECO-STM71233-0

The PTH is 1mm diam and the pin header pin is 0.65mm diam, so even the slightest trace of uncleared solder prevents re-insertion of a fresh pin header into the holes.

So which is it? Are you using fresh headers or the ones you desolder? Because the fact is, proper desoldering technique to achieve clear holes will end up with the header pins rotated and no longer perfectly perpendicular. You’d be a fool to try and reuse them, especially since they’re so cheap.