Question Help via scraping and soldering

[supertazon]

Hi,

I have a Wii mother board with most of the vias covered with solder mask. I’ve been practicing on unused vias to scrape away the solder mask and try to tin them. Unfortunately I can’t seem to get the hang of it, as out of 4 vias I have tried tinning, only one worked out.
Here I scraped two vias, I thought the copper looked shiny enough and tried tinning them but solder doesn’t want to stick properly. To make sure I was using my iron correctly I tinned the test pad just above and it worked. The via on the bottom right, next to the traces, I am not sure if the tinning worked out properly.

another example of a « tinned » via:

I am using this small file for scraping:

I must be doing something wrong.

What do you guys use as a technique to properly unmask the vias and solder to them? I’ve watched a YouTube video but the camera was a bit too far from the via to see the scraping up close.

 

[RedEnergy]

A file it's a bit too much
The problem is that a file needs to be used whit some force, it's not very precise and you can easily damage the via you are working with.
Instead try using something like a scalpel the advantage is that it has a thin tip, and you should be able to scrape away the solder mask easily

 

[RedEnergy]

Also try to check the temperature of your soldering iron

 

[supertazon]

Thanks for your reply.
That definitely worked a lot better, by using a hobby knife. I also looked at GingerOfOz' Wiiboy color build video where he scrapes the audio vias to mimic his moves. It's always great to have examples you can follow. For those interested here is the video timestamped: