Cost to change solder resist mask

Hi,

it would be best to ask PCB Manufacturers on their price for that. It really depends on how big the work would be..

So, if i want to tent some VIA's on a current pcb how much should I be getting charged to do this? I realise there are lots of factors but will it be tens, hundreds or thousands of GBP?

Let me try and expand upon this. Head Office are complaining about water damage to this PCB in service (think mobile phone from the 1990's). I am telling them to tent the VIA's as one of the big problems is VIA corrosion. They are telling me this is too expensive but I am thinking this is only a couple of hundred quid for something that will at least do no harm and will probably help a bit. Obviously there are other bigger problems but best to tackle one issue at a time with these guys.