I have had great success in the past using the reflow soldering method, using a syringe and needle to apply the paste to the board. However, I found myself repeatedly making the same boards so I decided to purchase some stencils.
I purchased a framed metal stencil for one PCB design and a 4 mil mylar stencil for the other.
They have worked well, until one day I forgot to clean the stencil after use. Now the solder has hardened and it is not wiping off.
Is there something I can use to dissolve the solder so that I can wipe it clean? Also, do I use different products for my metal stencil and mylar stencil?
NB. I am using no clean solder paste by AIM: http://www.aimsolder.com/products/No%20Clean