Well, all, it's time for me to clean boards for the first time. After doing a practice run on a nonessential board, it will be time to begin on the KA11 and friends found inside my PDP-11/20. I've done some research already, but several questions remain. I'd like to get answers to them and have some comments over my tentative cleaning methods. First, let's talk about fluids. It's been a while since I took a chemistry class. Questions: * Is there no difference between 'isopropanol', 'isopropyl alcohol', and 'propan-2-ol'? * Are there any better fluids (methanol?) for certain situations? * Can I find these at a hardware store? * Is there anything I should look out for when using those fluids? That is, is there anything (glue?) they can damage? My most important question deals with core stacks. Most of the board cleaning info I've found steers clear of core. This is unfortuante, as my core is not immune from dust and grime. What I have are H207s, each consisting of a quad-width G616 and a smaller G617 daughterboard. The small space between these boards is exceptionally dirty. My current plan for cleaning them is: (0) Leave the two board assembleds; disassembly would likely cause breakage. (1) Blow canned air over the assembly and through the inter-board space. (2) Dip and swish the assembly in isopropyl alcohol. (3) Blow air over the boards with an unheated hair dryer or more canned air. (4) If the assembly is still dirty, go to step (2). I've got more cleaning subjects to learn about, but in the interest of keeping the discussion more focused, I'll ask about them later. As always, I'm extremely grateful for all help that comes my way. -- Jeffrey S. Sharp jss(a)subatomix.com