Sure, For my line of work we do Ornamental and light structural steel (amongst other things) anwya, working with most non-ferrous metals (aluminum ie) can be a very unforgiving material. I have learned this in the hard way! When I do aluminum anodizing it is always easier and best to remove the old anodizing to truly see what the heatsink looks like raw. I have a local anodizer that happens to be world class and one of the few that still does bright dip anodizing. anyway, I have them remove the anodziing by placing the items in acid for a short while. Once back from stripping the old finish I begin sanding the worst areas with 120 grit on a pneumatic angle grinder. Its very tedious and you must watch for swirl marks, and cutting divits, etc. once I cut the worst with 120, i swap to 220 and start cutting the areas back down. then on to 600-1000 grit. after the 1000 you should nearly see a mirror finish. I then take a scotch brite pad and 00 steel wool which will identify any areas needing more work. The anodizing will bring out things you would NEVER see as an issue. You may be badly surprised when things come back with areas you never seen prior. Anyway, once I have my area sanded and tested if brushed I start this process. I typically use a block, etc. for a hard flat surface wrapped with 120-220 grit sand paper. This is dependant on the harshness of brush look. YOU MUST SAND 1 direction North/South or East/West. and it MUST BE STRAIGHT. if you go any direction besides straight the brush effect will NOT look good. I use my finger as a guide down the side of the material, etc. to keep my block straight. Once I am ok with all the brushing effect I once again knock down with scotch brite and pack with paper as to protect. Side Note: You can not have any stickers, adhesives, heatsink grease, etc. left on amplifier as it WILL infact create issues in anodizing.
Once amplifiers come back newly anodized I start assembly. If an amplifier is older I feel recapping with value for value is best. I believe this amplifier engineers spend great efforts in their sonic characteristics so I do not alter. That said I will upgrade to Panasonic FM, Elna Silmic II, or OS-CoN, and Nichicon MUSE KZ/FG series. I also tend to replace Foil type with Wima MKS2/4 and MKP2/4 I use Dow Corning 340 heatsink grease and reassemble. Let me clarify I see nothing wrong with increasing storage capacitance or filter capacitance I just do not know enough to make those decisions. same for bypass capacitors.
Hope this helps EriCCire
