Fred, thanks a lot
i tried it with micarta instead and worked a lot better!
i wanted to try it first and didnt have access to longer screws to be able to hold the micarta to the sander, so i used the spray adhesive to hold the micarta piece to the foam (discovered the foam was concave), im not even sure the micarta is straight, but its working ok so far and just needed to try it
just when i use it i hold the knife with a clamp on one side then switch, so to do them all at once specially small knives i will try holding the knives down with s magnet or something or try holding teh sander in a vise
will keep you guys updated
and hopefully i'll get my disc sander running soon
Owen, the random works well with teh hollow grind and doesnt ruin the top of bevel or the edge?
Eddie, its almost like stone washing but different,i thought about leaving it on a knife, but i felt its neither random nor patterned enough to be a good finish.
and the purpose of the sander is not for finishing, but to save you energy and time, but eventually you finish up by hand
for example i got my blades surface ground terrible, i need to start doing teh flats from 80g, so instead of hours of had sanding i go with the sander 80, 120, 220 then hand sand starting with 120, saves me a lot. yi could go further if i want to fo course. if i remember correctly Ed Caffrey went +1000g with the sander then started hand sanding from 600
i cant speak for others, but i wouldnt sand the flats on the grinder, except on rare occasion when the knife is almost the size of the platen itself, i always make mistakes and get gouges
as for the bevels themselves, the whole idea is the closer you get to the final finish on the grinder the better! when i did flat grinds mainly (when i first started) i used leave grinder at 220/320g and start hand sanding from 120/220g and go to 400. the
the better you get on the grinder the more time you will save on hand sanding, this will come with time, but sometimes you can make a large knife, then the sander definitely comes in handy!

hope that helps, i'm still new to this but if i can help with anything let me know