Here’s another hack I found effective for keeping most of the dust and chips off the threads on the Y rails.
I always had a fancy for putting guards along inside the length Y rails like I see on some machines. However I couldn’t work out how to attach the 6 mm plywood (my material to hand) without issue and I didn’t have a length long enough but I did have a 10inch strip in my scrap bin. So I attached that to the Xrail block using blue tape and CA glue 
and it works a treat, better than expectation and hasn’t fallen off after more than a year of use.
