what safe, and long lasting products are available for use on metal surfaces, [ jointer, tablesaw, etc] tops to make em slippery for boards without causing any finishing problems later on. And does it also help to "slick up" fence surfaces, or is that not an issue?
I’ve used paste wax but switched to glide cote, recommended by another member. Lasts a very long time and very easy to apply. GlideCote Table & Tool Sealant 10.75oz
Paste wax is good and long lasting. But if you want something you can spray, get something w/ Teflon or PTFE in it. I use it on my jointer mainly and have not seen any effect on finishing. And yes, I spray the fence also.
Another vote here for Glide Cote /Top Cote. I prefer it over hand applied waxes because its faster to apply, covers more thoroughly, dries quicker, and easier to buff. Granted, Glide Cote is way more expensive than hand applied waxes, but for me that convenience results in more applications. I've been using it since it first came out and was made by Sandaro.
I used to set jointer and planer knives for other people and always kept a good inventory of Top Cote with me. It always made my work look good because planing and jointing went so much better.