What type of washer for blower isolation

I'm sorry to post a thread that I know the answer is already here, I read it one time, but now I can't find it.

What type of washer do I need to insulate the vibrations between the fan and back shield of my stove. I know I read the answer on here at one point, but at that point my blower wasn't resonating horribly. Now it's enough to drive me crazy and I want to fix it.

Also, after I use a washer, there will be a gap between the shield and blower housing, what could I seal that up with?

I've never checked with a thermometer, but even with stovetop around 750 I can't put my hand oN the back shield without burning myself. On edit, for a second at least. I guess I need an ir gun more than I thought I did.......