I just recently started getting annoyed with the way the cups were marking up the top of the machine. I don't tend to care about the warmth of my cups. But it's a very convenient spot to store them. In a recent slayer thread I saw that Nicholas had some rubber mat on top of his Slayer. I might be wrong, but that's what it looks like and it got me searching for the perfect piece to put on my cup warmer tray. So I found a rubber pebble sink mat and cut it to size so it fit perfectly. I noticed, however that it covers most of the holes. I'm not sure how functional these holes are to the operation of the machine. I really want to keep the rubber mat there because it accidentally also solved all of my super loud vibration noises during a pull. So, how important is it to keep all of the holes in the cup warmer tray free?

Blocking air flow will reduce heat dissipation inside the espresso machine. In general, this strikes me as an unwise thing to do.

This was my concern, but I wasn't sure if it made sense. The giant gap in the side there isn't enough to dissipate heat sufficiently though? I can center the tray, but it worked out better to jam it to one side to reduce noise.

Heat can damage electronic components, as well as other materials. I believe it would be prudent to leave the holes uncovered, at least until you contact the manufacturer. Perhaps you can find another way to reduce the noise.

Thanks for the input. I'll figure something out.

I used that same stuff on mine but removed a bunch of the circles to keep the slots in the top open. There is still plenty of coverage so the cups have a place to set but I don't think I've blocked the top much more than just covering it with cups does. Might be less because the cups don't seal to the top any more.

Ira

I'd look for a sink mat or rubber mesh with a lot more holes. Something like this pad could be cut down & has enough holes to allow the heat to escape:
http://www.walmart.com/ip/InterDesign-C ... t/31955898 I have a roll of a black rubber mesh

or this one: http://www.bedbathandbeyond.com/store/p ... 1014723315

Was thinking to use a silpat for the same purpose. They are used in baking and transfer/conduct heat rather than insulate.
Any opinions or experience using one?

silpat.com

The silpats I've seen have no holes so while it would stop the rattle, it might cause the machine to overheat. The ones with connected shapes like the first picture make it easy to just remove some of the shapes without hurting the integrity of the mat. Mine is clear and the shapes are 3/4" diameter circles and I removed about 1/3 of them with no change to the usefulness of the mat but allowing 1/2 or more of the slots in the top to be left open. In my case I insulated the boilers so the amount of heat that needs to escape is reduced and has not seemed to cause the machine to feel hotter.

Ira

I usually recommend a product like this

http://www.addis.co.uk/sink-side/sink-mats/plastic.html

It comes in various colours (including clear) and can be cut to size...airflow is good, whilst still offering protection and anti vibration.