I've been in the process of upgrading both of my machines.

I just finished the quick-upgrade on my Expobar pulser -- insulating the boiler with 1/2 thick FDA approved silicon foam rubber ( obtained via another alt.coffee/home-barista member ). Very simply, I measured 3x, cut 1x and made a 'beer cozy' for the boiler. Tied it up with insulated wire. I did not insulate the top/bottom YET. the bottom will likely be insulated in the near future. I'm debating the top at all (too many items poking in/out of the boiler )

Just wanted to share some observations with people out there. Hoping for feedback.

a_ Overall brew temp is WAY lower. yes, i said lower. i didn't touch the pstat at all. i think this might be because of slightly less overshoot , as the machine doesn't cool down as fast. before water was always sputtering / flash boiling as i pulled a blank. now its almost to me not needing to pull a blank. steaming is not affected at all - still a powerhouse.

b_ The machine itself seems hotter. perhaps another member can touch their machine to test for me -- i never noticed very much before -- but the side to my machine is way warmer now. i believe this mostly due to the rubber just barely fitting in there -- i might have to redo this with 1/4 inch insulation. the silicon foam is definitely touching the boiler and the case in certain parts, and conducting heat. that said, its maybe 120-130°F on the case after 2hrs on - not much higher. but i'm still slightly concerned.

so far i'm not just happy, but ecstatic. i'll probably eventually redo the boiler with a thinner sleeve, to avoid the heat transfer to the case completely. but the shots i pulled today were by far the best i've ever pulled off the machine. water temp has been rock solid off it. much shorter cooling flush, and the temp throughout the pull seems more stable.

Congrats on the boiler job! I have to admit that I have been toying with the idea of using the ceramic fiber felt material that is used by pottery people and glass bead makers. It has very high temp threshold and can be very effective in 1/2in thickness'. I just haven't gotten around to it yet...

i first thought of the felt, but decided strongly against it.

the ceramic felt and fiber blankets are a little bit scary in terms of health concerns. under 99% of situations, there's nothing to worry about. but in the case of home espresso machines, you're putting one inches away from a vibrating pump. that translates to shedding and airborne particles.

one of my machines has the boiler directly above the grouphead and slightly exposed-- there was no way in hell I would put anything like fiberglass or ceramic materials in that place. so i started looking for silicon foam. luckily i found another home enthusiast who had my exact thoughts a few months ago.

that machine hasn't gotten the upgrade yet ( its cut, but its also getting a PID and new expansion valve system. ) I did put it in the Expobar though. The expoboar's boiler is tucked behind the group - there's no chance of shedding into my drink or onto my hands, but there was still the risk of air currents carrying particles out of the box through the vents. There's also a vibe pump back there.

If the expobar had a rotary pump, i think i might feel a bit easier towards ceramic/fiberglass. but something vibrating near that stuff is a bit too disconcerting for me.

If you look at some of the 1k+ machines, some of the retailers will offer them with a silicon sleeve, others will have a fiberglass shell.

Silicon insulation:
http://chriscoffee.com/products/home/espresso/vetrano
http://chriscoffee.com/products/h...sso/andrejapremium

Fiberglass/Ceramic Insulation
http://toomuchcoffee.com/index.ph...=viewtopic&p=29074
http://www.bellabarista.co.uk/Exp...encrypted%20v1.pdf

a home cut silicon insulation isn't as tight or nice looking as the factory installed ones -- but it comes close. personally, i feel safer with that in my machine than the other stuff. the expobar had some fiberglass or something on the inside of the machine between the water tank and the boiler -- i was ecstatic to take that off.

just a note: i'm fine with that stuff in walls, and between appliances, etc etc etc. i'm just not comfortable with that next to vibrating parts in unclosed spaces that I hover over and use to make food with. you might feel different, fine. I'm willing to spend the extra cash for the slight chance of living a few more years.

Glad the job went OK.

The right side of my machine is very slightly warmer than it used to be, because the rubber is slightly compressed between the boiler and the wall. The stainless is not going to suffer and the radiated heat is enough to warn the unwary that the surface is hot without causing a burn should they touch it.

The pStat duty cycle was about 15% before the insulation, 2-3% after.

I didn't pay any attention to the temperatures as I replaced the pStat with a PID as part of the project.
The nylon connector covers will last much longer subject to 130°F rather than 240°F.

The rest of machine is much cooler, so I think it's a wash that the side is slightly warmer.

A lot of things change when you insulate your boiler.

The heat that radiates from the boiler affects the environment of the head and affects its stability.

I found the best way to insulate my Cimbali was to put an insulation layer inside the side walls and under the top baffle. This preserves the environment for the head and tubing.

The unit comes from the factory with a layer of fiberglass between the boiler and the reservoir, so I left the effect of that by replacing the fiberglass with the foam that I use.

i'm not worried about the case, i'm just worried about heat tranfer from the case to various electronics.

the machine is ridiculously more stable now. its amazing. i'm pulling better shots on my expobar than the cafe/roaster that ive been buying beans from lately.

Where can one find this silicone insulation?

Thank you

Marvin

Marv wrote:Where can one find this silicone insulation?

Thank you

Marvin

http://www.mcmaster.com/nav/enter.asp?partnum=87485K66

What it looks like:

Kristi wrote:The heat that radiates from the boiler affects the environment of the head and affects its stability.

The heat radiated inside the box is mostly carried away by convection through the ventilation holes.

The water inside the HX is primarily what affects the head and an insulated boiler is much more stable. The heat radiated to the HX tubing in neglibile compared to the heat contained in the water flowing through it.

Adding insulation around the sides and top of the box is not a good idea as the heat is now trapped inside the machine to the detriment of the connectors, pump and electronics. The whole idea of insulating the boiler is to keep that heat inside the boiler and away from the other elements.