First of all - thanks to all the espresso research workhorses here who do so much research and sharing in order to further the coffee experience for all. If I am any example, your help reaches many people.

I decided early-on that I wanted to insulate the boiler in my Elektra T1 for power consumption reasons, and after accomplishing the task, I think I may have rushed into it somewhat. The consensus here seemed to be that ceramic blankets were the way to go, but now I am not so sure. Granted, the ceramic may achieve what your goal is, give or take somewhat, but after looking closer, it looks to me like melamine foam is the most effective (and most cost-effective) way to accomplish the task. Not to mention the fact that I did not really care for all the dust and mess associated with the ceramic blanket (I used the 1/2" Kaowool brand alumina ceramic blanket listed in the photo below supplied by McMaster Carr).


revised 3/15/2008 to add Melamine Foam info

So, unless my calculations are off, the fiberglass would be the choice, with comments:

1. 1" thickness fiberglass blanket is pushing the limits of workability and 1/2" is harder to procure. It may be necessary to compress the blanket more than you would like, reducing it's efficiency somewhat.

2. The K-factor for fiberglass (which is irrespective of the thickness used) or melamine foam is significantly better than ceramic or silicone in general.

3. The R-value for the examples given (which is respective of thickness) is significantly better for fiberglass and melamine foam.

4. The cost per square foot is significantly better for fiberglass and melamine foam, granted the sizes you may be forced to buy for each will vary.

5. Fiberglass or Ceramic either are relatively messy to work with compared to the silicone or melamine foam options.

The most attractive installation would likely be silicone or urethane foam rubber if done properly. However, the cost effectiveness for silicone was the worst of all three options, and without consideration to cost was still inferior to fiberglass. In any event, I have already done mine with ceramic and am mostly pleased with the results, considering it is nice to still have some cup warming ability along with much less heat-on time. However, if I did it again (and I just might if free time allows), I would likely use the melamine foam. The point here was just to share the research with folks who may be contemplating this modification.

Here is a picture of the results (it is encased in copper mesh just to keep it a bit tidier):



Cheers,

Brad
edited 3/15/2008 to add melamine foam info

If you enjoyed the mess of the ceramic, you'll be ecstatic when strands of fiberglass start cutting into your hands (and lungs, if you're not wearing a mask).

I've been there! And yes, I would definitely recommend a respirator or mask and latex gloves. That's also why, if I did the job with fiberglass insulation, I would wrap it with the high-temp tape to keep any fibers from coming free. In fact, I would probably use the tape on ceramic too. I don't know if people using other brands of the ceramic blankets had the same experience, but when I was done working the blanket with gasket punches and scissors, I had a respectable pile of silica dust laying on the bench.

Cheers,

Brad

The link below shows the product I used to insulate my Izzo Alex. Luckily for you guys, it's available in the US (manufactured in US). Seriously read the article all the way through, it's not a joke and 7-8 months on the product remains stable.

http://coffeetime.wikidot.com/insulatin ... -izzo-alex

After reading the MSDS, and although the ratings are probably overly cautious, even if ceramic was free, no amount of persuading could convince me to use it :

HAZARD CLASSIFICATION

Although studies, involving occupationally exposed workers, have not identified any increased incidence of respiratory disease, results from animal testing have been used as the basis for hazard classification. In each of the following cases, the conclusions are qualitative only and do not rest upon any quantitative analysis suggesting that the hazard actually may occur at current occupational exposure levels.

In October 2001, the International Agency for Research on Cancer (IARC) confirmed that Group 2b (possible human carcinogen) remains the appropriate IARC classification for RCF.

The Seventh Annual Report on Carcinogens (1994), prepared by the National Toxicology Program (NTP), classified respirable RCF and glasswool as substances reasonably anticipated to be carcinogens.

The American Conference of Governmental Industrial Hygienists (ACGIH) has classified RCF as "A2-Suspected Human Carcinogen."

The Commission of The European Communities (DG XI) has classified RCF as a substance that should be regarded as if it is carcinogenic to man.

The State of California, pursuant to Proposition 65, The Safe Drinking Water and Toxic Enforcement Act of 1986, has listed "ceramic fibers (airborne fibers of respirable size)" as a chemical known to the State of California to cause cancer.

The Canadian Environmental Protection Agency (CEPA) has classified RCF as "probably carcinogenic" (Group 2).

The Canadian Workplace Hazardous Materials Information System (WHMIS) - RCF is classified as Class D2A - Materials Causing Other Toxic Effects

The Hazardous Materials Identification System (HMIS) -

Health 1* Flammability 0 Reactivity 0 Personal Protection Index: X (Employer Determined)
(* denotes potential for chronic effects)

When done with the silicone foam insulation, I had no itchy skin, no gritty eyes, no dust, no bits, nada to clean up.
There is ZERO possibility of fibres floating around in the future. THAT peace of mind is well worth the tariff.

Should the need ever arise, I can cut 4 tie wraps and remove the insulation in under 5 minutes.
Double that to reinstall.

Wow, both are seriously neat installations. Nice work guys.

I have a machine that has a 4.5-liter copper boiler that was uninsulated. I used a ceramic felt product simply because I could get it locally at a heating supply house and it was pretty cheap for the quantity I needed. The product was labeled "Roll Pyrofelt Gasket - (1/4" x 12")" and was sold by the foot for ~$3 per foot. The material I used was only 1/4", but I wanted it to be somewhat lossy to still have an effective cup warmer. It certainly reduced pressurestat cycling significantly and you can rest your hand on the hot boiler no problem. It was a messy product and I wore latex gloves... if you have to work with it for any length of time, a dust mask would be wise. I also wouldn't recommend it in any exposed application... you just don't want to touch or disrupt it. I secured the felt to the boiler with a few wraps of copper wire and stitched the ends on with the same, much like Bob Barraza did on his Elektra in Insulating the Elektra A3's boiler. I also used the wire to "tie down" the boiler to the frame, but I first cut some silicone tubing lengthwise to fit on the edge of the metal boiler supports (to keep from cutting into the insulation and to help dampen any vibration). This ceramic felt product also does not fair well with a lot of handling, as it will tear if stressed, so you need to plan accordingly.

I can certainly see how the foam product Ian used would be much nicer to work with.

cafeIKE wrote:After reading the MSDS, and although the ratings are probably overly cautious, even if ceramic was free, no amount of persuading could convince me to use it :

Definitely a good point, and yes it's likely overstated. Your installation looks very good, BTW. For folks following along, here are the MSDS for all three products (or an equivalent):

Fiberglass Insulation Blanket

Ceramic Insulation Blanket

Silicone Foam Rubber


Cheers,

Brad

cafeIKE wrote:When done with the silicone foam insulation, I had no itchy skin, no gritty eyes, no dust, no bits, nada to clean up.
There is ZERO possibility of fibres floating around in the future. THAT peace of mind is well worth the tariff.

Should the need ever arise, I can cut 4 tie wraps and remove the insulation in under 5 minutes.
Double that to reinstall.

Nice! That looks like the insulation material of choice for me. Where did you pick this material up? I asked at my local heating and sheet metal shop on the way home from my office today and the man at the counter gave me the "deer in the headlights" look which I took as "I don't have a clue what you're talking about"...

It's from McMaster-Carr.
It's FDA Approved 1/2" Extreme Temperature Silicone Rubber
It ain't cheap. About USD150, but there is enough for two or three < 2L machines.
I used about 7" of the 24" to do the Vibiemme. Sold the rest.

i bought the remainder of the above silicone.

insulated 2 of my machines ( expobar + isomac ), gave away the rest to a friend who did his brewtus

silicone foam is the only option -- UNLESS -- you have an external rotary pump. if you have an internal pump (vibe or rotary), i think you're crazy using ceramic/fiberglass . the vibrations & air current will loosen up enough strands to get in the air and make me worry.