I recently acquired a 1985 MCAL (supposedly unused) and after pulling a few shots noticed some brown stuff leaking from the brass machine screws. I will also post a few other "mods" that might be useful to others.



The original gasket is "fiber" which could be paper, asbestos or a combination thereof. It was not nicely matched to the holes, but doubt that matters. It was glued to the machine with a glue that dissolved with acetone.



I ordered a sheet of 1/8" Teflon, (from Amazon). I am doubtful that the four screws will apply enough pressure for a good seal.



Here is a minor mod to the boiler cap. Mine had a lot of threads which was kind of annoying and unnecessary, so I removed them and also added a fatter o-ring.

teflon should work fine although like you say it will have less giving in,
also if the white looks will not bother you
just as reference you can see on our web page the original

The four group bolts should have more than enough pressure to affect a seal... the Ponte Vecchio groups use that white plastic type of seal (teflon?)- and although the holes don't match exactly they can be used on the Mcal groups... I just had my Sama (Mcal) group bolted right onto my Ponte Vecchio... using the PV seal...

On another note I recently removed a group just like yours from a Sama machine and there was a small residue of coffee oil where the group meets the frame... the only difference is the the Sama group has been drilled to make it a thermosyphon connection. But it looks like the design does let a bit of coffee flow back towards the boiler....

Thanks, Stefano. Your website is a great resource.

(Here is the OEM gasket:)

http://espressocare.com/Qstore/Qstore.cgi?CMD=011&PROD=1187289017&PNAME=A+-43+Elektra+Microcasa+Gasket

I'll give the Teflon a shot and when it doesn't work order the gasket and some other things.

By the way, Stefano, I'm curious regarding your opinion on the old versus the new gaskets. The old style creates an insulation layer between the group and the boiler and the new style has them more tightly coupled. Do you think there is any advantage to either?

dan

Pencil rubbing to establish size.


Center cut on lathe using razor knife in tool post.


Finished 1/8" Teflon gasket.




Cut the bottom off the PF which helped with more crema.




Temporary Delrin Tamper with lip for coffee to rim of basket height.



The Teflon gasket is very (maybe too) efficient at insulating the group from the boiler. After flushing a couple blank shots through, it is still cool enough to touch briefly, though pretty hot. I ordered a package of temperature strips and will try to roughly figure out how hot I want the outside of the group to be, and how hot it becomes in a stable condition (turned on but not used for, 5, 10, 20, 30 minutes), and how hot after 1,2,3,4 consecutive shots. Not sure how good those strips are for this sort of thing.

I had to replace my OEM gasket and thought I'd cool the machine down by making one out of .125 (1/8") thick Teflon. It did in fact cool the machine down -- so much that it was producing sour shots. Even after the third shot, the boiler outside temperature was about 150-155 F.

I reduced the thickness to .06" thick or 50%. It allowed the machine to heat up a bit faster, but not twice as fast. And still sour shots.

I reduced it to 1/32 (.03) of an inch. Heated up quite a bit faster. After two shots 168 F outside temperature drifted up to 172 F and stabilized in that range. I think the OEM gasket is probably about this thickness. So much for my improvements. The shots are fine now.

On a separate note, I think I've been over dosing. I've been using 16.5 -17 grams and getting pretty slow shots. Rather than increasing the particle size, I decreased the dosing to 15-15.5 grams (which I think is manufactures' specs) and the shots are sweet.

Another thing -- for straight espresso, I find a single pull is way better than two and it's better to have two or even three small dense shots pulled sequentially than a single double pull. For milk drinks, pull away!

Lesson 1: I shouldn't assume that 30 years after a manufacturer has released a product and if that product is still in production that I can jump in and start making improvements!

Lesson 2: If you need a new gasket buy one from Stefanos -- I'm sure they are as good or better than you can make yourself and less expensive!