Quick question (without context - see context below): I need a replacement head gasket that measures (with calipers):

Outside Diameter: 68mm
Inside Diameter: 52mm
Height: 5mm

I've looked in the predictable places (espressoparts.com, Stefano's espressocare.com, etc.), but, I haven't been able to find one that meets those specs. Any thoughts?

Now, the longer context:

This is for a little semi-auto (with a thermoblock, regular (non-pressurized) 53mm portafilter) that I picked up at an estate sale ($25) to tinker with. It is branded as an "Eterna," (see the photos below) but, I haven't been able to find any other information about this online (I found one post here, though, it is not the identical machine: http://coffeesnobs.com.au/brewing-equip ... chine.html ... but no real information) -- lots more references to commercial, lever-style "Eternas" that seem to be ... uh ... something else. There are no other labels on the machine anywhere, so I really don't have anything else to go off of ...

The machine was in beautiful aesthetic condition, no rust, immaculate inside, but it came completely gunked up with scale (esp. in the pump itself). I did a quick and fast semi-teardown of the parts of the pump that I could get off, and then I soaked parts of it in a descale bath (keeping the electric parts out of the solution, obviously). Lo and behold, it fired right up and spit out LOTS of muck. Multiple descales and flushes later, clean and functional! Fun little project.

Despite the crazy heat issues with the thermoblock (first thermoblock I've dealt with ...), it produces an attractive (nice crema, etc.) and tasty espresso (not amazing, but, perfectly serviceable). The steam arm, though, is completely insane -- WAY too hot, WAY too little steam to make any reasonable steamed milk. I'm not too worried about this, though, since I'll mostly use it for doing the occasional espresso shot when I move it to my office (no milk-based drinks there!).

Anyway, here are some pics ... Any help with the head gasket would really be appreciated ... THANKS!

53mm gasket almost always equals old Saeco/Solis rubber, from when they had brass boilers. Most Saeco shops will still have them.

Alan

Thanks for the recommendation, Alan (this is the second time you've come to my rescue -- cheers!). I did quite a bit of searching last night/this morning, but, I couldn't find any Saeco/Solis gaskets that would fit. One was very close -- it was 68X48X5mm, but, that 48mm ID was going to be WAY too small. If there IS one that somebody knows of that I've missed, though, please let me know!

Anyway, I am rolling the dice on it, but, I've ordered one that looks CLOSE to the right dimensions, though, not perfect -- it is a La San Marco gasket that is listed as 64X52X5.5mm. It is here:

http://www.espressoparts.com/SM_9?&search_id=2435773

In terms of the general shape (flat gasket -- something I should have mentioned in the original post, I suppose ...) it looks right. The 52mm ID is dead-on and the 5.5mm H should be fine. Obviously, the concern is the 64mm vs. 68mm OD. When I looked closely at the existing gasket, there is a clear "wear-line" where the portafilter/basket rests in the existing gasket, which comes in about 3.5-4mm on each side. It looks, then, like the portafilter/basket might still seat against the slightly narrower San Marco gasket, but, my concern is that there won't be enough buffer around it to keep that seal under pressure. This just seems like a "give it a shot and see what happens" experiment (and, I'll only be out $6 ...) since, for the life of me, I can't seem to find the original 68X52X5mm gasket.

If anyone has thoughts/warnings/tips I'd love to hear them. Otherwise, I'll report back once I get the San Marco gasket and give it a shot.

Cheers!

An update: The La San Marco gasket's OD turned out to be too narrow -- by just a tiny bit -- so I'm back to square one. I'll probably try the Saeco copper boiler gasket, but, I'm not too hopeful ... its ID is 48mm and I think I need something around 51-52mm. Might try some cutting on the gasket if I can't jam it on there, but, even if that works, it doesn't seem like a great solution ...

... I know that there are TONS of different head gasket sizes out there for lots of different machines, but, wouldn't it be great if someone enterprising could put a living document together for the community so people could contribute their experiences of this most basic and frequently replaced parts from machines that might not be the most obvious ones (something like this, which is for tamper sizes ... http://www.fareastcomponents.net/basesizechart.htm)? I'm on my second "recuperated" machine, and both of them turned into a journey in terms of finding head gasket replacements (my other machine -- an older version of the Victoria Arduino Family ... one that is so old that there is no support for it and I've yet to find any parts lists or manuals for it). The VA, I ended up working closely with Stefano's (and a hard-working caliper) to find a replacement (FYI, both the portafilter basket and the head gasket are identical to those in the current Elektra Microcasa Leva ... go figure). Anyway, a living document database would be helpful, I imagine. Just a thought ...