December 28, 2020

New Photo and Video Feed

 You'll now notice that I added a Feed tab to the top of the page.

When I started the blog, I would wait until I completely finished a project, then do one gigantic writeup at the end.  This habit was left over from when I used Instructables to document things.  As my projects got more complicated, that blogging style stopped working.   So I started the In-Progress section for shorter technical updates. When I (on occasion) finish something, I now throw a summary on the main page, and links to the relevant posts from the in-progress section.  I think this has been working fine, but I still tend to hold onto stuff until I've made enough progress for a proper technical blog post.  

Despite the relative infrequency at which I write detailed posts, I think most weeks I do something side-project related that someone on the internet would find interesting.  To avoid cluttering the proper blog, I made a new Feed section where I plan on just throwing up images or videos with one or two sentence descriptions.  "Hey, that sounds like Instagram", you might say, and you'd be right.  But I've avoided Facebook and Instagram this long, so I don't intend to stop now.  Maybe I'll get bored of this and it will fall by the wayside, but for now, enjoy.

December 9, 2020

La Pavoni Europiccola Lever Espresso Machine Restoration

I've had a La Pavoni Professional lever espresso machine for a couple years now, which I got on ebay and fixed up.  Getting it working turned out to be completely uneventful, so I never wrote up anything about it.  I recently restored a Europiccola for my sister, and this time around the restoration was much more involved.  It was in pretty rough shape when I got it - all the seals were shot, the sightglass was smashed, and the copper/brass plating was  peeling horribly.  But the heating element and electronics were in good shape, and core mechanical pieces worked.

I forgot to fully document the state I received it in, but here's what it looked like minus the grouphead:

All the seals needed replacing.  The trickiest of these was the seal in the top of the grouphead.  This seal is held in by a brass washer and a retaining retaining ring, which was made out of non-stainless steel.  It sits in a chamber full of steam, so I don't know what they were thinking there.  So the retaining ring was extremely rusted, so much so that the holes used for removing it with snap ring pliers were gone:

I was able to slowly chisel it loose and pry it out with a dental pick.  This is what was left of the original retaining ring (left), seal, and washer:

Here it is after installing a new seal, cleaning up the brass washer, and using a new stainless retaining ring.  Sorry for the blurry pictures:

This machine originally had a copper finish on the boiler and gold/brass finish on the grouphead and base, but both were discolored and peeling.  The finish on this  unit was strange -  on the outside, there was a clear varnish layer (the source of the peeling).  Under that, the boiler has an electroplated layer of actual copper, and the base has an electroplated brass layer.  Neither of those layers were in very good shape.  Where the copper/brass were wearing through, there were signs of a chrome coat beneath that. 

I took the boiler as far apart as I could before stripping the coating.  The sightglass attachment points are bolted through the boiler, with their nuts on the inside of the boiler, at a funny angle.  I'm sure there's a specialized wrench for removing these, but I didn't have that.  I used a 16mm wrench with a 12-point ratchet.  Because the opening at the base of the boiler is pretty small, the wrench couldn't be turned enough to click past one pawl of the ratchet.  To make progress, I had to turn the wrench a few degrees, remove the wrench, manually click the ratchet over two clicks, take up the backlash in the ratchet, put it back in, and turn the nut a few degrees.  And repeat several dozen times.  I couldn't get the wrench around the nuts holding on the pressure relief valve or steam wand, so I just gave up and left them on.

The original plated bolts holding that hold the grouphead on were a little rusty, so I got some new stainless steel bolts, turned the text off the caps, and gave them a polish:

A combination many rounds of paint stripper and scrubbing with a gentle polishing compound stripped off the varnish and electroplated layers, and revealed an almost pristine chrome coat on the boiler.  The base wasn't in quite as good shape, but a few cycles of scrubbing with scotch-brite and sanding with progressively finer sandpapers improved it.

Part way through stripping, the boiler had this really interesting crackle-texture:

The chrome on the base slowly being revealed:

The drip tray had a few deep rust pits in it.  I stripped the rust out of the pits, and sprayed a layer of clear high-temperature spray paint to over them hopefully keep them from eating all the way through the base.  Fun fact I learned in this process, some "high strength" toilet bowl cleaners are 5-10% hydrochloric acid, so it works really well for stripping rust or black oxide from steel.  

Here's what the pits looked like after a couple rounds cleaner:

I was amazed at the state of the chrome coat underneath all the gunk.  Going in, I was sure I would need to strip the parts all the way down and repaint them to make it look decent.  Lots of scrubbing later, here's what the boiler looked like:

Kind of interesting side note - I could have taken off all the copper with just paint stripper.  I noticed that when I wiped off the paint stripper residue, it was blue from oxidizing the copper.  Scrubbing was much faster though.  I used some glass stovetop cleaner, which is very gently abrasive and won't scratch the chrome.  Steel wool probably would have been much faster, but I didn't have any on hand.  Steel is softer than chrome, so I don't think it would have scratched the chrome.  

The base wasn't in quite as good shape as the boiler, but was able to get most of the blemishes out with scotch-brite and sandpaper.  In the end it doesn't look as nice as the glossy boiler, but the smooth brushed look is still much better than it started out.  Here it is going back together:

I stuck the logo back on with some 3M VHB foam tape:

The fully assembled machine:

Once it was back together I ran two rounds of Dezcal descaling solution through it, did two rounds of letting it sit full water with a couple spoonfuls of baking soda dissolved in,  and filled/boiled/flushed the water probably a dozen times to make sure dirt and all the chemicals I used were out of the system. 

Then it was ready to go.  Here's pulling a shot of Red Bird Espresso to test it out: