Much Progress Today
To follow up on past issues:
- Tested the circuit and did not have a switched neutral outlet. Thanks, Pat, for showing me how to check that.
- Replaced the gooey electrical tape with Rescue Tape.
- Installed a green pilot light on the right, tested pilot lights and they work to show when the machine is powered on (right green) and when the heating element is powered up (left red on).
- Fastened the pilot lights in place using Blu Tac and soft thread sealer. Used cable ties to tighten pilot lights too. Here's a photo:
Here are cable ties on the other circuits. I've left the hot (black) lead to the PSTAT long because it will need more length to connect with the Sirai PSTAT I'll install within the next few days. I'm again considering using a terminal block in the back to make the wire runs neater but I may live with it as it is because it works.
I sourced a miniature ice cube tray on eBay that fits well as a drip tray. This one's 1 inch deep. I could use something up to 1 3/4 inches but a drip tray is better than no drip tray.
Then I began to prepare the case parts for installation. This began with final clean-up, starting with the brushed stainless steel parts I intend to use. I had covered the workbench with an old (and ugly) towel to prevent scratches. While the polishing and prep was going on I brought the Prestina up to temperature to tighten the boiler bolts back to 15 foot lbs. The bottom bolt had begun a slow drip again, so this heat cycling is essential.
I should have looked at the backs of the panels first. There were some rust stains to deal with and buffing compound from long ago. I polished off the rust stains with a felt tip coated with Mother's Aluminum Polish. The I went over the smudges caused by handling these panels on the fronts again, and I was ready to attach them.
I took a break for lunch, turned the machine off and tightened all bolts to spec. When I returned I laid out the case parts for assembly. Sequencing things this way would allow the machine to cool so I could attach the case comfortably.
When I first took out the sheet metal screws I was concerned I'd gotten the wrong size because they were too small to grip the case. Then I vaguely remembered that these were fastened together with sheet metal screws and what I'll call "spring nuts" for lack of vocabulary, but I wasn't quite sure which ones and where. Old high res photos were helpful as well as just puzzling it out. I got out the spring clips and coated each nut and each new screw with anti-seize compound to prevent rust. After the way this started, I HATE rust! I replaced the old sheet metal screws with slotted heads with Phillips head screws because I also HATE stripped screws and fumbling to get a screwdriver to fit the slot. The old screws had also rusted a bit.
Here's how these work. When tightened the spring nut tensions against the frame for a very nice fit.
Now I began to attach the case panels, starting with a side and back panel. I checked an old photo to make sure the orientation was correct.
I was easily able to attach the two side panels and the Conti badge to the back. Now I had the back and sides together. But it's good I had some time. Because I don't have an installation manual, I redid several steps while figuring out how to assemble things and in what order. I began by taking off the group to position the front panel but found that with that panel attached, I couldn't attach the group. So I removed the panel, reattached the group and removed the portafilter holder. One of the hex screws is hard to get to this way. I managed it with a long hex key but would have done better to remove it while the group was removed. Well, I was finding my way.
Next I tried to attach the back and side panel assembly using the large chrome screws in the front that connect with square nuts encased in clips. At first I got these backward until I realized I couldn't reach the bottom nuts to tighten down the screws. Here's one installed backward.
Here's how they should go.
This is because the spring nuts fasten into square holes in the case, like this. But at first I couldn't get them in. The newly powder coated case left a narrower opening, so I had to use pliers to compress the clips slightly to get them to fit.
So I fastened the back and side panel assembly to the front plate and fit the cup tray on top, only to realize I hadn't attached what I'll call sandwich nuts, which clip the frame edge from both sides. It turns out these must be very precisely aligned. I realized the best way is to fasten the cup tray onto the side and back panel assembly before attaching to the front panel. Anyway, it's good I had time. I'm writing this so the next poor bugger who reassembles a Prestina doesn't have these headaches. Here are two sandwich nuts in place. I had to move them around a bit to align them with the screw holes in the cup tray.
Okay. NOW I was ready to attach the entire back case to the front, and it connects with just four large chrome screws through the front plate. And finally my Prestina could try on his new clothes!
There have been some happy accidents with this restoration. One of those was my inability to create a mirror polish. I think this machine looks much nicer with a brush finish.
Also I'm following Doug's suggestion to leave the group cover off to display the amazing engineering of the group. I'm really glad I did that. It makes this machine look well proportioned, not awkwardly boxy. Another fortunate accident is the color coordination between the frame panels and the brass parts in the group and the steam and water taps. The color is intended to match our granite counter. Also replacing the group cylinder with a new brushed aluminum one matches the brushed steel panels. The machine looks completely updated. I didn't think a Prestina could look good. I certainly didn't think a Prestina could look this
Still more to do, but this is really close to done. Next steps will be:
- To complete the drip grate after the steel plate arrives early next week;
- Insulate the sides and back of the boiler; and
- Install the vacuum breaker and the Sirai PSTAT. The pipe and fittings should also arrive on Saturday or early next week. After seeing that the back case comes off in one piece by loosening four screws I'll position the Sirai horizontally as the manufacturer recommends. This will also require making a bracket assembly similar to that used long ago by Bill Jackson.
If I feel ambitious in the future I may create a custom brushed steel panel that fits behind the group. Getting a flat fit will require an elbow fitting to replace a steam pipe that protrudes about 2 to 2 1/2 inches outward from the front boiler plate, but that would give a finished look. I'm still holding onto the old case parts should anyone want to restore this machine to its original configuration in the future.
To think this project came from searching for a Cremina for $250!