Conti Prestina ARRIVED!!

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TheWhiteYeti
Posts: 34
Joined: 5 years ago

#1: Post by TheWhiteYeti »

So my Conti Prestina finally arrived after a customs delay! Only one bend in the front panel as far as I can tell. It seems like it's probably had some work done prior to me getting and I was hoping some more knowledgeable people could help me identify what changes from the original design you see.

I don't think the PSTAT is the original and it looks like a piece of plastic is being used as the seal between the boiler and front plate.



I'm thinking I want to add a PID down the road, maybe a 9bar spring, but that'll depend on how she pulls with the current one. Very happy with it and thankful it arrived without much DMG!!

Paolo
Posts: 550
Joined: 17 years ago

#2: Post by Paolo »

CONGRATULATIONS!!!! The mighty Prestina has arrived!!

There couldn't be that many in circulation. It is great that you managed to snaffle this one...

It looks like the previous owner/s cobbled together bits here and there to keep vital signs happening. But it looks to be complete.

How do the body panels look?

This machine is aching for a sympathetic restoration!

Looking forward to seeing how you progress with this piece of espresso history.

TheWhiteYeti (original poster)
Posts: 34
Joined: 5 years ago

#3: Post by TheWhiteYeti (original poster) »

The body panels are in good shape other than the minor bend from shipping. Currently have the group cover off and am liking that.

I agree it could use some good cleaning, replacement of some poor fixes, and maybe new wiring (I like DrGarys color coding).



I honestly couldn't be happier, I had planned on spending a few years to track one down, very thankful for my dad who flew to Montreal specifically to get this and ship it to me in Seattle!

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grog
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#4: Post by grog »

That is probably a Teflon gasket which is fine, but may merit replacing in any event.
LMWDP #514

mikel
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#5: Post by mikel »

Congrats!
And luckily yours was serviced- while bolts are a mix, they look to be in way better shape than those on my Prestina when it arrived.
And it looks like they made two different boiler plates, some with a single element opening like yours and others with two separate holes for the element ends. Mine has two element holes and the aluminum sleeve on the group.
Cool machine!

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drgary
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#6: Post by drgary »

A quick look shows a machine in fairly good shape, assuming the heating element works. Pressurestats often aren't original and can easily be changed out. It looks like the group is attached with bolts rather than studs. I would change that out for studs and refresh other fasteners and washers with marine-grade stainless steel, slathered with anti-seize compound. The water and steam valves look like they're fastened with copper crush washers. If you refresh the rest of the machine and those valves don't leak, you're good for now. If they do leak, you'll need to disassemble and replace washers, o-rings, gaskets and such. A PTFE (Teflon) boiler gasket and group to boiler gasket aren't bad if they are still sealing. I would attend to the rust starting on the base, maybe touch-up and repaint. You'll probably need to refresh the piston gaskets and lube the lever pins. Anyway, those are things I would consider for now. When you fasten the boiler bolts an experienced Prestina tech told me to secure them at 15 ft/lbs, which you can do with a torque wrench. I got an inexpensive one of those at an auto parts store and have been able to fasten down those bolts so they hold. Once you put it back together and pressure test, you may need to tighten down the boiler bolts periodically until they're well seated. The bent front plate may be a challenge, because once something is bent, it's hard to remove the crease -- although the bend doesn't look severe, so you may just want to live with any residual bend once it's fastened down.
Gary
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What I WOULD do for a good cup of coffee!

negrocorto
Posts: 133
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#7: Post by negrocorto »

Yes, congratulations!

I don't know what's original and what's been added or changed, but I can tell you the differences between yours and mine when I got it. According to the people at Conti in Monaco, based on the info I gave them, mine was manufactured in the 60's, and it has the same one-piece cylinder like yours. Mine did not come with any electric switches; it simply turned on when plugged in; yours seems to have two switches. Also, mine did not come with what looks like an anti-vacuum valve like yours has. And as has been mentioned, that pressurestat doesn't look original.

Besides cleaning, descaling, and replacing all that I could, I had all the painted parts powder coated, and that took care of the rust on the frame while making it look great. Lastly, I would recommend insulating the boiler with some kind of non-toxic pipe insulation; the element will turn on and off less frequently, and the boiler will still generate enough heat to keep your cups warm on top of the machine.

turboyeast
Posts: 143
Joined: 11 years ago

#8: Post by turboyeast »

LS.,
I have a Conti prestina that arrived in a remarkable (total) original state.
It is equipped with a (more recent) 3-piece group. My take on the group is that the latter is less expensive to manufacture.
My machine produces 5 bar springpressure. In general I have not been able to produce satisfactory shots. There is a thread re: this machine somewhere here. Next week Iam going to install a stronger spring. I really hope that this improves the shots, otherwise I will shelve this machine permanently.
The marks on the pressuregauge indicate resp. 0.6 and 0.8 bar. Mine has a third mark indicating 1.1 bar.
Good luck, TY

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drgary
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#9: Post by drgary replying to turboyeast »

TY, I installed a new spring when doing my original restoration and the shots please my palate more than any of my other machines, so I wonder if the piston seals are in good shape or whether there is wear inside the cylinder. If your new spring doesn't give you satisfactory pressure, have you thought of adding a booster spring that would sit inside it? Double springs are a common practice.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

TheWhiteYeti (original poster)
Posts: 34
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#10: Post by TheWhiteYeti (original poster) »

Thank you all for the suggestions and tips - keep em coming :D I am realizing how much I have to learn and that I need to be patient when working on this machine.

I was able to disassemble the group yesterday and do some preliminary cleaning. I didn't notice any corrosion inside the group and the main seals looked okay (although, I still will replace those). After reassembling, I was able to fill her up and turn her on (when my dad picked it up he was given a demonstration, so we knew everything functioned)
drgary wrote:A quick look shows a machine in fairly good shape, assuming the heating element works.
No issues with the heating element from initial testing (looks to be a 1400watt element based on the Conti Plate).
drgary wrote:Pressurestats often aren't original and can easily be changed out.
PSTAT seemed to be set on the low end. The gauge didn't quite make it up to the first red bar (H20 temp around 185). I'll see how I like this PSTAT, but long term I'll install a PID.
drgary wrote:It looks like the group is attached with bolts rather than studs. I would change that out for studs and refresh other fasteners and washers with marine-grade stainless steel, slathered with anti-seize compound. A PTFE (Teflon) boiler gasket and group to boiler gasket aren't bad if they are still sealing.
Any idea on the length of the studs? I heard an air leak that seemed to be coming from where the group attaches to the boiler plate. (Maybe the teflon gasket is to blame, but when I pull the group off id like to replace the bolts and the gasket).
drgary wrote:The water and steam valves look like they're fastened with copper crush washers. If you refresh the rest of the machine and those valves don't leak, you're good for now. If they do leak, you'll need to disassemble and replace washers, o-rings, gaskets and such.
Luckily no leaking here, although I do need to clean the water spout (it spurted out hot water instead of having it flow nicely out of the 4 holes - especially as the water level got lower)

I did attempt to pull a shot out of it and quickly realized I need to replace the o-ring that sits between the bottom portion of the group and the middle section (water leaked between the two). I'll post a picture in the next post.

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