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Can't remove hardened La Pavoni sight glass seals

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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Thu Jan 14, 2010 11:41 pm

I am in the process of rebuilding a really old La Pavoni Europiccola - the kind where the group itself is threaded directly onto the boiler rather than having a flange and bolts. Also my sight glass brackets are cast as part of the boiler ie they dont screw off. Which leads me to my problem:

I am having a problem getting the two site glass seals out of the unit. I have removed the two nuts and the two brass washers but the black seals below them are absolutely rock hard and seem to be cemented in place. no amount of stabbing about with a screw driver, pointy thing or knife seems to help and I am starting to damage the brass thread with all this poking. Does anyone have any ideas about getting these out? something to soak them with? something that might dissolve or weaken them? I am really at my wits end and would appreciate any advice out there
cheers, Aaron
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Link to "Can't remove hardened La Pavoni sight glass seals"by Chert on Fri Jan 15, 2010 12:37 am

Hi Aaron,

I have not worked with a Pavoni that was that old or had that issue so I wish you luck on that one. I hope your email is correct as I have an unrelated question.

Thanks,

Flint
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Fri Jan 15, 2010 2:12 am

I was just wondering if I heated the whole thing up with a gas torch weather it would melt the seal out?
I guess they are designed for high temp applications, but its the only thing I can come up with at this point.
I'm also a bit worried it would just fuse it into the brass thread in the hole even more.
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Link to "Can't remove hardened La Pavoni sight glass seals"by ademello72 on Fri Jan 15, 2010 3:24 am

Hi Aaron,
You might try Will at http://www.espressorepair.com - Last time I was in there, he was working on one of the old vintage La Pavoni machines the same as yours - He may be able to provide you with some insight.
Also try Doug and Barb at http://www.orphanespresso.com/ - I'm sure they may have seen a similar vintage machine through their workshop at some point
Good Luck
Anthony
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Link to "Can't remove hardened La Pavoni sight glass seals"by itsallaroundyou on Fri Jan 15, 2010 1:04 pm

there are a whole assortment of organic solvents that attack rubbers and plastics. They are hard to get a hold of and pretty volatile, but sometimes they're the only solution (sorry, couldn't help the pun). Toluene or methylene chloride would probably soften it, if not dissolve it completely (you'd need to soak it for a while though, since they are so hard). Acetone also dissolves plastics, so maybe a soak in that is worth a shot before going to the extremes. i've read methyl ethyl ketone (MEK) and tetrahydrofuran (THF) might work (these two are nasty solvents and not to be handled carelessly).

I've used all of these solvents fairly extensively in a chemistry lab setting, in a fume hood, so if you need to use these, do it outside, with plenty of fresh air and ABSOLUTELY no chance of spark or flame nearby, as these are all volatile enough to explode. Don't forget gloves and goggles too :) (can you tell i used to teach lab safety to reckless college freshmen).

good luck!
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Link to "Can't remove hardened La Pavoni sight glass seals"by happytamper on Fri Jan 15, 2010 1:37 pm

I had similar problems with seals and gaskets on old machines. What I would do is use a dremel and this would remove the seal by shredding the rubber. Only be careful not to go too far and grind the metal.

Good luck.
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Link to "Can't remove hardened La Pavoni sight glass seals"by CRCasey on Fri Jan 15, 2010 8:57 pm

I would put a good bet on MEK. Just use good ventilation.

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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Fri Jan 15, 2010 10:45 pm

Thanks for the replys, Its just nice knowing there are people out there giving moral support.

Using a dremel is not really going to work as the sight glass ends are permanently mounted to the boiler, so getting the dremel bit in there is nearly impossible. I have been chipping away it the bottom one with a knife and very small screwdriver, but the seal is fused into the thread which is why I was wondering about solvents.
I am not sure how to use acetone as I think it would evaporate before it had the chance to dissolve anything.
I might give Orphan a call and see if they have any insights.
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Fri Jan 15, 2010 10:52 pm

Just another quick question:
Is MEK the same as Methyl Ethyl Ketone Peroxide?
which I can easily get hold of as it is the catalyst for Polyester resin.
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Link to "Can't remove hardened La Pavoni sight glass seals"by orphanespresso on Sat Jan 16, 2010 12:39 am

It sounds like you got the glass out so that is half the battle. Your current approach seems to be falling short as you are possibly buggering the threads, but the small screwdriver approach when done carefully (or use the screwdriver like a chisel) and then clean out the threads with a right angled pick, which you may have to make. If you have a small butane torch you can actually burn them out without getting the metal too hot or discoloring the chrome. Applying small flame, controlled, to the old seal will make it crumbly and you can use the pick to chase the threads clean, or a little wire brush can work as well.
Careful patience is the key and if you begin to get impatient or in too much a hurry put the job aside and come back to it later. A lot of times if you can get one small section completely out the rest can be pried sideways hard enough to snap and come out in pieces. As much as I like the solvent idea, since I work on other people's machines it doesn't seem good to be adding potential carcinogens et al to a food preparation appliance.....my own stuff maybe as a last resort.
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Sat Jan 16, 2010 6:15 pm

Thanks for the advice Doug, I will give the butane torch a go and see if I can at least weaken it a bit.
I have been picking away at it in front of the telly each night during the ad breaks. Its a pretty slow process but I think I'm getting there.
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Sat Jan 16, 2010 6:27 pm

OK it was as easy as that!
I just used a butane torch to slowly heat the seals (lots of acrid smoke) The seals didnt really crumbled as I had hoped but the heat did make them release from the threads and I was able to wind them back out of the site glass holder threads with a small sharp screw driver.
Now on with the rest of the restoration!
Thanks a million everyone for all your help and advice.
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Link to "Can't remove hardened La Pavoni sight glass seals"by crazy4espresso on Mon Jan 18, 2010 6:26 pm

Hi,
I'm currently rebuilding a real old Pavoni myself (have a thread on Coffeegeek with pics) and elected to skip the sight glass since it wasn't leaking. After reading this thread I may consider replacing the seals after all. Just wondering if you have the screw on type heating element, and if so what your experience was in removing it? I had a doozy of a time with mine! Any scale buildup in the boiler?
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Tue Feb 02, 2010 6:56 pm

my machine was bought in pieces for a much more ambitious project. What I got was a badly abused machine missing everything south of the top brass ring on the boiler. Base, element, etc is all missing.
The boiler was very badly scaled and will need several more hours soaking in citric acid before its clean.
My current issue is that my machine has the original brass sleeve in the group head. so in order to remove it, i'm going to need to make a specialised tool to engage the two holes in the sleeve so it can be screwed out (hopefully) In my hurry to get the machine stripped down, i knocked the shower screen out of the sleeve. I am hoping once I remove the sleeve that I will be able to reinsert the screen and recrimp the brass to hold it in place. Not sure if anyone's had a go at doing that...
So sorry I cant help you with the element, I am yet to cross that bridge.
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Link to "Can't remove hardened La Pavoni sight glass seals"by ademello72 on Tue Feb 02, 2010 9:49 pm

Aaron,
I've restored 3 or 4 La Pavoni's or La Cara's with the original screw out brass sleeve
I've seen various "tools" from a wooden board with 2 nails to a custom tool all work.

The method I use though is 2 hardened nail punches, put them in a vise so they line up with the holes in the brass sleeve and rotate the group head so the sleeve un-screws.

Another method is shown here

Sorry to hear you punched out the screen first though, I'm really not sure how you'd go getting that back on again - You might get lucky find it can just be pushed back into place from the piston side

Anthony
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Thu Feb 04, 2010 12:19 am

Well even thought the screen came out, there seems to be no damage to the brass sleeve. There was lots of gunk in the retaining groove in the sleeve and I am hoping that I will be able to put the screen back in and carefully heat up the brass and crimp it back over so the screen is fixed in position again.

Thanks for the advice about removing the sleeve, I will give your method a go. Its frozen in there pretty good though. I'm pretty sure I'm going to have my work cut out for me. The other problem is that my machine is not bolted to the boiler like later models, the group is threaded and screws directly onto the boiler. I have already tried to remove it and there is absolutely no way I can make it budge. So what ever I have to do to remove the brass sleeve its going to have to be with the boiler still attached.
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Link to "Can't remove hardened La Pavoni sight glass seals"by ademello72 on Thu Feb 04, 2010 1:55 pm

Aaron,
You might have a look through this thread Replacing gaskets for Europiccola from early 60's - I believe the OP had an older style La Pavoni as yourself
Good Luck..it is worth the effort :D
Anthony
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Link to "Can't remove hardened La Pavoni sight glass seals"by aaronmaestri on Sun Feb 07, 2010 11:24 pm

Well I managed to get the brass sleeve out over the weekend using the two punches in the vice method.
The sleeve is now de-scaled and awaiting the delivery of the rest of the parts for reassembly.
I am attempting to reinsert the shower screen. Not too sure how I'll go, but its worth a try as the sleeve was not damaged by the removal of the screen.
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