Eames Upholstery  

I'm quite certain that when you
remove upholstery from an upholstered plastic shell, the shell itself is not the highly polished shell that you think it might be and would not look appropriate without reupholstering the shell.

If it is a padded chair,
It can be done, but it is not fun (at least doesn't sound like fun to me). The foam is most likely glued directly to the shell and will need to be picked and scraped off, followed by stripping. As barry mentioned, the shell will most likely not be gel-coated. But you would want to coat it with Penetrol anyway after stripping.
There was at least one thread here that showed pics of a padded shell being refinished.
The tutorial at chairfag.com is another resource.

React, I had a LaFonda chair
with worn, tired green upholstery and petrified foam redone by my friend here in Minneapolis (Remnants) and at no time did I assume that an upholstered shell chair could ever made to look like a chair that had never been upholstered.
My friend, David, removed the upholstery and foam and put on new foam and the Ray Eames fabric I found on eBay and it looks great.
ONE THING TO BE AWARE OF: David was NOT able to get new edge piping (and he has an account with Herman Miller) - thankfully, the piping was in good condition, and he was NOT able to restitch it to the fabric. (Seems like there's a special machine to do that that David and most other quality mid-century reupholsters do not have access to.)
Anyhow, he did a beautiful job on my chair and the edge piping is properly glued in place and shows no sign of coming apart.
I suggest you consider getting the shell reupholstered. (I'm not even 100% certain that a shell made for upholstery is the exact same shell as one that's to be polished and naked.....

Shells look okay
If you can pull all the upholstery and all the foam off the shells can look okay underneath. Despite Barry's worries the shells are exactly the same underneath with just a few things to be wary of:
1- the foam is glued on - so it's going to take a lot of elbow grease to get the foam off. I'm almost 100 % certain that there is a gelcoat under the upholstery - it would prevent the fiber from shaling off (and going through the fabric) It may be a bit dull and in need of buffing. The normal gelcoat is actually pretty dull when it comes off the assembly line - most of the shells we see have had a decade or more of butt-polishing to gloss them up.
2- some of the shell chairs were drilled with 3 small holes to let air out as someone sat on the chair - patching holes in fiberglass is a pain (but not impossible) The earliest shells had unglued pads held on by wire. Those do not have any holes, but almost all subsequent armshells do.
3- some of the upholstered shell chairs didn't use shockmount - they just drilled the bolts straight through the fiberglas. See above about patching.
At worst - if it looks totally gnarly underneath you can take it to an autobody shop and they can spray on a semigloss clearcoat that will replicate the original gel-coat. As always - post before and after pics 😀

I have a shell...
Which is basically in brand new condition. It is very shiny! I will try to post a photo later.

New old shell

every one is right on...
every one is right on their postings !!!!
I do not consider my self a expert on anything but this subject,
having redone over 350 chairs in 5 years.
When you take that cover off the chair it is taped in 5 spots the tape is dry and leaves a bad mark the foam is the worst, we use high speed buffers, and it takes 30 minutes to grind to the fiberglass( also please wear a mask). I have seen it done where someone has taken off the cover and cleaned it and it looks great, the only thing i can say about this is, They must have a lot of time on their hands cause this is not how i would want to spend a Saturday, but if it is your passion to have a fiberglass shiny seat from the factory
go for it, cause when finished you will know you have accomplished one of the most difficult things to do, to bring a shell back to life, so I would be proud of your self after accomplishing that one.
we use solvents just to kill any of the old foam and then re foam with new spray glue,
we use a crimp cord from Germany. we charge 275.00
started 5 years for $225 and the cost of foam has gone up 3 times in 5 years,
My shop foreman and partner in this business, tells me it is taking 3 hours on these shells, at shop time of 60.00 a hour, so for 90 bucks it is a big whoop for us.
It is very time consuming but every bucket and side shell looks great when it leaves, If our company is known for anything it redoing the shell chair.
i truly am glad that we get to save a Eames shell chair a Icon and truly a piece of Modern History that every one loves from the new collector to the old, every one has that chair in their collection.....

This armshell was my lucky...
This armshell was my lucky find. The upholstery was quite rundown and when I removed it I found it was only glued to the seat base without any foam, but the piping was partially glued to the shell which was perfect, with no ventilation holes either.
As for redoing the upholstery, I recently did it on a sideshell. Luckily the foam was still intact and I could do the rest 🙂

Their was a series of ...
Their was a series of chairs that Herman miller did late in the 70 where they did not use the heavy foam they just used the cover with the cord, they did that a lot on the Lafonda chairs.

Very interesting, thanks.
They do lack the longterm comfort of fully upholstered shells.
Also the fabric was crumpled and out of shape, just looked disconnected from the shell and ugly after all the years.

Glue?
I posted a question earlier but no one responded, so I'm borrowing this thread to ask the same question again:
I have a vinyl upholstered Eames shell that the vinyl is separating from the underneath foam a bit. Can anyone recommend a way to repair this? Am I going to glue down the vinyl on the foam, and if so, what kind of glue?
Any suggestions are appreciated!

arm chair without piping
LRF,
You mention a time in the 70's where they did not use the piping, and instead, just put a cover on the chair.
I recently saw one of these. It has the tags/sticker/marks, but I was hesitant to buy it because it appears the cloth is "snapped over" the edges, as opposed to the black bumper piping.
Do you know what the shell looks like underneath?

ngised: when you take the...
ngised: when you take the cover off you get a big surprise. There is no telling what colour is underneath. But since the cover has likely been on the chair its entire life, the fiberglass underneath will be in showroom condition. The back of the chair is probably painted white or black, correct?

Need your web site
This is for LRF.
I know this is over three years old, but I think you are who I contacted a couple of years ago to reupholster some Herman Miller chairs, but I lost your web site and I cannot find. Don't know if you will see this, but if so please let me know how to contact you. Thanks. You can contact me at eamel at yahoo.com (not sure I am suppose to do that). Thanks