KatLondon wrote:

I haven't seen it make any appreciable difference in a platen that is rock-hard and, eg, making holes in the paper when you type. 

I'll make a very long story very short: I recently picked up a machine that I am very fond of, but was really disappointed by the fact that it blew holes through the ribbon and paper both. With nothing to lose, I went to work on its platen with many, many applications of rejuvinator that I allowed to soak over the platen for 45 seconds at a time. It's now at the point where it only tears the paper on a few keys, and I think that given several more applications it might be almost considered normal. I'm not claiming that this would work in every scenario, but using half of a $6 can of rejuvinator on a platen that otherwise should be recovered seems like something worth trying first.

 

QUICKBROWNFOX wrote:

[what brand of rubber rejuvinator you use?  

I use a brand called Blow Off (see below), which is also available under the brand name Max Pro. A word of caution: this stuff is potent and you don't want to get in on any painted surfaces or inhale its fumes. My lips once went numb from using it in a small room and I'm afraid to guess how many brain cells were lost too.


 

I got a can of AF Platenclene last year and was obviously doing it all wrong! Yesterday after reading this thread I went to work on my Lettera 22, using a cloth and wettish daubs in careful applications - in the open air, blimey, it Stinks! - and there is a marked improvement in the platen after one going over. I don't think I had really investigated the state of the platen on the Lettera 22 at all since getting it. It was not very pretty at all. It wasn't giving me holes in the paper, but there was a definite bite to the impressions which obviously wasn't at all good. I'm going to give it a thorough multiple application and will report back, as I am not sure whether the stuff I have is the same as Uwe's. But from the first go, it looks like it could be worth the effort. Using gloves, of course, and staying away from the pond. Must be kind to frogs!

Update on my experimenting with the AF Platenclene rubber cleaner/rejeuvenator:
Ok, after a narrow miss with Odour Eater foot spray - kept in the same cupboard...
The 2 platens I tried it out on, have definitely improved. You have to use a good wet squirt on a rag and wipe it on and let it sink in/evaporate, and wipe over.
I did mine without taking the platen out. I wiped the platen in strips, turning it two or three lines at a time.
I also protected the paintwork of the typewriter from accidental splash/spray by wrapping all parts of the typer except platen in cling-film - two layers. I also put a thick piece of brown parcel paper behind the platen where the rag was likely to drag along the paper table. I followed Uwe's description of doing this several times, over about half an hour,  and the difference at the end was marked.
Being in the UK it's difficult, like Kat says, to get hold of the more potent rubber rejeuvenating products. I think the AF Platenclene is a good UK product alternative to Blow Off (that product name is hilarious) for a platen that is a bit too hard, where the type impression is starting to come through the paper. I just typed a letter on one of the cleaned up platens, and was able to type on both sides of the paper. The punctuation marks are no longer puncturing the paper!
But like Uwe says, the stuff is really potent and must not be inhaled or allowed to get onto your skin. Take Care!
(I also put my used rag into an old, air tight, metal tea-caddy to save it for use another time.)

 

Kat, your skin could end up being badly cracked after a lot of exposure to this stuff
I have ezcema from time to time on my hands, so I have to be extra careful with irritants.
I'm not sure I would want to be using it every week though, the smell gets to me, even outside if the wind changes!