Conti Prestina Espresso Machine Restoration 101 (Completed and Indexed) - Page 9

May 4th, 2011, 10:40 pm

As of last night, I've knocked the washers off the back part of the boiler so all I have is bolt ends. Someone who used to repair these advised me on the Picasa site to take a stiff putty knife and wedge it at the gasket and then hammer it to free the back side of the boiler, which would help remove the other bolts. He advised against a chisel to avoid disfiguring the surface that weds with the gasket. So I tried that with mild blows to a flexible putty knife and it didn't yet budge because the gasket and sides of the boiler are very hardened to each other. I'm ready to try a stiffer putty knife. But I wonder if applying heat (how much?) and penetrating oil might also help soften up that gasket seal?

http://users.rcn.com/erics/ · #82: Post by **erics** » May 4th, 2011, 11:18 pm

Since the idea is to eventually separate the halves, you might consider using many non-metallic wedges and a lot of patience. Let the wedges do the work.

The emphasis is on many - something SIMILAR to the shims used on door/window frames.

#83: Post by **RayJohns** » May 4th, 2011, 11:50 pm

you might try getting some of the razor blades with the folded metal backs (which are very thin) and taping them down into the seam. Then wiggling them around. At some point you may be able to break the seal. The other thing, if you can obtain an air tight seal is to try putting pressure inside with an air compressor. Sometimes you can apply 10 or 20 PSI and pop things open (just be careful, because you can create an sort of bomb there if you aren't careful).

As long as you don't go crazy with the heat, it shouldn't hurt anything.

Ray

#84: Post by **Warrior372** » May 5th, 2011, 12:28 am

I just use a short and thick flat head screw driver along with a rubber mallet when I run into boilers that are seemingly sealed shut by an ancient gasket. Pound it in and pull it back.

May 5th, 2011, 12:58 am

Mike,

Do you pound it into the center of the gasket material? Also, is there any chance of marring the surface where the gasket needs to seal? In other words, have you had any problem with that after getting the separation done? The Conti repair tech warned against using a chisel, and your approach seems similar. And Eric recommended using many non-metallic wedges and letting them do the work. That seems like a safe way to go while getting the same result. But I started looking online for wedges and don't know what will be hard enough and have a narrow enough edge without being metallic. This is one of these "measure twice, cut once" situations where I want to think about how to do this and avoid having to re-machine the boiler gasket face or use some super type of gasket that would fill in irregularities.

#86: Post by **RayJohns** » May 5th, 2011, 3:21 am

you might pickup some wooden shims from home depot (for hanging doors, etc.) and see if you can hammer those in.

Also, they make plastic putty knifes that can often work along the same lines (you might have to cut them up into wedges though).

Ray

#87: Post by **Warrior372** » May 5th, 2011, 8:33 am

None of my machines leak

. I do pound it into the middle of the gasket. I have never damaged the metal surfaces on either the faceplate or the boiler side of a machine doing this, not to say you could not. I have never been in a situation where I needed to use Herculean power to pry one apart either. Since you are going to have to descale it anyway you might want to pry it apart as best as you can , if it is a paper gasket, and then just throw it into descaler solution now to help loosen it up (I use citric acid). That should help soften the paper gasket a bit. In this particular situation both have such thick metal surfaces you would really have to use some muscle to damage either. You could always sand it down too.

If you do not like that approach they actually make paper gasket remover. It is very commonly used in the automobile world to remove baked on gaskets: http://www.permatex.com/products/Automo ... emover.htm . It turns paper gaskets into mush.

May 5th, 2011, 9:20 am

Thanks everyone. Mike, I think I'll give your first suggested approach a try this weekend. It seems simplest and doesn't require any tools beyond what I have. If that doesn't work, the gasket dissolver and/or wedge approach is next. Last night I tried a stiff putty knife-like tool, and it just bent. It needs more thickness like a flathead screwdriver to drive into that hard gasket.

May 5th, 2011, 12:01 pm

Before leaving this morning I tried Ray's suggestion to wedge in a one-sided razor blade. The seal was too hard to allow any penetration. So on to the screwdriver taps when I've got a chance.

May 5th, 2011, 4:26 pm

Can you soak the boiler in water to attempt to soften the old gasket? I did this with the 2 MCaLs that I worked on in the past, seemed to help....