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  • Silvia quieting

    Hi all,

    has anyone had any success with quieting down the pump on their Silvia? Its not _terribly_ noisy but I live in an apartment with paper-thin walls and I would quite like to hush it up a bit. ( The Rockys another matter! ).

    I cracked it open (see pic) and found the pump is already isolated on very flexible mounts. Despite that, seemingly a fair bit of vibration still gets transmitted to the body, and possibly to the counter.

    Its a lot quieter running it with the panels off, so it seems most of the problem lies with resonance there, or in loose-fitting joints. Theres a mid-frequency clacking that radiates directly from the pump but its less bothersome than the lower-frequency vibration from the bodywork.

    Some initial possibilities that occur to me are:

    * Filling the pump recess with some sort of dense, sound-deadening ( removable! ) fill.
    * Applying some sound-absorbing liner ( which I happen to have ) to the panels.
    * Improving the damping in the joints somehow ( silicone sealant or tape? ).

    Has anybody had similar experiences? Either way, your learned opinions would be much appreciated.

    Cheers,
    Liam

    N.B.
    Gday Liam...... Please keep image size to a maximum of 640x480 pixels to ensure it is easily viewable in most browsers to avoid excessive scrolling, can be very annoying....

    Thanks,
    Mal.



  • #2
    Re: Silvia quieting

    Not sure whether its appropriate to place any foreign material in there, but if you decide to explore that option I would suggest going to a motorcycle spare parts shop and having a look at the sound deadening material they use in mufflers. It costs about $15 - $20 & comes in a plastic bag. Kind of looks like lambswool (but isnt). Pretty sure its heat & fire resistant too.

    Good luck

    Comment


    • #3
      Re: Silvia quieting

      Liam,

      Be very careful when placing any sound insulation around or near the pump. Like all electrical devices they get hot and rely on air flow over the surface to dissipate the heat. Sound insulation also tends to be thermal insulation...

      There is a good chance with insulation you will cook your pump! And then it will be really quiet - in fact DEAD quiet

      There is a reason the pumps arent insulated - and it isnt that the manufacturer is a cheap skate either!

      Comment


      • #4
        Re: Silvia quieting

        Thanks JavaB and SamR, thats good advice. I dont want to silence the pump that way!

        Seeing as I already have the liner, I might start off with that. Its some super-heavy vinyl that Jaycar sell for deadening car doors. Thats a pretty similar application so hopefully it will have an effect.

        I just went down to the hardware store for some spray adhesive to stick it on with and grabbed some thin weatherstripping while I was there. Ill try putting that in any joints to take care of any stray rattles. Will report how it goes.

        cheers,
        Liam

        Comment


        • #5
          Re: Silvia quieting

          Gday again Liam,

          The image below (extracted from a Bezzera BZ-99 Parts Manual) depicts the method used by Bezzera to isolate the pump from the rest of the machine (highlighted with red circles) and may be something that you could consider. This is an excellent isolation mechanism and still allows for ample air circulation....

          Cheers,
          Mal.

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          • #6
            Re: Silvia quieting

            OK, this is just an idea - dont know if its silly....

            Maybe you could tape some of that sound deadening material you already have to the back of Silvia, on the OUTSIDE of the unit. Might not look pretty but might give you some idea of whether its effective or not???

            Comment


            • #7
              Re: Silvia quieting

              If its quieter with the panels off then its either panel vibration or resonance. The first can be fixed by putting something soft like some felt between where the panels touch adjacent components, the second could be fixed with tar-loaded liners (or similar) as youve suggested (basically what they layer all over the floor pan and firewall of vehicles for the same purpose). Lead is another option if you can find it in this sort of configuration but itd have to be adhesive otherwise youll just recreate the problem in the liner. A friend of mine made a sub-woofer enclosure and lined the inside with lead sheeting to increase its dampening characteristics.

              Comment


              • #8
                Re: Silvia quieting

                Thanks for resizing my pic, Mal. I didnt realize it was huge till it went up & then didnt know how to fix it.

                The Bezzera diagram looks like a spring clip holding the pump to a damping block, is that right? I was initially thinking something like that but didnt know what to use for the damper. Maybe one of those gel wrist supports they sell at office shops?

                Further inspection has directed my suspicion to the top panel. It sits on four spring-steel clips that create about a half mm gap everywhere else. It also floats free all along the front, just over a ridge on the inside of the face panel. Ill definitely be weatherstripping that, maybe also around the watertank.

                None of this is to cast aspersions on Silvias quality, of course. The general construction is excellent, and clever. If the Rancilio engineers had set out to make it silent, Im sure it would be.

                Anyone else trying the liner, dont use Bostik Spray & Stick. It has about as much adhesion as a post-it note, but then a remarkable resistance to being cleaned off. Bah!

                Comment


                • #9
                  Re: Silvia quieting

                  any deadening of noise by sealing between the body and the panels will restrict the airflow inside the machine so that everything runs hot not suggested
                  sometimes putting the machine on a rubber mat helps this problem

                  Comment


                  • #10
                    Re: Silvia quieting

                    Can you try standing Silvia on something that will absorb vibrations, like a piece of "yoga mat" ?

                    Comment


                    • #11
                      Re: Silvia quieting

                      Its a coincidence, cos I had the hood off on my Minore on the weekend trying to see what makes it tick. And one of the things I was going to check out were my options of decreasing the vibe through the machine by the pump. I ended up chopping some rubber hosing into small rings and making little feet that the pump sits on. I also stuck some rubber grommets on the mounting bolts to assist. It did help a bit, probably more than I though it would. I would stay away from covering the pump altogether for the already mentioned puposes.

                      YeeZa

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                      • #12
                        Re: Silvia quieting

                        Well, Ive managed to get some of the liner onto the interior partition using regular contact cement ( I used Cargrip ), which worked well. The partition floats free at both ends and rings like a bell if you tap it, but it clunks like a piece of wood with the liner on, so thats promising. The liner is the square of grey in the pic. I put another rectangle on the underside of the flap over the pump.

                        The weatherstrip didnt work out so well though. Its very thin and squishy but, even so, made the backshell sit out by about 1 cm. The single screw that holds it down at the bottom doesnt exert enough force in the right direction to flatten it all out.

                        Also, it occurred to me that caulking all the gaps is going to make them retain water, which would be really bad. The whole unit is clearly designed to let water flow freely away. I clipped the weatherstrip into little bits which was a big improvement, and should also help stem the airflow problems several folks have pointed out, but it was still a bit thick. Ill have to find something thinner.

                        If this doesnt do it Ill try lining the backshell as well. Then maybe go the mousepad damper, though I think that might entail more challenging engineering.

                        Thanks to everyone for your contributions. Its an elusive problem and its great to be able to benefit from all your thoughts.


                        Comment


                        • #13
                          Re: Silvia quieting

                          Ive stuck another square of liner on the lid and found some filler to put in the joints. It was some very thin closed-cell backing from a stainless steel Ikea placemat I got for making a rocky chute out of. Even that was a little thick for the backshell joints, but it was good for around the lid. Thats the little grey bits around the edges in the picture.

                          Possibly Im in denial about having wasted my time, but I think theres a noticeable improvement. The pump noise is still loudish but the upper end has been attenuated, making it less of a harsh buzzing. I reckon Ill see how that goes for a while before lining the backshell or taking other steps.

                          One thing that concerned me a little was the lid lining is now right over the boiler where it gets hot. I took it off to have a look while it was still warm and nothing had melted, but it could deteriorate over time.



                          Comment


                          • #14
                            Re: Silvia quieting

                            Meh, after a weeks trialling, I have to concede this didnt make any worthwhile difference. Either I didnt go far enough or my thinking was flawed. Further contemplation suggests that the vibrations are transferred hydraulically to the boiler and thence basically to the whole machine.

                            Another approach might be to replace the ulka pump altogether with a fluid-o-tech one. Thats what Mals Bezzera uses and I saw one vendor that claims theyre the quietest. The fluid-o-tech catalog states explicitly they employ some sort of quieting technique.

                            Comment


                            • #15
                              Re: Silvia quieting

                              Hi again liamth,

                              Dont know if changing out the pump for another type is such a good idea mate.... Chances are that the existing pipework/fittings may not fit and you will have to bugger around with adaptors and such to get the Fluid-o-Tech plumbed in.

                              Ive never played around with a Silvia but did own an Imat Mokita which has a similar list of internal components and discovered that so long as none of the high-pressure pipework is touching the panel-work anywhere, it operated very quietly. Conversely, it could become very noisy very quickly if the pump rotated a bit and the back panel touched either the pump fitting or part of the pipework.

                              Id really go for the simple measures first if possible, rather than change-out the pump. Maybe you could record the sound the pump makes, compress the resulting file into a ZIP file and attach to your next post. Might help some of the long term owners of the Silvia help you to identify whats going on? All the best mate ,

                              Mal.

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