ID19 brakes - can I re-make my own Silent Block mountings?
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Thread: ID19 brakes - can I re-make my own Silent Block mountings?

  1. #1
    Fellow Frogger!
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    Default ID19 brakes - can I re-make my own Silent Block mountings?

    Hi all,

    i am reconditioning a pair of front brakes calipers for my 1962 ID19. The front mount in front of the radiator uses a Silent Block fitting to isolate the brake unit a little from shock. These are available from Europe at about $35 each incl postage.

    ID19 brakes - can I re-make my own Silent Block mountings?-image.jpeg
    Now the rubber on mine disintegrated getting them off the calipers and was blown away by hydroblasting. So I have clean inner bush and outer unit as seen in the photo. The ID of the outer part is about 26.7 mm and the OD of the bush is exactly 21mm. So the rubber took up about 5.7mm meaning it was around 2.85mm thick.

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    would I stand a chance of sourcing a rubber bush, some rubber hose or a piece of rubber sheet to make up my own Silent Block ? Has anyone done this? I cant see it would be too difficult although I suppose the challenge is to make sure that the rubber does not get squeezed out of the assembly under braking? The silentblock rubber was definitely glued or vulcanised onto the assembly but had gone hard as bricks and crumbled to small grains.

    Am I dreaming to think of making my own? Alternatively does anyone "rebuild" silent blocks in some specialist industry? Should I just buy some and wait for delivery? Has anyone any spares lying around they could sell me new or good secondhand?

    look forward to any insight. These were on ID and DS up to 1965 so on all Aussie IDs.

    regards leconte
    1962 Heidelberg ID19 "Axel"
    1965 Heidelberg ID19
    half owner 1974 GS 1220 Convertisseur Break

  2. #2
    VIP Sponsor 59 Floride's Avatar
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    Silent bloc bushes are easy to remake and the minimum quantity of polyurethane rubber available will cost $68. So you will need to weigh up if it's worth it bearing in mind that the 2 part rubber can be used to make other rubber bits and pieces.


    http://www.barnes.com.au/polyurethan...elastomer-1360

    The process: If you are reusing the same steel tubes they will need to be thoroughly degreased and scoured with course grit paper, file etc. this will ensure a permanent bond. Make up a simple jig to hold the tubes in the correct position. Mix the polyurethane quantities accurately or the rubber will probably not reach full strength.

    Working quickly, using a finger, massage the liquid rubber into the tube surfaces to be bonded, this will force the rubber into intimate contact with the metal (else it may trap minute air bubbles). Secure into jig and pour in rubber. The rubber will take 7-9 days to cure to full strength.

    I recommend 'shore 65' for general use.



    Attached Thumbnails Attached Thumbnails ID19 brakes - can I re-make my own Silent Block mountings?-img_3011.jpg  
    Last edited by 59 Floride; 23rd January 2016 at 11:15 PM.
    Buttercup, robmac, Lasya and 1 others like this.

  3. #3
    Fellow Frogger!
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    Thanks so much 59 Flouride! I had no idea how they were made. Given this info it is something I could try "at my leisure" but maybe not this time. I would need a pretty good jig to hold the inner ring exactly true and centred within the outer one although I suspect knowing how it is attached it is probably not critical. I am flad I asked and I suppose if anyone has two of these handy locally it would save me a few weeks wait.

    Cheers leconte


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    1962 Heidelberg ID19 "Axel"
    1965 Heidelberg ID19
    half owner 1974 GS 1220 Convertisseur Break

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    Hi again 59 Flouride,

    What is the shelf life of the 2 part solutions? Could I expect a few years out of them? How well does it flow into a gap less than 3mm? Is it like water, liquid honey, or thin/thick grease?

    Maybe I would tackle it. I love conquering DIY challenges and acquiring new skills like this.

    Regards leconte


    Sent from my iPhone using Tapatalk
    1962 Heidelberg ID19 "Axel"
    1965 Heidelberg ID19
    half owner 1974 GS 1220 Convertisseur Break

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    VIP Sponsor 59 Floride's Avatar
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    The shelf life would be 12 months at room temperature but I've kept product in the fridge for 24 months no problem (just don't mix the lids up).

    Naturally you do the mixing at room temperature and it has the consistency of honey, thus a steady stream can be drizzled with a fair degree of accuracy from a small mixing cup (also available from Barnes). For me, I often use a plastic syringe to inject the rubber into small moulds or silentblocs. Clean up immediately with acetone.

    If you have a look through my Fregate resto thread you will see many examples of making unobtainable rubber parts.

    ProjectGenevièvehttp://www.aussiefrogs.com/forum/res...nevi%E8ve.html

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    Fellow Frogger! Don B. Cilly's Avatar
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    Impressive.
    Would this compound be any good for making things like seals for LHM, or would there be one that is LHM-resistant?

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    VIP Sponsor 59 Floride's Avatar
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    Excellent question, I have asked my suppliers about oil and fuel resilience and they were reluctant to commit an opinion either way. I have conducted crude tests by soaking cured rubber in petrol and oil and couldn't find any deterioration in the short term. I have a silent bloc currently in use in my Fregate and it gets a constant oiling from an engine oil leak, so far it doesn't seem to be effected.

    But take these comments as being from an informed amater not a petro chemical specialist. Best to conduct your own experiments with LHM.

    Cheers G.

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    Quote Originally Posted by 59 Floride View Post
    Excellent question, I have asked my suppliers about oil and fuel resilience and they were reluctant to commit an opinion either way. I have conducted crude tests by soaking cured rubber in petrol and oil and couldn't find any deterioration in the short term. I have a silent bloc currently in use in my Fregate and it gets a constant oiling from an engine oil leak, so far it doesn't seem to be effected.

    But take these comments as being from an informed amater not a petro chemical specialist. Best to conduct your own experiments with LHM.

    Cheers G.
    A (very) quick review of chemical resistance tables indicates that polyurethanes in general have good or satisfactory resistance to mineral oils. However, if I recall correctly, the data sheet for Sikaflex 227 states only "temporary resistance to fuel and mineral oils". Possibly depends on the particular polyurethane.
    roger

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    Fellow Frogger! Don B. Cilly's Avatar
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    Rubber resistance chart.
    I found a huge one at http://mykin.com/rubber-chemical-resistance-chart .

    I then checked resistance to mineral oils, synthetic oils and gasoline.
    Put them down in a text file. Which I am attaching as I can't find a way to format it decently here (even tried CODE tags).
    Added a row for "motor oils" in general... fwiw.

    So, Polyuretane scores pretty good.
    Not as good as Viton or Kalrez, but not bad, especially as mineral oils are concerned.
    It scores "doubtful" on synthetic oils, but... you're not supposed to use those in Ds

    What I can't find out is whether the more widely resistant compounds are available in easy-to-mix form.
    Attached Files Attached Files

  10. #10
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    Too late now, but should such an HTML table show up again with all that garbage stuff in the margins taking up screen room, if you don't have a suitable WYSIWYG editor you could do this-

    1. Invoke user CSS to emulate an old fashioned text only browser.
    These can be found online if you don't have one. This step eliminates all the prettying up.

    2. Copy the table now clearly shown as text into an editor. Like this-
    ID19 brakes - can I re-make my own Silent Block mountings?-rubber.jpg
    Attached Thumbnails Attached Thumbnails ID19 brakes - can I re-make my own Silent Block mountings?-rubber.jpg  
    Last edited by seasink; 28th January 2016 at 01:08 PM.

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