E46 M3 - 'Subframe' Crack Repair & Reinforcement Process

Discussion in 'Redish Motorsport' started by [email protected], Jan 15, 2016.

  1. 15 Jan 2016 at 7:33 PM #1
    James@Redish

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    This E46 M3 came in to us for our 'Subframe' Crack Repair & Reinforcement.

    We went to great lengths (as with all our Subframe Repairs) to identify the definite ends of the hairline cracks that were heavily corroded.
    Along with identifying the broken spot welds which needed replacing.

    These pictures tell most of the story, but this M3 had a fair bit of corrosion on the panel we were working on, so we opted to go the extra mile and use the POR-15 Metal Prep & Rust Preventative Paints to combat that corrosion in the metal grain.

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  2. 15 Jan 2016 at 7:37 PM #2
    James@Redish

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  3. 15 Jan 2016 at 7:43 PM #3
    Mistercorn

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    You missed a bit :)

    Great job, I have the subframe off my E36 at the moment and the underneath is nothing like that in terns of corrosion, was that E46 particularly bad or are they all generally prone to rust around those areas?

    MC
     
  4. 15 Jan 2016 at 9:28 PM #4
    Rick M3

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    I think that one must have been washed out to sea in the recent floods :eek:

    Not seen one that bad before, but an excellent showcase for The Redish Treatment
     
  5. 16 Jan 2016 at 9:09 AM #5
    zed650

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    I thought mine was bad:eek:
     
  6. 17 Jan 2016 at 11:36 PM #6
    Gow

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    Now this is why I'm bringing mine to you on the 5th feb....absolutely thorough and meticulous process there
    Got to admit that looked pretty bad under there.was it a car that lives by the coast?
     
  7. 18 Jan 2016 at 7:30 PM #7
    James@Redish

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    Thanks Mistercorn!

    Glad to hear your E36 is in good shape.
    They're not all prone to corrosion levels like this.
    It's not that common, so we'd probably guess it either lived some years by a coastal area or driven a lot in the excessively salted winters that parts of Scotland may see compared with other parts of the UK maybe?

    James




    Yeah it had a quite a bit of corrosion didn't it.
    Thanks Rick, hope you and your M3 as well! :)




    Yours was OK seeing as you're coastal-ish (I guess) :muttley:




    Thanks Gary, looking forward to meeting you, and your M3 soon.
    Yeah we think it was either coastal, or higher UK/Scotland and excessively used during prolonged Salted periods perhaps?
    See you soon, James :)
     
  8. 18 Jan 2016 at 9:11 PM #8
    spawn

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    Amazing job James, hats off to the attention to detail!
     
  9. 18 Jan 2016 at 9:40 PM #9
    M3ark

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    Superb attention to detail, a shame it's completely hidden at the end.

    Do you offer a warranty for the work James and is this affected if/when a customer chooses not to have the resin injection?
     
  10. 27 Jan 2016 at 7:48 PM #10
    James@Redish

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    Hi Gavin,

    Thanks for the kind words.

    We're big fans of yours and your workmanship too!

    Best regards,
    James :D
     
  11. 27 Jan 2016 at 7:51 PM #11
    James@Redish

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    Hi Mark,

    Thanks for the message.
    Yes it is a shame it won't be often seen.
    This is a fairly standard subframe repair for us too.
    Our Underside Restorations are even more vivid: https://www.youtube.com/watch?v=yAzyc8S6boE

    Yes, we currently offer a 3-year guarantee.

    It's worth noting that we've been carrying out this repair & reinforcement process for over 5 years now without a single repeat failure in all that time. Plus the 'early' cars from day 1 to year 2 had smaller VAC Motorsport reinforcement plates, no side stitch welding, and no structural foam.

    So we're quite confident our repair will probably last most of the car's lifetime, but we have to put a limit on the guarantee which is currently 3 years. We may well extend it to 5 years as we've now passed the 5-year mark with no failures.

    Best regards,

    James :D
     
  12. 18 Feb 2016 at 8:36 PM #12
    Chris86

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    Hi james ive emailed you a few weeks ago regarding a subframe inspection/reinforcment and underside restore and have had no reply as yet. Just wondering if you's got it? I emailed as your pm inbox is full. Cheers
     
  13. 18 Feb 2016 at 10:22 PM #13
    James@Redish

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    Hi Chris, thanks for the message.
    Sorry to hear you haven't had a reply. I'll look into first thing in the morning when back at work.

    Best regards,
    James :)

    Edit; pm box space ok now if you wanted to PM also?

    Thanks,
    James :)
     
    Last edited: Feb 18, 2016
  14. 19 May 2017 at 11:57 PM #14
    rusticm3

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    Can you explain how the car underside went from gloss black rust protection to silver? Wast that just a layer of primer and then body paint on top of the por15?

    Also on this car you didnt seem to use seam sealer all over before coating?
     
  15. 20 May 2017 at 10:52 AM #15
    James@Redish

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    Hi rusticm3,

    Thanks for the questions.
    Yes the gloss black was POR-15 Rust Preventative Paint, and then we applied a high build primer, then a base colour (titan silver I believe it was), a clear coat on top, and then localised waxing.

    That's right, no seam sealer on this car.
    Over the years we've tried different approaches to the finished process, and various different products and techniques, and at that time we were trialling POR-15 Rust Preventative Paints without the use of Seam Sealers.

    For example, the next evolution of our Repair & Reinforcement Process went on to use sprayable seam sealer as per our video here:
    https://www.youtube.com/watch?v=hhDAQ97WnxA

    Neither are right or wrong, it's all about continued development and trialling new products to better the process. :thumbsup:

    James :)
     
  16. 20 May 2017 at 11:15 AM #16
    rusticm3

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    That's the conclusion i was drawing to that there was no right or wrong method either would be sufficient.

    So i can either etch prime, then use POR-15 rust protection then primer and body paint on top

    or;

    etch prim, seam sealer, then then finish with wurth stone chip guard

     
  17. 20 May 2017 at 11:28 AM #17
    schooner32

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    If your using por15 , it must go onto bare, clean , prepared bone dry metal. Once its cures you can do what you like but wait for it to fully cure. I had a reaction when I did it first time and I had to strip it all off and do it again. Really wasnt fun.

    Get the por15 degreaser, metal prep and follow the instructions. It is temperamental stuff and needs proper prep.

    You will need por15 etch prime to use over the black rust protection.
     

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