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Thread: Excellent overview of epoxy additives

  1. #1
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    Default Excellent overview of epoxy additives

    Pretty impressive and approachable presentation. He looks like and engineer. 10-15 things added to West epoxy and an explanation of the properties of the mixture.

    He starts with wood flour and ends with titanium coated diamonds.

    Last edited by bluedog225; 07-19-2020 at 01:32 PM.

  2. #2
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    Default Re: Excellent overview of epoxy additives

    Awesome! Thanks for posting this!

    How the heck did you come to stumble upon this work?

  3. #3
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    Default Re: Excellent overview of epoxy additives

    Random catchy link. I was looking at sea cycles. I think the guy built a catamaran. The power of the internet and so many wasted hours.

    But I can’t find titanium coated diamonds “fairly cheap.” Or any other way.

    I think his definition of cheap is not the same as mine. He has a laser table in his shop.

    I believe he says carbon fiber added to epoxy is about as strong as an aluminum weld.

  4. #4
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    Default Re: Excellent overview of epoxy additives

    "I believe he says carbon fiber added to epoxy is about as strong as an aluminum weld. "

    Now you went and ruined what might be interesting.

    In my past life, one of a hundred different epoxy/ carbon fiber compounds was tested at 75 KSI tension.
    That's 75 thousand #/square inch tension.
    Typical heat treated marine aluminum is around 30KSI, and un heat-treated weld is less.

    I'm surprised he didn't try to explain carbon nano fiber.

  5. #5
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    Default Re: Excellent overview of epoxy additives

    Reminds me of the crash-form tooling we made for pressing panels (like doors fenders, rocker panels etc.) as a substitute for foundry cast press tools.When the tool needed to be 2m long and 0.75M wide( as for the rocker panel) it sure was convenient to make the thing on the shop floor instead of sending patterns off to a foundry for casting a conventional one in iron.

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    Default Re: Excellent overview of epoxy additives

    I like the notion that we have always wanted to create our own body armor without having to spend too much on it. And which additive to get that shiny white Storm Trooper finish?

    But yeh, it is a good overview. On my last project I used large quantities of MAS Cell-O-Fill, which falls about halfway between Cabosil and Wood Flour. It mixes smooth -- doesn't get grainy like wood flour. And it sands much more easily than Cabosil.
    -Dave

  7. #7
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    Default Re: Excellent overview of epoxy additives

    Epoxy with metal fill (if lead) could possibly be used as a matrix along with basalt fibre rebar and cloth, to create a structural keel for a small boat, that gets around heavy engineering costs and inconvenience that goes with iron or else the environmental issues that go with smelting lead in the backyard.

  8. #8
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    Default Re: Excellent overview of epoxy additives

    Lugalong,

    What was used for the "crash - forming" tools?

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    Default Re: Excellent overview of epoxy additives

    Woxbox,

    I knew a guy how used to make replacement carbonfiber panels for F1 and other circuits in his hotel room at night using cardboard and bondo for tooling.
    Always ready to paint, sticker, and attach the next day.

    He wouldn't really detail how he did it. keeping his secrets in case aerospace didn't work out.

    He said he never really made any money because he tried to keep too high of standards for the finish. But he kept being asked to build parts.

  10. #10
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    Default Re: Excellent overview of epoxy additives

    Quote Originally Posted by upchurchmr View Post
    Woxbox,

    I knew a guy how used to make replacement carbonfiber panels for F1 and other circuits in his hotel room at night using cardboard and bondo for tooling.
    Always ready to paint, sticker, and attach the next day.

    He wouldn't really detail how he did it. keeping his secrets in case aerospace didn't work out.


    He said he never really made any money because he tried to keep too high of standards for the finish. But he kept being asked to build parts.
    I noticed years ago how that crowd loves their carbon fiber -- after seeing custom tool trays made of the stuff in pit row.
    -Dave

  11. #11
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    Default Re: Excellent overview of epoxy additives

    Aerospace never went that far, at my job.
    However, my last job was "affordability" if that can be applied to a $100M airplane for 1 person.
    Numerous parts were found to be equal in weight or actually lighter in aluminum, at a significant cost reduction.
    The problem was that the initial design was done on a very tight schedule. Choices were made on judgement or minimal engineering trades.
    Later it cost a great deal to re-engineer and re-tool the parts - along with extensive analysis requirements.

    But the love of composites was part of the problem.

  12. #12
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    Default Re: Excellent overview of epoxy additives

    Quote Originally Posted by upchurchmr View Post
    Lugalong,

    What was used for the "crash - forming" tools?
    We started casting a metal filled epoxy compound as a moulded surface over a cast iron 'body' that had been sand cast... this was for the smaller parts. Getting around to the bigger parts it was more economical to cut a base template of 11/4''or more( memory is not exact) mild steel plate, with sectional profiles/frames of 5/8" mild steel plate welded onto this and bored to accept regularly spaced, stringer-like 1/2" rebars to create an armature that was filled with a cement and aggregate mix (ferro cement). Over this we cast the same metal fill epoxy compound as on the smaller parts. This was done by setting GRP female moulds up so that the armature could be hung inside the mould with a space of a little over 1/2" between mould face and near match contours of the armature. Epoxy compound was poured in through a flue near the middle of the piece, and 'witnessed' around the horizontal flange of the female mould, which was aligned with the back edge or now, upper side of the armature base plate (considering the armature to be face down and base facing up, with the female mould face open upwards).Description probably sounds complicated because we are dealing with a male form that is flipped upside down for the casting process and then (once casting is done) flipping the whole shebang over the other way in order to remove the female mouds, which means the tool is upside down in it's orientation as a press tool.... except that it gets flipped again to go on the press.
    Last edited by Lugalong; 07-19-2020 at 09:08 PM.

  13. #13
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    Default Re: Excellent overview of epoxy additives

    One thing about being in an isolated engineering company was that such tooling as you describe never even crossed our mind. Partially due to the lack of similar parts, but mostly we were so inbred as to our parts/ forming ideas that we would have dismissed what you describe immediatly.

    I believe such a lack of crossover of ideas limited creativity. With an increasing spiral of cost.

    I almost wish I had of been layed off so I would have been exposed to more ideas.

  14. #14
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    Default Re: Excellent overview of epoxy additives

    Quote Originally Posted by upchurchmr View Post
    One thing about being in an isolated engineering company was that such tooling as you describe never even crossed our mind. Partially due to the lack of similar parts, but mostly we were so inbred as to our parts/ forming ideas that we would have dismissed what you describe immediatly.

    I believe such a lack of crossover of ideas limited creativity. With an increasing spiral of cost.

    I almost wish I had of been layed off so I would have been exposed to more ideas.
    Sure, it was an interesting time - being in touch with various people and associations/companies around the world, from the Composites Fabricators association USA to British composites guys and also with people linked to the South African defence force who were party to helicopter production there ( a real independant set up producing arms like he Rooivalk helicopter to combat Russian backed armies like the Cubans). This place HighTech Automotive, grew from a dozen or so guys in a cottage industry in the early 1990's, into the worlds largest privately owned car manufacturing company Superformance Replicars. While the engineering side progressed toward CAD CAM, the development side had freedom to innovate. Such that later in the 1990's we were producing hybrid carbon composites/metal components for the British company AC cars (producers of the sports car that became the Shelby Cobra, when Ford supplied motors). We produced hand made parts and complete cars for AC, who still made hand rolled alloy bodied cars using the original wooden bucks.
    Last edited by Lugalong; 07-20-2020 at 03:10 AM.

  15. #15
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    Default Re: Excellent overview of epoxy additives

    Thanks for posting! I'm new to this and have a lot to learn

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