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Scratch Build – In Progress Project: Blue Horizon - "MOTY" Nominee

Discussion in 'Project Logs' started by riekmaharg2, 8 Jul 2010.

  1. Nutman

    Nutman Never stuck with stock

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    IF those are stress cracks, you need to re-make the fittings. To strengthen a piece of acrylic like that, bake it in the oven at low temps for a certain amount of time (use Google to search for the exact recipe for this). This is common with especially extruded acrylics - cast acrylic is better at preventing stress crackings like these....
     
  2. riekmaharg2

    riekmaharg2 has finished Blue Horizon

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    I've just taken off the barbs and all the cracks are definatly on the out side, if they were stress cracks would I be able to crush it or pull it apart, as I can't. Each crack goes half way into the acrylic. Could it be the heat from sanding? I couldn't find anything on baking, I'm not sure what it would be called, I've tried strengthen acrylic and baking, and heat strengthen.
     
  3. RonanH

    RonanH mod-envious

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    Some information on annealing plastics... this is for plexiglas but it gives you the basic procedure... it's pretty much the same principle as the procedure to anneal or harden metals.

    http://www.rplastics.com/annealing-plexiglass.html

    edit: apparently plexiglas is acrylic :D
     
    Last edited: 13 Feb 2012
  4. Furball Zen

    Furball Zen Shut up and Mod

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    Yea plexi is the brand name for acrylic. Try getting cast cubes from www.tapplastics.com.

    Also, instead of sanding them down, why not try a round over bit on a router?
     
    Last edited: 13 Feb 2012
  5. Nutman

    Nutman Never stuck with stock

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  6. Cheapskate

    Cheapskate Insane? or just stupid?

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    There's a couple of reasons this could happen. One big factor would be getting the plastic too hot during shaping. Any contact with alcohol or cold will accelerate the cracking. You could have had too much stress on it cutting the guts, or it could be you just got some crummy plastic.:(
     
  7. Achron

    Achron Cad Pro Quo

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    Those aren't crazing marks from alcohol. Crazing will make the cracks look almost like the acrylic was frosted. Those are definitely stress cracks, and you need to remake them ASAP or get them out of your system.
     
  8. voigts

    voigts New Member

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    Stress cracks to be sure (called crazing). Having made many of my own reservoirs, I've had my share of issues with this. The kind of acrylic you use makes all the difference. Extruded acrylic is worthless when it comes to trying to machine anything. Only work with cast acrylic. Even working with cast acrylic, I don't machine sand anything. It is simply too easy to get the material heated up too much and cause it to craze. Acrylic also does not respond very well to having metal barbs used with it as the differences in expansion rates can cause crazing also. I've learned to only use plastic barbs with acrylic so that this is never an issue. I thought when I saw those that they look great, but wondered at making them out of acrylic like that.

    What happened to the link? There is no url in the code for it to link to.
     
  9. riekmaharg2

    riekmaharg2 has finished Blue Horizon

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    The link wasn't suppose to be a link, wups. I meant for you to search that name in the Google sketchup 3D warehouse on the File menu.

    Ah yeah it could well be the difference in expansion which would explain why the cracks didn't appear until I started using them. I presume they are cast as they started off as ice cubes. Sounds like you need a special oven for that annealing process :( I have been able to flame polish the barbs as I didn't have much to loose if it went wrong which healed all the cracks nicely but they could crack again and the only problem with plastic barbs is they don't look very nice.


    I've also finally decided how I'm gonna finish the rad cover, and I'm currently waiting for materials for it and for the new CD/DVD/HDD bays.
     
    Last edited: 14 Feb 2012
  10. Waynio

    Waynio Relaxing

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    Shame about the barbs mate, they looked awesome :( but you being you I'm sure you'll do something as good or better. :rock::D
     
  11. The_Gnu

    The_Gnu 8-bit addict

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    Awsome build mate.
    To bad to hear about your cracks. I would agree with the rest of the crowd that it looks like stress cracks. From the picture, I think it looks like most of the cracks are on the outside of the connectors by the barbs. Im instantly thinking that maybe the two outlets/hoses were pressed to much together when beeing mounted. Don't know if I explain good enough but picture the 90° angle beeing decreased.

    Don't know at all if thats the case but that was my first thought.
     
  12. voigts

    voigts New Member

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    Duh on my part. :duh: Got it. Thanks!
     
  13. GLA-58

    GLA-58 Member

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    OOOhhhhhh yyyyyeeeaaahhhh some things seem to happen just when one does not need them. :wallbash:
    But I wish to congratulate you with this superb build. :clap:

    greetings and peace of mind.
     
  14. KoSoVaR^

    KoSoVaR^ Professional Sleever & Modder

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    You are sick maaaan, thats awsome !
     
  15. riekmaharg2

    riekmaharg2 has finished Blue Horizon

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    After I flame polished the barbs to melt the cracks together it seems to have solved the problem, they haven't re-cracked :), maybe that's one reason why the DCC laing pump res's are flame polished after machining.

    Glad to be of help :)

    Cheers GLA-58 & KoSoVaR^ :thumb:
     
  16. Waynio

    Waynio Relaxing

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    That's good to hear. :)
     
  17. Bladesingerz

    Bladesingerz Member

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    I just read trough the hole build log man, its legendary work!
    I'm just a bit sad that you didn't finish the MB waterblock, that looked amazing!
     
  18. Sarakon

    Sarakon The German

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    Problem has been solved :D good good!
     
  19. jeckulz

    jeckulz New Member

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    I love you.
    Full homo.
     
  20. CraigWatson

    CraigWatson Level Chuck Norris

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    Seriously love this build - the simplicity of the l/c loop is brilliant, and that PSU cover is inspired, would be cool if you could somehow tie/anchor that 24-pin cable to the floor of the case at a right-angle, would set off the rest of the precision nicely :)

    Also - are you going to add a grommet (or at least neoprene edging) to the routing hole for the PCI-E cables?
     
    Last edited: 2 Mar 2012

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