Foam dam barriers for Liquid Metal safety insurance guide.

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Falkentyne, May 21, 2018.

  1. Maleko48

    Maleko48 Notebook Evangelist

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    Why is nobody advocating for proper conformal coating? I'd trust it more than nail polish myself.

    I've been itching to repaste my laptop recently as the stock paste seems to be losing it's luster after almost 1 year of use.
     
  2. Papusan

    Papusan JOKEBOOKs Sucks! Dont waste your $$$ on FILTHY

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    Just use kapton tape or similar tape + a very small blub paste inside IHS. Why make it so difficult?
    [​IMG]
    [​IMG]
     
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  3. intruder16

    intruder16 Notebook Enthusiast

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    I've repasted my laptop with LM 3 months ago. I used a foam/sponge barrier (around 3 mm thickness) like this:

    [​IMG]

    After applying the heatsink it compressed easily.

    [​IMG]

    7 days ago i opened up the laptop (almost 3 months later), lifted the heatsink and the barrier remained compressed (almost half the initial thickness). I used it as is again, applied slightly more LM (smallest drop) and there's almost no effect in temperatures. I guess i don't have to repaste the cpu anytime soon. The barrier works great!
     
  4. Falkentyne

    Falkentyne Notebook Prophet

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    Hi, good work I do have a question.
    When you used a barrier that thick, did you do a test without the barrier (best to do prime95 small FFTs with AVX disabled (e.g. CPUSupportsAVX=0 in local.txt), to get a baseline idea of what the temps should be like?

    This is VERY Important for anyone using foam that thick. I tried foam of that thickness (different color) and I noticed a 3C temperature increase when using foam like that on the CPU. I had to trim the foam down substantially (to about 0.2mm) to bring the temps down. The foam was interfering with heatsink contact pressure.

    Laptops usually have very atrocious mounting pressure. So it's important to make fully sure (by doing tests without the foam barrier) that anything that thick is not hurting the temps. You must remember that on BGA jokebooks, the surface distance between CPU surface height and the green housing it sits on is about 0.1 to 0.2mm at most. So anything thicker than that can potentially interfere with contact if its a thicker foam and several 0.xmm thickness!
     
  5. intruder16

    intruder16 Notebook Enthusiast

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    I actually did that. I wanted to make sure it won't hurt the temperatures. The reason it's not messing with temperatures is because of heatsink pressure. I've increased the heatsink pressure by adding washers to the screws. I added a couple to some screws and single washer on others to maintain a flat heatsink pressure. I did several tests before using LM and after. Add a couple more tests with or without sponge barrier.

    Also, the sponge is really compressible. I can compress the 3 mm thick sponge to 0.1 mm without any effort. I also took the liberty of checking the temperature resistance of the sponge myself. It passed (short test) but it won't be staying there for long as it can't regain it's full thickness & i also noticed a slight discoloration just after 3 months. I'll have to look for a more permanent solution sooner or later. But hey it works and i just hope it won't catch fire.

    I actually did not need the foam barrier but the constant travel and too much vibrations made me a bit paranoid so i decided on adding the dam for some peace of mind.
     
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  6. Falkentyne

    Falkentyne Notebook Prophet

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    Good work. It's important to let people know this precisely though, because they may look how awesome the sponge looks and then wind up using it and get horrible temps. Plus sponges are strange things. Some sponges can harden like a brick so its important to get the right one. That's why I always recommended the correct packing or window foam (if you can find it). Once you've seen it and felt it you then go "wow this will work awesome".

    I never noticed a problem using the "thicker" black foam with temps I tested on the GPU heatsink. The GPU had higher pressure because the core has a larger uplift from the surface, compared to the weak BGA CPU's.
     
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  7. intruder16

    intruder16 Notebook Enthusiast

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    Couldn't agree more. I did extensive research on LM before using it. In my case the heat sink is made up of aluminium with copper shims just above cpu & gpu. There's not a lot of space between the copper and aluminium and cpu die touches the edge of the copper. Slightly more/wrong application of LM and it'll ruin the aluminium. I can't explain it properly so here are a couple of pics from months ago when i applied and cleaned up the first application later (sanded with 1200 grit just once or twice):

    [​IMG]

    [​IMG]

    About the GPU part, i didn't take the risk. The copper shim is very tiny and there's a good chance the LM will contact the aluminium mountings. Here I've highlighted the GPU die contact area.

    [​IMG]

    I use eGPU anyway (Gigabyte 1070 Mini ITX) which gives me PCIe 3.0 x8 speeds. Perhaps the best eGPU solution out there.

    I wanted to do much more mods but stuff is limited here in India. Not much you can buy here.

    I don't post much in forums since everything's already available. I just lurk.

    EDIT: Fixed image
     
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  8. Mr. Fox

    Mr. Fox BGA Filth-Hating Elitist

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    Did you get the foam from leftover shipping or packing material (like I did) or did you buy it someplace? Would be nice for others to know where if you purchased it. Maybe share a link or something.

    It is not important for the foam to regain its original shape and the discoloration doesn't matter. All it needs to do is act as a gasket to serve as a barrier so you can handle the laptop like an ordinary laptop... toss it around in the backpack, fling it onto the bed or couch, or slam it down on the desk when you're grumpy or having a bad day, etc. ...without having to wonder if liquid metal is going to get dislodged and mess something up. I think using the foam barrier is a smart idea even if you don't actually need to. It's really cheap insurance.

    Nice job on it. You did great.
     
  9. intruder16

    intruder16 Notebook Enthusiast

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    I kind of got lucky with that foam. Like i said i never used the foam dam but read about it in clevo or alienware subforums i think.

    I went to a furniture shop one day and the store owner wanted to show me some more of the stuff i asked for so he took me to his warehouse where i found this piece of foam lying between two plywood sheets. I thought it'd work great for the foam barrier and took it (with his permission of course). If i'm ever going to run out of this piece of foam i'm going back to shop furniture's and hope to get lucky once again.

    [​IMG]

    Thanks for the tip! I was getting a bit paranoid about the shape and discoloration. That'll save me some time since i'll not open up the laptop again. It takes a lot of time to access the cpu by dismantling everything in my laptop. Thanks!
     
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  10. Falkentyne

    Falkentyne Notebook Prophet

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    Do you have a source or if possible a name or direct link for this foam? How dense is it overall? I'd like to try it. You said a furniture shop. You mean something like Lowes? I tried Michaels before but i don't know if they would have anything nice there. By the way, I can tell from the texture of that foam that it is completely perfect. That's the same grade of foam I had found left over from some item I bought, just a different color).
     
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