Friday, September 7, 2018

The Endless Fight Against Entropy

As the house and contents around me age every day, sometimes relatively new things break, not just older things.  Last night, one arm on my computer desk chair fell apart.  I don't recall exactly when I got this, but it's a "few year old" nice chair from Staples.  I'll WAG that I got it in '14.  The problem is that it has some sort of plastic arms and one snapped at a screw that holds the arm to the sides of the seat and back.  It had broken part of the way a few months ago, but I never got around to trying to fix it.  Today I had no choice.

It's hard to see, but the plastic cracked from top to bottom across that hole.  Probably a defect in the plastic molding, since the other side is fine and has never had any issues. 

My plan was to pull the pieces apart, coat as much of the broken surfaces as I could with some epoxy paste I have from fishing rod-making, and then clamp it until the epoxy sets.  It went pretty well and the chair is remaining with the long clamp in place overnight.  I may make a small aluminum or steel plate to go over both sides of the repair, held in place with a self tapping screw.  I think it would need either that roughly 30 degree angle or a shape that blended more with the odd curvature of the arm than a little 1x2 rectangular plate.  

Didn't realize I cut off the bar of the bar clamp in the picture until editing this photo for size, but you can see both of the long clamp's ends.


  1. Hope the epoxy patch works for you.

    And of course, if someone made a replacement armrest ring out of a couple glue-laminated layers of 3/4" plywood (they could disassemble it and trace the profile onto a sheet, then make a duplicate, with or without the side hole cutout, and drill the bolt holes, in about 1/2 hour with a drill, sabre saw, and a pencil), it would probably only last flawlessly for around 50-60 years, with the rest of the chair falling apart around it before it failed in the slightest.

    No points for guessing why I'll manufacture my own chair next time, out of wood, before I'll pay $200-300 for some made-to-fail craptastic piece of second-rate cheese whiz, designed by Hu Flung Poo, and made by the $20/wk artisanal craftsmen at the Shanghai Number 37 Chair Co. for about $7 in materials and labor before shipping and the office-mart 4100% mark-up.

    OTOH, there are original aluminum Navy submarine 1006 chairs from 1944 that still function flawlessly now, just as they will in another 100 years, and be nearly indistinguishable from new-made ones. Someone inclined could even make a solid base for one, bolt it to the legs, and screw replaceable caster wheels to the bottom, and make a roller chair that would still function 200 years down the road, provided you put 2-3 drops of 3-in-1 oil into the caster works every 50 years or so.

    Personally, I think this sort of thing proves the correctness of my old man's oft-repeated statement from circa 1960-1980: "The genius who designed this should have it shoved up his @$$ sideways."
    He wasn't a carpenter per se, except in the weekend Popular Mechanics sort of way, and yet I have three bookshelves and a full-size office desk made by him that are all 70+ years old, and look exactly like they did when he built them in his garage workshop.
    The only plastic involved is the plexiglass shield he cut for the desktop about 20 years after he made it.

  2. Hmm. Duct tape was found wanting?! This is serious.

    Good luck with the epoxy- sometimes it does not bond well to plastics.
    There is a plastic repair material called "Plast-aid", a two part mix that seems to work well on most plastics..

  3. Embrace the enthalpy!

    Good luck with the repair. Hope it works.

  4. SiG, you've hit upon one of the "design" things that simply irritates the heck out of me. Seems there is a conspiracy afoot to accelerate entropy by making things and then at a most critical point, making the piece that gets the most use, takes the most stress ... out of plastic. Other parts of the item can be made of metal but joints are particularly notorious for being made of plastic and in my experience, once the joint in gone, it can't be repaired easily and replacement parts cannot be had anywhere.

    So you are resigned to throwing the entire thing away which is still good and working, i.e. a desk lamp with articulating arm, simply for want of a good joint to hold things together. I've tried to jury-rig something together but have yet to achieve satisfaction.

    I wish companies would stop this practice and waste and just give consumers a product that will last for at least some extended period of time. Another example is the Swiffer dust mop. Metal poles, plastic handle, everything is good except the joint that connects to the mop head is a silly, weak little piece of plastic. It is this joint that must take all the stresses and strains of push & pull and compression and so forth and when it breaks, well, again, the entire mop is useless.

    It's the little things. A job well done would make life so much easier and pleasant but the little things like products designed to fail so that replacement is a must creates user frustration. Except in my case, I don't repurchase the same brand, I am put on notice about designed-in defects and will look somewhere else.

    1. Really good points. One of the reasons I bought this chair is I just assumed the plastic was molded over some thin metal just for appearance. Because it just seemed that was the way to do it. The arms are the only stress point in the chair. Right now, the only metal on that side piece is the little screw plate I added to it as the part of the repair. I still don't have much confidence in it.

      How hard is it to do things right? How much do they actually drop the retail price of the chair for making that thing out of, say, 1/4" aluminum or tubing or cheap steel, and then making it decorative with some plastic? A couple of bucks? In the Swiffer you mention, how much would making that plastic piece out a better material add to the price? 50 cents?

      I'm torn between implementing Aesop's first suggestion (laminate some 3/4" birch plywood and make two new arms) and replacing it with a well made chair. Taking a couple of days to make arms is almost as annoying as replacing it.

  5. Kiln-dried red oak? This is available at Lowes/Home Depot/Menards. surfaced 6 sides. It isn't cheap. But it is strong. (You would want to build a frame, not a panel - too much waste)

    You might (might!) find 2X2 ft squares of maple plywood at Home Depot. (They used to sell them as "hobby boards.") Probably not in 3/4 inch.

    The lumber yard near me that carries exotic woods, also carries various plywoods. (Maple, oak, cherry, etc. for cabinet-makers) Rarely they have 4 X 4 ft pieces (usually when something got damaged). 4X8 is pricey.

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