We were talking on the podcast about rope. But not just any rope – especially non-stretchy rope for using in a mechanical context. The hack in question was a bicycle wheel that swapped out normal metal spokes for lighter and stronger high-density polypropylene weave, and if you can tension up a bike wheel and ride it around, you know it’s not your garden-variety twine.
Now, it just so happens that I’ve got basically the same stuff in my parts drawer: some 1 mm diamaeter Dyneema-brand rope. This is an amazing material. It’s rated to a breaking strength of 195 kg (430 lbs) yet it weighs just under one gram per meter, and if you buy the pre-stretched variant, it’s guaranteed to stretch less than 1% of its length under load. It’s flexible, wears well, and is basically in every way superior to braided steel wire.
It’s nearly magical, and it’s just what you need if you’re making a cable robot or anything where the extreme strength and non-elongation characteristic are important. It’s one of those things that there’s just no substitute for when you need it, and that’s why I have some in my secret-ingredients drawer. What else is in there? Some high-temperature tape, low-temperature solder, and ultra-light-weight M3 PEEK screws for airplane building.
But our conversation got me thinking about the parts, materials, and products that are unique: for which there is just no reasonable substitute. I’m sure the list gets longer the more interesting projects or disciplines that you’re into. What are your secret ingredients, and what’s the specific niche that they fit into?
There’s a wide range of types of bolts and fasteners, and knowing that these exist and are available at the hardware store can make a lot of difference.
Just yesterday I needed a way to attach a board to a ramp for a snowmobile, and I used carriage bolts: rounded heads won’t bother the skis. My customer (victim?) was happy, but wanted the holes to be metal lined and described this funny metal tube with a wide lip around the top, I showed him a T-nut, and “yeah, that’s what I want”. Big T-nut and now the hole won’t wear or tear.
Knowing a bunch of types of fasteners (and where to get them) is useful for making things.
I’ve got a couple of fishing lure boxes with fasteners in multiple sizes in the workshop. Including Clevis pins, Hitch pins, and Lynch pins.
Dyneema is used for the lines on a kitesurfing kite. I’ve trusted my life to it many times. Amazing stuff.
Sounds like an ideal material for winching my 1200 pound dock out of the lake in the fall. I use steel rope now and am in constant fear of what should happen if it breaks. ChatGPT is always full of helful ideas for pizza toppings and home improvement tasks and suggested draping blankets over it, which I will do next fall.
if you lose your grip and drop it in the drink youll be in luck too. Dyneema floats.
I do pattern welded steel forging, I like to line my canisters with stainless steel foil, Stainless steel has a higher forging temperature than the carbon steel Im forging. Doing this prevents the 52100 ball bearings and 15n20 powder from bonding to the low carbon 1020 mild steel canister. Some people will just grind that casing off. Some try to form a barrier layer with whiteout with varying degrees of success. But my secret ingredient, Stainless Steel foil, gives 100% reliable results allowing you to cleanly and easily separate the canister from the billet with a quick cut down two edges, and a diagonal bisection of the end caps. Its a real game changer. I dread the day I NEED to get a piece done and havent access to SSfFoil.
We own a 110 year old house.
My go-to ingredient are 1″ to 1 1/2″ torx head cabinet screws
They don’t strip; they don’t split the wood; they have a giant flat head so no need for a washer. And they are pretty discreet.
I buy them in the 5 lb box
Also – I’m guilty of using hot glue and dollar tree foam board to cover some holes in the dry wall in low traffic areas
Is hot glue and foam cheaper or easier than the cheesy old cardboard backer w center string in tension and plaster method?
I don’t think it is…
I’d post the steps for patching drywall, but google.
yeah I think drywall is easier to repair than styrofoam. sometimes I use spray foam to fill a void, trim it flat with a knife, and spackle over it with drywall compound, which I can get to be as smooth as the adjacent wall. that’s often a better fix than trying to cut a piece of drywall to fill in some nasty hole.
What 110 year old house has drywall?
House of Theseus?
And thanks, I’m stealing the idea of hot glue and foam board for the cracks in my lath & plaster walls. (The horsehair isn’t holding it together). But a cartridge of PL has zero heatup time and needs no extension cord, so I’ll probably spring for that instead of hot glue.
More of them than you might think.
Drywall was invented in 1894. US gypsum bought out the company and patents in 1910. It was readily available and increasingly uses year by year but didnt become the dominant standard of construction until the post WWII housing boom demanded faster, cheaper, less labor intensive methods.
If someone is down there and carping about your materials used, let them fix it while they’re down there…
It’s pretty common for a repair service to listen to the needs/ideas of their client. As a client, you’re searching for someone more knowledgeable than you to help you in achieving a specific task. You are willing to pay someone for this kind of help. This means that an experience where one of the parties ignores the other would typically be a failed, pretty bad experience. So no, you shouldn’t try to shun off the clients’ ideas too fast… And the client should also be receptive to the repairer’s.
Keep in mind that tying a knot in the high-strength low-stretch line can reduce it’s strength by 75% or more.
When I used dynema on kites, we always put a sheath over it before we knotted it.
You dont knot a dyneema or spectra line, you either splice it when unsheathed or sew it. Knot always adds weakness and bulkiness.