The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • Pot Lid Repair

    For reasons not relevant here, we (temporarily) have a set of pots with glass lids. One of lids had a remarkable amount of crud between the glass and the trim ring under the knob, which turned out to be corrosion falling off the screw. Trying to remove the screw produced the expected result:

    CKC Pot Lid - broken screw in handle
    CKC Pot Lid – broken screw in handle

    For whatever reason, they used an ordinary, not stainless, steel screw:

    CKC Pot Lid - corroded screw
    CKC Pot Lid – corroded screw

    I figured I could mill the stub flat, drill out the remainder, install a new insert, and be done with it. The knob has a convex surface and, even though this looked stupid, I tried clamping it atop a wood pad:

    CKC Pot Lid - precarious clamping
    CKC Pot Lid – precarious clamping

    Two gentle cutter passes convinced me it was, in fact, a lethally stupid setup.

    Soooo, I poured some ShapeLock pellets into a defunct (and very small) loaf pan, melted them in near-boiling water, and pressed the knob into the middle, atop some stretchy film to prevent gluing the knob in place:

    CKC Pot Lid - ShapeLock bedding
    CKC Pot Lid – ShapeLock bedding

    That’s eyeballometrically level, which is good enough, and the knob sits mechanically locked into the room-temperature plastic slab. Clamping everything down again makes for a much more secure operation:

    CKC Pot Lid - clamped ShapeLock fixture
    CKC Pot Lid – clamped ShapeLock fixture

    A few minutes of manual milling exposes the original brass insert molded into the knob, with the steel screw firmly corroded in the middle:

    CKC Pot Lid - screw stub milled flat
    CKC Pot Lid – screw stub milled flat

    Center-drill, drill small-medium-large, and eventually the entire insert vanishes in  a maelstrom of chips and dust:

    CKC Pot Lid - OEM insert removed
    CKC Pot Lid – OEM insert removed

    Run a 10-32 stud into an insert, grab in drill chuck, dab JB Kwik around the knurls, press in place while everything’s still aligned in the Sherline, pause for curing, re-melt the ShapeLock, and the insert looks like it grew there:

    CKC Pot Lid - new insert installed
    CKC Pot Lid – new insert installed

    Wonder to tell, a 1 inch 10-32 screw fit perfectly through the pot lid into the knob, with a dab of low-strength Loctite securing it. Reassemble everything in reverse order, and it’s all good:

    CKC Pot Lid - repaired knob
    CKC Pot Lid – repaired knob

    Well, apart from those cracks. I decided I will not borrow trouble from the future: we’ll let those problems surface on their own and, if I’m still in the loop, I can fix them.