cross-posted from: https://lemmy.dbzer0.com/post/8959162

I had a rod that was threaded on one half and smooth on the other half. I needed the smooth half to be installed into brick.

method 1: chemical anchor

The normal way to do this (I think) would be to cut some grooves into the rod using an angle grinder, drill a hole that has a diameter that’s ~2mm bigger than the rod, and use chemical anchoring. But that stuff is pricey and only lasts ~1 year on the shelf. Thus cost ineffective for 1 use.

method 2: ad hoc chemical anchor substitute

Similar to the above, I wonder if general 2-component household epoxy would work as a substitute in the above method since people are more likely to have that on-hand. I suspect the issue is that it’s too thin and gravity would do its thing and the topmost area would not get filled with epoxy. Hence why I did not attempt it.

method 3: (What I did)

The rod measured at ø=8.8mm. I had no 9mm drill bit for masonry (and that would be too loose anyway). So I used a nominal 8mm masonry bit on a hammer drill. I’m not sure what the actual diameter of that resulting hole was, but it was too tight to push in the 8.8mm rod in by hand. So I tapped it in, dry (no oil or glues). It worked! It feels really solid. Feels like I got away with murder.

Questions

(method 2) Is there something could be mixed with common 2-component household epoxy to thicken it so it acts more like chemical anchor epoxy?

(method 3) Did I take bad risk with fracturing the brick? Is there perhaps a guide somewhere that safely maps brick hole diameter to metal rod diameter? Or is this something is never done and should never be done?

  • diyrebel@lemmy.dbzer0.comOP
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    7 months ago

    I could not pull it out with my hands after tapping it in. But to be clear, there’s only a sheer force to deal with, and it’s light.

    I cut a bicycle axle bolt in half, and embedded it in the brick so there is a bicycle sprocket on the wall. Then a chain wraps another sprocket, which turns a shaft that goes all the way though the wall to the other side, where it connects to a right-angle gearbox, which attaches to a water valve. It’s lightweight overall… just the weight of a sprocket, chain, and a small decorative wood thing out of wood to serve as a handle.

    This might come a bit too late but why didn’t you just get threaded rod and use one of these instead?

    I did not know anchors like that existed for machine bolts. That’s good to know! However, it would not have helped in this situation. The bicycle axle has non-standard threading (~9mm bolt with a thread pitch that’s 2 steps away from the norm). Since it had a special nut that interfaced to ball bearings, I could not bring in a standard bolt or threaded rod. And the threaded portion of the axle was short enough that no threads could have gone into the wall. I could have added threads to the bare portion, but my die set skips the ø=9mm size.

    I was asking more for future reference – whether or not I should ever repeat this. And I think you answered that. Even if I get lucky in the future on getting a perfect fit at that moment, temp changes could blow it. I guess I’ll assume anchors (chemical and mechanical) are designed to handle the temp changes.

    • chocoladisco@feddit.de
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      7 months ago

      Mechanical anchors handle in my experience pretty much everything. I like the plastic ones from Fischer. And they make them for pretty much any application you could wish for.