How thick is the wall?

[Dapplecreek]

Folks, I need to secure a piano to the wall, and need some stout tie-downs. I am going to drill through to the outside of the bus to secure them.

How thick are the side walls of a 2002 Thomas? Gotta go buy hardware today...

[I recognize that doing this is horrible, but my wife's safety is more important to me than aesthetics. I will be using stainless cap nuts and silicone, and will paint the hardware on the outside to match the bus. Apologies...]

[Drew Bru]

Any chance you can bolt D-rings to the ribs, or use E-track or something? Maybe tie in to the chair rail too? Not sure what your plan is, but I'm assuming it's something safer than running a couple eye hooks through the side of the bus.


I think my bus is 16-ish gauge steel on the sides.

[o1marc]

Inner skin/rib/outer skin, about 2"+

[jazty]

If you open a window you can then measure the thickness of the adjacent rib, which is the same as the wall, give or take a millimeter.


I agree with others, though. You're safer and better off to put something into a rib. Much stronger. You could use some stout rivnuts and d-rings. If you are going to go all the way through the wall it's still better to do it through a rib with one hell of a washer on the outside.

[PNW_Steve]

If I were me.....

I would attach to the ribs and the floor.

That's a lot of weight to secure.

[brokedown]

The chair rail is very strong. I've put eye bolts through the holes originally meant for mounting chairs and use them as attachment points to secure everything in my bus. Taking for granted it's a typical upright piano, if you're able to use large, flat feet (aka 2x4) instead of caster wheels on the bottom, I think it would be quite secure. For good measure I'd probably also attach to the floor if it's going to be a permanent fixture.

[family wagon]

Another vote for the chair rail. Drop a 2x4 on its edge on the floor and another on top of the chair rail; these are thicker than the rail and will prevent the steel rail from digging into the back of the piano during your move. Then use a ratchet strap around the bottom of the piano, hooked into conveniently-located pre-existing chair rail holes, to strap the piano to the wall. You might use a strap with hooks that fit the holes, or if not, then consider a pair of the screw-shut "chain links" through those holes to give something larger to put the strap through. This will be much stronger than an eye bolt vertically through the same chair rail hole.

With the piano strapped this way, even though it's near the bottom, it won't be sliding anywhere. If it wobbles at the top more than you're comfortable with then some D-rings, E-track, etc up higher would make a good anchor. It won't need to hold the full weight of the piano; the bottom strap easily handles that. This upper tie-down would need to be strong enough just to prevent the piano wobbling. Self-drilling #14 screws into the ribs would probably be adequate.

[Dapplecreek]

Great help, folks: thanks!

The plan was to bolt a D ring though the rib to the outside, with large washer, lockwasher, and cap nut on the outside (with silicone and paint). Pair of 'em for one strap high and pair of 'em for a strap low.


I would like to use the chair rail. But I'm not keen on the typical bent-loop eye bolt for this amount of weight and a fast stop. I see that someone makes forged eyebolts, but I'm guessing they are too big for the existing holes.

Screw-shut chain links? Can't see how I could wiggle that through the chair rail. Am I misunderstanding?

Just snag the hook at the end of the strap into the chair-mounting hole in the rail?

I have 1/4" rivnuts and can bolt down smaller D-rings into the ribs between the windows (or at the base of the windows) to hold the top of the upright.

[david.dgeorge07]

Putting ledgers of 2x4 on the floor and wall and securing them with carriage bolts, then anchoring eye bolts through them for ratchet straps could be effective.

[family wagon]

Sorry, I couldn't think of the right term for the device I was referring to. It turns out that Home Depot's name for the thing isn't much better: quick link. Alternatively, a shackle might be useful for attaching a strap whose hooks are too big to go through the chair rail directly. Both pictured below (hopefully).

[somewhereinusa]

Rivnuts will pull out, actually, quite easily. Stainless bolts, generally, unless you buy REALLY expensive ones aren't as strong as steel grade 5. If I needed to make really strong tiedown points I would use the d-rings you showed using grade 8 bolts through a rib with washers on the outside. I would drill a much larger hole on the outside to put a spacer over the bolt so that everything clamped onto the inside of the rib "hat"

[BlackJohn]

Use the chair rail for two lower eye bolts, 3/8" is lots. put square washers on both sides of the chair rail to eliminate any flexing. you only need drilltwo holes this way.
For something higher up, the pieces between the windows can be tapped to 3/8" holes wherever you need them. They are plenty strong but a square flat washer lets the jam nut of the eyebolt tighten up real good.

Ratchet straps across these two will hold that piano from going anywhere if sized properly. Easy to remove anytime if not needed in future and not hard on the eyes either.


John

[o1marc]

Originally Posted by somewhereinusa

Rivnuts will pull out, actually, quite easily. Stainless bolts, generally, unless you buy REALLY expensive ones aren't as strong as steel grade 5. If I needed to make really strong tiedown points I would use the d-rings you showed using grade 8 bolts through a rib with washers on the outside. I would drill a much larger hole on the outside to put a spacer over the bolt so that everything clamped onto the inside of the rib "hat"

"Quite easily"? The pull out strength of a 3/8" rivnut is between 500-1700psi, depending on which nut you use. They pull out easily when not properly installed, which is often the case.

[somewhereinusa]

Originally Posted by o1marc

"Quite easily"? The pull out strength of a 3/8" rivnut is between 500-1700psi, depending on which nut you use. They pull out easily when not properly installed, which is often the case.

The problem isn't the rivnut it's what it's being installed into.