Anchoring to Square Tubing?

[Emilie]

I'm about to install a front door and plan to attach door hinges to the bus' square tube frame. I would like to anchor the hinges to the tubing, but am a little lost about what is available that would accommodate a flush mounted hinge. Are expansion anchors necessary or would metal screws be enough? I'm just concerned about screws backing out from vibration. (Eventhough the bus will be parked 95% of the time)

[musigenesis]

Some pics would probably help so we know exactly what you're considering doing. You can also click on User CP in the upper left and fill out your details like what bus you have and where you are, which will help us tailor our responses.

Self-tapping screws (Teks makes a few different varieties) are commonly used to anchor stuff to the metal of the bus.

[Drew Bru]

That 5% of the time might make a difference, I dunno. You could try the self tappers and see how they work. Not sure if they'll work with a flush mounted hinge since the head won't be recessed. Blind Bolts, which are basically expansion bolts, are what we used instead of self tappers to mount our solar panel brackets but they're not recessed either. Only a couple bucks each and will have the carrying capacity for a door. If the self tappers "work" but don't hold up to the vibration, then you could try blind bolts using the same holes.

[john61ct]

huck bolts

[Cheezewhiz]

Largish Self tappers with locktite. Make sure your threads hit both walls of the square tube.

As far as a flush hinge, I'd imagine the only way to really accomplish that would be to add a strip of material where the hinge isn't.