M Smith, Whittier, Calif.
I just finished this small stair job last week — large custom box newels and an 8-foot run of guardrail with plain square balusters painted white (client supplied a picture).
I had a metal stanchion welded up from a remnant piece of 3x3-inch tubing with 1/8-inch wall thickness, and a 6x6x3/8-inch steel plate drilled for 3/8-inch lag bolts. Parts and welding cost me $55.
After some careful layout and blue tape on the floor, I lathered up the bottom of the plate with Bondo, set the stanchion in place, slipped the box newel over, centered it on my layout, and held it firmly in place for about a minute. The bottom of the newel was scribed to the floor so it sat plumb in both directions. I slipped the newel off, drilled holes for lags, and anchored it down. I lathered up the stanchion with PL Premium about three-quarters of the way down from the top, and added a healthy dose right at the weld joint area. I carefully slipped the newel over, and propped a stick against the ceiling to put downward pressure overnight.
The inside diameter of the newel was 31/8 inches — just enough wiggle room for the PL to get some purchase.
Result: Very solid install. The box newel itself has a lot of mass because the base is 7 1/4 inches, and it doesn't have a "weak link" like a traditional turned post, so they tend to be stout regardless of the install technique.
IamTheWalrus
Nice job, nice description. How would you have done it had you been part of the team for the from-ground-up build? It looks like you had to do what you did because you were invited to the party kind of late….
jimAKAblue, Sterling Heights, Mich.
What is the function of the Bondo?
M Smith
Because the bottom of the steel plate was not flat and the wood floor was not flat, [the Bondo] allowed me to set the stanchion quickly in the exact location I wanted it and plumb it in both directions. It also gives a void-free, solid base material so that when you tighten down the lags it stays true. It sticks to just about anything and sets quickly. I use it for a lot of applications where I have an uneven surface. In conjunction with PL, it can be a fastener-free technique for prefinished items.
Ground up? Would have been a solid 4x4 subpost down below subfloor as deep as you can get it, sandwiched and lagged into framing. As it was, on this job I was subcontracted by the flooring company, who had already torn out the old wood flooring and installed new, very expensive wood flooring, and then called me out to the job.
Newman, California
Don't use Bondo, it's not dense — use epoxy instead.
BobboMax, Portland, Ore.
I like everything except lagging it to the floor. You don't know what you're actually engaging, and I expect the lags to loosen over time as the floor moves. Not, mind you, that I have any better ideas, unless you could go under the floor and use bolts and big washers. Bellevilles [spring washers] would be ideal, might even work with lags.
Shane Gillespie, Tennessee
Very nice. I tell you what comes to my mind: The next remodel guy trying to disassemble that. He's gonna be scratching his head saying, "What in the world is holding this thing!"
Gary Katz, Moderator
Very very nice and clean. I like the Bondo idea a lot!