Tubing Repair

I had a welding business, and fixed a lot of types of things you mentioned. It all depends on the condition of the metal. If it is sound metal and just cracked, running another bead on there will hold it. For a while. I have run flat bar plates after grinding flat the welds. That works pretty well, and does not really cause more cracking unless the pounding continues. Weld all around to keep water from seeping in there and causing it to rust and bleed behind the patch. Support the gate while welding, as the added heat may cause it to sag. An aircraft cable diagonal with turnbuckle will take a lot of bounce out of the gate if you are really wanting to do it "right". An easier way is a long round rod with a piece of all thread on the end, then a ninety degree 1" wide tab with hole to stick the all thread end in, and a nut to tension. MIG it if you can, but if you just have a stick welder, use 3/32" 6011 with stinger negative and keep a small puddle with a whipping action.

BTW, what thickness is the metal?

HTh

Steve

I'd look into a gas shock or like absorber to soften the drop. It might be on the end of the cable/chain - or how is it pulled and dropped...

It might be pulling backwards not holding it up. So pick a good methodology.

Mart> I have a nice big gate, about 18 feet long, that I'm fixing.

On Tue, 01 Sep 2009 21:17:20 -0500, RoyJ wrote: (top posting fixed; I'm being anal today)

That's what I thought (and what I'm doing).

Thin -- it looks like it's 60mil wall, or less.

It's not bouncy as it is -- it's quite a rigid assembly, which is what causes damage when it whacks down on the concrete pad (which is also a bit broken up).

It _will_ get a shock absorber. It bangs going down, and it overcenters and bangs going up. As things stand now I could beef it up from now until Sunday and it'll still break eventually from the shock.

I've already figured out the geometry of the necessary shock absorber mount; I just need to find a source of a shock absorber that's valved to only work on the pull stroke and not the push (i.e. opposite of a car), and is relatively all weather.

It's gotta be a moderately standard industrial thing, if I can get my hands on the right phone number.

On thin tube, use 1/8" flat bar fishplates, Mig if possible, and put a diagonal on there, or one above the gate that runs up to the post if the post is high enough. Or you can even hook it at the center of the top rail and run it up to the post and that helps a lot. Point is, diagonal support helps take a lot of that bounce out that is causing the flex that is leading to weld failure.

Steve

Be sure to "wrap" the ends of your welds, and run "sealer beads" though- or you'll have moisture get behind them, between the fishplates and the gate. That's a recipe for potentially dramatic failure, as hidden rust eats it out. The last bang you'll hear is the gate landing on someone.

I'm sure you know- a sealer bead is essentially a very small fillet weld laid in just to prevent water from getting in. A "triggered pass" with mig (so you don't burn through), or downhand with stick (keep ahead of the slag) just to seal all sides of your weldments. Paint to preserve.

Don't ever tell someone I said the d-word, though.... It's a trick that we're never supposed to use....

If you're sure you don't want to wrap the ends with weld, be sure to use a decent sealant to keep moisture out. Paint alone won't work, as it dries it'll shrink and crack, letting water in.

"TinLizziedl" wrote

I've seen hundreds of posts and spindles that got full of water, froze, expanded, and ruptured the wall of the tubing, leaving it forever pregnantly deformed. And rusting more at the rupture.

Steve

Yep. I wasn't sure if you've dealt with it before, so I went on about it in case you hadn't thought about it. I live and work in a region that gets salt water exposure. Stuff around here rusts through if you just look at it cross-eyed.