My New Oxy-Acetylene Tank Cart

October 21, 2011

Thanks to everyone who guessed about my latest contraption in my last post. You all guessed correctly. You are a smart bunch. Even you, Charles.

No, actually, as Juan and Rick guessed, it is to hold the oxygen and acetylene tanks that I just got. Charles–Fugetaboutit.

My next task on the house is to make frames for windows, cut holes for windows, and fix the frames in the holes. So far, I’ve been cutting the container walls with a steroidal 9-inch angle grinder with a metal cutting disk. But let’s face it, this is really arduous and dangerous. Arduous because it takes a lot of muscle power, and dangerous because of the propensity for the machine to kick back and sever body parts. I’ve written before about my plasma torch that died an electronic death, not to be revived here in the harsh Panamanian climate of rust, humidity, electrical brown outs and power spikes, and geckos that have the propensity of dying on circuit boards, “melting,” and shorting out the whole mess.

So that leaves two choices:

Choice 1: Hammer and chisel. I remember when I was first investigating Panama as a place for us to live, I stayed at a hotel in Boquete. Early one morning, 6:15 to be exact, I heard a hammer pounding a chisel on metal. It didn’t stop. Finally I got up and got dressed and went to check it out. Two men were cutting strips off of 20-foot lengths of sheet metal roofing. No angle grinder, no plasma torch, no shears, and, bringing me to choice number two, no oxy-acetylene cutting torch.

Choice 2: Oxy-acetylene cutting torch. A torch is really low-tech. No electrical parts, no computer, just a hot flame that slices through metal. The cost had been stopping me, but it was finally time to bite the bullet and buy a rig.

I got a medium duty Victor brand set, complete with welding/cutting torch, hose, and gauges for the oxygen and acetylene. $245 at Pemco in Panama City. Victor is an excellent brand and I like the way the torch balances in my hand. Tools like this are exciting.

Next, I needed to rent the oxygen and acetylene tanks. $300 deposit for the two tanks, plus $75 for the gas in the tanks. I could have bought the tanks, but I would have had to return to the city each time they needed refilling. With the rentals, I can just swap them locally at the hardware store.

But they don’t just deliver out here in the hinterlands. The tanks need to be transported upright and I had no way to accomplish this with the Honda Ridgeline. So I welded up a goalpost rack for the truck. I used the existing tie-down fixtures in the bed of the pickup to affix my rack.

Here are the tanks strapped to the goalpost rack. Jabo is a gas, too.

And here it is in all its painted glory, along with the long-load rack that I made some time ago but just now got around to painting. The traffic police will be happy with the official reflective sticker, $1.

I used the goalpost rack again today to transport two, heavy eight-foot lengths of 4″x6″x1/4″ angle iron that I picked up for my next shop project, a sheet metal bending brake. But I digress.

The point of this post is the cart that I just made to hold the oxygen and acetylene tanks in my shop, and to make it easier to move them around the job. Here are some photos of the cart ready for paint:

I pretty much started the project by holding a length of 1.5″ square tubing in my hands and holding it up to the tanks. The rest just followed element by element. I love the lines, kind of retro, like something that would have been in my grandfather’s shop. I think it has a little Steampunk look about it. I considered clear coating it, but safety yellow won out.


And here it is with the tanks loaded and strapped in with the safety chains across the tanks and an additional anti-theft chain.

So that’s that, I am now ready to cut the window openings in the container walls. I’ve just picked up the windows I had fabricated, so my next post will about windows.

Thanks for all your comments on the Name That Contraption post. That’s all for now.

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Welding Frenzy ~ Welding On Shipping Containers

August 6, 2011

With the tilebacker walls in place, it was finally time to haul the welder up onto the roof of container four. The four-foot high wall that holds up the high end of the roof over the space between three and four was only tacked in place. I am now faced with the task of welding a forty-foot long bead, welding the wall to the roof of the shipping container.

Armando and I tried first to lift the welder with pulleys and a rope, but we were getting exhausted and the welder wasn’t budging far off the ground. When I bought the pulleys I wanted double-block (two wheels per unit) pulleys but could only find less mechanically-advantaged single-block pulleys. So we rigged an electric winch (thank you for the loan of the winch, Ivan) and effortlessly lifted the heavy welder to the roof. Once up on the roof, with the new ATW wheelbarrow wheels, the welding rig no longer bumps and bangs, but rolls across the corrugated roof very easily.

The wall to be welded is made up of metal siding cut from the wall of the container below. Here’s how the siding sits on the container. You can see that I have some significant gaps to fill while welding. White is the wall, red is the container roof.

This is the largest gap, about a quarter of an inch. Most of the spaces are about a sixteenth of an inch or the metals are kiss-fitting.

I really wasn’t looking forward to this welding task. If it rains, the gig is off. If it is sunny, working in a hot welding hood on the hot metal roof, body crouched so as to reach the area to be welded but avoiding flying sparks and splatter, legs falling asleep; no, I wasn’t looking forward to this task. But it had to be done, and afterwards no more water will enter the container below.

I also wasn’t looking forward to the job because I have been using number 6011 welding rods. These are the standard welding rod here in Panama and can be found in any hardware store and even some grocery stores right next to the duct tape. They burn paint away easily and work in any position. But they stick easily and this can be frustrating.

If you don’t know, the idea of welding is to touch the welding rod to the metal you want to weld, create a short circuit if you will, get sparks flying, then pull away slightly and maintain a gap that the fire jumps across, heating and fusing the metals. It is during this initial getting-the-sparks-flying stage that the welding rod can fuse itself (or stick) to the metal to be welded. If it sticks you have to wiggle the rod back and forth until it breaks free then start the process all over again. When I tacked the wall in place, there was a whole lot of sticking going on and I wasn’t looking forward to forty feet of frustration.

I have to declare here that welding is new to me. Previously my work life involved wood, glue, screws and nails. I learned a little bit about welding from Bob H. back in the States, just enough to get me going and make me dangerous as they say. I guess you could call me a back yard welder. I don’t know squat about the coefficient of this or that, or the temperature that bronze-molybdenum-strontium 90 alloy melts at. I only know to get the spark going and keep it going. So to all the professional welders who fall across this blog by mistake, those with multiple certifications in underwater welding and welding in deep space on the Space Station while holding a wet cat, please have pity on me for what I am attempting to do at this stage of my life, and maybe remember those first not-so-pretty welds that you made so many years ago. Thank you.

So for my birthday, friend Les gave me about ten pounds of not 6011 rods, but instead 6013 rods. I thought I would give them a try on this project. How bad could it be? As it turns out, not bad at all.

The ubiquitous 6011s burn real hot. They burn paint real quick. Lots of slag flies everywhere, the rods stick easily, and if you are thinking about last night’s fight with your wife and not paying 100% attention to counting the number of seconds that are passing, you can burn a hole in the metal the size of Texas.

Even though technically in the same family (I don’t really know this for sure, I’m making this up), the 6013s are a real pleasure to work with. If the 6011s are a stay-out-all-night rebellious teenager, the 6013s are their stay-at-home studious twin. Rod sticking is much, much less with the 6013s. They burn hot enough to eat through the numerous layers of paint on the container roof, but the burn is more surgical if you will. There is less flaming slag flying over the top of my welding helmet, thereby burning fewer holes my scalp. Both rods seem to want to burn well for me with 60-amps set on the dial of the welder:

The new (to me) 6013s also don’t burn big holes in the metal nearly as easily. And if I do burn a hole, I can close the doughnut hole much more easily. A blob of the 6013 seems to stay in place as it cools making closing the hole quite easy, whereas the 6011 blob shrinks as it cools, leaving the hole almost as large as when I started. And if I switch the amps down from 60 to 40, the holes close quite rapidly.

To weld, you have to keep the welding rod moving. There are numerous techniques: the back and forth wiggle, the circle swoop, etc. The technique that I found to work best for me is this: working in the general form of a backwards letter C, maybe something like this:  ]  , I start at the bottom left of the backward C.  I get the spark going and sit in one place on the roof of the container for a second-and-a-half to two seconds, burning paint and making a small puddle of molten metal. Then in the next second I sweep to the right and up, then over to the left. Then to prevent creating a hole, I get the heck out of Dodge, wait for the new metal to cool for a second, then repeat. I’m left handed and am working from right to left. So if you are right handed maybe you will find a forward C and left to right easier. Your mileage may vary.  If you figure that I move about an eighth-of-an-inch at a time, that makes only 3,840 repetitions in the forty-foot long stretch. It goes like this: weld, weld, weld, move, stretch, drink water, repeat. Simple.

Here is a photo of the mess I am making:

A lot of the mess is paint that has burned and flaked, and the weld cleans up fairly well with a wire brush. It looks to me like it will keep water from leaking into the house. Here is the weld all wire brushed but not prime painted. The roof was too hot and the paint probably would have boiled. Hey, maybe Monday I’ll fry some eggs for lunch.

I got to the half-way point today before I sensed the blisters on my knees from the hot roof. I quit about 2:00. Monday weather permitting I will be back at the second half. With my new knowledge of the 6013 rods and my experience today, I’m not dreading the second half at all. Still, it will be good to be done with this part of the job. I will have to repeat this process when I erect the wall over container two. Stairs will lead up to this wall, and a door will take us out to the roof deck. I am anticipating the hammock swinging in the breeze.

Thanks for the swell welding rods Les! That’s all for now. Happy welding!