Tag Archives: welding

Another thought on shutters

I’m spending an awful lot of time thinking these things through, but I would really like to get to a design that, once in place, works nearly right the first time (I’m still somewhat of a realist), and hopefully is replicable by others that want to do the same sort of thing!  I mentioned previously the idea of welding the fram on to the wall of the container, and then cutting out the shutter (now welded to the frame), and doing this on the inside. Today I was fiddling with doing the same thing from the outside, and while I think that would work just fine (and the 1″ or so shutters sticking out aren’t going to make the containers so far out of ISO compliance as to make them un-moveable, at least by land), I think the interior route still is a better solution.  If for no other reason than the baffels created will also provide to properly enclose the closed-cell foam insulation that will be applied after the shutters and interior studs are in place.  The shutter barrier being inside also means that there’s a flat square surface onto which it should be possible to mate the window/door units as well.

I still like the original model of cutting through and then edging the shutters in, which would still provide a flat surface and a baffle for the insulation, but I am not convinced I can work at the tolerances that requires in the field while learning to weld… Oh, and I am taking a class on how to weld in the near future :-D

For those interested, here’s a view of the new baffel shutter (in an exterior location) where you can see the baffels before being fit snug up against the wall.

How about shutters “inside” the building?

My current shutter design requires:

1) Cut out the shutter interior material (~4″ less than the final opening) out of the wall itself

2) Cut out the actual shutter space (this will create a 2″ wide “O” cutout from the wall, with the shutters already removed from the interior)

3) Weld 1″ wide by 2″ deep steel tube around the opening, and the shutter (after cutting the shutter in half and removing another 1″ from the new cut sides of the two shutter sides).  This is trick, and needs to be square

4) Insert the shutters back in the opening (tubing to tubing) and weld on the appropriate hinges.

I still think this will make a very nice shutter, but it is complicated by the fact that the shutters need to be cut out and then trimmed.  Keeping everything square is the big trick in this, and that’s where an alternate idea has presented itself.

We had dinner with friends Chad and Anna (and their charming daughter Nimue) this evening, and as we were discussing this particular component of the container process, Chad suggested just welding the frame to the interior of the container.  I thought this made a lot of sense, in that you can build the frame, add the hinges, make sure nothing binds (perhaps even add some cross bracing), and then weld the shutter frame to the wall.  You can add a baffle of either 1/8″ thick steel plate, or just add an appropriately cut out 1×1.5″ tube steel insert, which will fully connect the frame at the top and bottom of the shutter. If you leave an appropriately sized gap (1/8″ should be adequate) around the shutter frame and its mounting frame, you should be able to:

1) Weld the frame up on a known flat surface and weld on the hinges

2) Check for and remedy any twisted hinges, or areas on the frame that bind (which should be ok with the 1/8″ gap).

3) Weld the frame to the sidewall of the container

4) Drill through the container wall to mark the actual location of the shutter gap (between the wall frame and the shutter frame) on the exterior

5) cut through the exterior, either with a cutting torch, plasma cutter, a cutting wheel on a rotary grinder, or even a reciprocating saw (like a sawzall)

Using 1″ tubing would still take a small amount of the interior space away, but this would potentially be masked by the interior walls anway. The biggest benefit is the ability to attach the shutter to the frame prior to cutting out the shutter, and being able to make sure the frame isn’t binding prior to cutting out the shutter!

Now, with a 3.5″ metal stud set all the way to the “outside” of the corrugations int the side wall, there is stil a 1″ gap between the shutters and the wall edge.  This isn’t enough for the doors I’m looking at (5″ framed width is in the spec sheet), but perhaps I’ll look into some custom doors instead.  They’ll stil be thicker than 1″, but if I can get them down to 3″ rather than five, then they don’t stick so far into the interior as to look odd.

I think this model makes even more sense than the original, even if it means sacrificing an additional interior inch of space on one wall.

Welding with no power?

When building a house on a metal frame, eventually you are going to have to deal with the need to weld something.  No, really.  It’s the most logical solution. And unless you are building your container house out where you have a nice power supply (a 6+KVA generator would help), you’re going to have to figure out how to weld without the unlimited power we city dwellers have come to expect.

MIG welding headCertainly one solution is the generator->standard 220V welding setup.  But there’s the first rub.  You need a sizeable generator to power a welding rig (usually ~5+KW minimum) if for no other reason than to get the 220V plug which most MIG welders need. This might be fine if you already want a large generator as backup for your place, but most people would do fine with a 1-2KW generator, rather than the much more powerful 5KW scale generator. In addition to the size, there’s the fuel consumption. Going from hours per gallon to gallons per hour between the two ends of the spectrum.  There’s also getting the generator in place (again, not an issue if you plan on keeping it in/near the cabin), especially if you decide to rent one, where a good road makes this easy, but if you’re like us, where we don’t have a good path to where the containers will be, it certainly adds to the challenge!

One potential solution, given the fact that we’re looking at solar as a key energy provider for our studio, is to weld with DC.  It turns out that welding systems are DC anyway, but usually there’s a large AC/DC conversion along with start control and other fancy bits within the box that the welding head is attached to.  So why not just run direct DC?  Well, that’s just what’s avaiable, either with built in batteries (something like: http://www.hobartwelders.com/products/battery-powered/trek180/) or standalone with your own batteries (as in: http://www.readywelder.com/).  But since these systems are fairly straight forward, and if you can get away without the shielding gas supply, you could build your own (as shown here: http://www.instructables.com/id/SpoolGun/)!

I’m going to look at the build your own route myself, as I already have the equipment for a fairly sizable solar platform, and as long as I can get away with fluxed welding wire, this should work out really well! Interestingly enough, there’s a “solar golf cart welder” instructable as well (http://www.instructables.com/id/SolarWelder/)  which at least based on the commentary leads me to believe that I’ll have plenty of power for small welding jobs, though not perhaps for the behemoth job of building out the metal shutters. It does make me wonder about solar plus a generator->battery charger setup. As this might be an interesting “hybrid” setup. As the comment went, you might draw 150A for welding, but only for a short time.  And if you can feed in 30-50A (plus whatever the solar provides), it might well be that the batteries act more like a big capacitor rather than managing the longer term power storage that batteries are known for.

Clearly, there’s still a lot to learn about how much actual power is required for welding, and what the best methodology will turn out to be, but we’ll experience many of these options soon enough!