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Anybody processing inside of a Conex Box?

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July 28, 2010, 05:05 AM
Anybody processing inside of a Conex Box?
I was looking for a processing shed.

Thinking of an all metal structure.
With a floor.
And non flammable.
And preferably on skids.

Many of the photos of processor fires show a shed (or basement garage) reduced to a twisted hulk.

So, I started thinking about a conex box.

Heavy steal.
It would take a licking and keep standing.

An 8x20 conex box would be a great size for a shop.

Perhaps one could weld a 6" lip at the door... which would provide containment for about 1,200 gallons.

An explosion might blow off the doors so one might want to weld on a chimney.

Anyway, with a little design work, one could have a gnarly fire... and it would be 100% contained.

I suppose there is still risk of "heat damage", but it would all be radiant heat through solid steel. Enough for a secondary grass fire I guess, but a add few foot buffer and anything surrounding should be reasonably safe.

July 28, 2010, 08:19 AM
Is a conex box a cargo container like they put on the big ships? If so, I think it would work great as a processing area.

I doubt it would contain a fire as well as you hope it will because I believe the floors are made of wood.

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July 28, 2010, 09:08 AM

Shipping Containers...

Ouch, I was thinking of metal floors. I suppose one could weld a steel (treadplate) floor in place, but that would be a lot of work, and probably end up being rather expensive to do.

Getting a floor slippery could be a problem too.

I did see a Refer (refrigerated) unit that looked very nice. Insulated walls. Stainless Steel inside. Slatted stainless I-Beam floors (which could help with traction, but might be a pain to keep clean).

I suppose the problem with a wood floor is that it could burn (or worse yet, ignite with say a hot pump). And, it could leak oil outside, and thus loose containment.

I do like the idea of setting up a processing area that could naturally just burn itself out with little or no harm to anything outside of it. And a little portability would be nice too.

I suppose one could get a similar fire resistance with concrete.
July 28, 2010, 09:59 PM
Jon Heron
Around here they are called "sea can[s]" and they are used for all manner of things including homes! LOL
If you search for "sea can" on the web you will find all the specs you are looking for. All of the ones I have seen have had steel floors but that's not to say there are not some with wood floors...
The problem I see with them is head room, I think they are only around 6' high, if you have a short fat reactor this may be fine but would not work for me...


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July 28, 2010, 10:12 PM
My conex has a wood floor.

July 29, 2010, 01:30 AM
I have been inside conex boxes, but it has been a while so I just don't remember the floor. But I looked at some photos and descriptions of them with wood floors which I'm assuming are standard.

Metal floors are often slippery.

But, certainly could be replaced with steel, tile, or etc.

Dimensions vary, but for a standard 20 footer.

Interior container dimensions:
19’4” (L) x 7’8” (W) x 7’9” (H)

I assume an insulated unit would have less space inside. I'm seeing notes of Reefer units being:
17'11" x 7'6" x 7'6" inside.

There are also "high" units (perhaps only 40 and 45 feet long), but with 8'10" interior heights.
And High Reefer units having an interior height of 8'4".

Anyway, they probably seem a little more enclosed than most high truss workshops. But, an 8 foot-ish ceiling should be just fine. If I need something taller, I could cut a hole in the roof.

Truck boxes, of course, are usually Aluminum and potentially wouldn't give the containment of a conex box.

However, I suppose a boxcar would have a similar heavy steel. A little wider inside, and 10 foot to 13 foot tall. But, I think it is a little bigger than I'd want unless I was doing a lot of cutting and welding. Or I had more land.

Perhaps if it is operated with the door open, then this would all be irrelevant. An automatic door closer could be built, but I'd hate to get locked inside during an emergency.
July 29, 2010, 10:59 PM
Legal Eagle
Very few refer units will have a wood floor; the reason being that the air needs to circulate and it does that by dropping to the floor and then returning to the refer unit that way (and the thermostat which controls the cycle).

If the container is filled with stuff, either paletised or loosely stacked then the air cannot circulate with a flat wood floor, and so they slat the floors in raised aluminium like a Toblerone chocolate bar on the entire length of the container. This means that even if the container is filled to capacity that the air will still be able to move under the product due to these elevated "bumps" in the floor. Where a wooden floor is used it gets very slick (condensation) and palets/skids MUST be used to allow the circulation of air. The nice thing about using a raised refer floor is that it is lengthwise and is easily washed out using a garden hose (there are vent holes in all 4 corners)

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August 08, 2010, 04:05 PM
sound like a good idea to me..
don't worry about the wood floor..if you have fire it won't matter..but a sealable container with a CO2 injection is out in no time, should one start. what about filling the space with C02 while processing is happening and people aren't inside? no O no fire..

what about ceiling height?
many times I wish I had more than 8' ceiling in my wooded shed with wood floor. the floor should last forever with all the oil treatment it gets..yes I plan on running if a fire starts Smile

what about ventilation? are you thinking about a large fan on one end?
this would be good..

what about power? water?


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May 04, 2011, 02:13 PM
matt e
I do not know what one would cost now, but about 3 years ago we bought 2 of the 20' containers at work from a company called one way lease( i believe). And they were right at $3000 delivered. Now we have a 10k to unload them but I think the unloading fee was only slightly more, a couple hundred bucks at most. Ours do have wooden floors, but they are steel under neath them so regardless of a fire, it most likely would contain it just the same, maybe get a bit hotter in there is all. The containers are also air tight, minus the breather holes that they add, so you could cover them up and displace the oxygen if you so desired and make it fireproof while it was closed up I suppose.

This price was for brand new containers, I believe the used ones were significantly cheaper but we aren't allowed to buy "used" stuff. If you were interested in using one, this would be a good starting place to look. HTH


Edit: I called onewaylease just to check and in my area the New(used once) containers are $3300 plus about 400-500 shipping(about 175mi). That is if I unloaded it. You could rent a forklift for the day if you needed to, might be cheaper than having the trucking company do it. The lady told me that if they unload it they use a tilt deck trailer and you have to pay round trip vs a flatbed that you only pay 1 way freight. So you'd probably come out ahead renting a forklift. An older used one, 8-10 yrs, runs 2600 - 2800. This is all dependent on time of year, area, and the market. This particular company sells them east/west/gulf and a few other over seas areas I think. Might be able to find them cheaper elsewhere but as I said, it is a place to start.

This message has been edited. Last edited by: matt e,
May 12, 2011, 08:49 AM
I purchased 2 40ft units about 3 years back for about $1300 each, then buried them side by side in the front yard. Fun... They make a great processing shop if you can conform to the size "height" restriction. The floors are mostly wood 3/4" or 1" plywood over steel C-channel, but have one sheet of steel where they would set over the 5th wheel on a trailer.

They are built to be fairly water tight, all rubber seals around the floor joints. For containment purposes, we siliconed all the bolt heads and then epoxy coated the floor. So far it's holding up well but to do it over I'd probably go with a better coating like Line-X.

The biggest plus is you can easily weld uni-strut to the walls and cleanly mount all your electrical and plumbing. To bury them we had to reinforce the walls and build a roof to handle the dirt weight. They are incredibly strong in the floors and corners, but not the sides or roof area. Can handle 80K GVW stacked like 8 high, so do the math. If your using them above ground, you'll need to insulate them well to avoid condensation during the winter months. That was a big issue before we dried them in.

Here is a few pix when we were prepping the insides. Will take a new one today with all the equipment installed.



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May 12, 2011, 11:33 PM
Here are some more pics of our shop layout. Still allot of construction going on, but it's functional.

Some tricks to consider. Think of every placement. Our doors allows for a man door on one side while maintaining the function of the original swing doors. No way to shut them from the inside so it was a must. Also since we're setup underground we wanted a 12 inches or 1500 gallon of containment level "bathtub", so the door fans provide positive pressure and not pictured are other vent fans that pick up from the floor level where fumes would collect.

Uni-Strut rules... And fits well with PEX to keep most of the lines off the floor.

Looking at the front from our dock, things are still a work in progress.. The underground placement works super with a little geothermal cooling provided by our pond. Typical inside wall temps in the winter are 55F, low 60's in the summer. If using these containers above ground I would strongly suggest going insulated or some sort of cover. Before they were buried you couldn't stand to be inside without the doors open and fans running. Got well over 130F in the sun, so add plenty of venting or a good AC unit.

Hope this helps.


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May 14, 2011, 02:37 AM

Nice setup. And, you even have a built-in tornado shelter!!!

A bit bigger than I was thinking for home processing. There appears to be a 10-footer at one of the local yards that I was going to ask about, although perhaps it has been cut down, and I'm sure it could get filled up quickly!!!
May 14, 2011, 05:17 AM
Thanks keelec,

What I didn't show is the half of one unit the wife has filled full of crap.. Soon as I can get her stuff moved out we might have some extra room.

As for the Tornado shelter, was actually in there with a couple friends when a large tornado touched down just 5 miles away last year. We had no idea anything major was happening until the power started flashing. Walked outside just in time to see the storm moving off. So now all the neighbors think it's pretty cool.

With a little searching online, you can find 20' and 40' Conex units "out of service" very cheap. According to all the signatures inside, these had been around the world once or twice. I actually found the best deal on eBay. Seller listed them nation wide and sourced out of the closest storage yard. For the logistics I called up a local trucking company. They delivered both 100 miles with an F350 and 35' goose-neck trailer for $300. Next time I'd just go get them myself.

We unloaded with a tractor and excavator. Just lifted each end and pulled out from under. Easier than we ever expected, one could use blocks and jacks if no power equipment.

Good Luck


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