unheated seacan: stopping condensation

[jd99]

Now that my shop consists of an unheated seacan, I see that my motley tool collection is a condensation trap. Any ideas on how I can reduce this? Never had a condensation problem in my old shop, even though it was unheated for months at a time.

[BCRider]

You're not going to like this but I think to cure the root issue you'd need to insulate the can.

You can TRY things like dehumidifiers but a big steel box is always going to have a period where there's a strong temperature difference between inside and out which is going to raise the humidity inside. And depending on conditions even produce condensation.

You can fight this or fix it. Fighting it means using a dehumidifier. Fixing it means making the temperature inside more even. And that pretty much means insulation... or heat I suppose. But you don't really want to heat an uninsulated can.

[The Artful Bodger]

Ventilation is unlikely to be a complete solution but it is the easiest remedy is to try.

John

[darryl]

You'll want to ventilate anyway. I don't know how long the doors are shut at a time when you're in there, but you should have fresh air. Maybe consider an hvac system. There might be something small enough and thus cheap enough. But insulation might be needed anyway. I can see the whole thing being blown with spray foam on the outside until it looks like something the kids would like. I wonder how far a dollar goes if you buy the kit and spray it yourself?

[The Artful Bodger]

What can be done will depend somewhat on the local climate and I am afraid I dont know if you are in the woods of Alaska or out in the Tanami Desert.

[flylo]

Spray foam is fugly but does work.

[old mart]

I roofed a garage with the industrial thin steel "corrugated", the cheapest by far method, for a flat roof with a minimum slope, and the condensation drips drove me to distraction. The only cure was 1" thick slabs of expanded polystyrene fitted to the underside.

[jd99]

Thanks for the replies. A guy down the street sheathed his seacan in plywood a few
weeks ago. No one around to ask why. Mine will be unheated and unused for 5 months.
Both inside and outside had the paint burned off and the seals melted. The inside is
covered with baked on soot, so I don't expect insulation would stick. But, it's what is
available for now.

[flylo]

You'd have to clean or power wash it first & have someone with a truck mounted system. At least get a quote.

[BCRider]

Even the plywood he put on is easily three times the insulative value of the raw metal.

There's a HUGE number of videos on YT about converting cans to housing. I'm not saying you need to go that far by any means. But a thinner and cheaper version of what they do to "dry" the can out and make it usable might be what you need.

Losing the seals isn't good though. See if you can buy replacement seal moldings. You at least need to keep the rain out.

If you don't give it any sort of roof other than an entry cover that's OK. But you really should cover that over. ESPECIALLY if you don't replace the seals.

The other issue with the cans I've seen is that the floors are not really sealed. Perhaps it's to allow the cans to breath when used in their original application? But if you just drop the can directly onto the ground then ground moisture can come up and in through the joints between the plywood floor and the metal. You really do want it up on at least some small blocks just to let some air circulate. At least unless you know you have a steel floor version.

[1-800miner]

I am in the same situation. Three of them. All had floors burned out.
I layed down six layers of plastic before I put new ply wood on the floor. Haven't seen any sign of moisture in the floor.

Ceilings would drip last winter before I insulated them. I am waiting for winter to come and will see if it works.
I have a feeling insulation, alone will not do it. Maybe a couple of light bulbs as a heat source.

You need to pressure wash several times for new paint to stick. And it will take more than one coat.
I got lucky and found a guy that sells five gallon buckets of paint for fifty bucks.
I am on my third coat and still discolors. Not that I care, it is a shop.

[The Artful Bodger]

I have never tried it but I have heard suggestions to cover the top with a few layers of plastic and lay turf on top.

[jd99]

I think the idea of plastic and topsoil would work as roof insulation, like the old soddy roofs
of pioneer days. The can is up off the dirt on blocks. Had to replace the front floor
plywood which was burned out, but the floor is dry. I will tarp over what I can although
that won't stop condensation. Place is isolated and heating is not an option. This is the
second seacan I bought but the other one never had a condensation issue over 8-10
years. Too bad it blew up.

[The Artful Bodger]

Too bad it blew up.

I have visions of one I saw in Kabul which was blown up like a football shape with a fist sized hole on one side and the other side shredded!

[jd99]

Mines not that bad but it's rounder than it is square. Tried doing some body work with the
hoe but the metal is stretched so much it's like jelly.