Monday, November 22, 2010

Insulation project

Note: This post was started a few weeks ago.

Have you ever tried to sculpt polystyrene? OK, fine. "Styrofoam". Have you? It's kind of a bitch. Unless your knife is sharp enough to remove body parts without you noticing the foam binds and clumps and tears. It sucks.

There is another way.

With the car paid off and the bank account recovering I need to finish the back wall of the house before Yummy kills me. But first I'm putting up some more insulation. There's already a bunch of the multi-ceramic paint coating it. That should be about 20R insulation. But I'm being a bit of a pain in the ass and want to put more in there. I could do the Pink Panther fiberglass stuff. It's easy to install. But, it's really not very good insulation unless you're laying it on nine inches thick. Even then, it better not get wet. Not even humid. If it does then it's nigh worthless.

Besides, the point isn't really the back wall. The point is the underside of the house. The crawlspace. I applied the multi-ceramic stuff down there late last summer. It worked. When walking around in bare feet you could feel the floor go from cold to really cold when you left the insulated area. I shouldn't be walking around in bare feet in the winter, but I shouldn't be afraid of the air in the lower twelve inches of my house, either.

So I really want to put more insulation under the floor. There's space for six to nine inches of the pink stuff, but it WILL get damp. I can't get foam insulation sprayers to take the job of going under the house. So, really, the polystyrene sheeting is the answer.

The proper way of using this is in the full uncut sheet. It's four foot by eight foot and two inches thick. At least the stuff I'm using is. There's plastic on one side and some reflective foil on the other. It's supposed to be used on bare walls in unfinished basements. Or the outside of studs when building a house. That seems nuts to me. I'm a fan of studs. And fastening things to studs. And that sounds really bad when read out of context. I'm never getting elected President now.

What I was getting at is that I'm not going to use it "properly". I could lose the space under the house that would be taken by putting whole sheets of this stuff under the floor joists. It would be a horrible loss when doing future jobs down there, but I could do it. I could do it if there were a way to get a 4'x8' sheet of anything down there.

I need to cut apart the polystyrene both to fit between the floor joists AND so it'll fit through the hole into the crawl space.

This is where I get back to what I was muttering about at the beginning of this post. Cutting polystyrene. It sucks.

In place of a sharp blade you can use a really hot wire. A quick "sssssst" sound and you've got a nice clean cut. You find a wire that will heat without melting and something to run a current through it. That broken down answering machine shoved in the corner? That phone charger without a phone? Strip down those wires, put them on either side of a guitar wire, and you've got yourself something that will scar you for life. It should also cut polystyrene.

I've spent a good part of today (Saturday) working on something potentially very dangerous. I've tried the wires from the power supply to a MacBook Pro stripped down and connected to some other wires that I've run to a broken guitar string that Yummy's brother gave me. This hooked up to a wooden rig that holds the wires across a three inch gap. A block is clamped on that can be moved back and forth depending on how wide the space between the studs or joists is. I haven't fired it up yet. I'm a bit scared of it.

The finished theoretical polystyrene cutter.

There's another concern. I mentioned that the polystyrene is reflective on one side. Probably some foil. Probably conductive. What happens to the foil as the wire goes through it? Does it melt? Does it tear? Does it conduct electricity and bake whoever is holding the polystyrene? Does it conduct electricity, heat up, and melt any polystyrene touching it?

There is a plan B. If I survive the encounter with the electrically charged wire and foil I can try a soldering iron. If I wrap the wire around the soldering iron it may heat up the wire without getting electricity involved. I'm thinking this won't get the wire hot enough or that the wire will cool too fast when cutting the polystyrene. Otherwise this would be plan A.

* * *

I did a HomeDepot run earlier. I needed caps to put over the wires and some big clamps. And a piece of the polystyrene insulation to play with. At eight feet long it's just short enough to fit in my Prius. At four feet wide it's about three inches too wide to fit through the hatchback. Luckily someone with a seriously sharp knife was there to help me cut it. I was amazed at how clean the cut was. We scored one side and applied pressure. I should mention that this is how the company that makes this stuff recommends we cut it. It failed to break. We scored the other side. By the time it had cut 15'4" of this stuff the knife was dull enough that the polystyrene finally started to bunch and tear. (Sorry about that, little knife.) We applied pressure and it still wouldn't break. Two inches was just an inch too much for that trick to work. So the guy pulled a saw out of his car and we sawed the sheet in half. It was brutal. Bits of polystyrene went everywhere. There will be a lot of waste. But this was supposed to be a test sheet anyway. We'll just find a different way to get them home next time.

At this point I should apologize to my parrot Gandolf. She wasn't prepared for eight feet of polystyrene to march through my front door unsupported. I should have come through first instead of last. There might have been less screaming and flapping that way.

* * *

After writing all that I plugged in the MacBook power supply. There was a reason it was in my scrap electronics pile. I got current from it, but the multimeter said it wasn't anywhere close to what it was rated at. Instead of 16-18 volts I got 5.2v. That would be why it didn't run my laptop anymore.

I found another power supply. One that went to a cordless phone. 7 volts. It worked, but the wire still seemed under powered.

The third power supply was from an old Zip Drive. 10 volts. Lame.

A fourth was from an external hard drive. It would likely do the job, but the power indicator light would go out every time I hooked it up. Stupid safety precautions.

Finally, I found a power supply to who knows what. No, really, I've been carrying this thing around for years and can't remember what it originally went to. 16 volts. By now I've improved my design enough that I don't have to strip the wires. I plug that sucker in and the wire gets hot. Boom. Just like that. No worries at all.

I dance a happy jig and drag it out into the alley. I set the guard at 12 13/16". I put on thick leather gloves in case the foil conducts heat or electricity. I didn't need to worry about that at all. The biggest problem was that the foil didn't want to give. I marked the cutting path and cut through the foil. I tried again. I can see smoke boiling off of the wire. But the cutting is still going really slow. I'm guessing it would take half an hour, probably more, to get through all eight feet.

The Dougintology polystyrene cutter and wart remover.
I could take some gypsum board (Sheetrock) and make a table in the alley. OK, it would be a modified version of the wire cutter. It would allow me to set the foam on a surface and guide it more carefully. Also, I wouldn't have to hold it up the whole time.

Another option is to get out the circular saw. See what a high speed saw does to polystyrene. This is just a test piece after all, right?

* * *
I did get the circular saw out. I used a blade designed for cutting plywood. That was a beautiful cut. No, really. Very clean, very smooth. I like it. 

There was, however, a change of plans. Yummy called the contractor who worked on her parents house. He called his insulation guy. He's willing to work in crawl spaces so I agreed to let him have a look. He says the spray foam would be best, but we'd only be able to insulate as far as the hose reaches. My idea with the polystyrene sheets didn't appeal to him at all. That's just not how you use that stuff. He wants to put in some fiberglass insulation. Not necessarily the pink stuff, but close enough. To keep the moisture down he'll cover the dirt with some thick plastic sheeting.

It's not the insulation I want, but the price is reasonable enough that I can redo it every few years. Maybe I can find someone with longer hose by then and we can do it right.

He's coming to do this tomorrow.

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