Saturday, April 20, 2019

The solution to the roof problem

Today, between rainshowers I climbed onto the hood of the bus and looked at where I would expect drain holes to be on my roof vent. There were two drain like raised parts of the vent but they had been completely sealed with some kind of sealant and then I'd slapped pain over it all.
Both vents are afflicted the same way. Clearly not a good thing and shame on me for not discovering this until recently, having owned the bus since November of 2014.
As an interim measure I bought a plastic box to tape over the vent and was going to make a hole for my cheap Chinese plastic solar-powered fan. That plan was scuppered when I noticed I'd failed to check to see whether the bottom of the plastic box was suitable as a top. It turned out to have a lip all the way around which would collect water. Not ideal or even anywhere near ideal.
I'm pretty sure that - given the insane amount of caulking - I'll probably end up destroying the existing roof vent when I attempt to remove it. I'm feeling that removing it so I can treat rust and fully paint where it was before reinstalling is my best option. Fortunately we are heading into summer now so it really is painting weather. As luck would have it, there's a company selling just the right kind of vent.

I thought long and hard about getting a more robust solar-powered vent before realizing two things. Well, three actually but we'll go into the third later. The first was that none of the solar powered vents are really designed to be on the rooves of moving vehicles. They all claim to be designed for it but they're not. Branches rake across rooves. I drive a school bus daily for work and my bus roof is often raked by branches. A branch would make short work of destroying a mushroom style vent. The second is that a powered vent would be pulling air from the front of the bus at the same time my existing extraction fans will be pulling it toward the back. I have a feeling those fans would be fighting each other or creating stagnant areas. Now my third thing is cost - the cheapest steel solar vent is about $75. The cheapest rotary vent is about $100. Rotary vents are popular in Europe. The standard vent like I have is $25. It is designed to be whacked by branches. It won't fight my extraction fans and installed properly will be waterproof. I'll probably order one on Monday.

Once I have the new vent in place, I'll be able to touch up all the paintwork ruined by water seepage. That latex paint really isn't up to much! I honestly wish I had used oil based paint throughout. I have had some of my oil paint wear off where it's painted on the floor but how much use does that floor get? A lot, I can tell you!

Chatting with the work mechanic, he confirmed my suspicion that the roof vent is there to make sure the insulation in the bus is dry. It give it somewhere to vent. I hear a lot about people complaining about mold but none seem to pay too much attention to ventilation. There's an emphasis on stopping drafts but no realization that doing so is unhealthy.

I certainly did not complete all that I wanted to complete over the week's break. I wired up the new battery. I moved the bus. I confirmed that using two batteries in parallel stopped the insane voltage drop on the batteries. There's a C/8 formula for discharge on batteries. According to that, my 35AH battery should have been fine at 4.375A draw. As it was not, I added a second - I put the old Harbor Freight battery back in the system. That gets me up to a theoretical 8.75A maximum draw. I think though that the 3.8A draw I had going today was probably about as much as I dare put through the batteries.

Remaining to be done...

  • The horn quit working so I need to check what's got disconnected and fix it.
  • Change the front solar input to Anderson.
  • Add a solar charge line to the driving battery compartment.
  • Put a solar input at the rear.
  • Put the power line from the fuse box at the rear to the new handbasin pump.
  • Move the shower fan from its current location and wire it up.
  • Add a switch and USB power supply to the control panel
  • At a future point, run all my installed switches through a new fuse box inside the control panel.
  • Fix the leaking roof vent. I'll replace it. That seems the easiest option.
The underbus stuff is the stuff liable to give the most problems. It all involves lying on the ground under the bus. The tarpaulin does stop me from getting sick as I don't breathe as much bacteria from the soil. It didn't help last time because after I installed the battery there was nothing holding the tarpaulin down so it was flapping around and of course I had to roll off it for a while. Maybe I should try a respirator or something even though they're hot, sweaty, nasty things.

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