Well, the first real weekend of working on the van, and a mixed weekend it was. A brief break in the near-freezing weather made it feasible that primer and body sealant would cure, so it seemed time to make cuts to the body work that appear to logically precede any other activities.
It helps to have an artist for a wife. These scaffolding units cost $170-210 at any big box hardware store. Very handy for working on the windows and as a way to get up on the roof. And speaking of roof, leaning up against the scaffold, you'll see my variation on Hein's platform idea to allow easy working up there. As it turns out, the scaffolding would have been almost good enough (height wise), but for a few things, it was good actually being up there on the roof itself.
As it turned out, the platform was the just first of my recoverable errors. Hein used 2x6" on the edge of his platform - I opted for 2x4" because I had them (and the rest of the materials) just sitting around. But that meant that the 1x3" I used for cross supports touched the roof ribs in the middle, so I had to take the jigsaw to them and thin them to fit. The result was a much more flexible platform than I was thinking of, but it still focused the load on the rail gutters and gave me a place to sit and put stuff.
Almost everything I'm going to do the van is based on what I've seen here and in the Sprinter RV source book. For the fan, I adopted Graphite Dave's template model to mark the corner(s) of the opening. Things I learned along the way here:
- finding the center of the circle is hard. But finding the line through middle of it front-to-back is easy given MB frame holes.
- the fan opening can really be 14", it doesn't need to be 13 15/16th
- rather than cut a template AND a supporting (edge) frame for the fan, I used a single piece of 3/4" birch ply. I used it as a solid square for the template and then cut out the middle with a jigsaw to act as the supporting edge.
- spray paint goes everywhere. Mask. A Lot. More than you think you need.
- you're going to have to remove some of the MB acoustic dampening material. Do this BEFORE you cut the opening. You can do it afterwards too, but you will need a chisel and a hammer to bust this stuff off the metal and you might prefer not doing this right next to a newly-created edge. This was actually the most arduous part of the whole weekend. Ugh.
Originally I wanted to put the fan at the back of van and have the solar up front. But there's really no good place for it in the back - ribs get in the way - and we worried about the noise of it being overhead at night. So I simply went with the MB stamping up front. I was amazed that it was still a fairly close fit - the edges of the fan flange still rest on the roof ribs in front and behind the circular area. Not so much that I was worried though.
Having cut out the hole, I double-primed the edge. and then painted. Masked the second time around ...
Had to wait a good while for the paint/primer layers to dry, and since I was going to use a putty gasket, I decided to leave the paint to dry overnight.
The next day I drilled out the flange mounting holes, primed the edges, left that to dry for a couple of hours, and then layed out the putty. I'm suprised to hear people using butyl for this - the information I found strongly suggested butyl for fiberglass (e.g RV) and putty for metal (e.g Sprinter). Either way, I am sure you can get a good seal. 16 10/24 x 1-1/2" stainless bolts, washers and locknuts later:
I (mostly) copied Graphite Dave's idea of adding "strip washers" to spread the clamping pressure and reduce the likelihood of cracks in the (plastic) fan flanges. I used only 1/6" aluminum (hey, every little bit of weight counts, right?) and utilized the existing aluminum on the hinge side of the fan. This actually required 2" bolts and slightly larger washers for the 3 holes there. I'm split between this being a good move - reinforcing the fan hinge attachment - and a bad one - this strip was not not meant to be used this way. Ready for sealing:
I used UV-resistant Sikaflex to seal the edges and the tops of the screws. One thing worries me about the aluminum strip idea: there seems to be the potential for a very minor but real water entry path underneath it. The outer edge is sealed but the inner one ... well, if there is an issue, it is just a matter of more Sikaflex.
A couple of the other things got started. First, QuietCoat on the wheel wells. This is a visco-elastic polymer that appears to be one of the best things for vibrational noise. It gets painted on in several very thin layers. This was the first one:
And since it was going to rain, I drilled out the holes to mark the corners of the window cutouts (look hard - they are a bit tricky to see). A 1/8" new pilot point drill make this easy work. More on the window story tomorrow, which didn't go as smoothly as I would have liked.
Minor tasks partially accomplished: I primed all the holes left in the inner walls by the weatherguard shelves that were previously installed (a couple need some rust converter first). And I tried inserting the rubber plugs recommended by Hein to seal the sidewalls. This is SO hard, and in at least 1/3 of the cases, almost impossible due to inner wall framing being in the way. I wondered if temperature would make much of a difference. Some oil help a little to get things sliding, but I'm not sure if I want to use this approach for the remaining 9 holes. The plugs are nice though.