Couple things I did to seal it up:
1) Sealed all exposed Masonite edges with 4 coats of lacquire before applying the aluminum siding.
2) I setup step block so that the aluminium siding overhung the masionite by about 1/8" on all the bottom edges, this allowed me to created a channel to which I could run a bead of silicon between the frame and the sides.
3) The vertical joints were sealed with silicon underneath the edge molding. I did get lucky that when I routered the extra aluminum siding off it was an extremely tight joint so the silicon is just insurance.
4) I rolled the aluminum over the top edge.
5) Sealed around all the plumbing / power inlets / lights with butyl tape
My top overhangs the sides by 1" when closed, and 6" when open so the only areas exposed moisture in a rain storm is the very bottom edge, hence the channel created for the silicon sealer. The 1/8" overhang of the aluminum siding also works like those gutter leaf covers - the waters surface tension wants take it off the sharp point away from the Masonite above.
kludge wrote:Did I miss in the video where you sealed the edges of the exterior skin (masonite/hardboard) ???
I heard you mention it but I never saw you do it or what you did.