What Sources for Wall Channel?

[wrenchtech]

A high priority for me right now is to remove about six windows. My bus has the large 52“ x 26“ horizontal sliding windows. That is going to leave openings that should be strengthened with the addition of a vertical channel. I have looked around a little bit and am not seeing anything at the usual metal supply houses. What options are there for this channel, which I believe needs to fill out a 2 inch space between the inner and outer walls?

[musigenesis]

Your openings currently have no vertical support in the middle. The window frames provide some stiffening of the structure, but if you rivet/screw sheet metal over the openings on the outside this will probably more than compensate for their removal. Your only remaining issue should be preventing a sheet that large from "oil-canning", which a piece of vertical angle steel (with the sheet riveted to it) would handle.

[TJones]

From what I've read about roof raises the hat channel usually has to be custom bent.

Ted

[matthews2001]

skoolie.com sells hat channel!

[EastCoastCB]

Originally Posted by matthews2001

skoolie.com sells hat channel!

Theirs is pretty lame though. Only like an inch or so of overlap. Comes witht he flange tacked to it already.

[wrenchtech]

Originally Posted by musigenesis

Your openings currently have no vertical support in the middle. The window frames provide some stiffening of the structure, but if you rivet/screw sheet metal over the openings on the outside this will probably more than compensate for their removal. Your only remaining issue should be preventing a sheet that large from "oil-canning", which a piece of vertical angle steel (with the sheet riveted to it) would handle.

The channels in my walls are set at 29 inches apart. These large windows fit into the two wall cavities that are made up by three channels, with one channel falling right in the middle of the window. The channel in the middle, which would run to from the floor to the roof if there was no window, has been cut short and a horizontal piece of channel has been run across the top of it and over to the channels on either side, forming what frame carpenters would call a sill. I don’t know if there is the equivalent of a header above the window, because I have not been able to see that area yet. It looks like it would be pretty easy to fill in the missing piece with some angle steel as you say. I would like to weld that piece at the top and bottom to join it to the surrounding pieces, but if I find out that those pieces are galvanized I probably will skip that because the idea of welding on galvanized material in the enclosed space of a bus seems like a really bad idea unless I can lay my hands on a supplied air respirator.

When the three windows on each side come out, there will be a run of about 11’ that I will simply cover over. I will be using 18 ga cold rolled steel sheet. One piece measuring 94” x 30” and another at 39“ x 30“for each side. That seems to be the best way to make use of the 4’ x 8’ sheets that I Will be working with.

I am thinking of fitting them and then taking them down to have them painted before installing them permanently. I would paint them myself if it was warmer outdoors. As it is I will probably take them to a local auto painter.

[musigenesis]

Originally Posted by wrenchtech

I don’t know if there is the equivalent of a header above the window, because I have not been able to see that area yet. It looks like it would be pretty easy to fill in the missing piece with some angle steel as you say. I would like to weld that piece at the top and bottom to join it to the surrounding pieces, but if I find out that those pieces are galvanized I probably will skip that because the idea of welding on galvanized material in the enclosed space of a bus seems like a really bad idea unless I can lay my hands on a supplied air respirator.

My side exit door spans two "bays" between ribs so the center rib ends at the top of the door, like your windows. I was surprised when I demoed the bus to see nothing at all like a header above the door, despite the very elaborate and complex structural additions on either side of the door (including two extra lengths of rib channel). Wooden-framed houses require headers above window and door cutouts because the mass of the walls and roof above the openings would otherwise cause the head to sag and jam the door or window. In a bus the roof is basically an upside-down half-pipe and is self-supporting enough (and light enough) that there's no downward distortion as the result of a single cutout rib. Which is why I don't think you need to worry about continuing the cut rib in terms of supporting the roof - just in terms of keeping your sheet metal from oil-canning.

You can use a mask like this for welding galvanized: https://www.amazon.com/3M-Aura-Dispo.../dp/B013UKCUAO. Supplied air respirator is obviously better, but you won't be welding galvanized every day for years or anything. You'd have basically twelve small welds to make.

[wrenchtech]

Thanks again for your great insights from experience. I’ve had a little experience myself with welding on galvanized. Maybe it’s just me, but the one time I did it I got pretty sick right on the spot. The color went out of me. I look so pale and kind of grayish that my welding instructor looked at me and said are you OK. It was a project that I had brought to class an old old winch that had a galvanized body. I never wanna experience that again.

[musigenesis]

Originally Posted by wrenchtech

Thanks again for your great insights from experience. I’ve had a little experience myself with welding on galvanized. Maybe it’s just me, but the one time I did it I got pretty sick right on the spot. The color went out of me. I look so pale and kind of grayish that my welding instructor looked at me and said are you OK. It was a project that I had brought to class an old old winch that had a galvanized body. I never wanna experience that again.

I hear you on the galvanized, it's nasty stuff. I've been welding on my floor and the galvanized coating is almost entirely gone, but until I switched to a mask under my hood it was making me a little ill, too.

[banman]

Originally Posted by wrenchtech

Thanks again for your great insights from experience. I’ve had a little experience myself with welding on galvanized. Maybe it’s just me, but the one time I did it I got pretty sick right on the spot. The color went out of me. I look so pale and kind of grayish that my welding instructor looked at me and said are you OK. It was a project that I had brought to class an old old winch that had a galvanized body. I never wanna experience that again.

Regrettably you're more sensitive than average -- 3M makes a low profile filter mask specifically for welding galvanized -- it fits under a welding helmet. Normally supplied air isn't needed.

With the windows out and a fan going there should be adequate air-exchange. You could even do the welding from a ladder outside the bus.


But at the first hint you feel that's not enough be safe and stop.