Structural Question About My Roofrack

[Irish Reiver]

I am in the process of designing a simple roofrack that my 2 kids (20 & 18) can weld up as a project. The rack will never need to hold a rooftop tent or anything particularly heavy but obviously needs to be sturdy enough if one or both kids do some star watching or what ever.

The overall dimensions will be 90" x 50" (Full size rack) and I plan to use 6 Gamiviti gutter mounts.
For simplicity I was planning on using mild steel square tube for the main frame. I was going to go with 1" x 1" x .095". Each corner would sit on a 4" x 4" plate to keep things square and solid at the corners.

For the cross rails I was planning on using Tee bar (1" x 1" x 0.125"). These would be spaced out every 10".

Would very much appreciate if someone with fabrication experience can chime in and let me know if the tube and teebar is sturdy enough. Also are 6 gutter mounts sufficient.

Thanks in advance.

 

[iwashmycar]

I’m just passing through and clicked because your username and I’m drinking Irish Whiskey.

Sounds heavy as hell. That’s some thick tee bar.

Wouldn’t that be harder to weld than just squares?

Is there any popular branded rack you can sort of “copy”? I don’t even know what section I’m in here but those thoughts came to mind.

 

[Irish Reiver]

Weight is a concern but having never designed something like this before it is hard for me to get my head around the weight vs structurally sound dynamic.

Hope you have a good whiskey. My local ABC was selling a 12 yr old Bushmills single malt for $39. I added a few to my rainy day stash.

 

[Pighead]

Also are 6 gutter mounts sufficient.

I had one of those big, heavy, full-size Con-fer racks for a while. Think it had 4 mounts on each side...