Frame questions

[ozy6205]

I am doing a shell-on floor replacement on my '73 Argosy 20'. I have a couple of questions for y'all...

1) The rear-most cross-member is rotted through, and needs replacement. Mine measures 61" from inside both rail c-channels (which run from front-to-back), and needs to be solid (not the type of x-member with 3 large slots to save weight). I can only find one solid one (InlandRV), and it is not long enough (~57"). I would rather not have to have more welding than necessary. I am thinking of ordering a 11ga tube to replace it - do you think that will work alright?

2) The rear-most and front-most x-members are solid, 5" tall like the main rails. The other 4 x-members between them are only 3.5" tall. They have a pair of 2x4's sitting on top of them, running the length between those solid x-members to raise the floor support to the top of the rails. I would like to get rid of the 2x4's.

I am thinking of perhaps using angle iron across the top of the x-member, level with the top of the rails, and perhaps tack-welded to the 3.5" support in a few spots. I am thinking this would provide the needed floor support, while maintaining some flexibility. Any thoughts on this?

Attached are 3 pics, one of the damage to the rear-most x-member and a 2x4, then 2 more pics showing a 3.5" x-member meeting the rail.

[HiJoeSilver]

1. I'd take some measurements to a local metal shop, they can likely fab a replacement to your specs or very close. My rear cross member was different but needed to be replaced, metal shop fabbed one up in a few days. Make sure they temporarily tack something across the very ends of the frame rails to keep the proper spacing, welding on the inside of the rail can cause the part protruding past to bend outward due to the uneven heat.

2. I don't see why you couldn't use some 1/16 thick 1.5" square tube steel in place of the wood 2x4. It'll add a bit more weight but the thin wall should help keep it manageable. If you replace the axles later, add the additional weight to the axle rating.

[ozy6205]

Thanks, HiJoeSilver! I will check into a local metal shop and see what they have to say. I had not thought about the uneven heat bowing the rails - good point!

I will also check into the 1.5" sq tubing. The weight change should not be a problem, because I am not putting the fridge back in (icebox instead), nor the bathroom (moving bedroom there) since I have no plans on boondock camping...

I appreciate your quick response!

[Minno]

The shorter cross members are to allow for the gusset that goes under the seam between two plywood pieces when installing the floor. On our '72, the shorter cross members were only 3/4" shorter, perfect to support the gusset. Elevator bolts bolted the floor to all cross members, including the short ones. Vintage Trailer Supply sells floor screws you could use in place of the elevator bolts on the square tubing since you would not have access to install a nut on the bottom of an bolt.

Chris

[Greg1410]

I replaced a cross member be using two angle irons - one welded on top, one on the bottom and used three short pieces evenly spread out of angle joining the top and bottom pieces. Very solid.
Greg

[HiJoeSilver]

"I had not thought about the uneven heat bowing the rails - good point!"

I hadn't either until I went to put the rear bumper back on. Passing on my hard learned lesson.

I would have thought the welder would. Guess not.

Bumper was easy part to fix, but now the nice bumper compartment lid is to too short so I'll have to make a replacement.

[ozy6205]

Originally Posted by Minno

The shorter cross members are to allow for the gusset that goes under the seam between two plywood pieces when installing the floor. On our '72, the shorter cross members were only 3/4" shorter, perfect to support the gusset. Elevator bolts bolted the floor to all cross members, including the short ones. Vintage Trailer Supply sells floor screws you could use in place of the elevator bolts on the square tubing since you would not have access to install a nut on the bottom of an bolt.

Chris

Thanks! I will check Vintage for those