Trailer frame and wall metal size?

[RockyStones27]

I will be building a 4x9 trailer and was planning on using 2"x2" steel for the frame and 1"x1" for the walls. What do you think? What wall thickness too?

Thanks
-Novice welder

Sent from my XT1254 using Tapatalk

 

[Martyinco]

If it were me, I would make it all out of 11 gauge, plenty strong.

 

[HuntfishcampXJRay]

i am in the process of building mine and I used 11 gauge (1/8) for the trailer frame. I will be using 14 gauge 1x1 for my walls. Because they will also be reinforced by the structure of the walls. Don't want to be too heavy.

 

[azscotts]

I too used 1/8" (11GA) box steel for the trailer frame, and it came out perfect.

On the 1x1 for the walls, keep in mind that it doesn't need to be as thick because when you've got the walls attached, etc. those will provide additional strength and stiffness to the whole structure. Similar to aircraft construction, the monococque construction is plenty strong.

When I was building the wings on my plane, I could flex the rib assembly alone but once the skins were riveted on, I could sit on the wings with zero flex.

 

[RockyStones27]

Thanks everyone for your help

Sent from my XT1254 using Tapatalk

 

[workingonit71]

+1 on 11 gauge; used 3/4" plywood for walls

I started with a 50"x 60" trailer, of 11 gauge 1.5"x 2.5" tubular. Added a center spine, and extended the trailer to a 4'x8' by adding 12" to the front and 24" to the rear. All with more 11 gauge 1.5"x 2.5" tubular. Since I wanted a single beam tongue, I used a 3"x3"x.187" square tubing piece, 72" long, 28" underframe welded to the center spine and three crossmembers, with 44" sticking forward as the usable/visible tongue.

1. welded extension(s) to smaller trailer
2. finished frame, bigger wheels on orig. axle; deck mounted

I did not use steel or aluminum for the upper structure, though, using pre-sanded 3/4" plywood joined together with Simpson Strongties hardware, steel corner braces, stainless carriage bolts/nuts, and plenty of Loctite PL Premium adhesive,inside and outside every seam. Every exterior wood surface has 3-4 coats of varying strength polyurethane, covered by 2-3 coats of high VOC gray tractor paint (sides, front) or reflective aluminum silo paint (top front, top, rear hatch). All exposed edges of the plywood were saturated with penetrating 50/50 mix of poly/thinner and then coated with 3 coats poly, and then black with similar tractor paint. I replaced the original, spindly 1.25" square tube axle (of unknown weight rating), with a 3500 lb, braked, Dexter axle, shackles springs and frame attachment/reinforcement (of my own design).

• trailer with 3500 lb axle,; durable so far

After an incident where I went deep into an unseen chughole at 75 mph, my truck tires had broken belts (though 10-ply E range), but the trailer had no damage. At home, later, I inspected it for twisting, or structural seam looseness, and frame and suspension for anything amiss. All was well. So, I can recommend using 11 gauage tubing...it's stronger than it looks. And the monoque structure or the plywood fares well, if sufficiently glued and screwed together, and waterproofed, though it is a bit heavy. I didn't use metal for walls, because I couldn't source what I wanted, and feared dimpling (from exposure to hail, quite frequent here). Good luck with your build!