Light Car Hauler Build, What materials??

[docj88]

I have come to terms that I need another trailer. I really want to replace my single axle 5x14 2500lb utility trailer with an 6.5x18 foot flat deck. I really want a car hauler. The heaviest it would need to haul is my 3800 pound 88 Yota. I want to keep the weight down as much as possible as I will be pulling it with my half ton frequently to go get steel for the shop, which is why I need a longer trailer. I don't need a trailer rated to 7K pounds, but with the overall size and length the trailer would need tandem axles. 3500 lb axles are actually cheaper from my supplier than any other axle.

I'm thinking 4" channel iron frame with 2x2 3/16 angle cross members on 16" centers or maybe 2" channel. I would turn the 4" channel with the C to the outside and then weld d rings on the web of the channel to hook straps to. I would weld eyes and banjo holes into the floor to hook straps and chains to. Top it all off with 1/8 Diamond plate. I could turn it so the C was to the inside and it would look better but that is a lot of cross members to cope out to fit the rails right.

I've built a couple of smaller utility trailers and worked on more trailers doing repair work than I can recall. All of them had rails to help with structural support. I've seen what happens when poor designs fail. I have a tendency to overbuild which results in extra money spent and extra weight. I have not had a chance to really look at a car hauler to see what materials are used. I feel like the 2x2 3/16 would be fine for cross members but still I have my concerns. 3x3x3/16 would be plenty I know. If weight (or money) wasn't a concern, I would use 2x4x 3/16 rec. tube for the frame and 2x3x1/8 rec tube for the cross members.

What say you folks? What have you seen work, and what have you seen not work so well? Any design flaws on your rig you hate working around? Any features you never knew you needed until you got them?

 

[Benny]

I would put the C channel flat side out and weld on stake pockets, then flat bar to the outside of that. It makes strapping way easier and you can add side boards of needed.

2" x 3/16 angle would be plenty strong for a trailer like that.

 

[[486]]

can you get T bar? it is way stiffer than angle if you're welding one leg to the frame rails and having the other leg flat for bolting the decking to
though with the steel decking, you could just lay the angle down pointy side up, then drill 5/8" holes in the decking to plug weld through. I'd go with 1/8" angle.

Next trailer I throw together I'm going to poke around to see what it'd cost to hot-dip galvanize it.

ETA: if you make some integrated side rails at fender height outta square tube you gain a shitton of rigidity when compared to the weight of the steel, height of the profile makes a much larger difference than steel thickness
Figure it to the height of two pallets and you can make it into more or less a flat deckover real easy by tossing four or six old pallets in there.

 

[arse_sidewards]

Light, strong, easy, pick two.

If you're lazy just buy a trailer.

 

[PatJ800]

Having built and bought several trailers, I appreciate building when you need something unique. But what you are describing is a 7k commodity-grade trailer. Unless you have the steel on hand laying around, and free time, and an easy clear title; just buy one (even if brand new.) LIfe's too short, maybe I'm getting old.

Now if you have quantifies of a specific material laying around and are on COVID furlough then I'd be all for designing around material you have and building.

 

[docj88]

Having built and bought several trailers, I appreciate building when you need something unique. But what you are describing is a 7k commodity-grade trailer. Unless you have the steel on hand laying around, and free time, and an easy clear title; just buy one (even if brand new.) LIfe's too short, maybe I'm getting old.

Now if you have quantifies of a specific material laying around and are on COVID furlough then I'd be all for designing around material you have and building.

I completely understand this point of view. In fact, I considered whether or not I want to invest the time into it. When I see the price tags on the trailers I immediately think "I can build that for half the sticker price" and then look at the welds and scoff. I'm a "built not bought" kind of person. I hate paying someone to do work that I can do myself.

 

[Projectjunkie]

Where in Texas? Most trailers are built in north Texas or Oklahoma. I just made a trip to San Antonio and bought a trailer while I was there. You just can't beat it
I got mine from "the trailer guys" in big spring, but otherwise they're cheapest in the north

If i needed something custom, I'll build it, but for a regular ass 7k car trailer, just buy one IMO

 

[docj88]

Where in Texas? Most trailers are built in north Texas or Oklahoma. I just made a trip to San Antonio and bought a trailer while I was there. You just can't beat it
I got mine from "the trailer guys" in big spring, but otherwise they're cheapest in the north

If i needed something custom, I'll build it, but for a regular ass 7k car trailer, just buy one IMO

I'm in north east texas. There are 4 major manufacturers within 40 minutes of my house.
​​​​​​

 

[Muckin_Slusher]

;n265110]
Next trailer I throw together I'm going to poke around to see what it'd cost to hot-dip galvanize it.
.

Dirt fucking cheap. (although I'm 100% sure you're definition of cheap is different from mine...)

When I built my ice shack trailer I planned on galvanizing it. I remember it being cheaper than even painting it. Reason I didn't was it would have taken a trip to south ontario and a motel room while I waited for it to get dipped. I would also have had to strip it in the parking lot of axles and stuff.

 

[PatJ800]

If weight (or money) wasn't a concern, I would use 2x4x 3/16 rec. tube for the frame and 2x3x1/8 rec tube for the cross members.

My cheap no-name 7k trailer was built exactly that way (the frame might even be thinner tubing.) Title says "TNT Trailers" but no markings otherwise, which I purchased brand-new from local trailer dealer in WA state for $1499 about 6ish years ago, cash price but included WA title and temp tag. Towed it home and immediately replaced no-name chinese tires for no reason other than paranoia, kept two to refresh my spare inventory. After about 2 years I rewired it, even though it worked the wiring was cheesy. Used motor oil on the SPF deck once per year and its been a great trailer. Two braking axles. I could have not built it for that unless I had an inside line on material, which I don't. 16x7 7k are so common its hard to beat DIY.

I appreciate you wanting to build yourself and no doubt you will end up with a better trailer in the end. But not sure you will save money if you are buying the material.

 

[bgaidan]

I have come to terms that I need another trailer. I really want to replace my single axle 5x14 2500lb utility trailer with an 6.5x18 foot flat deck. I really want a car hauler. The heaviest it would need to haul is my 3800 pound 88 Yota. I want to keep the weight down as much as possible as I will be pulling it with my half ton frequently to go get steel for the shop, which is why I need a longer trailer. I don't need a trailer rated to 7K pounds, but with the overall size and length the trailer would need tandem axles. 3500 lb axles are actually cheaper from my supplier than any other axle.

I'm thinking 4" channel iron frame with 2x2 3/16 angle cross members on 16" centers or maybe 2" channel. I would turn the 4" channel with the C to the outside and then weld d rings on the web of the channel to hook straps to. I would weld eyes and banjo holes into the floor to hook straps and chains to. Top it all off with 1/8 Diamond plate. I could turn it so the C was to the inside and it would look better but that is a lot of cross members to cope out to fit the rails right.

I've built a couple of smaller utility trailers and worked on more trailers doing repair work than I can recall. All of them had rails to help with structural support. I've seen what happens when poor designs fail. I have a tendency to overbuild which results in extra money spent and extra weight. I have not had a chance to really look at a car hauler to see what materials are used. I feel like the 2x2 3/16 would be fine for cross members but still I have my concerns. 3x3x3/16 would be plenty I know. If weight (or money) wasn't a concern, I would use 2x4x 3/16 rec. tube for the frame and 2x3x1/8 rec tube for the cross members.

What say you folks? What have you seen work, and what have you seen not work so well? Any design flaws on your rig you hate working around? Any features you never knew you needed until you got them?

Late response, but keep in mind that 7k rated trailer is rated for 7k INCLUDING the trailer weight. My steel deck 7k probably weighs north of 2,000lbs empty. Just a quick look at PJ trailers - their 18' 7k steel deck is only rated for a 4,490 lb payload. That's not far off from what you need to haul. Unless you went with like a single 7k rated axle, you're probably stuck with a pair of 3,500's.


I'm thinking the trailer manufacturers already have the lightest/cheapest structures they can get away with so I'd probably copy a lot of what they're already doing.


Technically my 5k+ lb rigs are probably overloading my 7k, but they're a little conservative in their ratings - you should gain at least 10% when you add tongue load in to the equation. My biggest regret was not getting a 10k.