Building a roof top cargo box from 80/20

[sjpitts]

I have been thinking of building a roof top cargo box to put on the roof rack of my 80 series. When we go hunting we tend to move from place to place, and space inside the vehicle can be at a premium. So I have been wanting a way to put my sleeping gear on the roof of the 80 where it is out of the way. And I want it to be easy to load and unload. And I need it to be rain proof and dust proof.

Basically I would like the roof top box to store two cots, two large rectangular sleeping bags, a tent, and possibly a pad or two. These things are relatively bulky but not too heavy, and they tend to be not needed during the day.

So in my preliminary plan I need I thinking about a box that is about -- about 45 inches wide, 42 inches long, and somewhere between 6 and 10 inches tall. And I planning on putting hinges on the front of the box so I can tilt up the lid and load it while standing on the tailgate. And some latches to keep it closed.

I managed to pick up a bunch of 2020 series extrusions in 48 inch length for a good price. The 2020 is 20mm by 20mm (.78 inches by .28 inches), and is smaller than the 10 series stuff (1 inch by 1 inch) that is most commonly used. I then jumped on the 8020.net website and played around with their free design tool at ideabuilder.io

In my first attempt I made a design with a lower box section that is about 6 inches tall, and an upper lid section that is about 3 inches tall. And I attached the two sections with four hinges in the front.

Oddly enough I searched for 8020 plans for boxes and didn't really find anything. This is still suprising to me, so maybe I don't know where to look.

So I really need some input

First, what should I use for corner connectors or braces? There are tons of different examples on 8020.net and Amazon. But I don't know what works good and doesn't.

Second, what should I cover the box with? Originally I was thinking of aluminum, but that is pretty pricey. So now I am thinking plastic- and I have seen sheets of plastic that are not crazy expensive.

Third, what would be the best way to seal this box up to keep it weather tight? I found some rubber seals that seem like they might work on Amazon, but they are also a bit small.

Fourth-- where does plan suck? What would you change or ad?

And Fifth-- is this just a dumb idea?

 

[sjpitts]

Here are some more connectors-- and gaskets

And here is the rubber that is available to seal it---- although it is advertised as being for dust, not water.

 

[sjpitts]

So nobody has any comments?

Is that because a roof top box is just a dumb idea, or because making one from 80/20 is a dumb idea?

It did occur to me that maybe this box is going to end up way heavier than you would up on the roof. And maybe more expensive than I am expecting. Maybe I should do some math on both counts.

I saw an ad from a new company in Utah called Sikre that is making roof top cargo boxes for the Expedition/Overlanding crowd. They are pretty close to the size I want. And they are made in the USA. But they do open from the side, which seems less than ideal when you have a tailgate to stand on.

Sikre USA

 

[80t0ylc]

Why not instead just get a hard shell rooftop tent? It will sleep 2 and you can keep all your bedding or sleeping bags in it. It would probably be lighter than a cargo box full of cargo. Also, easier to remove when not in use. It would solve all your sleeping gear and place concerns, and you could keep your gear down in the cabin. RTT is only used when sleeping and out-of-the-way for the rest of the day. All of your daily activities and equipment is down where you can get at it without a stepstool or ladder.

 

[sjpitts]

Why not instead just get a hard shell rooftop tent? It will sleep 2 and you can keep all your bedding or sleeping bags in it. It would probably be lighter than a cargo box full of cargo. Also, easier to remove when not in use. It would solve all your sleeping gear and place concerns, and you could keep your gear down in the cabin. RTT is only used when sleeping and out-of-the-way for the rest of the day. All of your daily activities and equipment is down where you can get at it without a stepstool or ladder.

This is a very good question-- and it actually was my first plan. But when I raised the issue with my wife she objected--- something about not wanting to climb out of the tent in the middle of the night to use the facilities.

I might still try and find a used roof top tent to try out for a while-- to use on non-wife trips at first-- and then see if I can get her up there for a night or two.

And I did consider trying to find a "worn out" roof top tent where I would remove the tent and use the shell as a cargo box. I have had worse ideas.

All those options remain options.

 

[cruiserpilot]

I think you'd have trouble keeping that waterproof. Not an issue you want to risk with sleeping gear. I've seen those Thule
large cargo pods for really cheap from new prices on FB. Some are pretty fancy, open from either side. Another comment,
if it's lightweight cargo you can go pretty big, since average roof tent will run 150 lbs anyways.
Are you sleeping inside the rear of the truck at night? Cots? Or using ground tents?

 

[sjpitts]

Are you sleeping inside the rear of the truck at night? Cots? Or using ground tents?

90 percent of the time I am sleeping under the stars on a cot, with a sleeping pad and a nice big canvas sleeping bag. There are times when I also have a tent, but probably less than 20 percent of the time.

Looking at the weight stats for my gear---
My Cabelas sleeping bag is 11 lbs
My Teton XL cot is 24 lbs
My Thermo-Rest camping pad is 4lbs.
And a big tent could be 30 lbs.

So assuming I want to carry two cots, two pads, two sleeping bags and one tent the absolute most I would want to carry up there is ~ 110 lbs. And most of the time I would not need the tent, so it would be more like 80 lbs.

But it is bulky-- especially the big canvas sleeping bags. Those are the things that I really need out of the back of the 80.

I think you'd have trouble keeping that waterproof. Not an issue you want to risk with sleeping gear.

I have been worrying about waterproofing. Especially at the front, in the horizontal gap between extrusions that are connected by the hinges-- I don't think those hinges may press down as tight as I would need to seal-- even with some sort of rubber weatherstripping. So I am not sure what to do about that.

I've seen those Thule large cargo pods for really cheap from new prices on FB. Some are pretty fancy, open from either side.

I have looked at rooftop cargo boxes. And I should probably look some more. And you are right about there being lots of them for sale on FB and CL. My issue with most of them is that they are long and skinny for skis, and I would prefer more square. And as I said, I think it would be easier to load them for the tailgate.

There are lots of roof top bags that have a shape and size that would work for me. Those just seem like more of a hassle to load and unload.

Thanks for all the input

 

[John in Utah]

A few months late to this thread but it turned up in my search so thought I’d provide some tech as I’ve just finished up a big 80/20 camper build

1. Fasteners: best option is to have your extrusions machined to accept anchor fasteners. Tnutz.com will do this for a few bucks additional. These are the strongest internal fastening. The downside is you need to know your lengths exactly when ordering.
2. Covering: aluminum composite panel (ACP). It’s light, strong, and easy to cut drill and work with. Only downside is finding it for sale in small quantities as a private consumer. I found a plastic supplier in SLC that sold me 10x5 sheets for ~130 bucks plus a small order fee.
3. Sealing: the strips you linked won’t work, you’ll want to use something like Sikaflex at every possible ingress where you attach panels. The nature of channel extrusion is there are a lot of points water can get in. Since i live in a dry climate and was building more of a utility topper that also could be a camper I didn’t worry too much about it, but to be 100% water tight will take some effort.
4. Changes: I think you’ve massively overbuilt the structure in the design you posted. The panels will add a lot of rigidity to the frame. I’ve found that 80/20 hinges are a weak point, consider a piano style hinge although might require some additional drilling/fab
5. Dumb? No way, but I’m also bias…

Feel free to pm me with any questions