PDA

View Full Version : Unistrut for roof rack mount


Zundfolge
03-04-2019, 04:41 AM
I currently have 3 gutter mounted crossbars holding a steel frame I welded together from 1 1/2" iron pipe, and it's time to finish my rack dammit. I want to mount the rack to the roof and my idea is to use low profile unistrut to basically "mimic" the NCV3 roof mounting system, and attach my rack to that. I won't be loading it heavily very often, and if I do it'll be for short drives (I really need a work truck again). I was thinking I'd bolt through the roof into each of the roof ribs, gasket the penetrations, and lap sealant over the top and around each bolt, and make the rack attachment points also over the ribs.

Has anyone out there in the T1N world done anything like this before?

Unless anyone points out a glaring issue with this I will be moving forward with it, but I wanted to ask first if anyone has experience with it, if I'm crazy, stupid, genius, or any combination thereof...

billintomahawk
03-04-2019, 01:39 PM
Zund,
I had an old Yakima rack/bars that had seen plenty of Kayak and canoe action. I priced new racks and felt apoplectic but also creative.
I modified the stands for the old bars to sit flat on the Sprinter roof and through bolted everything down. I got some flat sheet red rubber at Ace Hardware to make gaskets and bought couple of calking tubes of white butyl rubber at Menards(White Lighting) and went at it.

I was important to seal the bolts up top and inside the roof to get a completely water tight seal.

My racks are on now but I haven't hauled with them yet due to a broken hip. They made the trip to Florida from Wisconsin and withstood -30 degree temps(F) plus 3 feet of snow. One thing to think about is a fan installation when locating your racks. I have a Maxifan in my roof also.

I have since paneled the roof with 1/4 inch birch plywood that is screwed into the ribs and removable. I mounted the racks to the roof so the bolts are recessed beside the ribs and the ceiling could be paneled easily. You could consider doing it that way and mounting next to rather than on the ribs.

I went as far forward and as far back as possible for my mounting points. My sea kayaks are 16.5 feet in length.

I'll try to post some pictures later today.

Hope this helps.

bill in tomahawk

ps.
Don't fall off the roof!!!!

Aqua Puttana
03-04-2019, 01:54 PM
I'm a big fan of Unistrut. It is strong and relatively easy to work with. It isn't cheap.

Check out the various finishes/types available before just using the standard green painted product.

https://www.unistrutohio.com/stainless-steel-unistrut

If you are looking to use a rubber cushion/seal I would recommend EPDM roof membrane. It will not deteriorate like some other rubber products may. I have a bunch of scrap EPDM. I can mail you a reasonable amount. PM me if interested.

Not that you asked...
Another possible mounting method would be to use lengths or sections of L-track. The cost may be similar and it should be just as effective.

:cheers: vic

Zundfolge
03-04-2019, 03:14 PM
Bill, I promise to not use the van as a flight training deck ;)

Mounting next to the ribs does sound like it'll make the interior panelling easier, my plan is to glue and fasten 1/4" (if I can find it, if not just 1x) T&G cedar to some 1/4" or so ply as panels to be held up the the ceiling via flanged l-track, so I will have anywhere from 1/2"-1" of material to hide the heads of bolts in. Thinking out loud the thinner version wouldn't accommodate for a bolt head, so perhaps the next-tp-the-rib mounting is a better option. I suppose the strut would be bearing on the rib no matter what, and I will consider fashioning a tab that connects to the rib for the extra peace of mind (whilst trying to KISS because I don't have endless time but I sure know how to pretend I do).

I've had the fan and panels mounted for a while now, and designed the rack frame around them. I'll be recessing ply between the crossbars to have a rooftop deck, which is really nice in the summers to help keep the van shaded.

I don't know if yours is a high top (mine is) but loading my 16' yak on top gets incredibly old incredibly fast! Someday I may opt to design my own pivoting-levered yak side-loader...

Vic - I may well take you up on the EPDM offer. Especially if you were in possession of longer lengths? Thinking just (2) 10' lengths of strut (at 1 5/8" wide? can't remember exactly) at the outermost edge of roof before it goes up and over and down. Would like them to run entire length of strut, then I through bolt, and seal the bolts as well as the entire edges of strut with lap sealant.

Maybe strut is available differently on your side of the country? Here I get 10' lengths of electrogalvanized lo-pro strut for $20/ea. Much cheaper than l-track.

Thanks to you both:cheers:

Pics show what I have now, made the rear overhang so I could actually load things against the rack and not against the back of the van. The plywood top was always gonna be temporary but it's been temporary long enough now :)

Aqua Puttana
03-04-2019, 03:36 PM
...

Vic - I may well take you up on the EPDM offer. Especially if you were in possession of longer lengths? Thinking just (2) 10' lengths of strut (at 1 5/8" wide? can't remember exactly) at the outermost edge of roof before it goes up and over and down.
Negative on 10' lengths. Maybe 4 ea. 5 ft.
I don't see where a couple joints here and there in the EPDM would be an issue. If continuous lengths are critical for your design you might check with a local roofing company.

...
... Maybe strut is available differently on your side of the country? Here I get 10' lengths of electrogalvanized lo-pro strut for $20/ea. Much cheaper than l-track.

...
L-track isn't cheap. I was thinking of the price for Unistrut ss product. Over the long haul the hot dip galvanize is better than electro.

:cheers: vic

Zundfolge
03-04-2019, 03:42 PM
Ah yeah, I'm too cheap to go SS in this case. I'll see if I can get HDG, otherwise I was thinking of using electroplated and putting a couple rattlecan coats on it too. 5' lengths would very much work, I'll PM you. Thanks!

Luc
03-05-2019, 02:18 PM
I did exactly this on my van to mount my solar pannel.
You can see it in the build section of the forum my van is the Van Gogh project.
I used aluminium Unistrut. Would probably use L-track if I had to do it again. Just for the fact that the profile is a bit more rigid, but I donít regret it


Sent from my iPhone using Tapatalk