Hey! I have a 5x10 trailer that I carry my atv on and want to add my two kayaks onto it. I have seen the TopTier, but I want something that will fit in the garage. Has anyone attached the J Rack type attachment to the side of a utility trailer on the side rails? I’ve seen one on the internet where someone welded his own, but not much else. Let me know and if you have please provide a photo!
Depending on the construction of your trailer and what width and weight of kayaks you have, j-racks may not be a safe option at all, especially attached to a trailer railing. The wind load on side mounted kayaks and the racks to which they are attached is especially severe and they could be torqued right off at highway speeds or less. Jerry-built racks for hauling kayaks are rarely a good idea. I have hauled kayaks and canoes for 20 years using square bar Thule racks (including with J racks) and also own a couple of utility trailers. I no longer use the j racks for any transport except short local trips with lighter and smaller boats (under 30 pounds and less than 23" wide) because of the wind load concerns. I suspect even steel trailer side wall frames are not designed to handle the sort of loading that directly mounted J racks would produce.
You might be able to construct a box frame with Unistrut to lay across the top of the trailer sides and have it attached structurally to the trailer somehow maybe with stove bolts through the deck, then use it like a conventional transverse roof rack with looped camlock buckle straps wrapped around both the Unistrut frame and the trailer rails to keep the whole load bound together.
I’m guessing that you want to haul your ATV and kayaks at the same time, and therefore don’t want to add cross bars that would block access for the ATV. But…, if adding cross bars is an option, here’s what I did with my trailer. It’s wood-sided but that’s unimportant for the way I mounted the cross bars. And the cross bars are also wood, but they could just as well be commercial steel or aluminum bars. The key thing is that I use turnbuckles to pull the cross bars down to the bed of the trailer. Hitch pin clips go through the turnbuckles to keep them from backing off.