When keders were introduced roughly 35 years ago, it replaced
the technique of lacing together the roof tops of tent
structures and saved many hours of labor and eased installments
in the industry.
It is by far the most effective and easy
way of harnessing paneled sheets to structures, whether on tents,
yacht sails, cars or tarpaulins. The keder concept has also introduced some challenges, such as
the eventual ripping of the keder. Though no one has the problem -
except from everybody else - the key to solve the problem is understanding it.
The patented Coverfeed® fittings are made to protect keder ends - the mother of most keder debacles - like
no other invention seen before.
hardshell the leading
edge of the keder
and protect the fragile
woven keder wrap from
fraying and ripping...
Mobile structures are typically built from crossbeams with tracks on top, that connects the next crossbeam with supports and a roof panel attached by keder. Hence a shade and shelter is established.
In the process of installing the roof panel - any panel actually - the keder works exactly like the car tire on the road; This is the transition point of the forces from the engine to the tires, that move the car the same way the panel apply forces to the to the structure on a tent via the keder.
Just by stretching a heavy PVC roof panel straight will give you an idea of the powers.
The forces involved enhances the trouble for keder when it meets uneven obstacles on its way, from being fed in one end to the transition over the ridge, to the other side of the crossbeam.
Everything from unaligned crowns to grafters. To most manufacturers in the industry this is well known factors and even obvious, but at Coverfeed® we'd like to establish our mindset when speaking of the way we have solved the problem.
To a tent owner, that is involved in thousands of other managerial factors before even raising a shelter, we aknowledge the costs and debacles it applies in the field, and offer our somehow nerdish support in understanding why the trouble arise in the first place.
We'd like to share our knowledge about the issue of keder damage and how we recommend ending it.
1. The entry feed
From flaked sheet to entering the feeding; First, your keder ends and
naked woven keder wrap will meet with the hard edges of the alloy
beam and then the whole keder will be bent 75 degrees and get slid
upwards across the eave line, constantly chafing at the truss end if
not featuring a prefeed roller.
2. Sliding upwards
This is the least deteriorating process to the keder and only the quality
of the tracks decide whether it will be a smooth ride. At the end of the
track (eave-line) there is still continous chafe. As the weight of the
sheet increases proportionally with the distance ravelled, the keder
is pressed increasingly harder toward the outside of the track, hence
adding furthermore friction.
3. Over the ridge/ peak/ crown
At this point, the ride is at the most critical point. Most crowns are
separate units aligned with the trusses and maybe even in another
matrial. An uneven alignment is a ’keder-eater’ along with the forces
of the pullers and the sharp turn. Together, this represent a key challenge
in protecting a keder.
4. Sliding downwards
Same issues going on as in 1, 2, and 3.
5. Downwards exit of keder end
As when entering the track, going out will make the sheet bent at the
eave line and then chafe the keder when gravity pushes down the
6. Fastening over the eave line
Tightening the sheet all across the whole surface, making it a nice and
smooth installment, takes a lot of downward racheting, putting a lot
of tension on the keder, especially the parts bending over the eave
line. Friction and chafe is unavoidable in this process and tensions