Well, I’ve had the hardware for two years, maybe it’s time to install the awning! Wouldn’t you know it started snowing today…
I’m doing this a little bit backward, in that I only wanted to install the upper clamp as part of the window removal and patch task on my Overlander. The installation instructions provide a measurement only for the bottom main arm hinge (down 71-1/2″), so you have to put the arm together and mount the hinge in order to see where the clamp falls on the shell.
When you put the arms together, you suddenly realize there isn’t any slop in where the clamp mounts to the shell–it’s defined by the length of the awning case in the fore/aft direction and by the arms and lower hinge in the vertical. Without getting the case out of the the shipping tube and mounting it on the arms, there is a risk that the clamps could be installed wrong. For example, if one ordered the case based on the length to the skin edges, rather than the rivet lines, it would be a bad day (and I can’t remember how I did it–crap). Ou can see by the green line in the drawing above that the clamps are meant to fall right on the rivet line.
I wanted a strong lower hinge attachment, so I began with two doublers. The casting has a step on its face, to provide for the skin lap joint, so you have to do the same with the doublers. The doublers were installed as two one-piece layers, then one was cut right along the skin line and the pieces reassembled in the right layers to provide a tight fit. Eventually the pop rivets will be replaced with bucked rivets, including some flush rivets under the casting.
In addition, there will be another doubler inside the shell with nutplates for the screws. This doubler will be installed (actually, it’s two doublers, one on either side of the rib flange) when the pop rivets are replaced.
As soon as I determine the exact case length (that sucker is heavy–not an easy task to move it), I’ll know right where to put the upper clamp casting in the fore-aft position. Then I can finally rivet in the window patch with bucked rivets. The window patch is its own doubler, btw, and there will be nutplates on an inside doubler, too. I’ve seen too many Zip-Dee hinges and clamp castings loose on vintage AS due to deformation of the skin where the screws were installed.
The awning is finally installed on the Overlander. Despite VERY CAREFUL MEASURING, the roller bar is about 1/2″ too long. This means that the rotary clamp wheel arms are slanted a little, which is exactly what I was trying to avoid. CRAP! But I’ve seen many installations that have this “deficiency” and it doesn’t seem to be more than a cosmetic issue.
Luke and I discussed this and his conclusion is that this has two causes:
1. The instructions say to measure the length at the skin seams a foot or so above the banana skin. He has found that the length there can be off from length measured where the rotary clamps are installed, which is 71″ higher up on the seams.
2. Zip Dee insists on calculating the length of the roller bar in a way that essentially ensures
that it will be a little bit long. He says he has decided to calculate it himself and order it that way. Anyone who is concerned about this should give him a call and order you awning through him.
Maybe the last warm days for awhile, so I decided to try and finish the awning installation. It has done fine with the upper hold-down fitting attached with just sheet metal screws, but from all the tear-out kind of damage I’ve seen on vintage Zip-Dee installations, I wanted something a little more robust. I can’t get at the inside of the shell at the aft attachment, but here’s the nutplate installation on the front:
As you can see, I’ve given up on making the shims pretty and perfect. Just stick some scrap in the gaps and rivet! The only precision piece is the patch holding the nutplates–getting it to fit close to the bend of the rib, etc.
The three dome rivets on the outside weren’t really necessary, but because of a small goof, they became “necessary.” And they’ll add some strength to the installation.
I really don’t expect to remove the awning hold-down, like ever. The nutplates are there for the increased load they can take without deforming the shell skin. I mean, I really hate the idea of a sheet metal screw holding something in the skin of the shell…hate it.
One thing I will say, it’s really a boon to be able to install flush rivets. All it takes is a microstop countersink (about $25) and a flush rivet set ($6).
PS–remember, the vista view was removed and skinned over. Putting a nutplate patch in the small space between the vista view and the rib would have been a bit more difficult.
The long Zip Dee on my Sovereign has seen better days. While removing the vista view windows I noticed that both the forward and aft upper brackets were loose. Since the rib and shell area under the brackets were accessible due to the other mods I was doing, I decided to strengthen the mounting area with doublers and a suitable shim on the exterior to match the new vista view window patches. Don’t be confused by the photos–they are a combination of the forward and rear brackets, so they may appear reversed if you make them all one installation!
The original bracket mount and damage underneath:
You can see how the skin is pulled away from the rib, here. Two of the new rivets in the vista view patch need to be drilled out to allow the new doublers to lie flat on the inside skin:
Here’s the total set of parts. The bracket, the shim under the bracket on the outside, two shims/doublers to equal the thickness of the rib flange, and then the inside doubler with three nut plates. The #10 aircraft screws that fit the existing holes in the bracket have a yield strength exceeding 1,000 lbs (thank you, Kip), so you could pick up the entire Sovereign on this pair of reinstalled brackets. The inside mounting plate and shims were fit to the existing holes by screwing the bracket in, which held everything in place, then match drilling the rivet holes.
One advantage of the nut plates is that I can remove the brackets and temporarily seal the holes using short screws–the outside shim would protect the skin from the screw heads. The outside shim and inside doublers were installed using Trempro 635 (same as the old Vulkem).
This has been slowing me down for a couple of weeks–very glad to be on the move again!
This same repair can be done fairly easily even if you aren’t modifying your vista view windows. It’s only requires drilling out about 7-8 pop rivets to peel the skin back far enough to gain access to the inside of the shell (in skins without a vista view) and a few more if you have to release the vista view inside slide cover.
————— from FLTLEVEL510 ————–
Both my front and rear upper awning mounts were showing signs it was time to find a way to tighten them up. Mainly a big gap between the mount and the skin. I really liked the work Zep did with the doubler plate but decided to use some PlusNuts to beef up mounting bracket. Here are photos of the job.
1. Mount pulling away from skin
2. Removed mount exposing the thin skin and the elongated holes from the original metal screws.
3. PlusNut and mounting to4. PlusNuts installed in skin
5. Countersink back of awning mount so the mount will sit flush on skin.
6. Finished product.
7. Front mount missing screw when factory installed the awning. Oh well!