Adding a window at a rib

[my3sonsdad]

I’m sure there’s a thread somewhere on how to fabricate one

[fwjumper]

Make sure that you securely rivet the end of the vertical member that you cut to the top and bottom of the window frame. Cut carefully so that the frame is a tight fit into the rib. After the frame is securely riveted to the trailer and the rib to the frame, you'll be fine.

[JohnTF]

I would say similar to a window in a house , the window dose not make any structural function [ other wise the window would break ] the window is separated from framing .
On either side of house window there are 2 king-studs [ carrying the load ] between bottom & top plate , below the window are jack-studs hold up the window , then above the window is the header - the header transfers the load to the king-studs through many framing nails --- the window carry's no load .
With remodeling / making holes in framing , you normally make box that connects with framing - then put window in box .

[my3sonsdad]

Originally Posted by fwjumper

Make sure that you securely rivet the end of the vertical member that you cut to the top and bottom of the window frame. Cut carefully so that the frame is a tight fit into the rib. After the frame is securely riveted to the trailer and the rib to the frame, you'll be fine.

It doesn’t appear the factory was this careful in their rib cuts and none of the 4 rib cut ends were riveted to the window frame. They were all cut below/above the river lines of the window frame. They look about this mangled at the cut:

[Camper Crazy]

I am curious to see what decision you make for the window. Please let us know and post a picture.

[A W Warn]

One thing I did not see mentioned above; The air conditioner's weight is carried by the rib you plan to cut. Also the weight of a person doing maintenance will be placed on that rib. When modifying that rib, the goal should be to transfer those loads to the trailer frame via the outriggers and floor diaphragm. IMO supplemental framing is required to carry that load.

[my3sonsdad]

I decided I’m going with Andy’s advice and using the larger window.

I need to clean up the donor windows this weekend and I trying to decide if I want to take the rear floor rot this weekend. May need to wait til temps will get high enough to do the install - still in the mid 40s here and DC Metro area and I’m working out in the elements. Haven’t check specs of the putty/sikaflex but I imagine they do better in warmer temps.

I’ll post pictures and maybe make a YouTube video of the process. I’m sure it’s documented in some thread somewhere but I couldn’t find it.

[my3sonsdad]

Originally Posted by A W Warn

One thing I did not see mentioned above; The air conditioner's weight is carried by the rib you plan to cut. Also the weight of a person doing maintenance will be placed on that rib. When modifying that rib, the goal should be to transfer those loads to the trailer frame via the outriggers and floor diaphragm.

Good considerations, but the AC is supported by 3 ribs forward of the rib I am cutting. I weigh 250# and I have been on top of my 26’ donor )that has 3 such rib cuts) to wash it a half dozen times over the years without it collapsing or creating issues. I’m not advocating ppl go up on their roofs or add ladders to get there but I think the 30’ will handle 1 rib cut.

[A W Warn]

Originally Posted by FishByFly

Off topic: where can one get “Airstream” coveralls

I used to see pro painters wearing these occasionally.
They are heavy-duty twill coveralls.
https://shop.aramarkuniform.com/styl...CABEgJTzPD_BwE
Have someone embroidery on the lettering/logo.

[A W Warn]

Originally Posted by my3sonsdad

Good considerations, but the AC is supported by 3 ribs forward of the rib I am cutting. I weigh 250# and I have been on top of my 26’ donor )that has 3 such rib cuts) to wash it a half dozen times over the years without it collapsing or creating issues. I’m not advocating ppl go up on their roofs or add ladders to get there but I think the 30’ will handle 1 rib cut.

The photo in post #1 is deceiving, to me, re that rib placement.
Hope all goes well!

[my3sonsdad]

Agree, I had to go check it to confirm.

[my3sonsdad]

Cleaning up the donor frame.


I’ve noticed waves in the aluminum at the river holes either from when they were bucked or removed.


I’ve read it’s important to straighten these out. Looking for recommendations on how to do so without making it worse.

[AlinCal]

https://www.harborfreight.com/6-inch...SABEgIDGfD_BwE

[my3sonsdad]

Thanks! I might go with the 3” version. I’m concerned the 6” seamer would alter the curvature of the frame in the sides/corners

https://m.harborfreight.com/3-inch-h...mer-66654.html

[AlinCal]

I have 3" wiss brand and they work great for straightening out wrinkles.
You need about 1/8" minimum to get into that groove.

That link was just first google hit and not recomending them as much as just giving you the idea they exist.

[my3sonsdad]

Thanks, I ordered one.

I got the frame all cleaned up. I used a 3M Special Adhesive remover that made quick work of it.



Also placed a VTS order for rivets which will take a few days. Clecos arrived today and tomorrow is looking like a great day for working outside!

[my3sonsdad]

Finally have a stretch of clear skies, longer period of evening daylight and warm weather to start installing the window.

Used the donor window frame to make a template of the window opening first with cardboard and then with subfloor construction paper.

Made a pilot hole from inside just above the existing rivet line.


Taped up the template to the location and did a check to make sure there wouldn’t be any conflicts between the existing body rivets and the existing river holes of the donor frame.


Made the initial window opening cut with a jig saw and cut the rib with the angle grinder.


The initial cut was just shy of a tight fit. I trimmed up the opening as needed with the angle grinder until the window frame fit without binding.

As luck would have it, there were a pair of wires running along the rib, likely from the refrigerator and wall outlets.


There wasn’t much slack in the run, so I will need to splice them and relocate them to the side of the window frame.
This appears to be standard gauge household wiring.

Tomorrow I plan to drill the new rivet holes and relocate the wiring. Since this is my first rivet job, I plan to practice first by reinstalling a smaller 18” window I removed from my donor 26’.

[kidjedi]

Originally Posted by my3sonsdad

Tomorrow I plan to drill the new rivet holes and relocate the wiring. Since this is my first rivet job, I plan to practice first by reinstalling a smaller 18” window I removed from my donor 26’.

You're buck riveting, right? Just want to make sure.

It's often better to have two people (sometimes an absolute necessity), but since you're doing a window you can do it yourself (reach through the window hole to do the air hammer on one side and the buck bar on the other).

And you've got butyl tape for between the frame and the skin, right?

[my3sonsdad]

Yes, I plan to buck rivet and make it a father/son activity

[kidjedi]

Originally Posted by my3sonsdad

Yes, I plan to buck rivet and make it a father/son activity

I do the same! My seven-year-old is a "Ribbeting" rock star. I seriously can't believe how good he is (way better than my wife, but don't tell her I said that!). Do practice for a bit on non-critical stuff though. It takes a minute to figure out how to hold the buck bar straight to the air hammer so the rivets mushroom evenly.


Good luck and have fun!!!