Earlier this past week I removed one of my windows
to investigate the integrity of the inside wooden frames. These were made from 3/4" 7ply plywood and allow the aluminium window frames to attach to the thin fiberglass walls with self tapping sytle screws.
As I had suspected the frames had suffered some rot and degradation from over 30 years of doing it's thing. It wasn't horrible but it wasn't great either. The original frames were in sufficient condition to allow me to use them as patterns for makling new frames. Originally I was thinking I wood replace the plywood with a sturdy hardwood such as birch or oak. Then I thought about the cost of some 40 ft of 3" wide hardwood and figured I would use thta money somewhere else more visible. A rummage thru the garage wood pile yielded a suitable sized pice of 3/" plywood (exterioer grade) which I promptly sliced up on the table saw into suitable strips. The original frames had beveled edges so as to not have a corner where the ensolite foam rubber wall treatment overlaps it. The original bevel was about 30 degrees but I chose to use 45 degrees as this was easier and made for less cutting. I built one frame complete today. The simple butt joins where glued with exterior waterporof white carpenters glue and then were stapled together with a air stapler. Result was a simple yet strong frame.
The easiest time to replace thw window crank operators is when the windows
are coompletely out of the trailer. The operators are cheap at under $10 and I plan to replace all 4 in my trailer. I stripped the window of all old sealant and cleaned all the aluminium up with a pad of metal wool. While they didn't come out like new they certainly have a sparkle to them and the overall result is well worth the effort.
As I didn't have a box of new Stainless screws I didn't attempt to install the window and it's new frame today. Hopefully the weather cooperates and I will maybe try tommorrow.!
I have attached a few pictures to show the overall project for those who might be interested to undertake this sort of repair.