Truck Cap Side Windows on the cheap

I picked up this Leer/Century cap with busted out side windows for $150. Leer wants over $400 per side for the replacements. I visited a couple local glass shops, both of which said they could make them at about $200 per side. That included templates, glass cutting then sending them out to be tempered....and I'd still have to have them tinted to match after the fact. For about $60 I picked up two 24x36 sheets of 1/8 tinted polycarbonate (lexan) to see if I can figure this out.

 

After persuading the window/frame assembly out of the cap (and removing the 1/3 slide window) I was able to trace it out on poster board.

 

I have a hobby CNC machine but it will only accept a 30x30" piece of stock. The broken 2/3 stationary glass is about 36" in length....so close. I transferred the measurements into CAD anyway. (idea!)

 

I made a 2 piece hand router template out of 3/4" MDF. Once cut out I had to glue the 2 part MDF template together. I covered it with masking tape to help prevent scratching when I put this up to the Lexan.

 

Looking good so far...

 

I should add that I accounted for the window channel by offsetting the CAD measurements by 1/4 inch outside. I placed my MDF template over the Lexan and traced out my cut lines. I lined up the bottom of my template (longest horizonal portion) flush with one of the factory cut edges of the Lexan. This is to minimize my cutting to 3 sides instead of 4. For the other 3 cuts I carefully set up a fence and used a 40 tooth blade on a circular saw to remove all but the last 1/8 inch of edge material. For the rounded corners I had to bust out a jig saw with a 'finish' blade.

 

Now that the window is 'rough cut' on 3 sides I turned to a 1/4 2-flute upcut flush cut endmill (w/bearing) and ran it around my Lexan (which is 2x taped to my MDF template)

 

All assembled.

 

The window channel is about 1/4" wide and my Lexan is only 1/8". I'm not sure what the thickness of the original glass is in these things but having used 1/8" Lexan my new window was rattling around in the frame a bit. I've seen others who have gone down this DIY road use silicone sealant in the channel to effectively glue it in place. Given that this is plastic it's going to scratch and show its age much faster than actual glass....so I didn't want to use silicone that I may have to fight with in the future if I choose to replace them again. The solution I came up with is to press in 1/8" window screen spline between the Lexan and the window channel (on the inside). This worked like a charm. It's in there nice and tight and the window doesn't rattle when shaken.

 

I should have mentioned that the 1/3 window has a screen behind it. That had to be removed to do this job properly. Window screen material is really cheap at hardware stores and pretty easy to put in a fresh new piece.

 

That's one of the two windows. Now on to the other one. Fingers crossed that my template works on the other side (only flipped)....but it wouldn't surprise me if this sloppily produced fiberglass cap is off by a little from one side to the other.

 

Well done!

 

Nice work OP. If you get to the point of replacing the plexi due to age or scratches check out lexan, it's frequently used for motorcycle windshields and is more scratch resistant then reg plexi.

 

Sorry, I thought I read where you used plexi, good choice

 

I did use Lexan (polycarbonate). More so because it's easier to cut/machine than Plexiglass (acrylic). But I think you have it backwards. Plexi is more scratch resistant than Lexan, but Lexan is more impact resistant.

 

Unfortunately for your use-case & material choice, acrylic is more UV-resistant than polycarbonate.

 

I wonder if a glass shop can actually replace the whole thing and frame
Not just class

I got lucky found a local secondhand whole replacement
But had a bent frame. Glass itself was fine.

so you’re saying DIY cheaper with something like Lexan?
Sounds smart.

1. I don’t see the point of glass in a shell. It’s not a windshield you have to clearly look through. They commonly get blocked with insulation and curtains
2. Glass adds weight to a shell
3. Glass is fragile and can break while off roading whether from shock or taking a hit

wonder if you could add sliding windoors
To have breathing mesh AND windoor ability for side cargo access

Home Depot sells sheets of some of this stuff. Don’t know if it’s the right kind. Only ever used it once to make a see through stationary display case.
don’t know if it’s easier to break in. Probably not. Glass is easy. Or if glass insulates better.
I think race cars use something like this.

and if it’s lighter and durable, you can put inside and outside gear mounts without worry or too much weight
outside there’s kits to mount gear on extruded aluminum bar.

Inside one I saw and was going to do is shelf mesh. Like the cube grid ones on Amazon. That’s also kind of a break in barrier.
And sleeker if you don’t want traction boards on the outside of your windows.

 

In this use-case/location I'd probably have gone with acrylic vs. lexan (polycarbonate) specifically due to acrylic's much better long-term UV resistance.

Lexan is physically stronger, sure, but I wouldn't expect that rear window location to be taking major hits.

Acrylic is also fairly easy to polish & buff up to remove single scratches or overall "cloudiness" caused by long-term road wear, i.e. microscratches. And it tends to be ~25-40% cheaper compared to polycarbonate.

 

yes.
I wonder how they respond to modifications and if that’s worth doing. Tint probably is.
for example they make decals that easily fit.
Like window decals that can give privacy. MAYBE reject heat more. But still let you see out of it. Flag forest topographic map whatever design you want.

totally up to OP. But say you’re camping in the bed. Decal would help cut light out and be less visible.
Whether it’s the sun going up at 6am or not. Can be safer to park in a well lit area. Then the graphic block out that light from inside.
Or if roof solar where person may not want light in their eyes but still wants sun on the panel.
Have dealt with that before. Night time look at where the tree is and in what direction the shade is gonna be come time for sun to rise in east squeeze power out of 100w solar.

Reflectix is common and comes in silver but can be had in black. Decal would hide it better.