Replacing a Topper Rear Window With Plexiglass/Acrylic

Updating this first post with some of the key takeaways.


-Yes, this is quite do-able, even for the less skilled among us.
-It's more complicated on the frameless windows. In fact, unless you have "skills", I wouldn't attempt this with a frameless window, unless you're somehow desperate.

-For plexiglass/acrylic (same thing, and called something different across the pond), go thicker than 1/8". 1/4" might not be necessary, but it's not overkill. Something thicker than 1/8", up to and including 1/4".
-There are certainly others, but this site (piedmont plastics) is where I got my plexiglass. Their camper window side of the business feels like an afterthought... I later found this site (eplastics), with far more options, different tints and thicknesses. Takes some navigation to find what you want, but it's there. I didn't order from eplastics so I can't give them an honest review, but their product selection is far better than piedmont.

-For glass, I found one day glass aka peninsula glass. You can submit a general idea of what you need to get a quote, which starts the conversation with them. I think submitting your request for a quote lets them know you're more serious and you get faster attention. Go to Types of Glass, choose Tempered, then go through the specifics of what you want from there, as best you can. You can sort out specifics through email once they respond - your quote submittal isn't set in stone.

-Unless you already know what you're doing and have a fully outfitted shop (in which case you likely aren't reading this thread cause it's borderline useless for someone like you), this will be more expensive than you expect. The plexiglass or glass will be the biggest expense, probably, but then there's tools and other incidentals. I needed a rivet gun, VHB tape, T-handles that required specially shaped adhesive-backed washers that were $12 each. Weather stripping. New gas struts. Little things. They add up.

-This site was really helpful for hardware, weather stripping etc. Real people with real customer service. Truck Outfitters

-For making templates, cardboard works great. You can use it for plexiglass sheets at home. But if you go the online-order-custom-cut-glass route, you'll need to be able to send your template through the mail. Unless you have some at-home computer program. I found Ram Board at Home Depot, and it worked well for me. Very very stout paper, borderline cardboard, which you can use for the template, then roll up and ship in a poster container. The link, if still good, goes to 100' rolls. I found 50' rolls at Home Depot. Still expensive for a truck topper template, unless you have a use for the rest of the roll, but like I said, it all adds up...$$
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Sort of a how-to, sort of a 'should you?', sort of a 'give me some ideas' thread. Was going to wait till I was done and just post the process in case anyone cared, but I think as I start to assemble things, I'll benefit from more pairs of eyes and advice, at least based on the late-night anxiety that hit me last night. Started with work stuff, then of course consumed everything.

You'll see where I have some questions.

This is an "all glass" rear window. While there is a frame, the window doesn't go into a channel in the frame. It's adhered to the outside of the frame. So that part of the project will be different depending on the style window you've got.

This topper was $340. I didn't think that was bad, and I still don't think it was. But you can decide along with me whether I "should" have taken the advice here to wait it out and find something with intact glass. This topper really is the topper I wanted. Color, window setup etc. But I saw a nearly identical grey topper with intact back glass come up on the Marketplace recently, for $200...I'll tally up the costs once I'm done with them. But even discounting my time, I'll be nearing $700 by the time I'm done with this, and have an acrylic rear window rather than glass. Had I just budgeted $700 and held out till a fully intact topper went up for sale, yeah, obviously I would have come out ahead. But that's how it goes. I regret nothing!

At the time I was looking, nearly everything had busted out back windows, and this one was actually a great deal and in otherwise great shape compared to others.

Anyway here's what I started with.



Overall, in really good shape. Just a very small patch of clearcoat starting to fail on top, inner felt lining needed to come out.

Back window.



Had the frame and hardware not been included, I don't think it would have been a good idea to buy it.

Next post will dig into what I've bought for replacement parts.

 

Watching someone else do something with his time and money? I’m in!

 

I figured.

So...supplies. This site has been the best for me, even though things can be found cheaper elsewhere. Here I'm sure of what I'm getting, and I also got real customer service with a knowledgeable person.

My frame has a "T" channel. All the T channel weather stripping on the website was 3/16", so any weather stripping with a T channel will fit my frame. Just a matter of deciding what type coverage I want. Initially bought this:



But with shifty` help realized this is closer to what I need for the bottom gasket:



This would have likely also worked well:



The T Channel itself.



Old T handles, which I'll use parts off, and new hardware:





Adhesive-backed washers are a key component of the handles. Two edges are flat, and that's what mostly keeps the handles from spinning in the holes.

Tape. No idea if this is the "right" tape. But it's at least not the wrong tape.




Now the actual thing. The "glass". I was looking at full sheets from Home Depot. Somewhere around $150, and way more material than I needed. And my previous experience going that route wasn't great. I intentionally didn't spend a ton of time making it pretty, but I really did want it tinted. Anyone who knows, knows that tinting plexiglass doesn't work out so well. There's supposedly a specialty tint for plastic sheets but I couldn't find it. This is what happens when a) you aren't experienced at tinting and b) you use glass tint on plexiglass.



It actually held up pretty well for about 2 years. Then all at once started peeling and looking terrible.

Not going to fly for the large back window of my shiny new(to me) topper. So what to do? Looked around and found this company. Piedmont Plastics. Specific to my application, AND they sell tinted acrylic sheets. More expensive, but I could order only the size I needed, already tinted. The price for just the amount I needed was comparable to the full sheet from Home Depot. Until shipping...Seems to me they don't typically service end-consumers. I had very few options for a single sheet, and all of them had "remnants" in their descriptions. That's ok though. They had a tinted 1/8" sheet. Good enough.



Those are the supplies. But anyone who's done a project knows the parts are only half the battle. Unless you already have a fully stocked workshop, then there are all the tools...

 

Having not completed the job yet, this isn't an exhaustive tool list. For example I know I still need one of these for the T-Handle holes:




A few of the rivets were loose, and a couple were completely missing. So...rivet gun. Expenses adding up.





Then I need to cut the sheet. There is a "scoring" method with a blade. I'm going with a saw.





These will help when with making the cardboard template, and when I finally use the adhesive tape.

 

Prep work. Whatever adhesive tape Century used, it worked. The glass completely shattered, but everything on the tape held strong.



After a couple failed attempts, this is what worked for me. There are definitely other methods that would work. Safety glasses and gloves!



Also needed to clean broken glass off the hinges.




If you read Amazon reviews, you'll see that the 3M VHB tape is either the best thing in the world, or completely useless. I'm going to guess at least 70% of the failure stories are from improper methods. I'm the sort of person who reads directions. There's more in-depth info available, but the basics:



I'm not planning to meticulously clean the surface of the window frame. Hoping a little tape residue and roughed-up metal are as good an adhesion surface as anything...thoughts?

 

Now what the final product will really depend on. For the Tacoma side window I showed, I just kinda cut. I want this to look far better. I know people who do quality restoration work, and cardboard templates are an indispensable tool. Realized with some help from the forum that just tracing the window frame wouldn't do it.





Clearly the frame sits inside the opening, and the glass hung out over the edges and made a seal with the weather stripping. Made the template just slightly more challenging but not a big deal. There's a little room for error here.






YES!



Maybe some 1/8" trimming here and there, but basically there.

Transferred onto acrylic sheet. I wasn't expecting the paper backing, but it definitely comes in handy.



Have some other more pressing projects this weekend, but I hope to make the cuts very soon.

 

VHB tape will stick to pretty much anything that isn't greasy, oily or dirty. I think you will be okay

 

Whoa good work

 

A lot of fake/knockoff "3M" products are sold on scAmazon. I'd highly recommend avoiding anything labeled "3M" on that site. Acquire from another source. I've personally gotten unboxed/white box/clear-bag items ordering these things on scAmazon over the last 10 years:

• 3M 3432 Red Micro Prismatic Tape (white label, generic box)
• 3M Steri-strip reinforced skin closures (clear baggie, white label)
• 3M 05526 Wetordry Sponge Pad (white label, generic box)
  
• 3M 03614 Super-Strength Molding Tape (white label baggie)
• $7 3M 38582 , 1/4 in x 5 ft
  3M 38582 Auto Exterior Attachment Tape (white label baggie)
• 3M Scotch rubber cabinet door bumpers (3 times now, I won't order on scAmazon anymore)

The only thing I've consistently gotten that was clearly 3M genuine at their store, that came in the OEM packaging expected?

• 3M Dynatron 550 Auto Seam Sealer
  
• 3M Super77 spray adhesive
• $8 3M 03609 , 1/2 in x 5 ft
  3M 03609 1/2" super strength tape

How in the hell did I keep track? Returns. I'm sure there's more than what I'm showing above, but I just flipped thru old emails searching for "from:Amazon 3M return" and the half dozen in that list popped up from the last 10-12 years. Most of the products still existed, but I'm guessing the sellers who peddled the fakes are probably long gone/shut down by now.

Long story short, scAmazon has a knockoff/white-boxing/generics/re-pop problem with things. People basically sell stuff on there with "3M" in the title, under the guise of, "Oh, well, we used 3M adhesive to make it" or, "The plastic adhesive cover film is 3M!", I guess?

Needless to say, never buy these types of product on scAmazon. And especially not the rubber cabinet door bumpers, because one of the sets I bought previously before realizing they weren't legit has essentially turned to gum/goo and I need to spend a couple hours going thru all our kitchen and bathroom cabinets to clean out the goo and replace bumpers with a known-legit product.

Anyway, work is looking good! Just saw that one comment and wanted to throw my 2¢ at it from personal experience.

 

I have thoughts on that too, but venting about that company (and I say "that company" because it annoys me that if I write the name, this site creates a hyperlink to "that company" that I can't remove) could send this thread to pages and pages of off-topic rants so I'll avoid it. We'll just say - you're right.

 

Yeah, it's the main reason I prefix with "sc", because I feel like it encapsulates what a flea market crapshoot that website has turned into.

 

You guys have it nailed, was my first thought when I read OP's comment about 70% failure rate....knockoffs. Such a damn shame too because you have the last few trustworthy businesses whose goodwill/brand are damaged ("3M! Oh that's the science guys who make expensive but great stuff!"), plus the local stores put out of business by these huge enterprises who started out with quality products and service (Wal-Mart, Seattle Lex Luthor) only for those same mega-importer platforms all to start selling shite products and giving zero customer service.

Also, I read this thread in the middle of the night when I was awakened by some sound, and then promptly had a dream my back glass broke and I had to find some plexiglass to fix it and tried PM'ing OP to see if he'd sell me his cardboard cutout (?).

 

I'll give you a great deal on that template. $$$ But I charge extra for appearances in dreams.

 

Finished this weekend.

First, I finally had to make the cut.



And t-handle holes



Then get the frame ready. T-channel was a pain, but once I understood what was going on, it went smooth. A "pinch" on either end to keep the seal from sliding out. Needed to un-pinch it, slide in the seal, then re-pinch.







Final test fit.






At this point I was ready for the 3M VHB tape. Cleaned and cleaned the frame with alcohol. Took a lot. Very lightly roughed up the frame and acrylic sheet with very fine steel wool. For this stage, I should have found a helper. I'll bet I could have pulled the tape off the metal frame without too much trouble, but as soon as the acrylic sheet touched it, it was 100% stuck. I was a little off with my placement, but not so far I couldn't work with it.

Then drilled the hinge holes.











There it is. Later I realized there was a little movement between the hinge and the window, and I imagine going down a rough road, that amounts to a lot of movement. Just took some flat, wide weather stripping and put it between the hinge face and the window, and that seems to have tightened it up.



Thoughts...I went with 1/8" acrylic. I would have preferred 1/4". But they only had tinted in 1/8", so that was a compromise. Because I had good luck with the last project like this, when I used a jigsaw, that's what I used again. But the last time I did this, I used 1/4" acrylic. For this thinner sheet, I should have cut using the razor-scoring method. The jigsaw put a lot of little cracks along the edge of the cut that may very well run and really compromise the strength of the window.

Obviously, for the price and effort involved and the fact that in the end my rear window is acrylic, not glass, it would be way easier and more cost effective to buy a topper with an intact rear window. I also think doing this job with a rear window that sits inside a window frame channel, instead of sticking to the outside of the frame with adhesive, would be way easier and way stronger in the end.

I do think that if you have a topper you love, and the back window breaks, this is a reasonable option. But I'd advise against buying a topper with a busted rear window, unless you plan to get a true glass replacement from the manufacturer. $$$$

One unintended side effect is that I really can't see out the rearview mirror anymore. The acrylic is tinted too dark. I still prefer this to a clear acrylic sheet that would allow everyone to see what's in the back of my truck, but I didn't realize the tint was so dark.

I also assume this won't hold up so well. Certainly I can't take the ice scraper to it in the winter. I'll need to just leave crust/ice on there and let it eventually melt. But hey, can't see out of it anyway! We'll see how it holds up to washboard and other rough roads, and general use.

For now, I'm loving having a fully intact topper.

 

Most impressive turn out! Nicely documented.

 

Just reading through this, great job! So many things could have gone wrong. Just getting the shape and measurements right. Then the cutting! As soon as I saw the jig saw I was like nooooooooo! Plexi likes to crack when cut like that. I did a project with plexi glass and had to buy a big sheet. I was mad about that due to the added cost, but ended up needing all of it as I learned what not to do. Cutting with jig just wouldn’t work, kept cracking the material. Ended up scoring with a knife to get great results. Yours turned out great, but the line that should resonate with everyone is, buy once cry once, or spend a little extra up front to get the one you want. It will save you money in the long run and likely be a better product.

 

Thanks. This is why I refused to rebuild an engine myself once, and am still hesitant on the timing belt/water pump job. You do it once, the first time, then realize how much better you'll be able to do it the next time; all the things you did wrong. Not a big deal with a window, but with an engine rebuild?? If I had to do this over again (and who knows, maybe I will have to do it over again): seek out 1/4" tinted acrylic, and go with the scoring method for the cuts, even though 1/4" wouldn't crack as much with a jigsaw. Easy to stop a couple runs from drill holes, but dozens of tiny cracks all along the cut edge? Not so much.

Yep, I wish I had looked into cutting methods more. Like I mentioned the jigsaw worked on 1/4". It definitely chipped the edges, but that can be fixed with sanding. No cracking. But yeah, on this 1/8", lots of little cracks. I'm keeping an eye on it now that it's on the truck and I'll see if they start running. I got some plastic welder stuff and may put that in all the little cracks. Any that start to really run, I'll drill a tiny hole at the leading edge. I had to do that in a couple spots on the hinge holes. The hole saw didn't crack things at all, surprisingly, when I used it to cut out the handle holes. But the smaller holes needed for the hinge bolts I could drill with just a drill bit, and I had 3 cracks that started to run from those.

 

So that was the best 5 days of my life with this topper.

When the tire shop guys had it to swap tires for me, for some reason they opened the back, and it cracked at one of the hinges. I'm hoping now anyone who had doubts this would work will chime in with more durable options?

There's a part of me that just thinks "1/4", even 3/16", with the same setup, and you'll be good." There's another part of me that's not so sure...Of course now that I've bought the tools, have the template, all I'd need is the sheet, and I'd be back in business two days after it got delivered.

But what I was going to ask about when starting this thread, but decided to skip, was how to reinforce the hinges. There is definitely a lot of the weight of the rear glass resting on the hydraulic lifts, maybe most of the weight. But a lot rests on the hinges. And when I open the window, there's a lot of force bending against the acrylic sheet at the hinges. That's what broke, probably at one of the cracks from drilling the hinge holes.

Possible a thicker sheet would take care of this. But I've been brainstorming ideas on how to reinforce this area, maybe with a large washer or some type of metal plate, so that the bending pressure is removed. Something more rigid so that the sheet doesn't flex there.

Sure, I could have been a hard-a** and made the guys pay. But for one, I was in there having them put on brand new tires, for free, after driving 200 miles including dirt roads on the ones I bought from them a few weeks ago. So they were already taking pity on me and possibly losing money on the deal. And I have to imagine that the hinge area was going to crack one of the next times anyone opened it. It just happened to be them. I'm the type that wants to be fair, not the type that wants to get whatever I can out of people. "Sure, it could have happened to you, but it happened to them! Take advantage of it and have them pay" etc.

No.



It didn't break this badly, it broke this badly trying to get the hydraulic lifts to let us close it after cracking at the hinge.

I have an email to a custom glass company that at least as of 2022 people were getting rear windows custom cut from for under $200. Which is hard for me to believe. I'll see what they say. Otherwise, I found another company selling full 24x96" 1/4" thick tinted sheets for $168. I can swing that, but only after I figure out whether 1/4" thick will be enough to avoid this problem, or whether there's a way to make that hinge more rigid.

Thoughts, ridicule, and I suppose even sympathy welcome.

I was of course tempted to keep this to myself. But since the point of the thread was a tutorial, it'd be pretty lame of me to let people think this worked out.

I do think that with 3/16" or 1/4" acrylic and some type of metal washer or plate at the hinge, I'll be ok. I'm very much open to ideas.

 

Man that sucks. Sorry the plexi didn’t work out. Might need lighter rated gas struts for the lighter material.

 

Thanks. Yes, a few things. The more I think, though I'm going to take my time because my days of spending money on this truck with abandon are over, I think that a thicker sheet (likely 1/4"), washers or a metal plate to stiffen the plexi at the hinges, and lighter weight struts will do the job. I think I could probably have nursed this sheet along for while without breaking it, knowing to be gentle. But I worried from the start that someone else, on a camping trip or something, would treat it like a glass window and break it.

 

I'm going to continue to document this, even though it's turned more into an experiment (maybe mostly in what not to do) than a how-to. I'm a little worried this isn't the end of the road for me...but we'll see.

Here's the progress. With a lot of searching, I found a couple things. One is this site, which had a far better selection of sizes and tint options than the site I bought my acrylic from. I could have (and almost did) bought a thicker, tinted plexiglass sheet from there. The other thing I found was this site. I'm sure there are a lot of other custom glass places out there but no internet forum posts from people in my situation ever mention anything. They only mention the topper company, plexiglass or plywood. I found one thread that mentioned this site. They're a part of Peninsula Glass/One Day Glass.

After entering my measurements and requirements into their forms, I got a quote for $300, shipping included. Decided it was my best bet. Scary thing was, this meant my template had to be very accurate. Doing everything at home, I could cut the rough shape, fit it to the topper, see where the bolt holes lined up, cut/drill accordingly. But with this glass, I'd have to just send a template, and I'd get back a cut piece of glass with four holes drilled in it. If my template was off, I wasted $300.

So I used my previous cardboard template to make a plywood rear window as a test of the template.







Fit pretty well. I decided my template was good enough. But I had to mail the glass company the template...so cardboard didn't really work. Found this Ram Board at Home Depot. Really, really stout paper. Almost cardboard, but I could roll it up for shipping.





Made an outline of the template on the leftover plywood, just in case...Can't hurt to have a few back windows.

Mailed it off. In the meantime, I really grew to like my plywood rear window...nice and light, lots of privacy. But I'll bet one winter and it'll look terrible.

Glass finally showed up.





Luckily, the holes lined up. There's a lot of wiggle room in terms of the overall dimensions/shape of the window, and it's not perfect, because my template wasn't perfect. They cut it exactly like the template, which is what they should do. But you can probably see in the photo the top left is higher/a slightly different shape than the top right. But good enough. The critical thing was that the drilled holes were the right size and exactly the right location, and they were.


The last two times I put the 3M VHB tape on the frame first, then lowered the window onto it. Both times were sketchy, really hard to get the fit just right. And once any part of the surface touches, it's stuck. You only get one go. Both with the plexiglass and plywood, it was good enough, but not lined up perfectly. Decided to try the opposite this time. Laid the frame on the glass, perfectly lined up, taped the outline with masking tape, then put the 3M VHB tape inside the outline. Then attached the frame.








Here's where I'm real unsure. The glass is thick. I told them my application and they recommended 1/4". It's thick. And heavy. Looking at the data sheet for the 3M tape, I'd need far more tape than there's room for on the frame to get the recommended amount for the weight of the window. Luckily the t-handles bolt through the glass and frame, helping to hold it together, and it's actually just the glass that attaches to the top hinges on the topper itself.

Thick, heavy.



Installed. I think the original glass must have been slightly curved. The 1/8" plexiglass and 1/8" plywood curved to fit, without me really realizing it. But this thick glass isn't going to flex. I flipped the orientation of the t-handle for more space, but it means the bottom doesn't seal all that well. I may be able to get the t-handle to close in the other position, but it was really tight and I don't like the idea of driving rough roads with the glass under pressure. I had to push pretty hard on it to get the handles to close in their original position.

I'll also need new hydraulics. These 28lb shocks will hold it open, but barely, and they're brand new.












Could have gone with dark grey instead of light grey tint, but it's definitely good enough.

Only time will tell how this holds up, in terms of: the bottom seal being tight enough to keep out dust and moisture, the ability of the 3M tape to keep the glass attached to the frame considering the washboard and other rough roads ahead.

I'm definitely not throwing away my temporary plywood window anytime soon...

Knowing what I know now, the only thing I think I would do differently is call more companies directly. There are sites with forms that let you enter many different topper brands, serial numbers etc., and offer replacement windows. On the search results page they list $395 but I see once you're on the site, you need to enter everything to get a quote. $395 might just be the low end...No idea if they're any good, but they have Century as an option, as well as "frameless". But I'd check with local glass shops and do more direct inquiries before going the "custom" route.


I think for a framed window, the company I used would be great. Most of my problem is this frameless window. Causes a lot of complications.

I'll admit I'm going to be nervous about shattering glass when I drive dirt roads for a while...

 

Did you place a grommet in the holes that you drilled through the glass? Or just washers on the outsides?

Fun project. My topper also came to me without a rear window, but it’s a framed window so replacing it was much simpler. I cut a plexi window for a while but was able to get a tempered piece of glass cut for a decent price (ok, it was crazy cheap by todays prices).

 

I didn't drill the holes, the glass place did everything. But yes, the hardware that came with the broken rear window when I bought the topper included two plastic washer/grommet things for the hinge bolt holes.