An accurate template is really the product that I think needs to come out of this thread... if I haven't already mentioned that. Sounds like Curly echos that opinion.

With this forum, that "product" would sell one copy :) Sounds like a few people want a template, a few others want a pre-cut sheet. I'm waiting to get some quotes using a couple of different production methods so I have an idea of what the costs would be for the latter.

As for the silicone, I've only tried that once. A bead between the window and the flange caused enough of the silicone to ooze out that I was able to smooth it out with my finger around the edge.

I used the most expensive GE exterior silicone I could find at Lowes. It is really great stuff. Just watch out because it dries quickly (20-25min to dry film on the outside), but it will HELLA STICK to absolutely anything. You can't even scrape it off of the lexan. Its almost like an uber silicone sealant/glue.

@Keith - How about if you do provide a finished window for purchase, would it be fair to offer a template for free/cheap to those that do wish to DIY?

ya I agree, Id rather have a template most likely

Yes, with this forum it would be like a fender roller. One unlucky idiot would buy it then it would just be mailed around the country in a poster tube until its ruined and another unlucky idiot buys it and uses it once.

But yes, you can't call yourself a DIY'er if you're unwilling to cut it out if you at least have a good template, I don't see the reason for a water-jet cut piece of art for a lexan window.

Water jet cutting is realistically less then 30 dollars a window. Is it worth 30 dollars to you?

Wow, this thread sure got carried away.

To me, a lexan window is, for the most part, for the DIY'er. Most people with hardtops aren't gonna go rip out the glass to save 5 pounds, especially if it's gonna cost them time and money. Only people you're targeting are people w/ busted glass looking for a cheaper fix and hardcore racers looking to shave every ounce they can. Your preformed lexan thing would be "cost of materials + cost of waterjetting+ R&D to get pattern for said cutting + extra shipping cost to ship curved piece". That's more than 30 bucks I'm afraid.

Yea, but people fail alot of times to see the hidden cost of DIY. You can buy an air jig, a piece of polycarb, a rivet gun, a box of rivets, high qaulity silicoln, punch holes in your hard top (basically 500 dollars because there is no retail value for a hardtop with rivet holes in it), a drill to drill the holes, drill bits to do it, a template, several hours of cutting to trim and fit, maybe a couple hours running to home depot or harbor freight for tools/parts. The possibility of cutting the polycarb wrong (another hundred), and having to start over, learning how to rivet, then making it look "right"

Other method... buy a piece of formed precut polycarb, it gets shipped to you, you call a guy who installs it. Total investment less then 350 I would think, cheaper then factory glass without the installation, lighter then factory glass, no damage to resale value of hardtop.

DIY has its place, but what is visibly off proabably shows up at about .01 inches. You telling me your going to be able to cut straight line (or even worse a curve) within a hundreth of an inch on a couple workhourses with a bowing piece of polycarb with atleast some of you at the helm of a jigsaw for the first time? There is reasonable, and then there is human limit.

I'd rather save the $30 and use it to buy a black and deck jigsaw that I can use for a few years. All I want is a template, period.

I don't give a fuck about a 1/100th of an inch. I just want close and flush fit.

Then thats another vote for template only.

Honestly Travis, its a great idea and I might've bought a pre-cut one if it was available for cheap at the time, but it wasn't. I already have rivets, drills, and now I have a jig saw I can use for future projects, some scrap lexan for the triangle windows, and some lexan cutting skills.

More power to you if you can get enough customers to make a decent profit from cutting a window. I guess I just hear more people leaning towards just using a template, and I'd worry that the market isn't there for you.

Well, I'll leave it alone, I was just trying to help out.

I'm sure you can find better things to do with your time that will cater to a larger crowd. Things that require more than a 30 dollar jig saw and a good idea.

Exactly what Pat said, its not that you don't deserve to make a great hardtop window, its that the window doesn't deserve your perfectionist style. This style could and should be applied elsewhere IMHO. Apparently traction bars are fairly important on some people's list for example.

Does anyone know how the stock rear window trim molding attaches? If I could just buy a new piece and make it work with a lexan rear, I wouldn't care about being off on my cuts because that would just hide it.

The only person talking about pre-bent Lexan is Travis.

If we start offering this, it'll be flat. There's no reason for it to be pre-bent. It would add expense for no benefit.

Based on my experience, it wouldn't be that hard to figure out the correct shape with a hardtop that has a busted window. It would require a bit of trial and error, but as long as you're smart enough to err on the side of cutting too little then you could do it. In the past, I've used the template to get in the ballpark and then done the final trimming on the top itself. The tolerances are legitimately within 0.5", not 0.01" if your cutting at home. If you're making a show Miata, then a polycarbonate rear window is a poor choice anyhow.

Ug, drilling the hardtop and window sucked! Its nerve racking as hell cause with any of the holes you could scrap your piece of polycarbonate. But I didn't do that, and have all 30ish holes drilled and bolted on (my rivet gun can't hold the 1/4" rivets I don't have, hence bolts).

I still have to mark some spots that I need to trim so it fully fits in the lip, un-bolt it, make the trims and deburr the holes, clean the lip, paint the lip, re-install and make any further trims, un-bolt it, lay down a bead of silicone, and bolt it up for the final time.

Yuk.

Oh and fiberglass splinters suck

Curly- got any pics of said job just to see what i can expect?

Yup I have some pictures, I'll make a separate thread as to try not to clutter this one any more.

enjoy

https://www.miataturbo.net/forum/t30104/

1/4" rivets would be overkill. 1/8" with a backing washer does the trick just fine.