Cntr. Window new plexi question

[Del Gurney]

Hello:
Just removed the old 1/4" plexiglass from front center window rock protector.
Was cracked and warped. Easier to shatter it when removing it was so brittle.
Very thin stuff I think, held in a channel by a spacer gasket. The channel will accommodate 2x the thickness.
Difficult to remove the rivets and retainers so will probably have to through bolt with SST @ top and bottom seam.
Before I take the frame to the glass shop.....
Anyone had to do this before?
Can I go with thicker plexiglass (weight issues?)
Or just buy a new complete one.
Thank you for any advice.
Del

[Hummer]

I think I would go with Lexan replacement instead of plexiglass as it is much stronger. It will be clear but you can have it film tented dark or have a screen applied to inside.

Lexan is what is used on the front covers of drink machines. I have a friend who owns one of the largest companies who makes the front covers and applies the art work. They buy it by trailer load and it is all clear and they apply screen to back side.

I have seen several churches that have had Lexan protectors applied outside to protect their stained glass windows.

[HowieE]

I agree with the Lexan. One word of caution when you go to the glass shop. Make sure they account for the gasket when measuring the sheet. I had given them a measurement and they said it was wrong and cut the sheet over sized. This caused the frame to expand when reassembled and a return trip to the shop for correction.

[Melody Ranch]

Geeze Del....if your in the Seattle area...just go to a plastic dealer. Ask for Lexan "SR" (scratch resistant) and they will cut it to your specs. They will even have different tints and colors for your choosing. Use Vulcum...or other sealant, and put into your frame.

[maroth]

I have an 89 Excella, with wrap-around rock guards (as well as the front flat piece), and need to get all 3 replaced. Is this a job better suited to plexi/lexan professionals, or is it something that I can do myself? I'm handy with tools and am an engineer (of various crafts), and I think I could handle this task easily. What "got-chas" would I need to be aware of if I attempted this myself? I've read above about the correct sizing of the panes, but what else should I be aware of? Will the plexi/lexan crack/break as I run it into the curved frames? I assume I can use the old plexi as a template? I like the lexan idea, but would totally love to install an iridescent or reflective material. any thoughts on that? Any advise will be greatly appreciated.

[garry]

I made my own with Lexan about 4X the cost of plexiglass but 4X better.

You can install the wrong side out so make sure you install "this side out" as marked on the protective cove sheet.

If you plan to cut "tape both sides" before you cut to prevent shatter or small cracks. You can make small final corrections with a metal file.

[HowieE]

I used dark Plexi only because the shop that cut mine did not have lexan.

As fpr the curve. 1/8 in plexi can be bent cold down to an 8 in radius far less than you will encounter.

The hardes part will be getting the frames apart as they used steel angles in the corners and they tend to bind to the aluminum frames. When I did my rear window I had to make a jacking arrangement with a beam clamp used in reverse to preload the joint while tapping the connection.

[Jim & Susan]

Here's the way we did it: http://www.airforums.com/forums/f226...tml#post496827

It's not hard to cut, just measure accurately. It'll take quite a bit of bending. IIRC, we bought a UV scratch resistant grade Lexan. Been almost 4 years now and still looks like new.

Jim

PS for Maroth: Spent many, many weekends at Camp Bullis near y'all.

[dwightdi]

The flat panel should not be a problem, since you are not introducing a stress. Use the outdoor rated Lexan (polycarbonate) other brand names are also acceptable.

The original curved sections are vacuum formed, so they have not remaining stress. If you try to cold bend them you will likely end up with residual stress which could cause premature failure. Buying the curved pieces would be much better than trying to make them yourself. If you are familiar with vacuum forming Lexan you could give it a try.

[maroth]

Many thanks to all for the advise. I am going to look for 1/8" Lexan (as Jim did) in a cool color (must be unique you know), and order 3 sheets 2" over sized for my frames. While those are on order, pull the plexi out of the frames (keeping in mind the binding actions -- Thanks HowieE) and make templates of all 3 out of thin cardboard. Then, when the plexi comes in, cut (as outlined by Garry) and insert, and reinstall the frame end piece. According to the replies, the bend on the end covers won't be an issue with stressing the material, although I will keep in mind the mention of it by dwightdi. As far as sealing the plexi to the frames, does anyone have any concerns about the gap? Should I use a filler sealant, or the standard rope-type material? Again, thanks for your replies, and to all please look me up if you're ever headed out I-10 West of San Antonio. I have a nice place in the Hill Country for a stop (with hookups). And to Jim, if you were at Bullis (and to all my military friends) for training, please make sure you let me know when you're in the area, I owe you a beverage of your choice for your service. Regards to all.

[dwightdi]

Polycarbonate will stress crack when exposed to some sealants in a stressed condition. Lexan used to be owned by GE which had a good tech service department to ask for advice. It is now owned by SCabic, which is a mid eastern company. You might try finding some recommendations on the web. The stuff is not cheap and I would hate to see all your work go to nothing with the wrong sealant.

[overlander64]

Since installing the Airstream rock guards on my Minuet, I have been thinking about what will be done when the deep tinted acrylic needs to be replaced. The one thing that I missed immediately after installing the guards is the obstruction of the "see-through" feature. While there is still some service life in the acrylic on my guards, I do know when the dark tinted acrylic needs to be replaced it will be replaced with clear Lexan to restore the "see-through" feature. For those considering replacing worn/damaged acrylic panels, clear Lexan can be considered if you wish to restore the see-through feature that is present in most Airstream travel trailers.

Kevin

[maroth]

OK then, I think I have enuff info to get this project underway. I'll keep notes and take pics for all to see. More as I get into this project guys. Thanks, and hopefully I'll be meeting some of you guys one day. Mario and Tina