Re-installing screens

I will be replacing glass in some windows and I saw an acryllic manufactured by Lucite that is supposed to be "better than glass." Just wondering if anyone has any knowledge or experience with using acryllic vs. glass in window applications. The manufacturer claims it is not only acceptable, but superior.

Hello- I recently took on a project that involves some 80 old wooden windows, both double hung and casement. Some have rotten lower sashes, some just need paint and sash balances. All of them need new putty, and the worst are the ones where people have tried to re-putty them with various materials and varying degrees of skill over the years. 75 years in fact, which means that all of them have been repainted several times, usually right over the old flaking paint. I've rebuilt three of them (2 casements and one doublehung) so far, but it's a very slow process. I hoping you guys have some tips to speed things along. What's the best way to get the old putty out? Everything I do seems to break the glass - that or gouge up the wood. I've ordered a heat gun - is that likely to break the glass like the propane torch does? Would covering the glass with something like foil or asbestos cloth (or whatever they make that stuff out of now) help? Or do I just bite the bullet like the glass guy does and break the glass right from the start? ($!) Sanding to remove old paint results in undersized sashes. Propane torch does the job but it's slow and messy. I am also concerned with the lead release using both of those methods. How about a chemical stripper - anyone tried that? What does chemical stripper do to glass? Does it dissolve glazing putty? Would having these sashes dip-stripped ruin them - and would I have to remove the glass first? Is there a service that rebuilds old sash balances? I talked to a guy who rebuilds his own, but I can't imagine it (he doesn't want to do mine.. ). They're not cheap and I need a lot of them - I don't want to replace them with new ones if I don't have to. The bottom part of the lower sash usually fails when the dowels that hold the sash together rot through. Sometimes I can get the old dowels out, sometimes I can't. Any tips on getting out the broken dowel pins? Any other tips? Thanks! Steve