Plexiglas

[Biofish]

I want to bend my own plexiglas to mold a curved windshield on my boat.. Any good websites that explain this in detail? ( i have seen the G-3 website... no help there)

What do you cut plexiglas with anyway?.. will a standard tablesaw do? or should it be professionaly cut?

Rob

[stan v]

This Old Boat, by Don Casey, dedicates a section to cutting and bending plexiglass. He uses a homemade heat set-up to bend. Seems straight forward enough. Book is easy reading, but needs more on the miracle of epoxy.

[Roger Stouff]

Welcome aboard, Rob...

[Dave Carnell]

A carbide-tipped blade cuts fine, though most generate enough heat to leave a melt flash. The 7¼" Matsu****a 1/16" kerf carbide-tipped blade cuts mirro-smooth with no flash. I make them available if you can't find a retail source.

[Dave Carnell]

A carbide-tipped blade cuts fine, though most generate enough heat to leave a melt flash. The 7¼" Matsu****a 1/16" kerf carbide-tipped blade cuts mirro-smooth with no flash. I make them available if you can't find a retail source.

[Biofish]

Hey Roger! Thanks for the heads up about this forum. I was stuck over there at the glen-l site watching for one of the two posts per day there!.. when i saw this forum with around 60,000 in all.. well, lets just say i was very glad.!

[trull]

I once used a pizza oven to heat up some lexan so that it could be bent over a form. It was trial and error with scrap to determine time, but worked well. Pizza shop was not open for business at the time. ;)

[JimD]

If you get some melted 'heat flash' from sawing plexy its not very difficult to clean off the edge. I use a belt sander to fair and tidy up the edge. Go easy with the sander or you could end up with more melt, but its another reason the lowly belt sander is one of my favourite tools...BioF - I know what you mean about the Glen-L forum, but there's still some useful stuff there from time to to time. I'm currently building a Glen-L boat (the little Minuet), thinking about e-mailing them as asking what they think of the thrashing the James Cook has been taking over here. You know what they say about opinions... smile.gif

[Bob Cleek]

Sometimes, doing it yourself may not be the most efficient way to go, even if it CAN be done. You might consider talking to a good auto glass shop about your needs. You may find that they can provide exactly what you need for a surprisingly reasonable price. One problem with most clear acrylic type materials is that they often scratch easily and crack and craze due to UV exposure after time. (Yea, I know Lexan is bulletproof, but...) After a lot of problems trying to work with Lexan, etc, using it to replace cabin windows (not curved), I bit the bullet and went to the auto glass guy. He explained that auto type saftey glass was a much better option. Turned out the stuff was about the same cost, if not less, than the plastic, and it came all cut and finished to the pattern I provided. Those outfits have suppliers that provide curved safety glass windows for cars on a daily basis. It may be a better solution for your application. Dunno.

[Norske1]

HEAT GUN WILL BEND IT...I'VE DONE IT ON A WIND SCREEN..LOOKS GREAT ...JUST BEND NICE AND EASY....GIVE THOSE ENERGISED MOLECULES TO MOVE AROUND smile.gif

[ 03-09-2002, 08:56 PM: Message edited by: Norske1 ]

[Ladyhawke]

My system.....leave the paper on (naturally) and cut with a sabre saw using a metal cutting blade. Run the saw slowly to minimize the melting. A little 3in1 oil doesn't hurt either. The plexiglass MUST be cut to shape before bending. For bending, I remove the paper and use my wife's hair dryer...on high! Keep it moving and take your time. I fastened :D the flat windshield portion and used the dryer to work the curve in place. Fasten right away.

[Mhija]

There is a good low-tech way to cut plexiglas
without using power tools which will not give
rough edges or heat flash. It only works for straight line cuts, though you can approximate
a curve with multiple straight cuts and a bit of filing. The tool to use has a hooked, hardened
steel blade that scores the plexiglas in a vee shape. It's available from plastic supply houses, glass shops, good hardware stores
or your friendly picture-frame shop might loan
you one if you ask nicely. Leave the paper masking on and score along a good metal straightedge, watch out the blade doesn't cut into softer aluminum rulers. When you've made a half dozen end to end scores you'll get an even curl of plastic. This is as the evil Martha S. says " a good thing "........
Put a dowel under the score tangent to it's center and press down on both sides of the plexiglas starting at one end. The score will run cleanly from one end to the other. Cut through the backing paper masking which is still joining the two pieces with a knife and you're done. The cut edge will be surprisingly clean. The thicker the plexi the deeper the score should be and the greater the pressure needed to bend and run the score. This method does require having a few inches of material on either side of the scored line to press on. You can also carefully run the score with a pair of pliers but you'll likely end up with a lot of sanding or filing to clean up the cut line. Note: Lexan is not acylic plastic but polycarbonate plastic......which is a whole different animal. You are better off IMHO cutting this with a saw. You can score it, but you'll need to cut almost clear through before it will snap cleanly.Lexan has much better resistance to cracking than acrylic plastic which is a nice feature for boat stuff. It also doesn't yellow as quickly. As for the scratching problem, you can now get " AR "
grade plastics which are abrasion resistant.
A lot more cash up front but they really stay
clean looking for much longer.