Plexi-windshield
 

I'm getting ready to shape a new plexi-glass windshield for my 20CC's giant console. Does anyone have any tips to offer before I ruin a perfectly good piece of plexi-glass. Thanks in advance.

Re: Plexi-windshield
 

Get a pro to do it? That's the way I'm going.

Re: Plexi-windshield
 

Make a cardboard template to size then cut your plastic.
Mark with chalk where you want the wrap around.
You need a real good heat gun, not a cheapie.
Go to Grainger to get one of the better ones.
Work the heat back and forth not to long in one place or it will distort the plastic. work both sides of the plastic equally. It will slowly give way and you will be able to
shape it. After you have it fit with at least a 1/4 gap
on the sides and front which allows you to put rubber grommets between the console and plastic. To get the edges
of the plastic smooth wet sand the edge to a nice finish.
Now take a propane torch and lighty go around the edge to smooth out completely. Practice on some scrap first. It is really not hard to do.
See ya, Ken

Re: Plexi-windshield
 

Ken,
Your description makes me want to try it myself as well. Do you need to account for any loss on the corners? If you plan 1/4 seperation and then bend do you loose some? Also do you use someting for a "brake" of sorts? Thanks

Re: Plexi-windshield
 

While your plastic is in the workable stage you have about
30 seconds before it starts to form, just reheat the area again before it sets. In this time frame the reheat only takes a minute to make the plastic workable again.
Do 1 side first, that will help you on the other side for the 1/4 inch gap. When you are heating the plastic making the 90 degree bend a wood saw horse works fine.
See ya, Ken

Re: Plexi-windshield
 

One thing for sure I don’t have the technique down. I did a web search about 3 weeks ago and learned all about it so I could do a small job with 90 degree angles on a 12” piece of lexan (much stronger and will not break) they said I could put it in the oven, well I could not bend it fast enough at first so I had to put it back in again and then it bubbled up I ended up throwing it away. Now I am considering Plan B. If you do it your self I would buy extra same thickness pieces and practice on them before I tried on your window shield. For me I would pay for someone who does it for a living from now on between buying the material + heat gun + the high degree of MY possibility of screwing up. It probably would be cheaper to get a pro to do it for me. But if you try yourself Lexan is the best material.

FellowShip

_______________________________________________

My motto: Just for the Grins :D

Re: Plexi-windshield
 

Thanks for all the advice. Probably the best being get pro to do it, but of course that would be too easy. The windshield is only going to be around 12" tall so I may be able to pull it off. I'm planning on trying a piece of plexi first since I can get it cheap and if that works out give Lexan a shot.
Ken those are some good points, especially the sanding portion.
Thanks again.

Re: Plexi-windshield
 

Ha Beau

I looked on E Bay and you can find stock there pretty cheep. My bet it is scrap from commercial businesses. I also saw heat guns there as well.

FellowShip

_______________________________________________

My motto: Just for the Grins :D

Re: Plexi-windshield
 

As far as scrap goes, check with your local sign manufactures.
They usually have piles of the stuff and are happy to get rid of it.
See ya, Ken

Re: Plexi-windshield
 

I clamped my plexiglass to a piece of plywood (to insulate the middle part) and used my gas BBQ grill to heat the corner to make the bend. Used rubber grommets and wetsanded the edges. It is not perfect...but for $35 you would never know I did it myself.

Re: Plexi-windshield
 

i made the windshield for my 17 Mitchell with no problem, I got the plexi from the local glass shop, cut about a third over size. I left the paper backing on the plexi and made some reference lines to measure from. I used two 2X4's in a vise as a break. Using the reference line as a mark( i left a couple inches extra on the end), I clamped the plexi between them and heated the plexi with a heat gun I bought from Lowes for about $20. When the plexi became pliable, i bent it 90 degrees to form one side. Using the refernce line, I could tell how much I lost width when I bent the radius. Using that information I layed out the mark for the other side and bent it. After it was formed, I drew the cut marks on the paper for final trimming with my jig saw. I cleaned up the edge as mentioned above. I made the windshield a little oversize to allow for rubber spacers, I made the spacers by cutiing thin slices of 1/4 marine fuel hose. Pratice on a few scrap pieces before you try the big stuff.

Re: Plexi-windshield
 

Boy you guys are inspiring me to try again.

FellowShip

_______________________________________________

My motto: Just for the Grins :D

Re: Plexi-windshield
 

Dito! Does anyone have any pix? I am dreaming up a jig to give it a shot :D

Re: Plexi-windshield
 

no much to look at as far as a jig or fixture, just two 2X4's clamped together. I fanned the heat gun only on the area that I wanted to bend using presure from my free hand, when it started to move I pulled the heat away and bent the plexi with both hands, didn't take much pressure. I used a quick square to check and adjust the angle. Try on a few scrap pieces before you use the big piece

Re: Plexi-windshield
 

I dropped the 1970 bowrider off at norva plastics here locally lastweek. I am doing away with the metal framework around the windshield and going with 1/2" plexi that is going to 24" high versus the factory 19" high so when I get the bimini and curtains made next month it won't feel too cramped for a normal sized person.

the price quote for fab and material was $700-$800

Re: Plexi-windshield
 

I rest my case , you can get a truck load of scrap for $700
I would experiment on my own before spending that kind of money. I'm by no means cheap, just like doing things myself.
Ken

Re: Plexi-windshield
 

Plexi seems to get exponentially harder to bend as thickness increases, especially over 1/4". .... That may be a part of why the estimate was soooooo high....

Acrylics in general are not very thermally conductive, which makes it difficult to heat the entire thickness enough to bend it smoothly, without getting the surface regions too hot and causing bubbles from outgassing.

Bending full thickness 1/2" sheet properly, takes some high dollar equipment.

I'd be looking at something in nominally 3/8" polycarbonate for the best in strength, toughness, and formability.


Darlene

Re: Plexi-windshield
 

I have a tined windshield on my 20 that I can't see out of very well with dark glasses, plus has a crack. Could I use the old one as a template for the bends ? or would that throw the sizing off too much?

Re: Plexi-windshield
 

Gigalot

That price quote is was over the top. I had my windshield replaced by a decent plexi shot in Ma. for $200. It was 3/8" which is plenty thick enough and he used my old one as a template. I would think you could do the same in VA.
Dink

Re: Plexi-windshield
 

You guys got me So re inspired to try again. I went to Lows and bought me a brand spanken new $39.95 heat gun. With adjustable temperatures set up them there Braces just like you guys said and pulled out a new piece of Lexan and Wambo success no bubbles or anything. I maid my two 90 degree bends and now got my little project done. You guys got me so inspired and pumped I’m think I might even venture out and do a new window shield after all now that I am a “PRO” and got my NEW Gun I’m looking around to see what else I can bend. Shoot after I do a window shield I might try a glass bottom boat.

Thanks Guys.


FellowShip
__________________________________________________ ________
Just for the Grins :D :D :D

Re: Plexi-windshield
 

Fellowship,
Sweet :cool:
Was it 1/4" or 3/8" ?
Not only does the local glass shop not bend it they dont stock it...into the big city I go! Now I just got to find my heat gun :D

Re: Plexi-windshield
 

Don't take it in the shower with ya :eek:

Re: Plexi-windshield
 

Ha Hermit

The stock I was using was 3/16” this was a small job 12” L x 5” W with two 90 degree bends to protect my switches and fuses from salt water spray. I will look for ¼” lexan to do my window shield. If you use Plexiglas 3/8” would be the smallest diameter I would use. The original Plexiglas window shield on my 23 CC was ½” thick and I know I could not work with something that thick with not messing it up.


FellowShip
__________________________________________________ ________
Just for the Grins :D

Re: Plexi-windshield
 

On the thicker plexi I was told to use a router to thin the plexi where you want the bend (inside bend) and the thicker pexi can then be bent much easier.

JW

Re: Plexi-windshield
 

Well since the wind was blowing 30 MPR of Saturday. I decided that it would be a good day to work on the boat. SOOOO I bought me some polycarbonate ¼” thick supposedly 250 times more shock resistant that glass. Then took my new fangled heat gun and presto changeo I bent me up a new CC window shield Just like a Pro. Boy what a difference from my first attempts a few weeks ago with out the heat guy. I even cut two new sliding doors for my instrument box with new tracks. Thanks guys for some of your comments on this thread that make me re think how to work with this stuff.

FellowShip

_______________________________________________

My motto: Just for the Grins :D :D

Re: Plexi-windshield
 

OK Finally finished my console work and had the $70.00 piece of 1/4" acrylic delivered (5’x18”). After a week of letting it sit in the kitchen I bent it up and turned it into a SeaCraft windshield :cool:. It came out great! Used the heat gun and the-two board clamp method (one with ¼ roundover). Also used a little bit of emery cloth to clean up the cut edges. Anyone have an edge treatment for the plexi?

Re: Plexi-windshield
 

way back in middle school shop class i worked with plexi. made many thigs for my dad's boat. you can get a great finish on the cut edges by: 1) file the edges to knock down the real rough stuff 2) wet sand with 3 different grits of wetsand paper<been along time forgot the grits but corse - then a finer - then real fine> 3) get out the drill with a white buffing pad, apply some wax and buff. I am not sure what the correct name for the buffing wheel is but i am sure you have seen one. they are usually on the other side of a bench mount grinding wheel. I say use a drill because it is eaiser to move the drill around then hold the windshield up to a bench buffer. Again not sure on the wax but it is a hard stick you apply to the buffing pad while it is turnig. If you get the edges very smooth with the file and wetsanding it will look cherry.

Re: Plexi-windshield
 

When I have used Plexi before, I would trim it with a router round-over bit and then take a propane torch w/ flame spreader and put the least amount of heat to it. (A heat gun might be better, but I have never used one.) It would smooth out the cut marks left by the router bit. Don't heat it too much or bubbles and distortion start.

I suggest some practice on some scrap first to get the 'feel' of it! ;) ;) ;)