TOPIC: Acrylic vs. Polycarb windshield replacements

This summer I have been asked on a number of occasions to help fellow boaters in our local boat club to replace their damaged acrylic and polycarbonate windshields/windows. Many of my friends really want to tackle a project like this on their own, but don't have the tools or the knowledge to do it properly.

Over the next few weeks, I will post tid bits of knowledge I have collected over the past several years as a manufacturer of replacement boat windshields that you can use to properly remake a windshield if needed. And if you get stuck, just message me and I will help walk you through any sticky points.

Topic #1 - Acrylic or Polycarbonate

Short Answer - 90% of the time the plastic windows and windshields you have on your boat are going to be ACRYLIC (Plexiglass).

WHY ACRYLIC?
Manufacturers choose to use acrylic for boat windows primarily for its superior clarity and UV stability. Modern acrylics have incredible outdoor life expectancy and can commonly last for decades. Polycarbonate on the other hand is a UV sponge that soaks in as many damaging UV rays as it possibly can, preventing 99.3% of them from passing through. This sponge effect also heavily (and quickly) degrades the plastic causing yellowing many people often comment about.

Aside from great UV stability, acrylic is far easier to heat form and can also be buffed back to glory if you ever get scratches on it.

Polycarbonate often gets bubbles inside the material if you heat form it because ambient moisture in the air is absorbed into the sheet and vaporizes when heating (you can anneal the sheets at 180 for 12 to 18 hours to get rid of the moisture though and that will reduce or eliminate the bubbles when forming).

Polycarbonate scratches incredibly easily and CAN NOT be buffed back to original luster. The more you buff it the more it scratches.

WHEN SHOULD YOU USE POLYCARBONATE?
1) In situations where you need enhanced impact resistance (i.e. ocean going vessels that may experience heavy storm or sea battering) and high speed racing boats where vibration can cause cracking in acrylic...most of us Fiberglassics don't have to worry about that.
If you are using polycarbonate to replace flat windows on your boats cabin WE HIGHLY RECOMMEND using AR-2 or MR-10 Polycarbonate. These designations refer to a UV and Mar-resistant coating that is added to the sheet which will elongate it's lifespan and prevent most scratches. It costs more, but is a far superior product.

2) When heat forming a sheet is not an option due to lack of equipment. If you totally lack the proper equipment to heat form an acrylic windshield you can often use 1/8" thick polycarbonate as a short term alternative to replace a curved windshield. There are limitations as to how great a radius you can create, but it does bend with pressure to most of the common radii we see on 50's, 60's and 70's glassics. USE EXTREME CAUTION when "cold forming" polycarbonate because as you bend it you are creating kinetic tension that can explode out the moment you let go...or the moment it pops out of your aluminum track.

If you have any questions about your particular situation please let me know.

Attached photos are all acrylic windshield replacements, so show how they look when properly formed.

Next post will be about heating equipment.

WOW !
Great info. I'll be watching this thread !
Thanks, so much ! I was going to make my flat pieces out of polycarbonate.
I'm sure you will get tons of questions ?
Like:
If I cut the acrylic with a jigsaw. Do you, sand the edge to get rid of the rough whit edge ? or use a heat gun or torch to do it ?

I'm looking forward to learning more. The top 2 pictures are of the windshield that came with my 1960 G-3. I know it's not even close to original and there's no mounting hardware so starting from scratch is probably the way to go. I'd like to ask is there anything that will buff the windshield on the 1960 Humber without doing more harm than good ? Thanks in advance. Mark.

I'm interested in having you make some new windows for my boat; email sent!

a great thread. i don't think it has been discussed before. john gambil (jag) started a thread on restoring windshields back in 2006, and many here have followed his instructions. ron

Yes I'm looking forward to it. I live to learn. My Wife calls me an infomaniac lol. Making my own plastics would sure give me an edge in interior finishing. I can think of lots of things to mold for both my boats. Course, the Humber already has cup holders, ashtrays, and lighters for all occupants. When I'm done gutting the G-3 I'm thinking of opening up the rear section like Savage did with his and I could make some stuff before I glass everything back together so it would be integral. Maybe a "wet" bar ? (pun intended)

Typically when I cut acrylic with a jig saw I make sure to leave plenty of extra room between my finish point and where I am cutting. Jig saws are notorious for causing hairline fractures that can splinter several inches into the sheet. After jig sawing I will use a table router and hand route close to the finish point then use a belt sander to finish it off to size. It's a long process but saves the acrylic.

A better option for flat pieces is to create a template that is at least 1/4" thick and use double stick tape to adhere it to a blank slightly oversized. Then use your table router to route off the excess. Leaves you with a nice clean finish on the edge and virtually no defects.

Using a torch on edges will only make what ever finish you have shinier. It won't eliminate the white you see in a lot of extruded acrylics after jig saw cutting or saw cutting it. To get rid of that sand the edge using an orbital sander and 320 grit paper. After you smooth it out with that you can flame polish the edge and it will look amazing.

ON those top two pics you are 100% correct that the 1960 G3 did NOT come with those. They are definitely remakes and not accurate to the original make.

On your Humber, if it has an acrylic windshield you can try using a 3 series product called Novus. Novus 3 is a heavy buffing compound that you use to get rid of the oxidation (I use it on an orbital buffer at 1000 rpm or less until is dries and then move to another area and apply more). Buff or wipe off the Novus 3 with a microfiber cloth and repeat the process with Novus 2 (a finer scratch remover). After using both of those products you can use Novus 1 or Brillianize to do a final cleaning. Both Novus and Brillianize should be available online or at your local plastics store. I get mine through a company in Placerville, CA that caters to fabricators. Not sure if I can mention their name in the forum, so I won't.

If these products don't work, I have another trick up my sleeve but the compound is about $30 and the technique is a bit more complicated.

Beautiful ! Thanks for the tip. I knew from looking at Member's boats that my piece of Lexan was a million leagues from factory. I might yet use it if I can trim it up with a little more shape to it. The jigsaw tip will be applied to that one and I'll have to try and find those products for the Humber. Much appreciation !

Great info!

I was wondering if you might know a source for the corner brackets on the trailing edges.
My windshield is in great shape but the brackets are cracked.

Thanks,
Chris

Brett-ThePlasticsGuy knows his stuff. I have seen a couple of the windshields he has done and they are nice. We have even talked about taking on my Aristocraft bubble of trouble later in the year.

I thought your windshield was glass like my Avalon. Have you seen a G3 windshield made by these folks? I think they may have been on the BDLC to Stockton, not sure. I will be needing a complete windshield for the G3 and also a new one for the Redfish.

Nope, my windshield is plexi. Yes, they did make a G3 windhsield for a customer, although, I don't know if they made Kent's windshield.

Any advice on trying to form a Funliner windshield? Been trying to find a replacement without and luck, at least not another one that's also not cracked

Out here in California I usually try and call shops that work on vintage boats to locate brackets and hardware. They run into this situation more commonly and sometimes have stock on them.

I have absolutely no affiliation with these shops, but I know that many of my customers use Sierra Boat Works in Lake Tahoe and Vintage Boat Works in Bakersfield for restoration work.

Sadly, most of the time that I have needed to replace brackets and hardware we have had to pull them off of other boats that were in poor condition and have them re-plated. Makes it tough on whomever will be buying and restoring the boat we stripped them from, so I am not a huge proponent of doing that.

mvislander01 wrote:

Great info!

I was wondering if you might know a source for the corner brackets on the trailing edges.
My windshield is in great shape but the brackets are cracked.

Thanks,
Chris

I may be wrong, but I believe some manufacturers offered the glass windshield as an upgrade. I don't see many models with glass from that era, but every once in a while come across them. The Aristocrat Damartinca is referencing has a VERY unique windshield that I have only seen in acrylic. Someone chuckled when they designed it, imagining how tough it would be to ever replace.

G3 windshields are fairly straightforward if you have the trim and plex still. Nice almost low profile look to them. Similarly, the Redfish has a basic 18" or so tall curved windshield that screws into place with aluminum trim. When I make my post about heat forming techniques I will give you some tips on how to approach it if you want to do it on your own.

16Again wrote:

I thought your windshield was glass like my Avalon. Have you seen a G3 windshield made by these folks? I think they may have been on the BDLC to Stockton, not sure. I will be needing a complete windshield for the G3 and also a new one for the Redfish.

I did make Kent's Glastron windshield also. He wanted to modify it though after I formed it to make it more low profile. So he routed off about 2" from the height and adjusted the top trim piece accordingly. He was having trouble with line of sight anytime there was bow rise at lower speeds so he wanted to drop it just a bit.

I will try and get him to post some pics of it. He did a great job and the process he used might be helpful to others trying to do the same thing.

damartinca wrote:

Nope, my windshield is plexi. Yes, they did make a G3 windhsield for a customer, although, I don't know if they made Kent's windshield.

If you have the model year of Funliner I'm guessing you have, the windshields are torture to form. The wrap around contour needs to be molded with a two sided mold (male/female) and the acrylic needs to be heated entirely in a large oven. You can't use a heat gun because the entire sheet needs to be evenly heated so it forms like putty.

damartinca and I are going to attempt his Aristocrat that is very similar if not identical to yours. If you aren't in a rush I can give your our feedback later this fall when we are done.

NJTriton wrote:

Any advice on trying to form a Funliner windshield? Been trying to find a replacement without and luck, at least not another one that's also not cracked

I believe the Funliner windshields are the same from 59 to 64.

I'm trying to think of a way to make two for my 1960 G-3, one for the driver and one for the passenger. Low profile with a racy look of course I can't afford to restore it to original so that gives me license to tweek it a little. Mounting hardware can be a nightmare though. That's next years boat so I'm just dreaming.

Hi Bret, welcome to FG. Super nice folks here; you will enjoy this site.

Kent shot me some pictures of his windshield after he had modified it a couple of weeks ago. Here is a picture when we were at Alamar Marina and restaurant this past Sunday. There were several of us that went out for brunch. More pics posted on the GSG on Facebook.

For the record, Bret, The Plastics Guy, has done several of our friends and Golden State Members' windshield, including this one. Quality work, a gentleman, and family man. For us local and nearby glassic members, we are lucky to have someone like Bret nearby for any windshield replacement work.

Brent made this windshield for my friend Kent on his '74 Glastron CV16


Eduardo

That's sure pretty ! I used to have a metalflake blue Glastron-Carlson CVX18 and always loved that bow point. For those of us at a distance I'm glad Bret is willing to take the time to tutor as well as create some nice windshields for those who are close enough ! If he does mail order I may just get on board and let a master do it right.

Bret:

Welcome to the website Sir! It is good to finally see someone on here that may be able to help us with our G-3 windshields.

FWIW, I have a one-family owned 1960 G-3 with the original windshield, however, it does have a couple of small cracks at the bottom. I was wondering if you have ever made a replacement windshield for a 1960 G-3 and if so, do you have any pictures of it?
Also, if you have never done one, would you need an original G-3
windshield as a "template" to get the dimensions exactly right?
Lastly, could you give us an idea of what it would cost to make one?

We have several G-3 owners in our ECGOA Glasspar Group that would be interested in getting you to help us if possible.

Thank you Sir.

Firstglassproject wrote:

I'm trying to think of a way to make two for my 1960 G-3, one for the driver and one for the passenger. Low profile with a racy look of course I can't afford to restore it to original so that gives me license to tweek it a little. Mounting hardware can be a nightmare though. That's next years boat so I'm just dreaming.

I think the easiest and cheapest way to remake a windshield for the 1960 G3 would be to use a strip heater and do 90 degree bends on triangular shaped corners (See attached sketch). It is by no means true to the original, but can easily be done by anyone with fairly minimal experience.

I am in the process of writing a post on plastic heating and forming equipment that will give you some technique you can use to make this on your own.

Once formed you can use basic mounting hardware and a bottom vinyl trim that are available on www.go2marine.com . Check out my post early next week that will walk you through heat strip forming.

Kent takes really great care of his Glastron. It was an honor working on it for him. Thank you Eduardo for posting that great pic.

FirstGlassProject - I am more than happy to help out anyone from anywhere even if it requires shipping. We have made windshields for boats in several different states and are grateful to help restore these amazing pieces of American history wherever they come from.

Firstglassproject wrote:

That's sure pretty ! I used to have a metalflake blue Glastron-Carlson CVX18 and always loved that bow point. For those of us at a distance I'm glad Bret is willing to take the time to tutor as well as create some nice windshields for those who are close enough ! If he does mail order I may just get on board and let a master do it right.

I'm going to be reading that but as I said, original is beyond my budget. Once I've learned enough I'm going to try for dual windshields. It's going to be fast, fun, and a little different from the rest. Not that there are a lot out there

Brett:

I got your e-mail today and wanted to thank you for reply!
I sent you a reply back with some questions.

Hi! I was directed to you on my thread of how to restore a hazy tinted windshield on my 1971 Centurian. I really think I would prefer to try and clear it up before replacing it.
Thanks for any helpful hints!

That's a beautiful interior by the way

Thank you very much! We love it! One of a kind!

themadhoofer wrote:

Hi! I was directed to you on my thread of how to restore a hazy tinted windshield on my 1971 Centurian. I really think I would prefer to try and clear it up before replacing it.
Thanks for any helpful hints!

WOW!!!!! That is a beautiful boat. I replaced a windshield on an 80's model Centurian a few weeks back and it had almost the exact same metal framework as yours. I love how they built those because they are incredibly sturdy and easy to disassemble if you need to.

In regards to the haziness. The first step is to determine what has caused the haziness. Surface haze is usually caused by weathering and oxidation, or scratches from improper cleaning. This is the EASY kind of haziness to get rid of.

WARNING!!! DO NOT USE ANY OF THESE PRODUCTS ON POLYCARBONATE WINDSHIELDS OR PLASTIC THAT HAS AN ABRASION RESISTANT COATING. THEY WILL STRIP THE COATING OFF AND DAMAGE POLYCARBONATE.

Using an orbital buffer (or microfiber cloth if you don't have a buffer) apply Novus 3 onto the windshield. Buff it on no faster than 1000 rpm in a smooth fashion almost like you are waxing a car. Work in small areas at first to see how well it is working and then move on. After the Novus 3 dries you can wipe or buff it off with a clean microfiber cloth. Repeat this same process using Novus 2 (a finer grit). Once the Novus dries, wipe it off with a microfiber cloth and inspect for any trouble spots that need closer attention. Hit those spots again with just the Novus 2 applying pressure as needed.

Once you are confident that the haze and scratches are minimal, I suggest cleaning the entire windshield with Brillianize. It's a great daily use Acrylic cleaner that won't harm the plastic and keeps it looking shiny.

If the scratches are too deep for this process to get out, there is a product called Miracle Cut 1000 sold by Hurliman's Own in Penryn, Ca that can take out scratches up to 1200 grit sand paper. So I will literally wet sand the scratches out using 1200 grit and then 2000 grit sand paper, then buff the area with my orbital buffer using Miracle Cut 1000. THIS PRODUCT ALSO WORKS GREAT ON GEL COAT RESTORATIONS.

So that is the easy happy kind of haziness...the not so happy easy kind of haziness is called CRAZING. Crazing is actually inside the plastic and not on the surface. It is caused by chemicals like ammonia (found in Windex) and can also be cause by alcohol on Flame polished edges. Decades of sun exposure can also cause crazing, but your boat looks like it has been kept inside or covered, so I doubt that is the case.

HI-
Met you at the BDLR to Stockton and didn't realize you were the windshield guy. Have you produced an actual G3 duplicate windshield?
Thanks
Jack

Bret,
Sorry I'm late this. Welcome aboard, glad you joined us and thank you for bringing your expertise to the group, we're all learning a lot!

Bob

HI Jack,

I have not had the privilege of making a '60 G3 windshield yet, but would be glad to. Compared to many of the windshields I have made it's actually rather straightforward.

Since there are so many folks on here trying to get replica's of that model windshield I'd probably ought to get to work on making a mold up for one of them, but need to find someone who has an original in decent enough shape that we can clone it.

Do you know of anyone in California, Oregon, Nevada or Arizona who might have one we could nab and use?

Brett

16Again wrote:

HI-
Met you at the BDLR to Stockton and didn't realize you were the windshield guy. Have you produced an actual G3 duplicate windshield?
Thanks
Jack

Not for sure but asked the guy who is thinning his fleet of G3's in Seattle last night if he had one, haven't heard back yet. Will keep you posted. I will also reach out to other owners.

Thanks
Jack

Jerry got back with me and he doesn't have one, only the frame no other hardware.

If I had a frame and a boat I could likely make the mold and pull a good part. I am sure we will come across one soon enough. I will keep my eyes peeled.

I am also looking for a 1957 Redfin Shark that has a usable windshield if anyone knows of someone who has one. It's for a restoration project in Albany Oregon.

16Again wrote:

Jerry got back with me and he doesn't have one, only the frame no other hardware.

I don't have a 57 although it was sold to me as such but I do have a 60 that is complete and you are welcome to use it to splash whatever you need. Boat trailers well as it came all the way from Nebraska. I'm sure we can work out something and I can deliver the boat to you. How long do you think you will need it, not that I'm ready to begin the restoration just curious.

Jack

If you start making them for G-3's can you give me a price on one ? I have a 60 and if it's within my budget to go original I would. Thanks Brett. Mark.

I posted and it vanished so I'll post again.

I was looking forward to this one. But it seems to have died. I hope it can continue.