Windshield and side window material

[BabuBoat]

I'm in the process of removing leaky, crazed, hideous looking windshield and side windows on my 1993 Hunter 42 CC Passage. Identifying the material is difficult. Searching through these resources I see polycarbonate and acrylic sometimes used synonymously. Given the stresses and thickness of the windshield (13mm thick), I'm guessing it's a polycarbonate material.

From my reading so far, Polycarbonate is not tolerant of UV (which probably explains their condition!), however it is stronger than Acrylic of the same thickness.

Questions:
1. What is the material that Hunter used?
2. Can an Acrylic be used on the windshield (perhaps 16mm thick for added strength?)? Concern is that, as the mast is close by, this will undoubtedly be stepped upon, either intentionally or otherwise.
3. Can Acrylic be tinted?
4. I have Dowsil 795, Permatex 81173 black, and 3M 4000 UV sealants. Can I use these on Acrylic, or Polycarbonate?

Thank you all for any help.

 

[Ralph Johnstone]

Searching through these resources I see polycarbonate and acrylic sometimes used synonymously.

Used by people without a clue.

Given the stresses and thickness of the windshield (13mm thick), I'm guessing it's a polycarbonate material.

You've guessed wrong. Carbonate shows UV damage and scratches far earlier than acrylic. It's also 30% more than acrylic. As far as strength goes, just WHAT are you planning to drop on your hatches and ports ?

1. What is the material that Hunter used?

Acrylic.

2. Can an Acrylic be used on the windshield (perhaps 16mm thick for added strength?)? Concern is that, as the mast is close by, this will undoubtedly be stepped upon, either intentionally or otherwise.

Acrylic is strong but MAY not handle the load over overweight people. Keep idiots like this off your boat. I doesn't stop every other boat manufacturer from using acrylic.

3. Can Acrylic be tinted?

It comes tinted. You can't add tinting.

4. I have Dowsil 795, Permatex 81173 black, and 3M 4000 UV sealants.

Nope, nope, and nope. Use sealant/adhesive Hunter used, Dow Corning 795.

 

[Crazy Dave Condon]

Former Hunter dealer. Dow 795 is correct sealant.

@Ralph Johnstone is correct. Call the forum store as they have the build list for your boat. Owner of sailboatowners/hunterowners is now owned by a former Hunter employee and staffed with other hunter employees

 

[BabuBoat]

Thank you both!

I contacted the forum store and they do not have the windshield for sale. Unfortunately, "the original manufacture of that part was sold and the company that purchased them either lost or discarded the bending mold."

Will try to get one fabricated by a plastics manufacturer. If that fails, then perhaps polishing what I have and re-bedding is the only other option?

 

[Ralph Johnstone]

If that fails, then perhaps polishing what I have and re-bedding is the only other option?

Sorry to hear about doing all that work and being no better than when you started. You cannot polish out the cracks and fog as they are right through the acrylic.

You will have to carefully remove the existing ports and hatches and take them to a plastic supplier/fabricator to use as templates. Search the archives to see how to remove the acrylic in one piece. Or, if they won't come out, you may be able to trace out a pattern with translucent paper.

 

[BabuBoat]

You will have to carefully remove the existing ports and hatches and take them to a plastic supplier/fabricator to use as a template.

Ralph, managed to remove the windshield without damage. If anyone out there has already gone this route, please share the vendor info.

 

[BabuBoat]

I put a bunch of photos in an album, but don't know how to link it from here.

So here are two photos.

The leak was happening just to port of the top centerline.

Seems a strange place (structurally) to put such a large opening, given proximity of the mast.

 

[Ralph Johnstone]

Seems a strange place (structurally) to put such a large opening, given proximity of the mast.

All mfg. put them in the same place. For the sake of appearance .

 

[Ralph Johnstone]

I put a bunch of photos in an album, but don't know how to link it from here.

It doesn't look as if a folder of files can be uploaded to this site in one fell swoop. Doing photos one at a time is not too bad. If they number in the hundreds, you could upload them to something like dropbox and provide an address. This is something I would be interested in seeing if you can spare the time to post.

 

[BabuBoat]

It doesn't look as if a folder of files can be uploaded to this site in one fell swoop. Doing photos one at a time is not too bad. If they number in the hundreds, you could upload them to something like dropbox and provide an address. This is something I would be interested in seeing if you can spare the time to post.

Please try this: Babu Windshield

 

[Ralph Johnstone]

Thanks very much for posting that. You learn something new every day around here. Those photos are now in my archives.

I notice you're tearing right into this and obviously experienced in this kind of work. Any chance you have a hobby woodworking shop ? If so, acrylic is a breeze to work with and using a template bit on removed glass will give you a +/- 0.001" fit as fast as you can run the router and at a fraction of supplied lenses. Well, maybe a little slower. I've already renewed three opening hatch lenses (they were almost opaque) and still making preparations to replace two portlights. Amazingly, the front portlight which you're replacing, still looks like brand new after 24 years. No idea how.

When you're finished, do this and they'll last forever. Wish I'd thought of this when I bought the boat new :

 

[BabuBoat]

I notice you're tearing right into this and obviously experienced in this kind of work.

Not at all experienced. More bold than I should be. But with thin resources, I am seeking the advice of those who made, or avoided, the mistakes.

Any chance you have a hobby woodworking shop ?

No. But I do have tools, and some experience in their safe use.

Yes, I am told that a router is my friend in this stuff. However I am not certain it will help with the upper lip of the windshield where it mates to the window frame. There's a 15-20 degree slope here, which extends about 40mm. So I'm trying to find a plastic fabricator who can do the job.

Agreed on the covers. That's next

/m

 

[Ralph Johnstone]

No. But I do have tools, and some experience in their safe use.

Safety be buggered. Had to deal with government safety thugs all my working life. Now I like to cut it as close as I want.

However I am not certain it will help with the upper lip of the windshield where it mates to the window frame.

Can't see how that fits together. A pic might help if you could show how it comes together.

I should have mentioned before if you can pick up a used router, you'll save a fortune if you cut all your windows from stock material rather that going to a fabricator.

All except that front hatchlight. It's just got to be heat formed in order to fit the curvature of the cabin. Maybe even if you could cut it to size and only get it heat formed by a fabricator might save some $$$.

PM me if you need tips on cutting new acrylic windows from an existing pattern of an old window.

 

[Paul Cossman]

Hi Mark, I've been through the job with the windshield a few times myself. I actually bought a new one in 1998 or so, and Hunter put me in touch with the outfit that contracted to manufacture them for Hunter. I've searched, but have no info on the outfit that did it. It cost me about $2K in 1998 dollars, and it had to be shipped on an 18 wheeler from FLA to CA for me.

Since then I have removed and rebedded the windshield a couple of times. It looks to me from your photos that the windshield is still intact and not broken. You might want to just rebed it and put it at the bottom of your to-do list.

For rebedding the thing what you want is the black Dow Corning 795 sealant. It is now called Dowsil 795, and is the same stuff. You'll need about a case (12 cartridges) to do the whole windshield. It cures with moisture, and takes about a week to fully cure. HOWEVER, if you apply it in sunlight it will go off on you and skin over very rapidly (30 minutes or less), and not give you enough time to work it onto the windshield (or as I do it, work it onto the fiberglass of the boat). So be very careful about doing it on a cool day and out of the direct sunlight. That way you get between 40-50 minutes to work it and set the windshield in place before it skins over too heavily.

I have also rebedded my side windows (ports) several times over the decades. Be careful removing the acrylic (Plexiglas) or it will crack. Thirty year old acrylic is very brittle. But if you can get it off without damaging it, you can then clean the acrylic and the hull and rebed it with Dow 795. Works great. Right now I'm in the middle of dealing with having cracked one of the ports while removing it. Here in NZ it ain't easy to find the correct thickness of acrylic for a replacement, much less getting it machined properly. But it ought to be much easier for you in the States. I finally found an outfit here that will copy my port-side aft acrylic tinted window (the one over the chart table) for $120 NZD (or about $70 USD). I'm happy with that, especially since I don't have the skill to do the bevel and chamfer over a 20 mm length around the acrylic. If it works out like I hope, I'll probably replace all of them (since they're so crazed I cannot see out of them anymore). But bear in mind the crazing is just surface crazing, and doesn't really compromise the strength of the port. They're plenty strong. I'm told by the plastics experts that the surface crazing is more a function of solvent damage to the surface than it is any kind of sun or UV damage. (I know nothing of such things, and just listen to the experts).

Bueno suerte!!

Paul