source for fixed port polycarbonate?

[bugbitten]

I'd like to start gathering materials to replace the fixed ports on my 9.2A. Has anyone come across a good source for the plastic? My understanding is that they are 3/16" Lexan, or polycarbonate, more generically. When searching for that, I come across acrylic, too. Is that synonymous? I'd also like to duplicate the original tint.

Here's an Amazon listing that looks about right:
http://www.amazon.com/Cast-Acrylic-...437&sr=1-3&keywords=polycarbonate+sheet+clear

Seems pricey until you factor in shipping from other sources.

Anyone know of a source in the Hampton Roads, Virginia, area? Either for the raw materials or to do the whole job?

I've read the threads about temperature, cleanliness, roughing-up the edges of the plastic, using the original Dow Corning type sealant, etc. I also have "the letter" on hand for S2's instructions. Seems a daunting task!

John

 

[jluke]

port

I'd like to start gathering materials to replace the fixed ports on my 9.2A. Has anyone come across a good source for the plastic? My understanding is that they are 3/16" Lexan, or polycarbonate, more generically. When searching for that, I come across acrylic, too. Is that synonymous? I'd also like to duplicate the original tint.

Here's an Amazon listing that looks about right:
http://www.amazon.com/Cast-Acrylic-...437&sr=1-3&keywords=polycarbonate+sheet+clear

Seems pricey until you factor in shipping from other sources.

Anyone know of a source in the Hampton Roads, Virginia, area? Either for the raw materials or to do the whole job?

I've read the threads about temperature, cleanliness, roughing-up the edges of the plastic, using the original Dow Corning type sealant, etc. I also have "the letter" on hand for S2's instructions. Seems a daunting task!

John

I went to my local glass shop, they cut one for me in tinted lexan for $40. 10" X 36".

 

[Forrest15112]

I agree with Jluke. I'm about to replace all of the ports on my 23.5 and have contacted a local glass shop. They will cut it for me or sell me bulk pieces that I would cut. I will probably make some paper patterns of the ports and have them cut it. They also make panels with UV protection. I haven't looked into it, and am not sure if it's a coating or a component of the plastic, but definitely something to consider.

 

[bugbitten]

Probably the thing to do is tackle the worst one first. Trace a template, have a shop cut it for me, and then try installing it myself. If it's too huge a headache, then maybe get a pro to install the rest. What thickness are you requesting? My understanding is that, if you go thicker than 3/16ths, you'll have a bear of a time getting the window to follow the proper curve. Or are your sections mostly flat?

John

 

[Bob McKee]

Fixed Port Installation

I installed my ports with stainless steel Phillips head bolts, dimpled washers with a neoprene sealing washer attached and T-nuts glued on the inside of the hull. Most of the interior wood was removed to access the window area, the wood pieces were screwed into place and are easy to remove. I used 1/8" butly window installation tape between the window and the hull, be sure to open the bolt holes in the tape before installing them so the bolts don't wind up the tape when you tighten. I used 3/16" thick Plexiglas and should have used 5/16" or 3/8" because the windows are starting to crack, thicker plastic would stand up better, I intend to increase the number of bolts on the long axis of the ports when I replace them again . The windows were cut to shape by Commercial Plastice in Seattle but the plastic is easy to cut with a router and tracing bit and that is what I would do now that I have learned how to do it. There should be a plastics retailer near you that can supply and advise the best plastic to use. I was told that Lexan is stronger but less resistant to sunlight. In my opinion, I wouldn't attempt the factory installation method. Bolts will hold, seal alone won't and I couldn't stand to deal with the mess.

 

[Forrest15112]

I've read that screwing it in place can cause cracking because the acrylic sheeting expands and contracts at a different rate than the deck. My ports were held in place with Dow-795 and the front piece which is curved some was anchored with a few screws. If you put any screws in, it's recommended to oversize the holes to allow some expansion.
My panels appear to be about 3/16's of an inch thick, and are beveled slightly on the side that the sealant attaches to. I will probably wait until Jan-Feb to replace mine because between now and then is the best weather around here.

 

[bugbitten]

Bob,

I've read your various posts about your bolted-down solution with interest. I'd also thought that slightly thicker Lexan would be the way to go, but others have said you'll find it very difficult to bent it to fit the cabin's curves. What do you think of that objection?

When I've seen some of your posts that have mentioned pics, I think they've been deleted. Have you got any, with or without cracks, to share?

Thanks.

John

 

[Bob McKee]

Port Polycarbonate Photo

This photo is in Boat Info - Owner Modifications
My success in posting photos is marginal, don't know if it is the site or my skills. Probably the latter.
I am going to replace some of the ports soon and will go to 5/16 or 3/8 Plexiglas. I used 5 bolts top and bottom and will add more to spread the loads better, I will report how many total when I am done. The bolt holes are oversize to 7/32 for 3/16 bolts to (hopefully) allow for some expansion/contraction due to heat and cold. I think that there is enough flexibility in the Plexiglas port and the fiberglass boat to allow the ports to seat.

 

[bugbitten]

Thanks, Bob. I did go to the knowledgebase and found your larger version. I hope you don't mind, but I'll add it below so folks won't have to search. Looks good, I have to say.

Here's the direct link to the knowledgebase piece:
http://sbo.sailboatowners.com/index.php?option=com_mtree&task=viewlink&link_id=7932&Itemid=257

John

 

[patrscoe]

Bob,
It looks like a few screws created a star-shape cracking. As I commented on previous posts, I like the concept using bolts, would make installing a little easier and a lot more secured. I have seen factory O'days windows installed this way.
I am still debating to install per factory or using bolts. It is my Fall project that I need to complete before I put her on the hard.

 

[Bob McKee]

Port Replacement

I removed the port in the photo yesterday, it was badly cracked. The surface under the port is nearly flat so compound contour isn't a problem. Commercial Plastics in Seattle is going to make a new port from bronze color, 3/8 Plexiglas, they will radius the edges and drill the holes with a smooth plastics drill. My original holes were 7/32", they advise drilling larger 1/4" holes. The old port was 1/4" thick, the new one will be 3/8". When I get the new port I will add four new holes top and bottom and maybe two new on each end.
The price is $54 + local sales tax and it will be done in a week. If this works well I will have the rest of them done.

 

[bugbitten]

Bob,

I think I'm going to try to piggyback on your order. I sent you an email. Any tips on sources for the glazer's tape? With that many bolts holding it in, I might be tempted to use the butyl tape I already have for bedding deck hardware. The nice thing about your solution is that it's not so tough to try different bedding solutions.

John

 

[jrowan]

I don't agree with using screws to secure the plexiglass material. We used screws to replace the ports on our O'Day 34 years ago, and they began to crack again, directly around the screw holes within a year's time. Remember that the hull & deck do flex somewhat when under heavy load while healing over, etc. I've worked extensively with plexiglass for art galleries making book and art mounts in college. It takes bending under heat well, but doesn't like to be drilled & screwed. It's too bad that all the production builders, other then Island Packet use weird trapezoid shapes that you can't replace with a standard size opening ports. Opening ports have good gasketing and generally last a lot longer.
I also think that glass ports, while they can leak around their older rubber gaskets, but hardly ever crack. I replaced our forward ports with Lewmar #2 Ocean Series and its great to get the improved ventilation as well as an improved look. But if you're replacing the ports because of cracking, the DONT USE SCREWS, or they'll just crack again.
If sealant held them in place for 30 years and remains flexible, then stick with it.

 

[BobM]

Hybrid

While the instructions in the 13 page letter just say to use a silicone sealant with tons of it gooping into the interior that needs a second person inside to control or clean up, I think I will go with a hybrid. When I do mine I will see if it makes sense to seat them on black butyl tape and with the butyl tape to keep the silicone out the cabin, complete the job with silicone so I can get the nice surface that it had from the factory. The only thing I don't know is compatability between butyl tape and silcone (can't remember the exact type they used but it is in the letter) but I will do a small experiment to check it before trying it.

 

[Bob McKee]

jrowan,
Are you talking about screws or bolts? I will be using 3/16" bolts with sealed washers through 1/4" holes to allow for expansion and contraction. I originally used 1/4" thick plexiglas and the ports lasted 10 years, I am going to replace them with 3/8" plexiglas and will increase the number of bolts to spread out the loads better. The intent is to not have the bolts touching the plexiglas.

 

[Lost Parent]

Windows

I don't agree with using screws to secure the plexiglass material. We used screws to replace the ports on our O'Day 34 years ago, and they began to crack again, directly around the screw holes within a year's time. Remember that the hull & deck do flex somewhat when under heavy load while healing over, etc. I've worked extensively with plexiglass for art galleries making book and art mounts in college. It takes bending under heat well, but doesn't like to be drilled & screwed. It's too bad that all the production builders, other then Island Packet use weird trapezoid shapes that you can't replace with a standard size opening ports. Opening ports have good gasketing and generally last a lot longer.
I also think that glass ports, while they can leak around their older rubber gaskets, but hardly ever crack. I replaced our forward ports with Lewmar #2 Ocean Series and its great to get the improved ventilation as well as an improved look. But if you're replacing the ports because of cracking, the DONT USE SCREWS, or they'll just crack again.
If sealant held them in place for 30 years and remains flexible, then stick with it.

I just did mine on my Catalina last week
Used Dow Corning 725 I believe and did a 1/16 in thick bead around opening as wide as window frame was and then a 1/8 bead in middle of this and then pressed window into place and held for 10 min and now they are in place and real hard to get off..I know as i put one on inside out and had to remove it and do over used masking tape on outside around the outside of the new window so it was easier to clean , on inside it did not gush out to bad so just let set up and then removed excess wth plastic scraper ...no screws and this was on a slightly curved cabin

 

[jrowan]

Glad to hear you did it right Lost parent. I've witnessed it not only with our boats, but also with friends who used screws to attach plexiglass panels for replacement ports and it never lasts very long before cracks develop.

 

[Lost Parent]

No screws , I am in the RV business and every few years a manufacture comes up with this NEW IDEA of useing acrylic and screwing them on bad news as they all crack and the warranty kills them until they get it right

 

[bugbitten]

Man, here I go again with the facilation. It certainly does seem that the preponderance of opinion is to do it the factory way. BobM's idea of a hybrid, using the butyl tape to seal and position the Lexan, while finishing up with the Dow Corning sealant (I think I have 795) to level off the exterior makes a lot of sense, if the gray tape doesn't show through. I'm not sure you'd get enough grip from the butyl, though, if you have to bend the panel any. My understanding is that the Dow Corning stuff is the same adhesive/sealant that's used to keep glass panels from falling out of skyscrapers, so it's pretty strong stuff, but it's not going to be doing much more than sealing if it's just spread along the outside joint.

And then again, if West Coast Bob's bolted panels lasted ten years in their original iteration, you'd think the newer, more robust version would hang in there quite a while. I do like solutions that I can do without an extra pair of hands and that I can undo fairly easily if I screw up.

John

 

[patrscoe]

Lost Parant,
Is the Dow 725 similar to Dow 795? I have heard 795 is great but very hard to work with.
And holding it in place for 10 min was enough to set the window in place and not move?
I was trying to figure out a way to set the window panel thinking it will need pressure on it for several hours or it will just pop out. Which would not be good.... go home and then come back to find all the windows popped out, laying on the deck with black Dow 795 silicone smeared all over.

Patrick