Companionway opinions wanted

[Roger Long]

Help me make up my mind. I'm stuck on the fence and looking for some ideas to get me to go one way or the other.

This companionway rebuild project

http://home.roadrunner.com/~rlma/09Winter.htm

has hit a snag.

While disassembling the slide, I didn't realize that one of the screws was caught in the plastic and jacking it down until I heard the crack. Considering how easily it went, I think three decades of sun may have taken their toll on the Acrylic.

A replacement piece of MR 10 Lexan is $380 buck. Ouch!

I'd planned on installing the Iroko strips described but may only be able to get teak at $28 bucks a board foot. Ouch!, again.

I'm thinking now of just going with 3/8 or 1/2" inch marine plywood and oak strips, all painted white with non-skid on the tops of the strips. The boat has two big clear skylights and lots of ports so the light coming through the companionway isn't very critical. I could replace one of the drop boards with plastic if it ends up too dark.

OTOH the varnished teak strips on the smokey Lexan would look great. OTOH this is a not a fancy yacht. I'm heading north so the solar gain would be nice but I'm not sure $500 nice. I could also put varnished teak strips on white painted plywood but I've got more than enough stuff to keep varnished.

What do you think?

 

[David in Sandusky]

Keep up the quality

You've got a great boat - I'd really consider buying the lexan, and doing it right.

 

[Rich (P303)]

Go for the look you want... you will have buyers remorse whatever way you go anyway!

 

[Tim R.]

How bad is the crack? Does it extend into the body of the material or just go to the edge? Any way to cover it using some SS strips?

 

[BobM]

Hi Roger,

I think the plan for raising the sea hood is sound, as is the wood compainionway slider, but am less confident in the application of teak strips to 3/8 inch lexan using screws. S2 did just that in the forward hatch by tapping it and screwing the strips down from the top of the 1" thick lexan hatch (tough to repace now, but needs it as it is badly sun degraded). You can probably see them in my Avatar, or certainly in photos in my profile.

My concern would be that the the holes would weaken the 3/8 inch sheet, especially after prolonged sun exposure, making a dangerous situation potentially even more hazardous. You said the sheet is a bit weak now. If you go that route (teak on acrylic) I'd suggest you try to just adhere the strips to the lexan. Have you thought about using an automotive grade 3M double sided tape made for adhering body panels? (see the link) The profile of the battens will be important as well. If you go the adhesion route surface area is your friend, but certainly from a load perspective height is. But you know all these things so I'll just shut up now ;-) By the way, you can sometimes find large sheets of 3/8 clear lexan on ebay (large sheet available now for $75), but it might not be the ideal grade.

http://products3.3m.com/catalog/us/..._0/command_LongDescOutlinkHandler/output_html

 

[Maine Sail]

why not..

Why not make yourself a new fiberglass replacement hatch with a smaller 12"X12" or 14"X14"cut in for a skylight in it. Surely a smaller piece of acrylic would be considerably less costly.

You could even laminate the fiberglass replacement right on top of the old piece of acrylic if you waxed it well. You could then cut a 12"X12" or 14"X14"opening in the middle and then rabbit the edges to recess in a new piece of acrylic with Dow 795 then fair, finish and non-skid it. The materials would be cheap and it would be strong especially if you cored it with balsa or foam..

Laying up fiberglass is actually quite easy...

 

[Roger Long]

How bad is the crack? Does it extend into the body of the material or just go to the edge? Any way to cover it using some SS strips?

It isn't bad but wouldn't end up under one of the wood strips or I might be tempted. It also happened easily enough to make me suspect the integrity of the 1980 material. I'll have a lot of work in this by the time I'm done and it would be a bummer to have it crack futher the first time I stepped on it.

 

[Roger Long]

I would blind fasten from below using just 3 - 4 screws in each strip. After fitting, I would mask everything and then put the strips on with epoxy. Lexan is pretty tough and 3/4 inch strips would be nearly strong enough to stand on by themselves. Still, stress concentration is hard to predict when things flex. The attractive thing about plywood (which I would do the same way but with more screws) is that it is more forgiving if someone really jumps on it. A plywood hatch would also be a bit lighter.

 

[Steve W (NY)]

Don't use Lexan

Or at least I was told that at the Annapolis boat show. there was a company that made replacement hatches and portlights and stuff. I asked them why all of there stuff used acrylic (Plexiglass) and not polycarbonate (Lexan) and they said that Lexan crazes very quickly when exposed to sunlight. Ironically, some lexan drink holders I made from my dads boat three summers ago are already crazed.

I'd stick with Acrylic based on that. But maybe someone has other opinions.

Take Care,
Steve

 

[Ross]

Lexan is much stronger than acrylic. As far as crazing is concerned My Lewmar hatch is 10 years old and has some minor crazing. I would look else where for lexan prices. I was able to buy 3/16 lexan in 4x8 foot sheets for 148 dollars two months ago. Wood has the advantage of better insulation and blocking direct sunlight.

 

[Benny]

You may not have our problem, but we always end up keeping a towel on the lexan lid to keep the heat provided by sun rays away from the cabin. We also replced the port hole screens with aluminum foil covered cardboard and have added foam insulation to the skylights. Welcome to the cave... (the galley portholes and the head provide enough light) I would not object to using wood but would not consider plywood for maintenance and longevity issues

 

[Roger Long]

(Don't use Lexan )Or at least I was told that at the Annapolis boat show.

That's why I use MR 10 which is Lexan with a UV and scratch resistant layer on each side. It's made for high strength glazing in commercial buildings so they are pretty serious about longevity. It's true what they say about regular Lexan but they aren't telling you about MR 10 because they either don't know or would prefer to sell you cheap stuff.

MR 10 is about 10 times the strength of Acrylic. I got new skylight lenses cut to size by the local window glass company for less than buying Acrylic replacements from the company that made the skylights.

http://home.roadrunner.com/~rlma/2007Work.htm#Skylights

 

[Roger Long]

You may not have our problem, but we always end up keeping a towel on the lexan lid to keep the heat provided by sun rays away from the cabin.

I don't expect that to be a problem up in Newfoundland and Labrador

However, you have reminded me of something that does bear on the issue. I've had some bothersome condensation from the plastic slide late in the fall when cooking vapors rise up to it. That might be a good reason to go with wood. The white painted underside of the hatch might make it brighter than plastic. Usually, if it is bright outside, the slide will be open anyway.

Leaning towards wood at this point.

 

[Roger Long]

Laying up fiberglass is actually quite easy...

Yes, but I can work with wood in the basement (where it's warm enough to work with glass) without getting a new girlfriend

Besides, I hate working with it almost as much as she hates the smell.

 

[Ross]

Consider four small lexan panels in the plywood hatch, that would give you the best of both worlds, the strength of the wood and the light source of the skylight. With a router cutting holes to fit the plastic would be easy.

 

[BobM]

I like Ross's idea. Make a grid out of teak or iroko so it has structural integrity (it would look like a teak grating on an old sailing ship) then route it and fit smoked lexan panels in it. You can usually by narrow lengths of wood and lexan more cheaply and the lexan could be thinner and the final look would, I think, be very cool.

Question regarding MR10, my forward hatch is about 1" x 24" x 24" and frameless. The gasket is mounted in the deck and the seal is against the flat surface of the lexan. The lexan is 27 years old and crazed badly. The MR10 sounds like a good solution, but do you think the UV coating would delaminate at the exposed edges over time if I used it? Thanks Roger.

 

[Roger Long]

The MR10 sounds like a good solution, but do you think the UV coating would delaminate at the exposed edges over time if I used it?

I'll get back to you in 10 - 15 years about that

My edges are actually sealed with Silicone in the recessed frame. My impression looking at the panel was that the outer layers were pretty integral and tight. It looked like one continuous piece of material except when a bit of the harder outer layer hung out slightly after sanding the corners for a better fit.

I think it would be worth a try but I would check with the manufacturer if delamination in a few years would be a major bummer.

 

[Steve Dion]

here are some interesting things about the different product options.

http://www.acrylic-designs.com/plastic_FAQ's.htm

 

[sailingdog]

The UV coating isn't a laminate on MR10 polycarbonate. IIRC, it is a coating, not a laminated film.

Personally, I like the idea of making a new sliding hatch that has provisions for putting deadlights in it. However, I wouldn't go lighter than 3/8" acrylic or polycarbonate, since the material still needs to have a fair bit of strength.

Drilling holes into an acrylic or polycarbonate slider to attach a grate would be a bad idea, since the holes might become the starting point for stress cracks, making a bad situation worse.

Don't forget to make some way to keep the slider from moving, in both the open and closed positions at a minimum. I've seen a few injuries that have occurred when the sliding hatch has moved unexpectedly. One was from when someone's footing went out from under them since the hatch slid closed and caused their feet to slide. The most serious one was when someone was coming up the companionway and the slider closed unexpectedly and hit them in the back of the head.

 

[Roger Long]

Decision

It will be wood for the reasons given here:

http://home.roadrunner.com/~rlma/09Winter.htm#Woodslide

Thanks for all the comments. It was quite helpful.