Clear Washboards

[BrendanChandler]

My 1985 Beneteau Idylle is fitted with a sliding hatch, the front section is hinged to fold down over the companionway to the bridge deck.

I woulld like to fit clear washboards which could be used in bad weather to protect the opening from water and in rain to keep the rain out yet letting light and air in.

Ideally I should like to let air in so I need some air holes. Presumably these should be
in the top washoard so that any water entering the cockpit and getting on to the bridge deck does not get below,
in the centre line of the washboard so that if knocked down, the minimum amount of water gets below.

Perhaps I really need two different top washboards, one for foul weather without the air vents?

What material should I use so that it does not scratch easily?

How thick should it be?

What is the best way to lock the top board in place so that it can be unlocked form above and below?

I need to add a rail to hold the wachboards in place between the rail and the existing frame for the existing hatch. What material should I use, teak?

I would welcome any thoughts. I am more experienced at sailing than at altering boats.

Brendan

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[ParaHandy]

don't use acrylics (eg perspex) use polycarbonates eg makrolyte (might have got trade and chemical names wrong) which you can swing a hammer at and it won't break but all do scratch to a certain extent. buy thin sheet (6mm? its v. expensive) or go the whole hog and get exact width and build edges up where it slides into hatch etc This type of material is also sold tinted ....

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[Neraida]

Polycarbonate is extortionately expensive, we replaced the washboard when we bought Neraida, took it to a local place and had it made in 12mm acrylic, doesn't scratch easily but not shatterproof like polycarbonate (it's supposed to be bulletproof). Cost us £60, quote for polycarbonate was £240!!!!!!!

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[BrendanChandler]

or go the whole hog and get exact width and build edges up where it slides into hatch etc

What do you mean about build up edges?

Thanks for the advice.



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[Twister_Ken]

Cheap and cheerful

We have timber washboards for normal use, and a a single piece of acrylic for the want-daylight-below situation you describe. The acrylic normally lives under a bunk cushion and is not thick enough (4mm?) to be secure against vandals or waves, so is only used in when we are aboard, and parked. It's a low cost alternative; would that approach be good enough for what you want?

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[BrendanChandler]

Re: Cheap and cheerful

Perhaps something like 10/12 mm acrylic would be a compromise.

Would that be strong enough to keep a sea out. Probably not suitable to keep a burglar out though so would keep existing sliding hatch.

Where would I go to buy it? I have never seen an acrylic shop and can you buy it cut to shape?

What should the ratio of the sizes of 2 wash boards be? Both of the same height?

Do you just have holes for ventilation or do you have a fitting over the holes to keep rain out?

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[Neraida]

Re: Cheap and cheerful

I found a place in Southampton that took the old washboard and made an exact replica, very well finished too, PM me if you want contact details.

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[johna]

Re: Cheap and cheerful

Brendan

Not sure where you are located but speak to Philip Muller of Eastleigh.

0238 0260296 or mobile 07778 563918

He supplies acrylic and will make any shape for you.

For my curved hatch cover I laminated two sheets of 6mm by screwing down to formers at each end. For wash boards the sheets could be bolted together or as suggested elsewhere use 10 or 12mm thick material.

John

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[oldsaltoz]

I can understand someone wanting to fit a clear washboard to let some light in and keep the rain out. But I would not fit this at sea in even moderate weather, as it's ability to withstand a wave over the stern is doubtful to say the least.

Take care.



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[MainlySteam]

We have acrylic washboards but they are at least 12mm thick (possibly 14mm from memory) so are comparable with a hatch glazing of the same size, and have never been a worry. However, in a boat with a cockpit open to sweeping seas (such as with an open transom), which I would not like to have in any event on a cruising boat, I would certainly go for something stronger.

John

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[Twister_Ken]

Rufty Tufty Clear Washboards

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[Talbot]

use of polycarbonate on its own in this area is also suspect, not because it is likely to break, but purely because its inherent flexability means that there is a real danger of it flexing sufficiently to pop out of the washboard slots.

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[MainlySteam]

<<<What is the best way to lock the top board in place so that it can be unlocked form above and below?>>>

Not sure what you mean here but will try and cover the bases. If you are talking about fastening the top washboard in place then a lashing down to a saddle mounted inside and beside the companionway or a horizontal bolt on the board (again inside the companionway) is common. I prefer the lashing as bolts have a habit of needing to be exactly lined up, getting tight etc.

If you mean how do you locate the top washboard and sliding hatch combination so that it can be opened from both inside and out, one way is to fit a vertical spring loaded bolt at the inside top of the washboard which latches into the underneath of the front rail of the sliding hatch. That can be opened from inside. To enable it to be opened from outside use a bolt that has a ring on the operating end of the bolt and take a light line from that downwards through a hole drilled at an angle down through the washboard (unless you have a drill press you need someone to drill this hole without the drill running off) to the outside of the washboard with a figure 8 knot in the end. It is important that the hole slopes down at the correct line of pull angle, both to enable the line to run freely through it when pulling the bolt down against the spring and also to stop water running in. The bolt should be one of the ones which, like a door latch, has a rounded side at the latching end of the bolt so that when the hatch is fulled aft over it the striker plate on the hatch pushes the bolt down and automatically latches. You can get ss bolts which have all of these required features.

I would not put vents in washboards myself for a boat to be used in the open sea, and in my experience any grilles, or what have you on a vertical surface will not be resistant to rain driving against it in very strong winds. In our own case the sliding hatch pulls about 1.5 to 2 inches further aft than is required to latch flush with the washboards so that the aft end overhangs the washboards leaving a ventilation gap up under it over the top of the top washboard should air be needed and conditions allow. The hatch is friction fitted so that it does not slide back and forth in this position (removing the complication of needing a seagoing latch) but the hatch cannot slide open as if it slides back the inner edge strikes against the back of the spring loaded bolt on the top washboard mentioned above.

John

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[MainlySteam]

There is no way any polycarbonate or acrylic thick enough for the job can flex enough for that to be an issue. With our own boards I suspect that one could support them horizontally at their edges and stand on them without any visible flexing at all.

Polycarbonates used to have a problem with UV stabilisation, but I see UV stabilised polycarbonate sheet is now readily available. As someone else pointed out it is expensive whereas acrylic is not and is entirely satisfactory (is used in quality hatches by the likes of Lewmar).

John

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[FullCircle]

Re all the above, much wisdom abounds. However, I would say that the physical properties of Makrolon (Bayer Plastics) is somewhat understated. The Riot Shields used by Police and Army, and the visors, are made from Macrolon. It is a High Strength Polycarbonate polymer, and is used in 6mm form for windows on Ocean yachts. It has a very high resistance to impact and flexure breakage , or to sharp object impact at high speeds. It has also a resistance to flex under continual load, but obviously a 6mm will flex. Therefore decent side guide depth is needed to stop the washboard popping out. If you check with a reputable plastics dealer, they will give you the comparisons of strength.
Personally, I would use the aftermarket grilles available to screw to the outside of the board to allow air in. Wonder just how much water would come in through a downward pointing grille even if you inverted for a short time. Not enough to worry you I am sure. Even so, you could have a rotating plate on the inside to block the air in times of trouble.

Product description
Makrolon is the brand name used for the polycarbonate produced by Bayer AG and Bayer Antwerp N.V. (Europa), Bayer Corp. (USA) and Bayer Polymers Co., Ltd. (Thailand).

Makrolon is an amorphous, thermoplastic molding compound.

It is noted for its high light transmission, high heat resistance, high toughness, high creep modulus, high dimensional stability and good electrical insulation properties.

Glass fiber reinforced Makrolon has a particularly high rigidity, coupled with very good dimensional stability.

The production plants for Makrolon have been certificated to DIN ISO by the competent certification companies.

Characteristic features:
Inherent color
Clear and transparent, like glass

Toughness
No fracture without notching; very high notched impact strength

Dimensional accuracy, dimensional stability
Particularly high, since no dimensional change due to water absorption or post-shrinkage, high creep modulus, high heat resistance, isotropic behavior

Heat resistance
Glass transition temperature up to 148 °C

Resistance to ignition sources
Flammability classification up to UL 94V-0/1.2 mm or UL 94-5VA/3.0 mm; maximum temperature in glow wire test up to 960 °C

Electrical insulation
Volume resistivity 1014 Ohm x m; dielectric strength 32-35 kV/mm (1 mm wall thickness)

Miscellaneous
Makrolon grades for food contact and medical engineering applications







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[MainlySteam]

<<<Wonder just how much water would come in through a downward pointing grille even if you inverted for a short time. Not enough to worry you I am sure.>>>

I agree, however, that is not the point. What we do not like seeing in our own boat or the others we are involved with the construction of, is the rain coming in. In my experience any grille type thing on a vertical surface, unless it has a cover over it open at the bottom, or some troublesome or bulky sealing arrangement is prone to letting wind blown rain in. Not too much of a problem if one is in and out with wet gear on, etc at sea, but is a nuisance when the boat would otherwise be dry laid up in its berth or similar.

We would never put 6 mm plastic in an exposed position if supported only on 2 opposite sides unless it was further stiffened (the easiest way of which is to use thicker material). Otherwise you run the risk of them being driven into the boat. In the hatches and ports you mention the plastic is supported on all 4 sides and so is immune to that happening.

An aside on washboards is that they should be heavy enough not to easily blow away when loose, especally if they can be accidently laid in exposed areas such as the cabin top - thin plastics may not qualify in that respect. Silly? No, we and others have even had heavy frp dinghies blown off our decks when not lashed down, let alone the other lighter things that disappear.

In the end if one is just going to toddle around the bay, or one has a little leaky ill fitted boat that is going to be wet inside regardless, then of course these things do not matter.

John


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[maxxi]

Re: BrendanChandler

'Talking Plastics' in Havant near Portsmouth. Total understanding of yachtsmans needs and able to cater to most (plastic) needs.

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[vyv_cox]

For many years, on our last three boats, we have used timber washboards for strength and security. To maximise light in the saloon when on board, and to keep out modest amounts of spray, we have made a 'flap' of hood material that is largely a trasparent window. This clips to the sliding hatch and is attached by bungees to small hooks at the bottom of the companionway. Its width extends right across the companionway. When not in use it rolls up on top of the sliding hatch or is stored below.

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[extravert]

My X99 had clear washboards, which were ~10mm thick. From other X-Yachts I have seen, many others have clear washboards too. I think a mainstream manufacturer like X-Yachts would not use them if they were not as safe as other materials. They make some pretty hefty ocean going boats, and I have never heard of any problems reported on X-Yachts discussion groups.

A few problems that I can think of with this material are

1) if sufficiently strong, they are heavy
2) they are expensive to replace if lost or damaged during a forced entry
3) when they get the inevitable scratches they cannot be redecorated like wooden ones can.

Personally, I don't think safety or lack of strength is a problem.

<hr width=100% size=1>One day, I hope to own a real boat.

 

[Twister_Ken]

OTOH, you don't have to revarnish the things every year.

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