Acrylic Windows

[Guest]

All,

Can anyone advise on the optimum thickness of acrylic for coverage of non opening windows to be installed on a blue water catamaran. I am having issues sourcing anything with a tint apart from standard thicknesses of 3mm & 5mm which, having worked with the material on other applications, I'd consider to be too thin. The maximum aperture size will be 460mm x 980mm and the total number could be cut from a sheet 3m x 2m.

Any thoughts will be appreciated.

Rgds,
Rich

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[colvic]

8mm is regarded as the standard, or so I was told when doing the same as yourself. Not having too much time we settled on 6mm as the largest area was no more than 600 x 450mm. After five years we have had no problems whatsoever, but we just coastal hop down the Med coasts and have only had to put up with a few hours of really heavy weather.

What did make me cross was the fact that a 2mtr x 1mtr sheet of 10mm tinted was under £40 in Barcelona the other week. This winter we may well replace just to have the benefit of the tint.

Phil

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[trays]

What it he best way to cut acrylic?

Ray

<hr width=100% size=1>Ray

 

[richardandtracy]

The crucial dimension is the minimum one, taking the stress as a beam of infinite width. For any 'shortest dimension of the span' under 600mm it was recommended by my boat's designer that a minimum thickness of 3.2mm (1/8 inch) was used, except in the hull where the minimum was to be 6.35mm (1/4" inch). I thought the 3.2mm was too thin so opted for 6mm throughout. With a further 6mm double glazing near enough that load could be shed from the outer pane to the inner as the outer deflected.

I tend to go for belts, braces and then a couple of nails.

Regards

Richard


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[richardandtracy]

Give it to somebody else to bother with.

If it's thickish (6mm), then a hand wood saw or a metal cutting jigsaw works. At 2mm I've only got a jigsaw to work, then running very fast with a fine tooth metal blade. I think it would work better backed by some cheap plywood - but I never had any available at the right time.

Regards

Richard


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[burgundyben]

as always the other question here is acrylic or polycarbonate?

acrylic cheaper but tends to shatter, polycarb wont shatter is dearer but scratches more is my understanding

perspex is acrylic and makrilon is polycarb I think.

Try aquarius plastics in guildford they made my curved windscreens.

<hr width=100% size=1>Sod the Healey - I think I'll buy an E-Type.

 

[Robin2]

I recommend polycarbonate because it is so easy to cut. I just used a jigsaw with a new medium toothed wood cutting blade. On many of the curves the cut was perfectly polished.

Any time I tried cutting acrylic it cracked (admittedly thinner pieces).

I could not break an offcut of polycarbonate with a hard blow from a lump hammer.

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[Blue_Blazes]

Nice new, fine toothed wood cutting jigsaw blade. Use a decent variable speed jigsaw on a low speed setting. Don't force it, allow the jigsaw to work at it's own pace. Worked for me when cutting new windows for my father-in-law's Huntress.

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS

 

[Guest]

Phil,

Thanks for the info. I have now spoken to a couple of plastics suppliers who do not seem to have issues with stocking tinted material in thicknesses other than the standard 3&5mm and they are coming in considerably cheaper than the more widely advertised companies. I'll probably swallow hard and stump up the extra for 8mm but use someone who can cut to approximate size rather than go for the expense of a whole sheet. Ain't it always the way that you find items for a fraction of the price just after you've spent a small fortune on the same gear elsewhere.

Rgds,
Narbs

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[Avocet]

Polycarbonate is much more shatterproof (virtually "unbreakable"). They make police riot shields out of it. It does, (as has been said) scratch much more easily than acrylic and in time, goes "milky". I think I'd be inclined to stick with acrylics (like "Perspex"). I've been told (but never tried it) that it is very easy to cut with a jigsaw provided you don't let it get to hot. Either use a slow speed and take your time or use a higher speed and keep the blade well lubricated with WD40 or some sort of spray-on light oil.

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