Thickness of GRP lay up

[Joker]

When the survey was carried out on my incredibly disintegrating Huzar, the surveyor took a sample from the hull below the waterline. This was a 55mm disc, varying in thickness, apparently, from 9.2 - 10.1mm.

What sort of thickness of GRP would you expect the hull of 30 foot to have?

 

[Clyde_Wanderer]

When the survey was carried out on my incredibly disintegrating Huzar, the surveyor took a sample from the hull below the waterline. This was a 55mm disc, varying in thickness, apparently, from 9.2 - 10.1mm.

What sort of thickness of GRP would you expect the hull of 30 foot to have?

I would scrap it.
My hull is 127mm below the waterline, they must have went on strike shortly after starting to lay up your hull, sounds like another Marie Celest!

 

[dt4134]

When the survey was carried out on my incredibly disintegrating Huzar, the surveyor took a sample from the hull below the waterline. This was a 55mm disc, varying in thickness, apparently, from 9.2 - 10.1mm.

What sort of thickness of GRP would you expect the hull of 30 foot to have?

Is that part of the hull cored? Are those measurements for the outer hull?

 

[Joker]

127mm sounds a little unlikely; that's about 5 inches.

The sample is from below the waterline, where the hull is monolithic. The sandwich section is above the waterline.

 

[jonjo]

Ignore the fool who thinks you should scrap your yacht because the laminate thickness is not 127mm like his yacht.

15mm to 25mm are more typical figures but it depends on how close to the centre line and how near the keel support.

The MAB brigade will be along in a moment to tell you their old Nicholsons and Westerlies have +30mm of laminate but such claims are irrelevant. Your yacht is a modern design that will be highly reinforced in the bilge area with a large drop-in floor moulding.

Comparisons are further complicated because your yacht has a foam sandwich construction, is this sandwich construction taken all the way around the hull under the water line?

Where were the core samples taken?

 

[30boat]

Ignore the fool who thinks you should scrap your yacht because the laminate thickness is not 127mm like his yacht.

15mm to 25mm are more typical figures but it depends on how close to the centre line and how near the keel support.

The MAB brigade will be along in a moment to tell you their old Nicholsons and Westerlies have +30mm of laminate but such claims are irrelevant. Your yacht is a modern design that will be highly reinforced in the bilge area with a large drop-in floor moulding.

Comparisons are further complicated because your yacht has a foam sandwich construction, is this sandwich construction taken all the way around the hull under the water line?

Where were the core samples taken?

127mm is not a very likely figure .I would expect to find 20mm or so near the keel tapering off to something nearer to 12mm further away.

 

[macd]

I would scrap it.
My hull is 127mm below the waterline

If it were that thick, the underwater area of a typical 30-foot GRP yacht would weigh something in the region of 5 tons (excluding keel weight), which is ludicrous. It would also cost rather a lot to produce....perhaps £25,000 in resin alone (although I daresay it'd qualify for a hefty bulk discount).

127mm also sounds a suspiciously accurate measure for something as thick, and un-uniform as a GRP hull. Surely anyone describing such a massive chunk of laminate would opt for 125 or 130mm? Is it by any chance 12.7mm...a dimension that maybe began life as "about half an inch" (which it is exactly. Mind you, it's also exactly 5 inches). Apart from anything else, you'd struggle to source skin fittings to span such a thing.

 

[Pete7]

Our Moody 31 is 20mm between the bilge keels. Measured when I changed the sender units to the depth and speed instruments which required larger holes to be cut.

The laminated front and back plates in my flak jacket were about 10mm.



Pete

 

[DannyB]

I don't know how thick my hull is, but the sun shines through it on a sunny day, and that's scary.

 

[Robin]

I don't know how thick my hull is, but the sun shines through it on a sunny day, and that's scary.

The hint is in the name 'fibreglass' as in translucent and has nothing to do with thickness!