Glass bottomed boat

[wassermensch]

I have a slab of 1.5in thick glass, 5' x 3', and want to put it in a punt, so that I can view the submerged wildlife in safety and comfort. It has a 45 degree edge, so should plumb in with a bit of mastic, all I need is the punt. Any insights?

 

[freddiemercurystwin]

You're gonna need a bigger boat! OK serious answer, you're stark raving mad!

 

[wassermensch]

Yep, its been said before, maybe too much time and an overactive imagination.

 

[foamit]

You're gonna need a bigger boat! OK serious answer, you're stark raving mad!

I think we need a new forum heading JOKES

 

[Alarm]

Been in glass bottomed boats loads of times abroard, whats so unusual?

Just masticing in will not cope with the water pressure nor the twisitng of the hull.
I suggest you contact a shipbuilders for a possible answer. Maybe do a search for some in Florida or the Carribbean.

Good luck.

 

[freddiemercurystwin]

Been in glass bottomed boats loads of times abroard, whats so unusual?

1.5in thick glass, in a punt! You for real? Or just as mad as the OP?

 

[chappers]

Wassermensch you are mad as a hatter, and i mean that in the nicest possible way.
No problem with fitting a bit of glass to the bottom of a boat, my mate bought an old survey boat that was rotting on loch lomond it had a hole through the hull for a sampling bucket and next to it another glassed over hole for viewing through.
Think about reducing the size of the glassed area and reinforcing around your cutout.

would love to see some pictures of the waterwheel when finished too

 

[muggles]

Might be easier to build your punt from scratch around your piece of glass than to modify an old one. Make up a good frame for the glass, seal in with some strong waterproof adhesive such as Serious Stuff Ultra then go from there. Do it right and you'll end up with something far superior to any modified old boat, do it wrong and you'll end up swimming, would be great to see the end result if it works though, and the waterwheel looks interesting too

 

[ladylola]

Have to agree with muggles there, 3 feet of hole or glass is a sizeable chunk to take out of a punt , there will in all probability be issues with the structural integratity of the hull. It will in all likeyhood need some sort of steel reinforcing in the same way as a softtop car does.
If you go ahead please post pictures and as chappers says of the waterwheel too.

 

[wassermensch]

I sail in a very sheltered bay, the Findhorn, never a wave bigger than 1 foot, and the seals swim under the dinghy as we go, I would love to see more than their heads poking out to look at us.
It is a lovely piece of glass, and big enough that I can cover up a lot of it to ensure waterproofing. I will build from new to get it big enough to be stable and strong, and so will stop looking for something to hack the bottom out of, doesnt need to be pretty. Might use some of those 45 gallon plastic barrels for some guaranteed buoyancy.
Very many thanks, I will put some pictures on, I am down t'mill tomorrow, will take some photos of the wondrous supports for the waterwheel I have built.
\thanks to everybody, even those casting doubts, it is important to stay grounded -to a degree!

 

[mointainwalker]

@wm

out of interest, how much does the glass weigh ?

 

[wassermensch]

The plate glass weighs 70 lbs, not a huge amount, and stabilising at the lowest level, I have a piece of 7 ply I am just fitting it in to now, and will fix that to the boat, lots of waterproofing, gaskets mastic and varnish.

 

[mointainwalker]

This is completely conjecture on my part, but I cannot imagine how a piece of glass 5' x 3' x 40 mm ( approx) is 30 kg approx) I would have guessed at several hundred kg.

Is this calculation or actual ?

 

[wassermensch]

I can just lift it on my own so just assume it to be about 75lbs, that seems a fair estimate of my strength, it is plate,comes up to my chin and is crystal clear, it will easily be strong enough to resist the water pressure on a 3 foot deep boat. I must have got the dimensions wrong, as it would float at 75lbs. I suppose I had better get the scales and tape out, and do the math, otherwise I could be shocked, I do tend to "wing it" quite a bit, -lazy.

 

[Neil Cadman]

Plate glass is out of the question. It is too brittle and too dangerous when broken. But if you did use it you would have to use a polycarbonate layer on top and bottom. And in which case you may as well skip the plate glass and just use polycarbonate. I would sell the plate glass and get a good polycarbonate glass. I would also consider using a smaller size and use it in framed panels, max 600 sq.