OD16 glassbottom project begins!

[Fishnchamp1]

First off,... I've never built a boat, and now I'm building one with a hole in it on purpose Ok, now that thats out of the way... Has anyone ever done anything like this before? I searched the market high and low for a small boat with a glass bottom and just couldn't find one other than a lil dingy thing that couldn't hold two of me and an engine. With nothing much better to do but drink rum and tell stories , I've decided to go ahead and make this idea a reality. If anyone has any posts or weblinks to similar projects, I would greatly appreciate the knowledge. Again, sorry Jacques for the bastardization of your wonderful boat!

Check my gallery for some drawings and pics to get the creative juices flowing!

http://gallery.bateau2.com/thumbnails.php?album=426

[fishingdan]

I admire your ambition. It looks like you have a great start.

What is your plan for the viewing area? Glass, acrylic or other? How will it be secured to the hull? In addition to the "glass" on the hull bottom, will you have another "glass" at the sole level?

I'm also curious to know how you plan to use the boat. Will you operate it at planing speeds?

I'm looking forward to your progress.

Good luck with the project,
Dan

[Fishnchamp1]

I purchased a 2'x4' sheet of 1" acrylic, that should serve as my window to the sea. As thick as it will be I think..., hope, that I should be able to still bring the boat up on plane. inside the hole in the keel box I plan to first use some 3/8 wood and build a box about 1.5' -2' tall to protect the window from foot traffic and other mishaps. I will wrap the glass used over the hull as a preventative measure, in case the window ruptures or is displaced. technically by doing it that way the boat should still float if some mishap occurs. We will see! to secure it to the hull i am going to build a 2x2 frame around the inside of the opening in the hull and mount it so that the acrylic should be fairly close to flush withthe bottom of the hull. the only problem i could forsee with that is that the keel begins to taper in the middle of the glass so there will be some difference, but only and inch or so. Thanks for your interest, will continue to post pics (slowly I'm sure).

[Charlie]

In the homebuilt world there are glass bottoms that show up now and then but they are usually DISPLACEMENT hulls. Displacement hulls usually top out at 5-9 mph. If you expect to run a glass bottom boat at planing speeds you had better get a second opinion. The hull stresses at 25 mph and up can be rather severe. Especially when seas are rough.
Also, on a stitch and glue boat the skin of the hull is more of a structural member than on a conventional wooden boat. If you cut holes in it you are weakening the whole structure.
And don't ever let your boat insurance guy know about the alterations you have made.

[Fishnchamp1]

good call on the insurance note! What kind of seas can this boat handle without structural modifications (also take into account tiller style engine is planned for this project)?

[PatrickO]

I think you are also going to need an inspection. You might think about how to make your "glass" a structural component of the hull. A thousand stainless screws around the perimeter? How tough is 1" acrylic? Does it flex much?

[wingnut]

Can't wait to see Jaqs response in the morning. He may just pull a "Schultz" from Hogans Heroes and declare "I know nothing!".

But best of luck anyways. You may want to look at this site also:

http://www.pbase.com/dr_dichro/electric_boat

Here's a shot of his window openings. Nice shine too....

http://mishilo.image.pbase.com/u32/dr_d ... indows.jpg

[ks8]

some plastics can get much more brittle with temperature drop. If you go out in 40 F water, that panel may be more brittle than in 70 F water. Check those specs well! Don't build a glass bottom just cause you've got a piece of acrylic. There are probably websites that can get you more specs on various grades of acrylic, Lexan, etc. Obviously, this can be done right, and be rewarding, or not.

Success may require more expense, but then, it will be more likely to be a success.

see my other comments on the other thread...

I don't pretend to be a plastics engineer or naval architect ... but there is more to consider in this project than meets the eye...

[Fishnchamp1]

PatrickO - 1" acrylic has negligable flex, I hit a piece of it with a hammer to test it and there was no visable movement. I plan to use stainless hardware to attach it. I think that with a good fit this window will probably be a strong point in the hull.

Wingnut - I've been waitin to see Jacques' response also ( Don't kill me! ) Sweet fisnish on the link, thanks for the info!

ks8 - I hadn't put any thought into that, thank you. I'm sure there would be a problem if this was taken to cold climates. Thank goodness I am a big wuss and wont leave Florida, unless I take it to the bahamas (towed behind or on another boat of course ) I wonder it expansion would be a problem in colder climates? i.e. would the hull have a diff expansion rate than the acrylic and cause difficulties because of this?

[Jerry-rigged]

Another source for info may be http://www.ClassicAquasport.com. Some of the early Aquasport 222 hulls had glass port-holes in the bottom, in front of the console. As I understand it, in the days before good fish-finders, guys would (in Florida's clear water) idle around above a reef looking thru the windows for snapper or grouper. Seeing fish, it was baits down!

Those hulls were definitely planing hull, but I think the windows were small, like 6"x6" or so.

Jerry

Edit - Check this thread - http://www.classicaquasport.com/forum/v ... ndows+hull