Solid dodger construction –Aluminum or SS extrusion source requested

[Cheechako]

Originally Posted by Greggegner

I understand about glass, not using it probably will use polycarbonate. I know how to build with wood/epoxy and they look good. If I can find a couple of extrusion shapes that I can be welded into a shape that will accept the "glass" I think that would be both stronger and require less hours to do. Having 90 degree vertical windows would be easy and functional, but the wife has high visual requirements. Tilting the sides 10 degrees complicates the build.


Greg S/V Sweet Dreams
Pearson P385 out of Racine Wisconsin

Yeah aluminum would be a nice dodger. You will want one extrusion removeable to replace plastic etc right? Why not just flat bar? welded inside and thru bolted on outside to hole glass and seal?
or... I wonder if you could buy alum window frame bent to shape with rounded corners but no glass included from someone like Diamond Seaglaze?

[Lodesman]

Originally Posted by Cowboy Sailer

Lodesman, what do you mean? (referring to "safety glass" vs tempered glass) I used to own a glass shop. I know about tempered, laminated, wire glass and chem-tempered.

Let me google that for you

[Greggegner]

Originally Posted by Lodesman

Let me google that for you

So what glass would you use? While not bullet proof, I want a tough window.


Greg S/V Sweet Dreams
Pearson P385 out of Racine Wisconsin

[deblen]

Marinelite Windows Ltd | Custom marine windows for pleasure crafts and fishing boats: sliding windows, fixed windows, durable, tough.

[Lodesman]

Originally Posted by Greggegner

So what glass would you use? While not bullet proof, I want a tough window.


Greg S/V Sweet Dreams
Pearson P385 out of Racine Wisconsin

Depending on weight/thickness restrictions, I'd opt for a heat-tempered and laminated product, along the lines of this: http://www2.dupont.com/SafetyGlass/e...-princess.html
http://www.seaclearllc.com/seaclear2fix_005.htm

[Cowboy Sailer]

Note: Tempered glass (laminated or not) cannot be cut or have the corners ground down after it has been tempered. Some standard sizes (like shower doors and entrance doors) are reasonably priced. Custom tempered is very expensive. A quarter inch thick 12 inch by 24 inch with all four corners cut to a three inch radius is over $200! So if you made your framework and then ordered custom tempered glass it would be very costly.

[UNCIVILIZED]

There are a HUGE number of varieties & Specifications of glass, & a good percentage of them will work for what you're doing. Look no further than the pilot house/bridge windows of professional vessels which work offshore routinely in Hurricane strength weather conditions.
For example, Coast Guard surf rescue (bar crossing) boats.
Let alone the stuff which is literally rated to stop large caliber, heavy (and in some cases, literally armor piercing or worse) bullets.

Cheechako, it sounds like someone either under spec'd the glass & the loadings which it would see, a bad batch from a QC perspective was used, or it was improperly mounted, thus not allowing it to move properly so as to adapt it's movements from the flexural loads. Thus avoiding failure.

Ultimately, from a visibility, & maintaining a seal standpoint, glass beats Acrylic & Lexan. Such is why Beth Leonard & Evans Starzinger changed to it in their dodger on Hawk.
Although there are plenty of great types of coated Acrylics, Lexans, & laminates which will also do the job quite nicely. Hell, some of them are used in jet (including combat) aircraft windshields & armor.

Just do some research on the various materials in question. And push come to shove, many years back, "Professional Boatbuilder" did several, VERY explanatory, & lengthy articles on the topic/types of glass & appropriate applications.

As to ventilation, it's fairly easy to incorporate an opening deck hatch, in lieu of a fixed window, as part of the dodger's structure. That, or to put such a hatch into a large expansive window in the dodger. Or simply use window panels which are easily unboltable/fastened in place by QR dogs/levers.

[Cheechako]

"Cheechako, it sounds like someone either under spec'd the glass & the loadings which it would see, a bad batch from a QC perspective was used, or it was improperly mounted, thus not allowing it to move properly so as to adapt it's movements from the flexural loads. Thus avoiding failure."

Yeah, it surprised us all. Built to USMC specified contract criteria. Rubber mounted. I would have thought the whole window would have popped out of the rubber gasket before doing that. Can only write it off as an anomaly, maybe there was a defect on the finished glass edge that was unnoticed and couldn't be seen after the break...

[Sailorman Ed]

Understanding that you cannot cut tempered/laminated glass, is there a source of smaller size pieces at a reasonable cost that can be used? Design the openings to fit an existing available product? My old Prout had glass windows that were 38 years old when I sold it - not perfect but in much better condition than 5 year old plastic ones.

[UNCIVILIZED]

Originally Posted by Cheechako

Yeah, it surprised us all. Built to USMC specified contract criteria.

Ergo, built by the lowest bidder
Surely sorry to hear about the injuries though.

As a quickie FYI to those new to glass, out there, reading this. What you get as an end product depends on a LOT of things, & the process pretty much starts with the Ores, like in steel, & the various "recipes". Which are added, & specified all the way to the end product, much like the steps between Ores in the ground to winding up with a good knife, after the multiplicity of necessary steps & testing along the way.

Start with Ore selection, & what minerals are in it that you want.
Refine the Ore using various processes & QC checks.
Melt the various components down via processes X, Y, & Z.
Blend them, again with more specified steps & QC.
Set up to pour, pulltrude, etc. the liquid by steps A, B, & C. Including now introducing some "coatings", & chemicals, which become highly structural, & integral parts of the glass.
"Tune it" with various heat treatment processes, & chemical applications.
Add more coatings to imbue other properties... ad infinitum, in terms of steps & consistency measures & processes all the way through until it's done & ready to install in your dodger frame.

Or as another take on the same idea, think of all of the steps they must take in order to go from pulling crude oil out of the ground, up until it's a polyester Dress Shirt on the shelves, ready to wear.
Talk about "refined".


Back to dodgers, if you've got a bit of talent, a LOT can be done with composites, in relatively little time.
Steve Rander & the guys @ Schooner Creek Boatworks, did the one on "Jelik", in the article (below) more or less as an afterthought, in very little time. Ditto on materials used.

It was just 2 layers of 6oz CF on either side of some Divinycell, & some Lexan glued on with a bit of Plexus. And the longest part of the process was having the computer draw up some mold stations, cutting'em out, and aligning them, prior to adding the materials which would actually comprise the structure.
http://wyliedesigngroup.com/press_fi...%20Builder.pdf

[Greggegner]

The "glass" is solvable and can be changed if I don't like what I first choose. Ideas on the frame material/construction would be appreciated. I am searching for a metal extrusion that will act as a frame where it can just be welded. The fact that it will be tilted in complicates this.


Greg S/V Sweet Dreams
Pearson P385 out of Racine Wisconsin

[Cheechako]

Originally Posted by Sailorman Ed

Understanding that you cannot cut tempered/laminated glass, is there a source of smaller size pieces at a reasonable cost that can be used? Design the openings to fit an existing available product? My old Prout had glass windows that were 38 years old when I sold it - not perfect but in much better condition than 5 year old plastic ones.

Cant cut laminated tempered glass? it aint made to size for every application....

[Cowboy Sailer]

Tempered glass cannot be cut after it is tempered. Float glass is cut to shape first then it is tempered. Laminated glass can be cut to shape. It is more difficult because one must scribe and break each glass side then pull it apart enough to get a thin blade to cut the plastic center layer. We had a very high yield cutting straight lines; curves are very difficult, not so certain of success.
For custom tempered jobs we would cut the ordinary, float glass to size allowing for the change in shape and size that occurs during the heat tempering process. Then we sent the glass to a tempering shop. Sometimes it broke during tempering. Sometimes it did not fit after tempering. All this drives up costs.
Entrance door lights and shower doors are the only mass produced tempered glass that I worked with.