Technical Duvall frame casting, how to prep for glass?

I’ve got got an older Duvall aluminum frame casting. I’m trying to find the “correct way” to cut and channel it for glass. I haven’t had any luck searching out the process, only how to mount to the cowl. Thanks for any help on the subject.


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The groove in my windshield was cut on a Bridgeport. It is about 1/4" deep and slightly over 1/4" wide. A glass shop should be able to tell you just what they want.

 

I've seen guys say (but I've never tried it) that you can cut aluminum with woodworking tools with carbide bits. Maybe get a good router and route the groove into it?

 

Te alum framework is modle specific,,,,not a universal fit to all roadsters.

 

That doesn't really address his question about how to cut and channel it for glass, does it?

 

She’s a Beauty! Talking to a Glass shop is probably a good idea before cutting. I did find late last night Speedway’s instructions for the thickness of the glass. I think theirs ’s 6 or 6.6 mill off the top of my head.

Cutting that groove is going to be interesting, I’ll have to check in with some of my machinist buddies. I have a mill but I’m not sure what the best way to tackle that cut is? The other part that has me a bit baffled..it looks like on the outside edge of the frames they have a dog leg cut to screw through and lock down the glass. The straight cut in the middle seems relatively easy.


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I think my machinist friend sort of cut the groove freehand. I think he had a bearing that went against the frame that helped him with the depth of cut. After the groove was cut, I made patterns for the glass shop out of 1/4" lauan plywood. The glass is held in with silicone. The glass shop can help you with the correct adhesive.

 

I`d dog it down to the mill table and walk around it w/ a keyway cutter.

 

I'm guessing he doesn't have access to a mill, otherwise he probably wouldn't have asked the question. Maybe he can make a new friend who has a mill?

 

refer to post #6

 

Oh. Maybe he can make a new friend who has experience with a mill.

 

I can see how that would be beneficial.

 

Wood working tools work on aluminum

 

At the risk of being pedantic, the frame we are seeing is not a Duvall. It is more of a Hallock style.

 

And some time to kill!

 

Looks in your nice photo,that you have a top?,I'm interested in how the windshield header is made an how it holds to windshield ???Thanks

 

I don't have very good pictures of the top but it's made of maple and oak. (I wanted it to be like the old woodie roofs). I used steel to join the windshield header parts together in the center. That steel piece is also a way to connect the top to the windshield in the center. I will also have steel connectors to the windshield side posts but I am still working on the design.

 

Very interesting,nice work too,thanks !

 

Thanks for all the replies .. yeah I do have the mill, I’m probably capable of cutting the channel..still feel better if I can sucker my machinist buddy. I could see a router with the carbide bit probably working pretty well for the channel too. When I looked at the photos of a finished Duvall windshields the outside post has kind of overlap cut into the aluminum to screw through and hold the glass. That’s the one that really has me puzzled. What way to cut that without losing a lot of material? It must be something obvious that I’m not thinking of ...

 

Hmmm....Aren`t there very small counter-sunk screws that attach through the top piece and into the cowl posts ? Maybe have your machinist pal cut a mortise/tenon on those pcs. and drill/tap with them clamped together.

 

Yep.. he told me to bring it by and hell take a look. I was surprised he didn’t have a really good answer for cutting that overlap without losing a lot of material. If worse comes to worse I guess I’ll break out the jeweler saw...


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And I guess that would be a tongue and groove or some sort of half-lap joint...Some carpenter I am...………...

 

Yeah, looks like a half-lap joint 3/4”-1” I’m guessing.. i’m with you, I’m no carpenter.. I like metal, you can always weld it back like the ‘ol man use to say...


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I snagged some 3/8" x 3/8" x 3/8" 20 ga. steel channels at work years back...
you could clear a 3/8" wide flat along the upper and inner surfaces... drill small holes for tapping, countersink 'em...
slightly enlarge the matching channel holes and punch or hammer a clearance "dent"...
now tap the w/s holes to anchor the channels... use countersunk screws...
must be wider at the top [3*] to let the glass be dropped/ forced down...
this should let the glass fit flat across the bottom of the channel...
use stainless, aluminum or paint it to match something... HIH...