Re: [PSUBS-MAILIST] uniform? acrylic viewport thickness

Well Bill: Thats how it's done. The blowing thing is for those of us that have no $$$$$$$

Akins <lakins1@tampabay.rr.com> wrote:

Hello everyone.

I'm just curious about something. I know you can make a plywood sheet with a cutout and a frame that holds the edges of the acrylic so you can heat and blow it up.

But why not just make an inside form that is the exact contour of the inside of the acrylic bubble that you want, maybe out of smooth balsa or something. Then make a

corresponding outside form for the bubble. Then stack the outside form over the inside form and the airspace inside would be the exact size without any thinner points all

around. Then just pour in the molten acrylic and let it dry. Although this would require basically two forms stacked on top of each other, wouldn't this do away totally

with any problems of the bubble having thinner spots? Just a thought.

Kindest Regards,

Bill Akins.

----- Original Message -----

From: HUNTR2@aol.com

To: personal_submersibles@psubs.org

Sent: Wednesday, February 23, 2005 10:45 PM

Subject: Re: [PSUBS-MAILIST] uniform? acrylic viewport thickness

Hi Phil,

Question... If you heat the acrylic evenly with several heat lamps, and leave the center just a LITTLE bit cooler than the rest of the project, Would the apex of the bubble retain more of it's thickness and result in more even thickness over the whole dome? This might be accomplished by a ring of lights over the project.

Gene