Prepping for windshield glassing

[sbalmos]

I've been starting to do prep work and thinking through the whole windshield seam fiberglassing process. I watched the great videos by the factory for the -14. In the -14's plans, apparently, there are templates for the various major pieces, especially the curved side layups. And a metal template.

For the template, I'm thinking I could just create a 3" radius cone piece, sort of like how they show in the -14's videos, but 3" based on our plan's noted width of the seam? What about getting a copy of those curved side layup templates? Not worth it since they're for the -14?

Couple more weeks until I start on it, but just mentally stepping through everything before I start Yet Another Weekly Spruce Order.

 

[A5555]

Scott, I have four different contour sanding blocks I used for each profile around the canopy. I simply made them from paper templates I estimated. You can have them or make from them. Steve

 

[BillL]

I've been starting to do prep work and thinking through the whole windshield seam fiberglassing process. I watched the great videos by the factory for the -14. In the -14's plans, apparently, there are templates for the various major pieces, especially the curved side layups. And a metal template.

For the template, I'm thinking I could just create a 3" radius cone piece, sort of like how they show in the -14's videos, but 3" based on our plan's noted width of the seam? What about getting a copy of those curved side layup templates? Not worth it since they're for the -14?

Couple more weeks until I start on it, but just mentally stepping through everything before I start Yet Another Weekly Spruce Order.

Scott, I did this a few weeks ago on my 7. I stumbled on using two squares with the intersect edge of the coverage area for the glass. Where the two intersect is the tangential curve radius. Then, I sectioned off the work area and cut some selected radii out of cardboard. I used a roll of paper on hand then to mark the sides and made a template to transfer to the other side. Much like the 14 video.

One thing - due to the angle of the canopy changing, with a fixed width, it will make the center appear lower than an even vertical distance from the canopy skin. You might want to check that in the masking process.

I second the sanding block radius idea, I made mine from small pieces of 2x4 - and used the edge. I created the radius against a disc sander (bench).

Here is how the radius was determined.

 

[sbalmos]

Steve - Thanks. Probably will just borrow.

Bill - Interesting. You're taking me way back to geometry days (eek), but I get where you're going. BTW, it looks like you ran a blob of Sika on the back side of the windshield to hold it to the top skin, rather than clips?

 

[BillL]

Steve - Thanks. Probably will just borrow.

Bill - Interesting. You're taking me way back to geometry days (eek), but I get where you're going. BTW, it looks like you ran a blob of Sika on the back side of the windshield to hold it to the top skin, rather than clips?

I am surprised that was visible, it is a mixture of epoxy-flox with black tint. I extruded it in there, then added a second layer to fill it out when the first was tacky but firm. I flame treated the edge before application for better adhesion. A test piece was quite strong.

Flame treatment = passing a propane flame tip at 12 in/sec over the portion of the plexi to be bonded. Per West Systems recommendation.

 

[sbalmos]

Ah! Fascinating (so says Spock). So you would've had to have scuffed and flame treated the windscreen, and then attach to the canopy frame, and also extrude in at least the first layer of epoxy, within the same work session?

 

[BillL]

Ah! Fascinating (so says Spock). So you would've had to have scuffed and flame treated the windscreen, and then attach to the canopy frame, and also extrude in at least the first layer of epoxy, within the same work session?

It really sounds bad when you say it that way - - but a little different order.

Scuffed the canopy -mounted canopy - mixed epoxy - flamed the edge - no damage to the antiglare paint, then applied the epoxy. Flaming literally took seconds. No real rush or speed required anywhere. I did lay some poly under the edge and cleaned it with alcohol before the flame - let it evaporate before the flame. After the second layer of gap filler was applied, it was trimmed down with a razor just before hard, then allowed to fully cure and sanded before the glass overlap part of the process. Try some experiments - the flame passes fast enough that a piece of paper won't catch fire.

A small point - the first filler was applied with attention to what it looked like on the inside, then the second layer was for a fully filled gap and the plane of the plexi was extended down to the aluminum.