Enclosure Front Window Pattern

[regalman190]

When patterning a vinyl front window for a boat, I normally just lay the plastic up onto the front bow (2-sided tape) and then using snap strips attach the plastic to the snaps on the boat making sure I get as many of the wrinkles out as possible. When I finish the window and install it there always a few wrinkles. it makes me crazy!
I read about another technique and wanted your opinions.
This technique is the same as I do now with one exception. The plastic is gathered between snaps as if creating darts. Obviously there isn't a dart in the vinyl. The pattern is cut and taped along the dart lines. Then, the vinyl is cut to this new contour. Just did a window pattern this way and I'll be installing tomorrow and I'm interested to see how it comes out.
Anyone out there do there window patterns this way?

Joe

[Can-Vas]

Never have, but I'm curious how it turns out Joe...

Fill us in when ur done

[Peppy]

They did that in a recent Marine Fabricator I think. Seems like there's a lot of room for error. Like how can you tell if you pulled against the last dart with your current dart? I prefer to build it all at once then I can see if I screwed up.

I bet there isn't anything wrong with your current patterns. I would guess it's something to do with the cutting table. I had similar problems and moved the zipper on the main top 'up' (away from the window) >1/4" and it snugged up the window appreciably. I think it has to do with the radius there where it goes around the corner. If your zipper on the main top is too 'down' the radius is larger than what was drawn on the pattern resulting in the window being to long along that circumference. Meaning there's too much fabric bunching up on the zipper meaning you get wrinkles. It's better that your main top zipper has a radius LESS than what was patterned then the window fights against that curve, pulling out all the wrinkles because it's on the verge of being to short.

UP = tighter radius = less circumference = less wrinkles = Going to fit?

DOWN = larger radius = longer circumference = more wrinkles = more trims?

What I've found anyway. Sorry if that doesn't make any sense...I could likely make you understand over some beer. *urp* How's it working?

[Mike8560]

Ive not heard of that method Joe, I didnt follow peppy completly but I think he was saying your wrinkle are comming from a missalinged zipper placment. I find it more pronounced on a smaller radius bow  then a larger curve. youve got to gather your shorter zipper sewn onto the window. I like to streach my zipper i sew ontop the top. I trim bolth sides of the zip tape to lenght then take each piece    when im workig with each window. if i streach the tops half then i dont have to scrunch/ gather the widow 1/2 as bad.

[rustyeod]

Joe
I do it very similar to you but I think what gets me thru the process is to spend whatever time is needed to get every wrinkle out.  I also trace the bow at the same place every time and subtract 3/4" from the traced (top) line and sew my zipper onto the bimini following the fwd seam.  Wow, it is so hard explaining how you do things.  I hope you understand what I am trying to say.

Rusty

[Peppy]

Wow, it is so hard explaining how you do things.  I hope you understand what I am trying to say.

Rusty

I hear you! Yes Mike thats what i was trying to get at (I think! I have myself confused too!) Missed placed zippers. When your dealing with a curve a 1/4" +/- will affect the circumference greatly. Stretching your zippers sounds good too.

And you said it Rusty, 10 minutes extra on a pattern can save you 2 hours on the trim table!

[regalman190]

Installed the windows on Saturday. Worked pretty good. And, yes, it was in the MF magazine. I'll post pics later.

My issue has not been misaligned zippers. I trace my bow line onto tape on the frame, including my zipper starts and stops, so each piece I pattern has the same curve and zipper marks. I take extra time to make sure the zippers are in the right spot when working patterns on the table and when sewing them in.

The wrinkles are not at the top of the curve along the bow. The wrinkles have been vertically at the curves midway down to the bottom of the windshield. And for quite some time now I've been thinking that it's almost like there is too much material in the window. That's why darting the pattern worked. It takes out the vertical wrinkle in the pattern. It's similar to darting a cover at curves and corners.

I'll post pics later.

[Mike8560]

Are you saying you have wrinkles  in your pattern?  P

[PDQ]

The wrinkles are not at the top of the curve along the bow. The wrinkles have been vertically at the curves midway down to the bottom of the windshield. And for quite some time now I've been thinking that it's almost like there is too much material in the window. That's why darting the pattern worked. It takes out the vertical wrinkle in the pattern. It's similar to darting a cover at curves and corners.

I'll post pics later.

If I understand you, the slack you are experiencing is when the line of the screen doesn't follow the same line as the curve on the bow, which in turn produces a vertical wrinkle that runs from the apex of the radius on the bow down to the screen? Does that make sense?

I think I'll wait for an image before going further, but yes, darting the wrinkle out is an option but if the window follows around the radius then depending on what you do with that dart on the cutting table will determine the final outcome. 

[regalman190]

I totally understand about the top curve. I believe I have that down. Since my curves are marked on the bows, I trace that curve onto my window pattern as well as zipper start and stops. Then, on the table I extend the zipper marks and cut the curve 1" lower to allow for the zipper. That is the way i was taught.

Here is a picture of the window installed.





Whatever the cause of the wrinkles before was, this darting of the pattern between snaps helped me a lot.

[JuneC]

Whatever you did, I think they fit very nicely.  Good job on that one.

June