Flexible window material recommendations

[Bran]

Hi, I would appreciate some recommendations for flexible window material in the uk. I am looking at replacing the front windows on the canvas hood on my Broom, the windows slope so any distortion is more noticeable than if they were vertical. I will be sowing them in.
I can see a few websites, eg pro fabrics, cjmarine, atwoolls, but would appreciate recommendations from people that have first hand experience.
Many thanks.

 

[bigwow]

Kayospruce keep a range of different thicknesses of window material

 

[Bran]

Kayospruce keep a range of different thicknesses of window material

Thanks I will have a look.

 

[Hurricane]

I think you will find that this material is all pretty much the same
I use the Medium Weight one from ProFabrics/Point North.
That is the .5mm thick one.
This one:-
CLEAR WINDOW PVC - MEDIUM WEIGHT | Profabrics

As you are finding, the canvas part of your covers outlasts the window material.
Apart from discolouring, the biggest problem is shrinkage.
When fitting new window material, make sure that you allow for the shirnkage of the old window material.
Also check how the old window material was fitted to the canvas.
If it has been welded, you will need to cut out the welded part of the old canvas.

To fit new window material to the old canvas, I allow about 25mm overlap.
And then stick it in place using Venture Tape.
Venture Tape is a strong double sided tape - I use it everywhere - especially when sewing - fantastic stuff.
You just stick your canvas together and the sew through.
You can get Venture Tape from Kayospruce but they are usually only trade only so you would need to set up an account.
I have had success from this supplier of double sided tape:-
Sailmakers double sided clear Acrylic basting tape for fabrics,canvas,sails. | eBay
For fixing window material, I use the 25mm wide tape.
Then I sew two rows of stitches (not zig zag) around the window to hold it in place.

My sewing machine is a Sailrite so it handles jobs like this easily.
A domestic machine might struggle but it would be worth trying.
The Sailrite is particularly good at sewing consistently spaced stitches.

I will post a photo of the last job that I did - it is here at home at the moment and, as usual, a photo is worth a thousand words.

 

[Bran]

I think you will find that this material is all pretty much the same
I use the Medium Weight one from ProFabrics/Point North.
That is the .5mm thick one.
This one:-
CLEAR WINDOW PVC - MEDIUM WEIGHT | Profabrics

As you are finding, the canvas part of your covers outlasts the window material.
Apart from discolouring, the biggest problem is shrinkage.
When fitting new window material, make sure that you allow for the shirnkage of the old window material.
Also check how the old window material was fitted to the canvas.
If it has been welded, you will need to cut out the welded part of the old canvas.

To fit new window material to the old canvas, I allow about 25mm overlap.
And then stick it in place using Venture Tape.
Venture Tape is a strong double sided tape - I use it everywhere - especially when sewing - fantastic stuff.
You just stick your canvas together and the sew through.
You can get Venture Tape from Kayospruce but they are usually only trade only so you would need to set up an account.
I have had success from this supplier of double sided tape:-
Sailmakers double sided clear Acrylic basting tape for fabrics,canvas,sails. | eBay
For fixing window material, I use the 25mm wide tape.
Then I sew two rows of stitches (not zig zag) around the window to hold it in place.

My sewing machine is a Sailrite so it handles jobs like this easily.
A domestic machine might struggle but it would be worth trying.
The Sailrite is particularly good at sewing consistently spaced stitches.

I will post a photo of the last job that I did - it is here at home at the moment and, as usual, a photo is worth a thousand words.

Thank you, that’s really useful. I will be using my trusty Singer, checked its manufacturing date, 1917! It has done a fair bit of maintenance so far so should be ok... probably.

 

[Hurricane]

Here is the pic that I promised.
The photo is from new cockpit covers that I made myself.
I'm using the same white PVC that Princess use on new boats.
The pic is from the inside and shows the 25mm overlap of the window material.
I have also turned the inside border of the window over to give a nice edge.

I laid it all out on a flat surface (the floor) and stuck the window in using the double sided Venture Tape.
If you are careful, the new window material doesn't move while you sew it.

I hope that helps

 

[seanfoster]

Hi Bran,

I thought I'd add to this thread as I run a marine canvas business, and I'm regularly asked to replace windows in covers!

First of all the material - unfortunately pvc window material is the achilles heel of a boat cover, on average you will get about 5 years from the material before it starts to go cloudy and become brittle, this is due to the plasticisers in the material leaching out over time, and not helped by UV. There are products available which will restore (to an extent) these properties such as boatsheen, but when it's past it's life, it's time to replace it.

In the US, a different type of material such as Strataglass or Osea is used which is a press polished vinyl. It comes in sheets rather than rolls, but costs 10x more than the equivalent gauge PVC window material, it is much more optically clear, and has a scratch and UV resistant layer built in, it lasts in tropical climates up to 10 years. It's avaible here from Kayospruce, but not widely used due to the cost!

PVC window material comes in 3 common thicknesses - 20 thou (0.5mm), 30 thou (0.75mm) and 40 thou (1mm) (also a 0.25mm thickness, but really is far too thin).

20 thou is very comonly used, however I only use 30 thou as it is much more optically clearer than 20, and sits much better in a cover with less ripples, 40 thou can be used, and would give even more clarity, but doesn't like being rolled up very much.

I buy all my materials from Kayospruce in Fareham, you don't need a trade account to use their counter, but don't think they will be serving customers at the moment, they may take phone orders. Point North basically sell Kayospruce products at retail prices, so you might be better off with them.

Kayospruce do a Taiwanase range of pvc which is cheap and chearful but does the job, also a range called Crystalview which is the next one up, and one that's not shown on their website but is far superior is a range called Renolit made in Germany, which is what I've been using and is a really good product.
One thing to bear in mind is that all of these materials scratch easily when manhandling them for fabrication, so be careful when dragging them over a floor or table.

A problem when replacing windows is losing the shape of the cover, the way I install a new window is to leave the old one in place, put the new one in very slightly bigger than the old one (about 12mm in all directions if possible) hold it in place with seamstick, add a binder border to the rear face for a nice finish, sew everything in, then cut the old one out.

There is a good video here on how to do it.

One thing to mention, I use a Juki walking foot needle feed industrial machine to go through two layers of canvas, 0.75mm PVC and 2mm thick binding using v60 UV resistant polyester thread (which is about 20 times thicker than domestic cotton!)
A Sailrite machine can handle this, but a domestic machine definately can't (I know, I've tried!)
By the way, nylon thread should never be used outdoors as it is not UV resistant.

If you need any more info let me know!

 

[Scubadoo]

Seanfoster, I found your video very helpful, I might now just try doing it myself. Thanks for taking the time to write this up

 

[Bran]

Thanks for all the information, much appreciated. I have been using v60 thread so have lots of that, my machine has surprisingly been handling that ok so far. I will let you know how it goes.
Thanks again everyone.

 

[timbad]

Thanks for all the information, much appreciated. I have been using v60 thread so have lots of that, my machine has surprisingly been handling that ok so far. I will let you know how it goes.
Thanks again everyone.

+ 1 for Salrite and Kayospruce
Thanks Hurricane & Seanfoster great information

 

[Hurricane]

I can see that sewing the new window in and then cutting the old out keeps the shape.
But I'm not sure that I like the finished job as it will have some of the old material doubled up.
Also, the Sailrite video doesn't make any provision for the shrinkage of the old window.
In Sean's post above, he suggests about 12mm all round.
Obviously that depends on size and age but it sounds about right to me.

So, if you are going to allow (say) 12 mm for shrinkage, why not simply cut the new window to the new size allowing for the shrinkage.
Mark it all up, remove the old window completely and then sew in the new window to the marked points.
That way you will have a proper job at the end and none of the old material left in the job.

 

[PetiteFleur]

I also have used Kayospruce for both window material & acrylic. I use a Singer 20u machine which is a semi-industrial sewing machine and is good - reasonably priced on ebay. I also sew the window in place before cutting out the old window. Must use venture tape.

 

[seanfoster]

Good information here form everyone, one thing to add, you might want to ask your local sail maker or cover maker for a price, I usually charge around £50 to replace a window up to 1m2 (as long as it's brought to me, and clean!) so might be worth it if you are struggling for space, equipment etc.

 

[Hurricane]

Good information here form everyone, one thing to add, you might want to ask your local sail maker or cover maker for a price, I usually charge around £50 to replace a window up to 1m2 (as long as it's brought to me, and clean!) so might be worth it if you are struggling for space, equipment etc.

Good advice
We often dig so deep into a problem that we forget that there are professionals out there that do this kind of thing all the day.
Especially those small jobs, it isn't worth the hassle of buying a cheap sewing machine and then the frustration of getting it working.
Factor that in with a much better end job.

 

[Bran]

Thanks all, I have had the windows replaced before by a cover maker at a reasonable cost, however I very much like doing these things myself. I may have a go at making the whole cover myself in a couple of years time, so this is just a bit of practice. Doing the cover myself will partly justify the purchase of a decent machine, it has to replace an elderly but capable small machine.
Getting a decent cover made when you want it and how you want it is not always that easy. I do almost everything else on the boat so why not the canvas? More skills to learn, that’s what I enjoy.

 

[seanfoster]

Thanks all, I have had the windows replaced before by a cover maker at a reasonable cost, however I very much like doing these things myself. I may have a go at making the whole cover myself in a couple of years time, so this is just a bit of practice. Doing the cover myself will partly justify the purchase of a decent machine, it has to replace an elderly but capable small machine.
Getting a decent cover made when you want it and how you want it is not always that easy. I do almost everything else on the boat so why not the canvas? More skills to learn, that’s what I enjoy.

Have a look at the Sailrite videos for making a new cover, there are hundreds!
I'm not saying this to drum up custom, but be aware that making a cover (depending on what type of course) is a very time consuming and skilled task, I've been doing this for 10+ years and still learning, but by all means go for it.
Never use an existing cover as a template as it will always lead to fitting problems, each cover should be patterned from your existing frames and fixing points.
Patterning can take up to a day for a large cover, the accuracy and fit of your pattern will ultimately reflect the fit and quality of your new cover and is a complex skill to learn on it's own!

 

[Bran]

Have a look at the Sailrite videos for making a new cover, there are hundreds!
I'm not saying this to drum up custom, but be aware that making a cover (depending on what type of course) is a very time consuming and skilled task, I've been doing this for 10+ years and still learning, but by all means go for it.
Never use an existing cover as a template as it will always lead to fitting problems, each cover should be patterned from your existing frames and fixing points.
Patterning can take up to a day for a large cover, the accuracy and fit of your pattern will ultimately reflect the fit and quality of your new cover and is a complex skill to learn on it's own!

Thanks for the tips, all taken onboard, literally! I’m not expecting it to be easy and am weary that there will be mistakes, I just like to push my limits, especially now I am retired and looking for projects.
Thanks again, much appreciated.

 

[Hurricane]

Have a look at the Sailrite videos for making a new cover, there are hundreds!
I'm not saying this to drum up custom, but be aware that making a cover (depending on what type of course) is a very time consuming and skilled task, I've been doing this for 10+ years and still learning, but by all means go for it.
Never use an existing cover as a template as it will always lead to fitting problems, each cover should be patterned from your existing frames and fixing points.
Patterning can take up to a day for a large cover, the accuracy and fit of your pattern will ultimately reflect the fit and quality of your new cover and is a complex skill to learn on it's own!

Having just spent 2 years learning how to use the Sailrite, I agree 100% with what you say.
The cockpit covers for my Princess 67 take me about a month to make.
I do it as an enjoyable pastime so I don't spend much more than a couple of hours a day.

I've been sewing with a sewing machine for about 20 years - used to make spinnakers for my Hurricane sailing catamaran.
But spinnaker fabric is very light and runs through a domestic machine really easily.

I started this thread two years ago.
Sailrite
At the time, I wasn't sure if it was worth buying a Sailrite.
But now that I have had one for a couple of years, I really like using it.
There is absolutely NO electronics on the machine.
Everything is good old mechanical components.
Support from Sailrite is excellent - mainly in the form of videos.
Apart from "how to make" videos, Sailrite also have lots of videos on the actual machine - ow to maintain it, and more importantly how to fix it.

Have a look at that thread.
I have made loads of mistakes.
Most of my mistakes have been in buying cheap materials.
In the thread, you will see that I made lots of covers using some cheap grey fabric.
That was the BIGGEST mistake.
The material didn't last in the strong Med sunshine.
See in this photo


So, rather than using Sunbrella or the cheaper Sauleda fabrics, I managed to track down a good supply of the linen faced PVC that Princess use.
This PVC is really easy to work and I know that it lasts about 10 years because we bought our Princess from new and she had that particular material fitted.
The PVC fabric has a finished face on one side that has a linen style texture.
See this doorway/zip mockup.


The above photo also shows how consistent the Sailrite's stitches are.
There are 6 thicknesses of material stitched in the above photo plus the needle went through the plastic part of the zip.
I think you would find it impossible for a domestic machine to do a job like that.

But, as Sean says, patterning is probably the hardest bit of the job.
I'm afraid I guilty of using the old covers as a template.
Sorry Sean, but you are absolutely correct - old covers don't make good templates.
And remember, old covers have always shrunk.
To make templates, I use a product called Fibertex - see here:-
PE Fibertex 183cm Patterning Material (4 colours)
I am also using it to template up the synthetic teak decks that I'm currently making.
To get an idea of how to use the template material, here is one of the many videos that Sailrite have on Youtube.

For me though, it has been a worthwhile challenge.
My covers aren't as good as you would get from a professional but I'm getting better all the time.
And during the lock downs it has been really useful to have a project that keeps the mind active.

And, of course save money.
I have paid for my Sailrite several times over now.

 

[14May1995]

For what it’s worth...if using a domestic machine buy a Teflon foot - won’t stick to the plastic! Replaced my windows (in the Med) about 3 years ago! Still looked fine but had complete set of new covers fitted last month. They’ll be old by the time we see them!?

 

[Bran]

As an update I am fairly happy with the job I made of replacing the front windows. This is a summary of the main points learnt:
The original windows were welded in and were replaced a few years ago by a canopy company who sewed them in using a backing of similar material, looking a bit sad now. I took onboard the comments about fitting the new windows before removing the existing windows, but this would have resulted in a very messy finish:, this is the original window looking from the inside.

So I templated the 3 original windows, plus took lots of measurements, then removed the original windows.
Using the templates and measurements I managed to sew the new windows in, managed to get a roll of clear tenara thread at a reasonable price from eBay.
final result:

Many thanks to all who contributed, the result would not have been nearly as good without your input. Maybe I will tackle the rear windows soon, the whole canvas is getting tighter due to shrinkage.