Sewing vinyl - how to stitch?

[jlinder]

I have rebuilt some cushions on my boat and they have come out pretty good, but I notice that as time goes on the stitches I used are not as tight as they should be.

I suspect that I used the wrong stitch or method on the vinyl. Not out of the question since I started by just sitting down and sewing and guessed at the best approach. (I have vinyl and thread designed for boating so it is not the material). I have been trying to research this on the internet but have been coming up empty.

What I am looking for is examples - what stitch to use, procedure, is there backing to use, etc. Pictures would be great. (I look at my cars upholstery and see it is sewn very differently, so I know I have a lot to learn.)

Can anyone help?

 

[gewf631]

Re: Sewing vinyl - how to stitch?

I look at my cars upholstery and see it is sewn very differently, so I know I have a lot to learn.

I think the stitch you refer-to, is called a "flat-felled" stitch (the same you'd see on blue jeans). It amounts to runing your stitch, but leaving an extra half-inch of material (that you might normally cut off). You then fold this stitch underneath (to one side), and run a new stitch with all 3 layers maybe a quarter-inch from the original (I've seen it with 2 layers, but 3 is better).

If you Google that stitch, you should be able to find some examples.

Also, see if your local library can get a copy of Karen Lipe's, The Big Book of Boat Canvas: A Complete Guide to Fabric Work on Boats - otherwise, it's about $15 on Amazon. This book will take you step by step through work such as this.

Finally, this forum might also be some use.

 

[burroak]

Re: Sewing vinyl - how to stitch?

Go to www.sailrite.com and look in the menu on the starboard side, click on "instructions and tips". It may be helpful; price is right anyway.

If someone is looking for a Dad's Day gift idea, Canvaswork & Sail Repair, by Don Casey, at Barnes and Noble is a good bet.

 

[bruceb58]

Re: Sewing vinyl - how to stitch?

I have done mainly canvas work but have done a little upholstery lately. You pretty much only want to do the one stitch. You really don't need/want the sew the flap that is left over from your seam allowance. It will just weaken the vinyl because of all the extra needle holes.

The flat felled seam that gewf631 mentioned is a little more complicated than the one he described. The one he described is commonly known as an overlap seam. The flat felled seam looks like this:

 

[BillP]

Re: Sewing vinyl - how to stitch?

Tight stitches are all about thread tension and nothing else. Upper is adjusted on the machine and lower on the bobbin case (the tiny screw that holds the leaf spring). Large thread requires more tension.

What size needle and what size and type thread are you using? What machine?

bp

 

[bruceb58]

Re: Sewing vinyl - how to stitch?

The thread size that should be used is a #92, and you should only use polyester thread because it is UV resistant. If you used a nylon thread, that could be one of your problems.

What kind of machine are you sewing with?

 

[BillP]

Re: Sewing vinyl - how to stitch?

For what its worth...Most marine shops use polyester thread for exteriors and interiors because it does double duty for both. However, nylon sews easier and is fine for interior work where uv isn't a problem.

Also, many modern home machines don't handle V92 size thread very well. V69 or V46 is smaller and better for them. Older home machines from the 1950-60s operate with V92 ok. Industrials do V138 thread with ease.

bp

 

[bruceb58]

Re: Sewing vinyl - how to stitch?

I was assuming he was talking about exterior upholstery. I agree nylon is fine for interior.

 

[Mark42]

Re: Sewing vinyl - how to stitch?

I used a simple $100 home grade sewing machine to stitch my top. It was my first attempt at sewing up a convertable top and although not all the seams are straight as an arrow, the tension applied by the sewing machine was enough that none of the seams are coming loose.

So my point is that you might just want to play with some scraps and the tension adjustments to see what kind of results you get from your machine.

Also, becasue you are sewing vinyl, the thread may have more resistance to pulling tight and may require the sewing machine to be set at a higher tension to get tigher stitches.

 

[bruceb58]

Re: Sewing vinyl - how to stitch?

Mark42,

What type of thread are you using?

Those $100 machines use plastic gears and have a very tough time surviving more than one full boat cover.

 

[Mark42]

Re: Sewing vinyl - how to stitch?

Bruce,

The thread is what Rochford supply suggested for sewing a marine convertable top. I ordered the material, thread (that huge spool) and all hardware from them. So I'm sure they set me up with the right stuff.

I was not sewing vinyl, more like shark skin, so it did sew with no problem. I think most people underestimate the power of a simple sewing machine. In fact, home machines are designed to handle heavy material like vinyl, denim, fake leathers, etc. So boat materials are not a real problem if you don't force it and run the machine until the motor gets hot. Just give it a break.

I have never had a sewing machine die from use. They die from NON-use because of being stored in a damp basement the mechanisms rust up, etc.

BTW, I didn't see any plastic gears in that machine (I think a Sears).

But I am sure it I subject that machine to repeated extended hard use, it will eventually fail.

 

[bruceb58]

Re: Sewing vinyl - how to stitch?

When I sew canvas, I am sometimes running through 7 layers of sunbrella if I am atatching a tiedown and cross a flat seam. You don't want to do that too many times with a home machine.

When I do a snap in cover, I sew in webbing strap for reinforcement along with double fold binding. That is 5 layers of Sunbrella and a layer of binding!

 

[jlinder]

Re: Sewing vinyl - how to stitch?

Thanks for all the help everyone. Sorry I have not answered all these posts as i have been swamped with work and unable to get back to the forum for a while.

The machine and thread I used is very similare to what Mark42 shows in his picture. In fact, the thread looks exactly like the spool I have.

I suspect the biggest problem I have is in the way the vinyl was put together. The overlap join looks like it would be a big help.

I hate to admit it, but when I started I just did a simple join, sewed the vinyl together from the back side, then reversed. After time the vinyl stretches and on some seams you can see the threads. Just my ignorance.

How do you do welting with the overlap seam? With the seam I used I just sandwiched the welting between the vinyl, but with the overlap I am confused.

Also not sure on the needle size. Finding places to purchase sewing supplies is getting tougher these days, and I was just happy to find a place that sells needles for my machine. Anyone have a good place to purchase supplies for plain old home sewing machines to sew vinyl?

Thanks everyone for your responses.