Sewing vinyl -- Help!

We have been doing some heavy duty canvas work for our boat, dealing with Sunbrella fabric. We were using a Brother home sewing machine. The last project, a sail cover, spelled finis for that machine. It just burned out but it had delivered yeoman service for many years.

Now we have a new project rebuilding the dodger. (A dodger is a canvas

-- Sunbrella -- enclosure with heavy clear vinyl windows, all supported on a metal frame with various big zippers to enable installation, removal and folding.) This job would need more than a small domestic sewing machine. So seeing a good buy, we bought an industrial high speed lock stitch sewing machine, a Yamata GC8500. This is one humongous mother of a sewing machine! It does 5,500 stitches per minute, is driven by a ½ HP motor and weighs, all up with table and motor, some 225 pounds. (For those interested, we bought it from Harbor Freight. Shipping for the whole shebang was only nine dollars. But some! assembly was required, like two weeks worth.)

We have figured out how to make straight stitches in any number of layers of fabric, though controlling the speed of this monster is a real and not yet mastered art. The problem lies with the clear vinyl plastic windows. We did this job once before with the old and now defunct machine and had no problems. But this machine is so fast it literally melts the vinyl, even causes it to smoke. We are not able to get more than a few inches of stitching of vinyl to Sunbrella before any number of bad things happen. The thread balls before the needle. The upper thread breaks. The upper thread shreds. There?s a bird?s nest on the bottom side. Etc., etc. Correcting one problem seems to cause another.

We are using best quality polyester thread. We bought a new presser foot made of plastic. We are using No. 18 needles.

Any ideas on how to deal with this problem would be most welcome.

Reply to
Gogarty
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Hi, I have a Yamata industrial also, cant think of model # but it does both straight stitch and zigzag. Have you tried a teflon foot, or is that the plastic one you mention? I believe most industrials can be tweaked to not go so fast, but no idea how to go about it. AC

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Reply to
AC

I have no idea, but there is an upholstery forum I know of where a lot of the people are experienced with boat covers etc. Ask your question here:

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Reply to
Lee & Cathi Thomas

Have you had the assembly of your machine checked by a professional? Speed can be adjusted by changing the pulley. Sounds like you have your machine threaded incorrectly or the needle in incorrectly. Practice on scraps is another way to learn to control the speed. You might be using the incorrect thread for your weight project. Can't tell from the pics I found online, but that is NOT a walking foot, correct? Your project would feed a whole lot better if you had a walking foot machine. It may be that you purchased an industrial that's suitable for garment making, but not heavy work.

ps

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Reply to
small change

5500 spm!! I would temporarily slow that bad boy down by changing pulley size, rather than relying entirely on feathering the clutch to control speed. You won't lose too much time in the overall project, my guess. (My mom said in jest that I always took my photographs at 1/1000 second because "He's so impatient"; same principle)

Maybe add a thread lubricator too. The needle is getting very hot, obviously. Maybe put a dry lubricant like teflon powder on the vinyl along the seam path. Maybe a leather needle would work better on vinyl to cut through, too.

JPBill

Reply to
WB

It pretty much is the wrong machine for the job. You should have looked into walking foot machines. That said you can do one of 2 things, aside from practice feathering the clutch and that will get better with time as it wears in. Change the motor pulley to a 2 inch O.D. pulley should reduce the maximum speed by at least

1/3 maybe half depending on how they set it up. The other is far more expensive but it will allow you vastly more control over speed, purchase and install a servo motor for it these have a radio like dial on them to turn the speed to near zero or maximum and everywhere in-between, it has no clutch and is the next generation of industrial machine motor.
Reply to
Ron Anderson

You wouldn't be the first one that's made a poor "Industrial machine"purchase. Industrial machines are very single purpose, they are not all the same. I too purchased a too-light duty machine for my first one, so don't feel too bad.

Reply to
small change

Reply to
Melinda Meahan - take out TRAS

Many thanks to all for your comments.

After a great deal of twiddling and fiddling with timing and tensions we are getting it to work properly. It ain't pretty yet but it is secure. Just needs a lot more practice on feathering the treadle but we are not burning the vinyl anymore, have stopped breaking threads, no more rats' nests on the bottom side and are getting even and good looking stitches. Straight stitching not yet but the first part of the job was a circular window and it's done.

As to individual comments: no, it is not a walking foot. I can certainly see how that would help. The Teflon presser foot does help.

Changing the pulleys is top priority. There is just no way we need anywhere near 5,500 stitches per minute.

I am no judge of sewing machine quality but this one impresses me as very well built indeed. One thing it's not going to do is jump around the floor. It does appear to be a discontinued model since the site now mentions an

8500 but not GC8500.

As for Harbor Freight, we have bought a lot of stuff from them and have had no complaint about anything so far. They slap everything with their own brand name (mostly Chicago). Dig a little on the Model 03914 Sewing Machine Single Needle and you find a Yamata GC8500. How they ship this thing, including motor and table, from California to New York for nine dollars beats me.

We buy a lot from Sailrite but not sewing machines. I have also had very good advice from them on their web site. But they are not cheap. And the Sailrite 111, top of their line, is in fact a Yamata but geared down with different pulleys to 3,500 stitches per minute. They also sell the servo controled drive for this machine. Big bucks.

For the kind of sewing we will be doing, this machine will be fine. We also have a table top machine with all sorts of bells and whistles. It's not up to this job. An elderly friends gave us an ancient machine that folds away into its table and doesn't work. And we have a tiney littl;e machine taht my wife got from some mail ordser place that actually works off batteries for tiny jobs. We keep it on the boat.

When all else fails there is always needle and thread and a leather palm. My wife's hand sewing puts most machine sewing to shame.

Reply to
Gogarty

Good thing it is the stuff you use and not something you sell. If you can get it to sew with size 69 thread that is a near miracle and anything lighter is just poor choice for that type work 99 or 138 would be far better. Good luck in your endeavor.

Reply to
Ron Anderson

Grin. You betcha. We are calling this our Mikado Dodger. A thing of rags and patches.

If you can

I know nothing from thread size numbers. What we are using came from Sailrite. The label says "Ultra Dee Bonded Polyester" Also "DB 92" and "T-90." Is one of those the thread size?

There is much more work to do. Cushions and upholstery.

I can't tell you, people, what a huge load off my mind success with this thing is. I was sure we had bought a very expensive anchor. We have had this thing since early March. In the end, proper timing seems to have been the solution. But you won't find much help on that in the manual. Sailrite's web site steered me correctly.

Reply to
Gogarty

Those are both the size just 2 different designations and I do not buy for 1 minute you can get that machine to sew well with it. Best of luck to you

Reply to
Ron Anderson

Thanks. But it is sewing just fine now.

What astounds me is how much tension is needed on the top thread to get it to sew just fine.

Reply to
Gogarty

That is because you are trying to pull to thick of thread through the thread clearances. Take a look at the hook, at 12 o'clock there is a position finger. Watch the thread while turning the machine by hand. Be sure there is some materiel under the foot. You should be able to see it bind there. That clearance is to small for that heavy of thread. The machine is designed as a dress makers machine for light to medium weight materials. and regular all purpose sewing thread. I wish you luck

Reply to
Ron Anderson

Again, thanks. Job finished. The sewing wasn't complex but the geometrics were. The "Mikado" dodger is quite a complex shape. It might have been easier to builkd a new one from scractch. Now we are just doing yards of straight stitching.

I have bookmarked your sites.

Reply to
Gogarty

You should give Ron's opinion a lot of respect. He's been a sewing machine repairman for lo these many years. How long is it that you say you've been sewing? Sharon

Reply to
Seeker

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