09 March 2010

Swedish Furled Foam

Cabin Boy's build is now proceeding smoothly... I'm perfecting my planking technique, but nothing to exciting to report, so I thought I'd take a bit of a diversion...

While finishing up Cabin Boy, I'm also preparing for my 2000 mile voyage on the Blue Moon.

One piece of Blue Moon equipment that desperately needed replacement was the bunk cushion. The old one was grungy, damp, and well past it's due date. I chucked it onto the garbage pile while I was down in Florida, and thought I'd just buy a replacement.

That was until I got a quote for $450! No way I was going to plunk down a King's ransom for a bit of foam. Surely I could make one myself for less? And -- more importantly -- learn a valuable new skill.

Luckily for me, my mom had given Helena her old Singer sewing machine. This machine dated back from the 60s and had all metal parts. It looked tough enough to sew a few layers of vinyl.

Only problem was, neither Helena or I had any idea how to use a sewing machine.

Luckily, you can download anything from the Internet, so I found the old user manual for the machine on the Singer site, sat down, and Read The Manual.

The machine needed a bit of cleaning, a good oiling, and a new drive belt, but once it was tuned up, and I'd figured out how to thread the needle and bobbin, I was off and running. As my mother said, anyone can learn how to use a sewing machine in a few minutes, and she was right.

I had ordered 4" firm foam from FoamByMail.com. They have quite a few choices, so I called up customer service for advice. I ended up buying the HD36 High Quality foam with Dacron Wrap for a bit over $100. It came by UPS in a few days. Here's what it looks like:

HD36 Foam with Dacron Wrap

The Dacron wrap is mainly for comfort, but I thought it would also make the foam a bit more moisture resistant.

For a cover, I ended up following the Pardey's advice and making a vinyl cover. The Pardey's use a vinyl cover for water proofing, and then add a cotton slip cover for comfort. I'll add the cotton cover at a later date. I bought 5 yards of very nice vinly for about $40 at a local fabric shop. It feels like leather. Nice!

I turned my living room into a lofting floor and cut out the 4 pieces: top, bottom, and two long strips that I'd butt together for the sides.

I planned on sewing the foam into the cover: no zipper, velcro, flaps, etc. The reason was simple: the friction between the dacron and the inside of the vinyl was about 50,000 lbs. No way you'd be able to pull the foam out of the cover, unless you had a big opening on the long side. If I ever need to remove the foam, I'll just take out the stitches on one side and re-sew.

Living Room Loft Floor

Once the pieces were cut out, I marked the sewing lines on the inside, using what sewing people call 'chalk', but what I would call wax. I left plenty of border to work with. After sewing, I trimmed it back to about 1/2"

Measuring and Marking the Sewing Lines

Then it was time to pin the pieces together and start sewing. This was pretty easy, at first...

Sewing the First Few Seams

But quickly got complicated as the mass of material being moved through the machine got bigger and heavier. But a heck of a lot easer than sanding Blue Moon's bottom!

It gets big and bulky, quickly!

Faster than I expected, I had all the seam sewn except for one on the short end, through which I intended to insert the foam.

One seam left open to receive the foam

Now, it would have been absolutely impossible to insert the foam full size. I'd cut the cover for a fairly snug fit, and the friction between the dacron cover and the inside of the vinyl was fierce.

If I hadn't thought of a trick, I would have left the long side open, which is probably what the commercial companies do.

However, while trying to figure out how to get the foam inside, I remembered something called Swedish Furling. I guess this is a knot the Swedes use to tie their furled sails up. (I'm of Swedish ancestry, but this is one fact that wasn't passed down from my great grandfather, so I'm assuming.)

You can find a how-to on how to tie this knot on the Internet, or in Brian Toss's book, but here's what it looked like applied to the foam:

Swedish Furled Foam

It's hard to tell from the picture, but the foam is probably 'furled' by about 30%. That makes the foam small enough to slide into the cover easily.

Of course, the trick is untying the foam after it is inside the cover. For that amazing trick, I've made a little video:

The family that builds together...
Just click on the video to play

Once the foam was inside, all that was left was to sew up the last seam by hand.

And, of course, to try it out.

Ahhhhh! A few hours work. Savings: approximately $300. And that's not counting the value of the now tuned-up sewing machine and the ability to use it for other projects.

Bottom line: if I can do it, anyone can. Definitely worth the effort. You can find one of these all metal Singer machines on eBay for under $100.

>>> Next Episode: Planks and a Scarf

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  1. Thanks for the ideas! My husband and I are contemplating the same project for our Bahama 30's old cushions.

  2. Clever idea with a flawless execution.

    Congrats all the way around!!!

  3. Yes, I thought that little trick was worth a video. Sure glad it worked!

    By the way, I'm wondering what people think of videos. Worth doing?

  4. I thoughoughly enjoy all your postings on the building of your sloop and all the maintenance on the Blue Moon. Thanks for sharing!
    All the best, KT


  6. Just started reading the blog John (for the celestial navigation primer)so this is a bit late to have helped this time but a trick to insert the foam is to place it in thin plastic (like at drycleaners) and apply a vacuum which reduces the dimension by at least haf so it is easily inserted into the envelope.


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