Those are plastic coil zippers with metal pull tabs and are a little more fragile than your other zips. The white corrosion (from the metal pull breaking down) needs to be dissolved before they can be freed, as they are being 'welded' in place by the corrosion. Then you'll need to lubricate and try to remember to unzip back and forth once a year to keep from this happening again.
A little hot water MIGHT help in dissolving that corrosion...

[QUOTE=Capt. Sam;16307]This is not a very technical issue but I didn't see a more appropriate forum ...[/QUOTE]

This would be a perfect topic for a category we don't have: Things that make you say $&#@!

I have thrown away plenty of seldom-used items that had that kind of zipper corrosion. It is very frustrating. I once tried WD-40 and it actually worked after a while. I am sure there is a better solution, though.

Howard, are you in the top/upholstery business? It would be good to have a Top Guy here since that's a pretty common $#4@%&# area.

Sam,
You might try a drop or two of PB Blaster on the white powder corrosion. That stuff works wonders for other types of corrosion.

I had the same problem, and ended up doing the following

1. Cut away at the metal of the zipper-pull with wire nippers until it fell to pieces.
2. Then unzip by just running a finger down the length of the zipper.
3. Remove the cushion, and turn the cover inside-out.
4. Replace the zipper-pull with new unit -- these are available from multiple sources on the internet. My zippers were "coil" variety 4.5 mm. Most zipper pulls will have a tiny number right at the top end that indicates the size.
---> Sailrite.com has several very good videos on zippers, zipper types, and re-threading new zipper-pull.
5. You will have to use a seam-ripper [any fabric store, or Amazon] to carefully open the stitching across the end of the zipper to place a new zipper pull in place.
6. Then resew just about 1 inch across the end of the zipper. I did it by hand, I don't have a sewing machine.

This was reasonably easy, and I didn't have to replace the entire zipper, and now the zippers all work perfectly. I suspect it was a lot cheaper than getting it done professionally.

Peter L

I have the same issue with my zippers. Peter, you mentioned turning the cushions inside out. How does one deal with the buttons?

I used WD40 and left them overnight - they all worked for me.

[quote=stu jackson c34;16322]I have the same issue with my zippers. Peter, you mentioned turning the cushions inside out. How does one deal with the buttons?[/quote]

I cut the thin twine connection between the front and the back, and then when I put the foam back in I used whipping line, and ran it through the cushion between the front and back with large needle, and tied tight to maintain the tension the way it was originally. It was actually very easy. While the foam was out I washed in the washing machine with bleach. The cushions look great, smell great, and the zippers work. I have done my whole set -- a great winter project.

PL.

Careful washing though - some material shrinks significantly and you might not be able to get them back on over the foam!

Bud; Yup; since I retired from the Coast Guard a couple years back I started a small home-based business doing dodgers and biminis, after taking a couple of courses and practicing on my last boat... (full enclosure).
I do just enough work to keep it fun, (mostly word-of-mouth), but I'm out cruising from mid-June to mid-Sept and somewhere warm for 3 weeks every Jan/Feb, (leaving for Cuba tomorrow - yippee!!); so I wouldn't call it full time by any means.

Cuba! You lucky dogs! Been there three times and what a great experience, our favorite spot in the Caribbean now. But we'll keep that a secret.

You lucky Canucks. We Yanks have a bit of difficulty visiting Cuba, but maybe that will change sometime during the next three or four years.