Seized Zips

[Stormin Norm]

I have some seized zip's on an old cockpit cover which I am trying to free up, the zip is plastic but the carriage looks aluminium. I imagine they are salted up so can anybody tell me how to dissolve the salt and free them again.

Many Thanks

Norman

 

[ccscott49]

I tried fresh water, but the slider just disintegrated, why they make them out of painted aluminum for a marine enviriment is beyond me! This one was one a zodiac bag for the dinghy, really cklever!

 

[dickh]

Almost impossible - it will be a die cast material which corrodes fast in salt water. try soaking in hot water and scrubbing with a tooth brush but almost certainly it will have had it. You can get replacement sliders from people like www.baselinehardware.co.uk or www.pointnorth.co.uk
make sur e you get plastic replacements, if available or accept you have to replace the sliders every 2/3 years.

dickh
I'd rather be sailing...

 

[ccscott49]

How do you get the new ones on, are they split? My zip is sealed at the end. ie, not the jacket type zip.

 

[vyv_cox]

The deposit is not sodium chloride, which would dissolve easily, it's a mixture of carbonates and sulphates of sodium, potassium and magnesium. In theory this should succumb to a weak inorganic acid like hydrochloric very easily, but in practice my experience is the same as yours. The zip collapses during the process, not because the acid attacks the aluminium, it doesn't, but because the whole thing has been generally eaten away during the corrosion process. The answer seems to be to replace the zip in most cases, but you just might be lucky.

 

[AndrewB]

Had most success by applying vinegar and Coca-cola, alternately, plus careful picking with a needle. If you do succeed in opening it, the zip will still have to be changed, as it will go again very quickly.

Get a plastic one next time ... or use velcro.

 

[poter]

I am afraid that if the zip is a metal slider it has probably had it.
In the middle east we had to be very carefull with all metal zips as they corroded very quickly without some protection. We eventually came up with a silicon jell as being the best way to keep the salt etc away from the slider but working the zip and then just washing after each trip will do as well.


poter

 

[dickh]

Most of my bunk cushions I have replaced the sliders, they are not open ended, so I had to split/cut the closed end, and wriggle on the new slider. Had to sew up this end to prevent the slider coming off though, bit untidy but I didn't have to replace the zip which would have been expensive.
I also made sure the zip was not in the same place as previous, obvious by the staining, even though the zip was opened a little. And worked the zips at every opportunity.

dickh
I'd rather be sailing...