I am using YKK zips and am wanting to change a normal zip to a head to head opening zip. I have tried this on all my zip types and it works ok on the antique brass sample but on the silver or nikel types the puller that faces the incorrect direction does not slide smoothly.
I have also tried it on some Excella tape I have. I have spent time at YKK trying to resolve this issue without success. I was hoping for a special slider or wondered if the teeth are different for this application but it does not seem so. I have tried rubbing the zip with wax paper (a You tube suggestion) which helps a little but not enough to satisfy me.
Any suggestions or relevant info would be appreciated. I have a large stock of zips and do not want to have to buy special head to head zips for small projects.
I tried to order the excella tape from leather box but they couldn't ship to the UK. Said they were working on it though.
Unfortunately, to get a smooth opening and closing zip with 2 sliders head to head, you will need to use tape with teeth especially designed to do this. That way you can pull on each slider and they move apart with equal smoothness. A special slider is not needed, special teeth are.
You will find a link to YKK Excella tape that can be used in both directions on the course supply page for 'The Cutler Briefcase'.
Alternatively take a look at Riri 'Simmetrica'. So called because each tooth is symmetrical, which is what you need.
https://www.riri.com/products/riri/chains/simmetrica/