The zip on my AV undersuit has finally broken - the tag on the top slider broke off, the bottom slider fell off and all the teeth are looking very sad.

Does anyone have recommendations for replacement zips? Something big, chunky, and durable - good for cold fingers and lots of mud. I'll probably have a go at stitching it on myself, though if anyone can recommend someone who does oversuit repairs that might be best - the way the zip goes up around the side of the neck on the AV makes me think that stiching a new one on might be difficult.

Dennis Jump has repaired several of my suits (even though I didn't buy them off him); I guess you can Google him for details. He does a good job, quickly.

I just tried Googling 'jump suits' and got a load of rubbish, but 'dennis jump suits' works.

We've done one (well my wife has)

Used a unbranded chunky zip , works fine. Unpicking the zip was tedious and took longer than usual. Putting the new one in took two attempts. Wifey didn't realise the zip went round the side of the neck and tried to put it in straight, when I pointed out the error she took it out and did it properly. There are enough reference points in the suit to make it fairly easy. A sewing machine was used

By the time my zip went a lot of the seams had started to wear thin and had some small holes appearing, these were sorted at the same time. Might be worth checking before paying someone to put a zip in.

The type of zip that an AV suit comes with is called a coil zip, braided zip or nylon zip and they wear out. Chunky zips last a lot longer. YKK call their chunky plastic zips 'vislon' zips and the best size is number 10 or 8. The best quality zips are very cheap to buy.  http://www.ykkfastening.com/products/zipper/vislon_zipper/vislon_standard.html

You need to decide if you want to be able to pee easily without taking your suit down. If you want to pee then a double slider zip is best. I've always gone for the holding it in option. It makes for a shorter zip and a stronger more realiable job. For that option you want a single closed end zip. I have always gone for the shortest zip I can manage with which is about 16". Closed end chunky zips of the right length are quite easy to get because they are often used on cushion covers.  http://www.ykkfastening.com/products/types/s_zipper.html

Don't get black. Get a light colour and use contrasting colour thread because it's easier to see what you're doing. It's a very easy sewing job but if you can't do it yourself look around for someone advertising that they do alterations and repairs. They are all around the place if you look or ask in your local haberdashery shop when you're buying your zip.

I wouldn't recommend hand sewing for a zip and I guess you don't have a sewing machine or you would not be asking this question. Just in case you do want to do it. Unpick the old zip (there is a tool called and unpicker, very cheap). Close the new zip and pin it in from the top down with the garment laid flat and without stretching the fabric. Make it wide so the fabric is away from the zip teeth. You can either sew over the pins if you're confident or tack it by hand and then remove the pins before sewing. Sew the zip in and sew together the seam between the bottom of the zip and the crotch with a zig zag stitch. You can add a reinforcing patch across the bottom end of the zip for a stronger job.

Buy a cheap second hand sewing machine and have a go. It's satisfying and you can sometimes make better outdoor gear than you can buy.

Would you consider replacing with a velcro fastening?

Dennis is my go to guy for oversuit repair.

I save good zips off throw away coats etc and hand stitch using button thread doubled through the needle.

Saving old zips gives a source of sliders as well.

I now buy new PVC rainsuits and pay Dennis to add replacement chunky YKK zips before I even use them - it still works out way cheaper than an overpriced plastic caving suit.

Thanks for all the replies, lots of really good info! One day I'd love to own a sewing machine, but I don't have the space and move flat too often. So I've emailed Dennis to see if he can do the repair - seems a lot less likely to fail than doing it by hand!

I got the suit back from Dennis today and it looks very nice - double ended chunky YKK zip, and it looks as good as new! Would recommend if you're not able to fix a zip yourself.