First, you need to cut the old latex gasket off the fabric. It’s very important that you don’t cut into the fabric since this might cause a leak. Cut as close as possible to the fabric.

I usually leave about 2 mm of the old gasket on the side of the fabric. Most manufacturers glue their gaskets onto the fabric, so you will have to leave the part that is glued on the fabric.

The remaining latex is the part that you glue the new one onto.

Use the sandpaper to roughen the latex, this makes the glue more effective.

Next up, put the Nalgene (or any other) into the sleeve and make sure you have a tight fit. Use the rubber bands to make it sit in place, and not move around too much.

Take the new gasket, put it on top and make sure the gasket is pulled down so it fits on top of the old gasket.

Add a few rubber bands, and fold the gasket over the rubber bands.

Use the sandpaper to roughen the part of the new gasket that you are going to glue together with the other.

Add the glue in a fine layer on both the old and the new gasket. Black Witch cures quite quick, so you need to use the brush to spread it out right after you added it.

If you are using Aquasure, you don’t need to hurry, as it takes about 12 hours to cure – but don’t get any of it on your fingers, use gloves!

Let -Black Witch- glue sit for about 5 minutes or until touch dry, before using the popsicle stick to fold the new gasket over the old.

After connecting the gaskets, try to push any air bubbles out, as these can cause leaks.

Using Black Witch you should be good to go by now, but I usually leave it overnight before using it.

Aquasure (unless mixed with Cotol-240) needs to cure for 12 hours before it’s good to go.

To make it Bomb-Proof, I add a thin layer of Aquasure along the border of the seal. Here I use the masking tape, to protect the fabric and the gasket.