I have used magic water in the past mixed with my walkers white earthenware slip.  It is good but sometimes it wont cooperate.  Today I wanted to join and no magic slip made up

The best time to join is when all the pieces have the same moisture content.  This is often very hard to achieve.  One way is to put all the pieces in a plastic bag and seal it  Leave it on a shelf overnight or longer and some how like magic they settle with the same moisture content.  This works very well in slab construction.  I learnt this by accident when I couldn't put a slab pot together.  I put the bits in plastic and decided to forget it.  I got over it and all the bits were the same and went together like magic when I went back

Today I had to join.  They were little birds on a tile base  The parts were getting hard I used the following technique

Using a small brush put water on the approximate target
Using a small brush put some slip on top

Repeat on item to be joined
Place the two pieces together with firm but gentle pressure
Now they should be joined

​So easy, so simple

Keep looking at your joins  If you see any cracks paint with your slip

Recently I saw the exhibition Pieces of Shaun Hayes of Canberra (Often found in the Walkers Ceramics shop)  See his virtuoso joining  at his exhibition at The Stanley St Gallery

​http://stanleystreetgallery.com.au/artist/shaun-hayes/