Most tap plastics carry the thicker stuff up to 1" and thicker on special order
Edges must be straight and square, most guys use weldon #4 because it's a little slower drying than #3. For very small gaps, #16 works. Much thickersd compared to #4 which is like water.
There is a technique of using "pins" in betwen the pieces to be "joined". What this does is raise the pieces up high enough maybe .032" so when you apply the "solvent" it will "wick" in between the two pieces and soften at the same time. After several seconds have gone by, you pull the "pins" out and just let the weight of the "top" piece settle into the softened area's. You aren't really "gluing" the pieces together but actually softening it up to "weld" together so to speak.
hth
