Johnson and Allen make the best weld crack detection dye penetrant inspection spray cans in the world, which has been a very popular product here at Spectrum Welding Supplies Ltd for 20+ years.
Here below listed are the x3 J&A DPI spray cans used in conjunction which each other to uncover any weld defects:
JAC-2 Cleaner: 400ml clear spray (in stock)
J.A.P Dye Penetrant: 400ml red spray (in stock)
J.A.D NEOPEN Developer: 400ml white spray (in stock)