I ran into a similar problem with copper plating which is used as a heat treatment carburizing mask. Nowadays they use paint-on compounds to prevent absorption of carbon during carburizing; but copper plating is the traditional method and more certain. You do not rely on a employee carelessly painting areas too thin, or getting splatter on areas that should not have compound. You plate the entire part and machine away the areas that you want to absorb carbon.
The electroplater used an alkali process, apparently more environmentally friendly than the traditional acid copper plating. However the copper plating blistered, even at the relatively low temperature of 135C post-plating bake to drive off any absorbed hydrogen during plating. It would not have survived the heat treatment temperature. The parts were re-done with the acid copper plating and it baked and heat treated perfectly.
-Doug