I don't understand why it is necessary to iron down rubberized bellows
cloth. I have been using hot glue and bellows cloth for nearly thirty
years and have never used an iron to settle the glue out. When I
started out learning the player business I worked with an old
gentleman who actually worked in several player and pump organ
factories; he showed me the ropes from a factory type point of view...
They never ironed the cloth down and they never had it fail. I have
had players that got caught in basement floods and the hot glue still
held pretty well on most of the bellows. The only time that I have
ever used a hot iron on cloth was in removing it. heating the edges of
the cloth with an iron only helps to break down the rubber barrier and
dry it out even faster than nature. Leave the iron in the laundry room
where it belongs and let the glue do the work it should, all by itself.

Jim Jelinek