| Search our quarter-million Q&As |
Home of the finishing HOTLINE since 1989
-----Cleaner info required for galvanised steel
2001
Hi there, I work with a 5 stage pre-treatment process for Galvanised steel. (Cleaner, rinse,zinc phosphate, rinse, chrome passivation)
The cleaner we are using at the moment is Novaclean which contains caustic alkali,organic chemical additives and organic surfactants. It contains Potassium Hydroxide).
At the moment we have to have the cleaner tank temperature at between 35-45 degrees in order for the cleaner to work properly on the metal parts.
Does anyone know of a cleaner that can be used at room temperature or a lower temperature?Or know of a cleaner that doesn't contain as much alkali. The problem we are experiencing is that the pipes in the cleaner tank keep cracking due to substrates sticking onto the steel pipes and these are expensive to get repaired or replaced.
I would appreciate any thoughts on the matter.
Thank you,
Lisa WallaceFG Wilson - Belfast. Northern Ireland
Hello again
Refer to my answer to your later question. I assume your problem is scaling of the heater tubes. The KOH will etch the zinc and the dissolved metal will tend to scale up the heaters. I would suggest a low temp cleaner-coater which will clean without zinc loss and then a dry-in-place resin-chromate process I referred to.
The high pH cleaner is required to give a satisfactory surface for the zinc phosphate to react with.
Roger Bridger- Croydon UK
2001
Sorry! Finishing.com is temporarily Read-Only.
Ted Mooney is retiring but I have several offers to take it over.
We're working hard to make sure we find it the best new home.