Polymer Coatings on galvanised Materials
IMPORTANT NOTIFICATION TO ALL CUSTOMERS
In recent years we have seen the use of a clear polymer coatings on galvanised products increase. Whilst the polymer coating has its benefits to protect the galvanised coating from exposure to the environment (in accordance from my enquiries made with steel suppliers) we have seen two different types of polymers in the market. One of these polymers does not appear to have any adhesion issues, whilst the other does.
It affects the application of powder coating as the powder is effectively applied on top of the clear polymer layer which is trying to bind to the coating rather than directly to the metal surface. This potentially impacts the adhesion and associated durability of the applied powder coating. The suitability of these polymer galvanised products for powder coating varies by manufacture (and product).
We strongly recommend customers supplying these materials to us confirm with their metal supplier regarding suitability of such materials for powder coating.
Unfortunately, it can be difficult to identify whether the material has a polymer coating and testing of every piece is not feasible or practical as you can appreciate. We have in the past conducted our own testing and sought advice from our powder suppliers, however as each metal supplier has multiple supply mills it is extremely difficult to track and identify which are problematic.
If suitability cannot be confirmed, we recommend removal of the polymer layer thought a quick whip blast and prime prior to powder coating to provide the most durable coating for these products.
In circumstances where customers request, we complete powder coating without confirming the suitability for powder coating or against our recommendation of whip blast preparation we are unable to provide any assurances to the performance or life of the coating either in the short or long term.
Please forward this information to the relevant purchasing people within your company so that they may be made aware of potential issues to raise with all your metal suppliers to ensure that material is suitable for powder coating.
Should you have any queries please do not hesitate to contact us in relation to this matter.
