How to get the best out of your Anodising and other tips

Here are some general pointers to take into account when getting anodising done:


1.  Anodising does not hide marks present on the surface of the aluminium before anodising e.g. scratches, clamp mark , die lines etc.........  These marks must be removed before anodising.  In some instances chemical etching can be used to reduce the impact of these marks but you will end up with a matt finish.  Etching will blend in fine lines but will have virtually no impact on more pronounced marks that may be present.


2.  When sending your job away to be anodised, make sure the parts are packaged in a way that they cant be easily damaged or marked during transit.  We have had instances where brand new parts have been sent to us with all the parts able to rub together in the packaging.  Needless to say there a cost involved in getting the parts ready to anodise.


3.  If the parts need to be welded, do this before the product is anodised.  The anodised coating has very high electrical resistance, effectively stopping welding and the anodizing needs to be removed before welding can take place.  (To remove the anodized layer for welding either use mechanical means or apply caustic based chemical e.g. oven cleaner - please take all safety precautions)


4.  If welding, then use 5356 welding rod for the best looking results.  TIG welding is generally considered to be more suitable for aluminium to be anodised than MIG.  MIG welding generally results in very high localised heat around the weld that cools very quick after welding.  The result of this very quick cooling are structural changes to the Aluminium around the weld that wont anodise properly and wont take dye - No good for that decorative look.  This problem can be reduced or eliminated by preheating the aluminium around the area to be welded and works by slowing the rate of cooling after welding is completed.  As TIG welding typically requires pre-heating, problems with anodising are less common.


5.  If you have a product that needs to be formed or shaped in any way, then this needs to be done BEFORE anodising.  While the anodised coating is very hard and resistant to wear, it does not like excessive tension.  Should an anodised layer be bent past a critical point the anodising will get fracture marks.  These fractures can become openings to corrosion.


6.  If you have a colour sample available, please send this either with the job or email a photo.  This will help us to get the colour you are after.


NOTE:   While every effort will be made to match the colour this cannot be guaranteed as there are many variables that impact on the final colour.
NOTE:   'White' is not available as a colour, this is due to the fact that the particles that make up white dye are too big to fit into the pores generated by anodising.


7.  When packaging avoid putting any tape directly on the aluminium parts to be anodised, as it is difficult to clean off and is not removed by the anodising process.  This can result in anodising defects.


8.  Remember that anodising is only suitable for aluminium and its alloys, this is because anodising is an oxidation process.  Iron products such as steel would just turn to rust if they were to be anodised.  Other metals such as brass, etc are also adversely affected.


9.  If the product has any non-aluminium metal attached, this either needs to be removed prior to sending the product or let the anodiser know so they can mask it before anodising.


10.  Avoid leaving finger print marks on un-coated Aluminium products as these can become imprinted on the surface of the metal.  In some cases these marks will show through in the final product.