White Anodizing

[wklein]

Working on a large oyster recently and another similar boat, they both have had white painted masts from new, they look really good from a distance, however when you look close the paint is bubbling around any stainless and the whole thing is very powdery.

I have to admit anodizing is a bit of a mystery to me, but they made black and gold masts with dye in them. This then fades and looks rubbish.

So my question is why does nobody make white anodized masts? The white would be much less likely to fade and much more resilient than paint.

 

[VicS]

Working on a large oyster recently and another similar boat, they both have had white painted masts from new, they look really good from a distance, however when you look close the paint is bubbling around any stainless and the whole thing is very powdery.

I have to admit anodizing is a bit of a mystery to me, but they made black and gold masts with dye in them. This then fades and looks rubbish.

So my question is why does nobody make white anodized masts? The white would be much less likely to fade and much more resilient than paint.

Colouring is done by dyeing the aluminum oxide layer formed in the anodising process.
You can't really have a white dye. The aluminium oxide is white anyway.

 

[Rigger Mortice]

I don't know the answer but the usual problem with white pigment is that it tends to yellow with age. It may be just as bad as the gold or black after a few years.

 

[MM5AHO]

"The white would be much less likely to fade and much more resilient than paint. "

I'm not sure about this. Is it a fact or an ambition?

 

[Rigger Mortice]

"The white would be much less likely to fade and much more resilient than paint. "

I'm not sure about this. Is it a fact or an ambition?

If fading is the tendency of colours to become whiter, then it is fact.

Wasn't it "OMO" which "washes whiter", but also made colours fade?

 

[VicS]

I don't know the answer but the usual problem with white pigment is that it tends to yellow with age. It may be just as bad as the gold or black after a few years.

Anodising is coloured with a dye like fabric, not a pigment like paint. In fact it is possible to use some fabric dyes to colour anodising.

Not so sure that a white pigment yellows. A common white pigment is TiO2 Its not that that yellows it's the other constituents of paint that yellow I think you will find.

 

[lw395]

I would have expected there to be some chemical surface treatment before painting, possibly anodising, possibly one of the chromate processes.
Sounds like they stinted on the Duralac!

 

[wklein]

Interesting. I said whites don't fade mostly because of my experiences with coloured gelcoat, because white is more reflective than other colours and
when things fade they get lighter so would remain white (i guess)

Its very difficult to get any paint to stick to anodizing so they generally remove it before painting it (or don't anodize it).

 

[ianat182]

Perhaps the white powder coating process would be anothe option,as used in manufacturing and wheel trims etc, in various colours. I've no knowledge of how the items are primed or which metals can be powder-coated, but there is a small business here in Wickham/ Fareham that does this work.


ianat182

 

[pvb]

Perhaps the white powder coating process would be anothe option,as used in manufacturing and wheel trims etc, in various colours. I've no knowledge of how the items are primed or which metals can be powder-coated, but there is a small business here in Wickham/ Fareham that does this work.

I don't think many powder coaters would have an oven big enough for a mast!

 

[pvb]

Its very difficult to get any paint to stick to anodizing so they generally remove it before painting it (or don't anodize it).

Masts are generally painted with epoxy primer after preparation, then sprayed with polyurethane paint. Durability obviously depends on the quality of preparation, together with the care taken to inhibit corrosion where stainless fittings are attached.

 

[MM5AHO]

I powdercoated an old aluminium cabin roof vent/hatch frame a few years back. I wasn't so sure how well it would handle the marine conditions, using an architectural grade of powder for it, but it is showing no problems so far.
Powdercoaters oven sizes vary greatly. We do items to 10m, but I've seen ovens to 25m length capability.