Aluminum Guy

Re: Bright Dip and UV Stability

I am a newbie to the Forum, but could use some help.  We manufacture auto roof racks, and are interested in doing a bright dip finish on 6063-t5 aluminum.  The clear anodize and black anodize we have used in the past has stood up well to UV fading.  How does Bright Dip compare? 
cheers,

DustinGebhardt

Re: Bright Dip and UV Stability

By "Bright Dip" I'm assuming you are referring to a chemical process to brighten or polish your aluminum parts?  Bright dipping a part gives the part no corrosion protection compared to the great corrosion protection of anodizing aluminum.  The bright dip exposes bare aluminum to the atmosphere, which then can ready oxide (aka rust) and turn powdery and dull.

Anodizing creates a very durable and hard oxide layer, but without all the powdery mess.  Dyeing is black or leaving it clear should have a very minimal affect on the corrosion protection of the part.  And UV stability really only applies to a dyed part.  Clear-sealed parts are rarely affected by UV radiation, unlike dyed parts, which can fade or discolor over time.

With that being said, many anodizers use a bright dip within the anodizing process to help brighten up the parts before they go into the anodize bath. 

And you wouldn't happen to be making Surco racks, would you?  My Ford Expedition is just aching for one.

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer

Moen

Sanford, NC

Aluminum Guy

Re: Bright Dip and UV Stability

Dustin, thanks for the advice.  I was unsure on the relationship between bright dip and anodizing.  Sounds like we would first bright dip the parts, followed by anodizing to establish UV stability.  Correct?
No, we are not Surco, RockyMounts.  Check out www.rockymounts.com and we could help you out.  We mostly do bike mounts for cars and pick ups. 
cheers,



DustinGebhardt

Re: Bright Dip and UV Stability

I'm not sure how UV stability pertains to raw aluminum, but with a bright dip process, you should see the exact same performance as raw aluminum.  Esentially, you are polishing or brightening the metal, which does not really affect its properties.  In fact, you may make it worse, from a visual standpoint, because you would be able to see small spots of oxidation easier on a bright, reflective surface.

When most people talk about UV stability, they are talking about paints, powdercoatings, dyes, etc although I have also seen a normal nickel acetate seal for anodize turn yellowing over time when left to exposure.  And dyed anodizing can be very hit or miss, depending upon the type of dye used.  Colorfastness is key for outdoor use.

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer

Moen

Sanford, NC