[JEM]

Hi, is corrosion on mirror base common? Is the base aluminium ?
Can it be painted / touched up easily, thanks

 

[SeanFulop]

Yes that is aluminum corrosion, it seems like all QP5s that get used have this happen. Yours is really bad, by the looks of it. I've heard that it can be repaired for a medium-grade sum at a quality body shop, and eventually I'll be seeking to do mine.

 

[Catmanv2]

Common thing on all the cars, sadly.

C

 

[friendgr]

I have the impression that this thing is starting upon the first chip of the aluminum (mostly from small stones)
Once a small piece of color is missing then the water is getting inside the color and the corrosion and eventually peel off is starting.....

 

[JEM]

Thanks guys.
Anyone have tips on removal of the triangular cover on inside of door and mirror base? Before I break something

 

[SeanFulop]

I have the impression that this thing is starting upon the first chip of the aluminum (mostly from small stones)
Once a small piece of color is missing then the water is getting inside the color and the corrosion and eventually peel off is starting.....

No, mine corroded right underneath good paint, thus bubbling it but there is still no paint missing. I'm not sure where the water is getting in, it has something to do with the mounting of the mirror on the swivel.

 

[greyhound]

MHO is that the corrosion on the mirrors stems from the fwd inboard chamber in the base. Its the only area in the base without a moisture drain hole. And it looks like during initial painting this area gets very little attention down inside. My solution is to drill a drain hole in that area but before it corrodes. I was lucky and found a set on ebay without corrosion for about $250. I drilled holes and installed. I bought setup from "automotive touchup" to repair but then found replacements. A good shop should be able to repair fairly cheap???
As far as removal, takes about an hour. You'll have to remove inside door panel, see youtube. The cover inside the door for mirror pops off. Under door panel is power connector for mirror quick disconnect. Then 3 bolts for mirror assy to remove from car. 2 bolts to remove outside triangle from mirror. 3 bolts on bottom of base to remove from mirror. You have to take yellow cover off power cord to feed thru base to fully separate the 2. Just cut zip tie and slide back cover out.

 

[greyhound]

here is my old base with new extra hole drilled.

 

[greyhound]

 

[[email protected] Enzo`s Atlanta]

Just my 2 cents and I'm not a metal expert or anything..I don't think that is a moisture issue...I think the problem is the quality of the aluminum...Like one step above pot metal...I think it is very porous aluminum and oxidizes underneath the paint...Some Jags came with magnesium cam covers and it would do the same thing...Greyhound, aren't you an aircraft mechanic? Maybe show that to one of your guys in the shop? Surely, some of those guys know a lot about different grades of aluminum...Maserati doesn't make the mirrors BTW...I want to say that they are Valero..I frequently use old broken Land Rover mirror parts to fix Maserati ones ....Jason

 

[greyhound]

We don't have metal experts in the field or would ask them. If it were the whole assy being alum then why only corroded in the same spot every time? I've seen approx. 10 different samples on ebay and all same area. I'm simply surmising based on the fact that in all cases I've seen it seems to emanate from the same exact area in the base on both sides of car. The only real difference from the rest of the base itself, is the lack of drainage and maybe the poor finish inside. The area is obviously open to moisture. Of course there are other examples of same corrosion in trunks and doors? My take is drilling a small weep hole cant hurt if damage hasn't occurred yet? otherwise striping and retreating may help? The new used mirrors I got were from 05 with 42K on them. no damage. Has Maserati never addressed the issue even to say why?

 

[[email protected] Enzo`s Atlanta]

I would drill the hole...As far as refinishing...I would strip everything with a gel type stripper and then wash with soap and water...If the pitting is bad I might try using one of those aluminum repair rods and a torch to fill in the pits and then sand it down or some Bondo if necessary...Take to a body shop to prime/seal and then repaint....Jason

 

[JEM]

Thanks greyhound and Jason for your feedback

 

[SeanFulop]

I seem to remember that the Corvette C4 generation literally had pot-metal mirrors, after 10 years or so all the paint would just pop right off the whole mirror. I also think that if it was metal quality issue the paint would come off more generally and not just in that one spot all the time.

 

[[email protected] Enzo`s Atlanta]

Ok. Another crack pot theory....The corrosion is really only at the base where it screws together...How about a galvanic reaction between the aluminum and the screws holding it together.? Just a thought...Jason

 

[JEM]

Yes I agree with galvanic corrosion. I was going to suggest stainless steel bolts but looking at tables that would be worse then steel. When I reinstall I will see if I can try and seal with Duralac (however may be useless as the bolt needs to engage the Al to hold it!

 

[greyhound]

In the sample I posted there are 3 screws for mirror and 4 screws for base to car and the corrosion is nowhere near the screw holes.....just sayin

 

[[email protected] Enzo`s Atlanta]

It was just a theory....You are stealing my line BTW..Just saying... Jason

 

[SeanFulop]

I guess I have extra time on my hands-- I actually read about aluminum casting because of this question. What I learned was that it is possible to have casting problems like too much air in the metal in a particular area of the casting mold. So, Jason's original theory could still be the correct answer even though the corrosion is always occurring in one area of the mirror base.

 

[[email protected] Enzo`s Atlanta]

I don't do internet theories.... Jason