71 Outside RV Mirror loose floppy head

[Norman S.]

Does anyone have a fix for a loose mirror head? The "ball" connection is allowing the head to flop around. It's an original 1971 mirror in otherwise perfect condition. I hate to replace it. Anybody ever heard of a way to somehow refurbish the "ball"? Is there any safe method to remove the mirror glass (dated) without breaking it? If so, would the "ball" be accessible without the glass in place? Thanks.

[Joe L.]

Re: 71 Outside RV Mirror loose floppy head

Norm------

Quite a few years ago, there was an article in the Restorer regarding this very repair. If I recall correctly, Terry McManmon was the author. In brief, the mirror glass can be removed by soaking the mirror head in a bucket of solvent which degrades the adhesive used to attach the mirror glass to the casting. Then, the strap which forms part of the "ball seat" and is rivetted to the casting can be "distorted" by peening it. This upsets some metal and makes the ball seat tight again. Finally, the mirror glass is reattached using silicone RTV as the adhesive.

[Mac Peppers]

Re: 71 Outside RV Mirror loose floppy head

as always, what joe says works. i just did one. soaked the mirror overnight in lacquer thinner and the glass comes right off. peened the rived a little to tighten it up and replaced the glass with silicone.

[John M.]

Re: 71 Outside RV Mirror loose floppy head

Norm,

You might want to consider an adhesve that is intended for mirrors. Commercial glass and mirror installers will not use silicone. They claim that something that outgasses from the silicone will attack the silvering on the back of the mirror over time.

Regards, John McGraw

[Terry M.]

Re: 71 Outside RV Mirror loose floppy head

Excellent tip John.

FWIW: I used black RTV to reattach my RH (yes, it is not stock) mirror on my 1970 in 1988 – that is the mirror in the 1989 Restorer story. No sign of mirror deterioration to date, but the car does spend most of the time out of UV light -- if that matters.

Of course one can never be too careful, and using a material designed for the application at hand is certainly better than hoping to be lucky.

[John M.]

Re: 71 Outside RV Mirror loose floppy head

Terry,
The other downside is that if the pivot ever needs tightening again, the solvent will not release the glue like it will with the standard mastic cements. One can assume that if it needed tightening once before, that it will need it again.

Regards, John McGraw

[Joe L.]

Re: 71 Outside RV Mirror loose floppy head

John-----

If silicone RTV is used, it will always be degraded and loosened by a petroleum solvent. Most other adhesives probably would be, also. But, with silicone RTV one is "guaranteed" the solvent will cause it to release the mirror.

The main problem with RTV as far as possible mirror deterioration goes is that it gives off a weak organic acid (acetic acid, I believe) during the curing process. However, there are special RTVs that don't have this characteristic. These are the ones that are labeled "safe for use with oxygen sensors".

[John M.]

Re: 71 Outside RV Mirror loose floppy head

Thanks Joe,
I was allways under the impression that RTV was almost impervious to most solvents. I only know about the deterioation of the silvering because of a failed mairror at my home. It was installed with silicone, and 3 years later I had black spots everywhere that the silicone was. The glass company that replaced it told me at that time about the harmful interaction.

Regards, John McGraw

[Terry M.]

Re: 71 Outside RV Mirror loose floppy head

There is a story about mid-year outside rearview loose mirrors in the Fall 2005 Restorer. Look for it in your mailbox soon.

Not quite the same as C3 mirrors in the way the glass is removed, but the same in the way the head is tightened.

[Joe L.]

Re: 71 Outside RV Mirror loose floppy head

John-----

Silicone RTV is decidedly NOT resistant to many solvents and, in particular, gasoline. It should never be used where it is so-exposed as it will fail rapidly. There is an RTV that is solvent and gasoline resistant. It's called a fluroelastomer, but you won't find it in auto parts stores. It's primarily an aerospace material and sold only by specialty suppliers to that industry. It's VERY expensive; like 100 bucks a tube, or something like that.