How to make my rear view mirror tighter?
 

My rear view mirror is fine, but I just bought a dash cam that attaches onto the mirror. The extra weight makes my mirror droop every few minutes, so I had to take the dash cam off.

How can I make my mirror less moveable? I don't want to glue it in place, but want to make it a lot harder to move. I don't see any way to tighten the mirror, it's just ball and socket; I don't even think they lube it. The ball simply rides on the plastic rim.

I'm thinking what I need is the opposite of a lubricant, something that increases friction, sort of a glue that won't dry.

Any suggestions?
1991 300d, 208k

Got the same problem on my daughter's SD with a large convex mirror mounted on the original. I took it off and put little dabs of 5 minute epoxy on the ball, enough to cause more friction, not to glue the ball to the socket. Seems to have worked pretty well.

If the socket pulls off the ball, you might consider a small piece of self-adhesive felt stuck in the back of the socket. I used a 1cm square piece in the driver's side mirror on the SL to keep it from drooping when the door is slammed.

I don't know if this would work, but for carbon-fiber bikes, they make a product called "carbon fiber assembly compound" or "carbon friction paste". It is a grease-like material with microscopic beads of glass or sand or something mixed up in it. It is used to keep slippery materials from sliding. Normally, I think it is applied to a seat post, which is then clamped down in the seat tube clamp. The extra friction of the paste keeps the seat post from being able to slide down. Anyway, I have no idea if it would work and even if it did work, I have no idea how long it would work. But I just wanted to let you know the products exists if you want to try it.

Heck, I have some which I could squirt in a small plastic bottle and send your way if you wanted to try it. I bought it but haven't ended up using it for anything. PM me if interested.

Super glue gel

Clamp the camera onto something else?