Most silicone RTV releases acetic acid when curing. They smell like vinegar. They are corrosive. This is why Ford says no to their use. There are a few that donot, they will say non corrosive in the label. They will not smell like vinegar. Here is one that does not release acetic acid.



Permatex 82180 Ultra Black Maximum Oil Resistance RTVSilicone

 

Or this.

https://www.amazon.com/Electric-GE28...keywords=ge285

 

This only occurs when my tires are in water. Wet streets or rain. The silt is brown or sandy color. I'm pretty sure it's cast off from the road. My truck is Blue Flame Metalic. No blue dust. But thanks.

 

This is aluminum/metalic color. It does not state anywhere that it is non corrosive. Did you actually buy some? Does it smell like vinegar?

Seems like they would state non-corrosive somewhere in the description, if it was. Not saying it isn't, just skeptical.

 

After much research - it is non-corrosive. This included a call to GE to verify - this caulk has an ammonia by product to help it cure vs the Silicone 1 caulks they offer which have the acetic acid. It is designed for aluminum siding/gutters/stainless steel/bare metal.

The color isn't perfect - but I was looking for something to slow/stop the water from dripping in where the two glass panels meet on the panoramic sunroof.

Have you found anything else besides the Ultra Black RTV? I didn't think that would be flexible enough to let the roof open/close as this GE Metal caulk would.

 

Ammonia has alkaline properties and is corrosive in some instances. Although aluminum is used in refrigeration systems that contain ammonia, the problems can occur when there are contaminants or other metals present.

Aluminum can act as an anode when in the presence of other metals particularly stainless steel. Normally the oxide layer of aluminum is quite protective except even the slightest trace of chloride (i.e. road salt) in the environment a galvanic corrosion will take place.

I suppose that is why Ford just says "NO" to silicone. Perhaps a chemist can weigh in here to render an opinion?

 

Duplicate Post.

 

Very good points and great discussion. I've seen the memo from Ford and it doesn't specify painted aluminum or bare.

What's your take on this?

 

First off the area in question was painted and has bed liner over it as well. don't see that an RTV will get to the bare metal and corrode it to a point of any kind of failure. But it will probably void the warranty on the bed.

 

I would agree with you, my concern would be it oozing into the gaps/joints and getting to the unpainted areas in-between/underneath. Those areas are not painted other than overspray. They should be primed though.