|01-29-2009 02:37 PM|
|Kevin45||If a hole is painted, you push a clip thru it, it strips the paint off.....then silicone or whatever will not stop it. If you put silicone around it, the clip will displace the silicone also. I would be more concerned with a sealer trapping moisture and causing problems than not having any sealer at all. If you drill a hole and are down to bare metal, then a brush with a little epoxy prime will work. Holes have lasted for years without rusting. What causes the rust is moisture that gets trapped in conjunction with the bare metal. In years past, people did not really take care of cars like they do today. Weeks would go by with dust, dirt, mud, etc, getting caught in the moulding. Bare metal around holes was in contact with this, then rust would start by bubbling the paint first. Cars today from the factory are painted then assembled and holes do not have silicone or whatever to seal them (although there are not as many holes) and they don't rust if taken care of.|
|01-29-2009 11:29 AM|
I aways wondered about this when I drill holes before I pop rivet plastic trim pieces on later cars.
Some of the rust holes that I have repared were old rivet holes that were not treated properly before applying the rivet. So I knew that I needed to treat the holes after redrilling a new hole after the repair. Will use the suggestions above on my next repair.
|01-28-2009 08:51 PM|
I wound up using 3M body caulking that was laying around the garage. It had a waxy consistency that shedded water . I just rolled up a good hunk and applied it at the hole before pushing the trim clips into it. It's worked great over the years with no rusting at all, and the vehicle's sat outside exposed to the elements for most of this time.....
|01-27-2009 05:43 AM|
Thanks for the replies, baddbob and Eddie.
To make something so simple in theory, a lot more complicated, a few more questions...
Is RTV silicone, the kind that smells like vinegar, bad for bare steel? Is the type that smells more like ammonia better?
What about for a trim piece that snaps into a hole. Hard to describe but I'm sure you guys have all seen something like it...a tab shaped like a sharp "V" (think of a spring steel bent into a "V" shape) that goes into a round hole. Is there any simple way to seal this aside from a lot of goop around it? I'm thinking not and I'm overanalyzing this.
|01-25-2009 01:38 PM|
|Fast Eddie D||
I always use RTV Black when I install screws into sheet metal. Just a little on the threads. It's like baddbob said, ya gotta seal it somehow. The RTV is no problemo to get apart later on, so it works for me.
I really don't know what's best to use; maybe that strip caulk for installing some windows and mirrors, etc, would be best. That stuff is still fresh years later when you take her apart, and still reusable. I use the 3M strip caulk. It "never" dries out; some of the OEM caulk was still serviceable after 20 years, and some of it had hardened into like a dry foam. I guess service life in my climate is 14-16 years.
|01-25-2009 06:37 AM|
|baddbob||The screws will take the paint and primer off of the screw hole so you need to use a sealer. Strip caulk works handy for this, Windshield butyl will also work, seam sealer, pllumber's putty, heck-even roofing tar will do the job. A dab on each hole and some on the screw threads and it'll be fine.|
|01-25-2009 12:10 AM|
Protecting screw holes or trim holes in body?
Quick question...on a freshly painted metal surface where you have trim that snaps into a hole (the paint in the hole will get scratched by the trim piece), or if you have to screw something directly to the body (something like an antenna mount), what is the best way to protect the metal so it doesn't rust out?