Caulking T-top/windshield molding

[Wayne B.]

I'm moving right along with reassembling my 70 and was reading threads on using 3M strip caulk on the upper molding. I saw one thread saying stack the caulk two high and two deep along the front edge and another line behind it...or maybe I'm just being dense The pic on the left is the top front of the car and the pic on the right is where I assume the caulk is supposed to go but after reading the threads and then going out to the car and looking, that just doesn't seem enough to me to really feel safe about water getting in there. As you see I'm blessed with no rust and would like to keep it that way. Would it be better to just take a box of the stuff and pack the whole thing to keep water out or just about an inch wide and all the way to the top rim on the front edge? More along the edge to the interior of the car?

[Patrick H.]

Re: Caulking T-top/windshield molding

Wayne,

On the 72 I repaired this past winter, it had caulk applied to each of the areas where a trim screw would attach through the stainless header. It then had a "squiggly" line (think multiple "S" shaped or like a snake) weaving over the area from your front pink line to your green line.

I left much of the caulk as it stayed attached to the stainless. I added a thin strip at your green line and at your front pink line just to be sure.

FYI I completely cleaned, sealed and filled in the trough between the windshield and your front pink line. No way water is getting in there again.

Patrick

[Wayne B.]

Re: Caulking T-top/windshield molding

Thanks, looks like another case of "more is better". I ran it across the back molding similar to your pics in another post, I like the way it molds to fill gaps and it certainly keeps a grip on things.

[Pete B.]

Re: Caulking T-top/windshield molding

I will be dealing with the same thing but.....

Keep in mind, the service life that these cars saw in the first 10 to 20 years of their life will never be repeated. These cars were driven in snow,slush, left in the rain, driven through car washes, beaches and back roads...get the picture?

For me now, at best, my completed cars get washed two or three times a year, driven gently then back in the garage and the under cover. I dont think that I'm that unusual.

[Wayne B.]

Re: Caulking T-top/windshield molding

You're right there Pete, most of these don't get driven like they used to but it's not often you have the things apart like this and that area is a bit of a pain to service so if it's opened up might as well seal it like it was driving in a hurricane daily.

[Jim T.]

Re: Caulking T-top/windshield molding

Wayne,

On the 72 I repaired this past winter, it had caulk applied to each of the areas where a trim screw would attach through the stainless header. It then had a "squiggly" line (think multiple "S" shaped or like a snake) weaving over the area from your front pink line to your green line.

I left much of the caulk as it stayed attached to the stainless. I added a thin strip at your green line and at your front pink line just to be sure.

FYI I completely cleaned, sealed and filled in the trough between the windshield and your front pink line. No way water is getting in there again.

Patrick

Patrick request your opinion on why the rust began in the windshield header piece where you filled in the trough.
I replaced my 70's header and two corners because of rust back in 1987. Did not expect to see this kind of damage. My opinion is that the windshield adhesive sealer lost its actual sealing contact with the steel windshield frame and trapped the water to start the rusting. As early as 1975 I had some minor leakage, just a few drops of water off my inside rear view mirror onto the center console. My 70 was bought new in Dallas and spent the these first five years in the Texas weather elements.
Wayne what I used to seal the gap between the top windshield stainless trim and the t-top stainless was 3M strip chaulk. After I worked it in and smootheed it I masked off the area around it and painted it in 1987. 3M can be painted. It still looks good today.

[Wayne B.]

Re: Caulking T-top/windshield molding

Wayne,

FYI I completely cleaned, sealed and filled in the trough between the windshield and your front pink line. No way water is getting in there again.

Just curious, if the water slips in over that first "dam" you created wouldn't it fill the deep trough behind it? (didn't the Titanic sink that way?) Would filling it leave the water no where at all to get in or is that just beyond gross overkill? Probably take a half pound of seal on each side anyway so that may fall in the "silly overkill" catagory.

[Patrick H.]

Re: Caulking T-top/windshield molding

Just curious, if the water slips in over that first "dam" you created wouldn't it fill the deep trough behind it? (didn't the Titanic sink that way?) Would filling it leave the water no where at all to get in or is that just beyond gross overkill? Probably take a half pound of seal on each side anyway so that may fall in the "silly overkill" catagory.

What I described is only a part of it.
I put plenty (OK, more than that) in front of the dam and under the windshield trim. Trust me, there ain't no water going in there.

I sat there for a couple of hours with a stainless steel probe (medical instrument) pushing caulk down into the trough, then placing it along the top of the windshield and under the trim. I jammed tons of it between the windshield trim and the stainless header before I smoothed it out and "painted" it silver. Way overkill, but I do not want the car owner bringing it back because of any leak.

If I recall there are 20+ feet of new Strip Calk on that car now.

Patrick

[Patrick H.]

Re: Caulking T-top/windshield molding

Patrick request your opinion on why the rust began in the windshield header piece where you filled in the trough.
I replaced my 70's header and two corners because of rust back in 1987. Did not expect to see this kind of damage. My opinion is that the windshield adhesive sealer lost its actual sealing contact with the steel windshield frame and trapped the water to start the rusting. As early as 1975 I had some minor leakage, just a few drops of water off my inside rear view mirror onto the center console. My 70 was bought new in Dallas and spent the these first five years in the Texas weather elements.
Wayne what I used to seal the gap between the top windshield stainless trim and the t-top stainless was 3M strip chaulk. After I worked it in and smootheed it I masked off the area around it and painted it in 1987. 3M can be painted. It still looks good today.

I don't think that water can easily drain from that front trough if it gets in there - at least as built and filled at St. Louis. It just sits there and begins to rust the area underneath. Throw in a screw hole or two and that's it.
However, fill it to the brim with StripCalk and that won't happen.

As I understand it the car I repaired has been garaged its whole life.

Patrick