70 Windshield and pillar post reveal sealing

[Bill L.]

70 Convertible

Now that I have all the stainless removed I noticed they used a variety of seals. It appears there is a foam on the underside of the center reveal. There also appears to be some type of double sided tape on the pieces where the pillar post moulding are inserted (the tape is on the side next to each side reveal). Lastly there appears to be some type of caulking on the two side reveals between the actual pillar post and the reveal.

What should I be using in these areas and where can I get the correct materials.?


Thanks,




Bill

[Alan S.]

Re: 70 Windshield and pillar post reveal sealing

Hi Bill,
I've posted a couple of pictures of the retainer and molding from my 71 coupe. The first 3 pictures show the seal between the two pieces. It seems to be the same material as 3M strip caulk except it has a string running through it. (The only other place I saw this used was to stick the poly barriers to the inside of the doors although it's called out as a different # in the AIM). I used the 3M caulk when I put it back together.
The 3rd picture also shows the sealer in the 'slot' of the molding. I used the strip caulk here too.
The last 3 pictures show the 'molding supt rvl' for my coupe. I post them because they show 3 interesting seals. 1st, a foam seal with adhesive on one side, this is on the front and rear (as shown) of the molding. 2nd, there is also a flat sealing material that seems to have come off a roll?, note the lines in it. And 3rd, lots of roughly applied caulk similar to strip caulk. There was also a bead of dry, hard, light colored caulk on the front of the molding portion over the windshield. It seems to be the same material that is used to seal various fiberglass to birdcage seams in the interior.
My feeling as I took the trim off was that the majority of the sealing that was being done was accomplished by the globs of dumdum (strip caulk) that was everywhere.
Regards,
Alan

I added the last 2 pictures in the next post. I hope it's not too confusing.
EDIT#2 the pictures really got mixed. The first 2 on this post and the 1st one on the second post go together. SORRY!!!!

[Alan S.]

Re: 70 Windshield and pillar post reveal sealing

Here are the last 2 pictures.
Bill, I see you're from Maryland. I live in Westmister.
Regards,
Alan

[Bill C.]

Re: 70 Windshield and pillar post reveal sealing

Hi --

DocRebuild sells the rubber/foam strips that go between out and inner pillar post moldings. The outer one (holds the WS) has a channel on the back side, this thin rubber/foam strip goes in there.

As far as what to use for actaul sealing, I used the 3M thin ribbon strips.
They come in a blue box, each strip is around 10" long and maybe 1/4" to 5/15" wide.

You can lay them down (like in the pcitures that Alan posted).

It works great.

On The T-Top molding, be REAL sure to run 2-3 strips, side by side in the rear, close to the edge.
Up front, go 2 wide and stack 2 high. Place these strips as close to the front edge of the stainless as possible. it should get pinched between the upper lip of the window frame and the front leading edge of the t-top molding.

As suggestion - put the 3M box in t he refridge until you are ready to start working, it is a heck of a lot easier to manage when cold, the strips get really gooey when they are room tempurature.

Hope this helps some.

[Chuck S.]

Re: 70 Windshield and pillar post reveal sealing

Excellent summary, Alan...it's like I was looking at my own car.

I'm not sure what role the foam seals were expected to fill except as a water dam (closed cell foam!?) that easily conformed to the molding shape without being forced. It wouldn't take a lot of force pushing down on that T-top divider molding for damage during assembly.

The windshied header was also sealed wierdly...huge gobs of dum-dum with foam seal dams, for backup I suppose.

I have no clue why there were two colors, gray and tan, of essentially the same "dum-dum"product. I'll probably try to replicate the foam seals with something, but otherwise, I think the closest sealant these days will be 3M StripKalk as you said...in basic black.

[Alan S.]

Re: 70 Windshield and pillar post reveal sealing

Another issue that arises in dealing with the SS windshield trim is the tiny SILVER bead of material that seals the 2 pieces of A-pillar SS trim together and also the 2 pieces of SS Windshield Header trim. The bead is very visible after everything is back together. Is it cosmetic or is it a sealer too?
My pictures show the drivers side A-pillar SS trim. The same material is used on the header. It looks somewhat gray in the pictures but is more silver than gray to my eye.
It looks like it went on at about the consistency of thick tooth paste. It seems to have set up hard, and after 35 years it is brittle enough to easily crack.
My solution involves Michael's Craft Store. I'm curious what other people are using?
Regards,
Alan

[Patrick H.]

Re: 70 Windshield and pillar post reveal sealing

Another issue that arises in dealing with the SS windshield trim is the tiny SILVER bead of material that seals the 2 pieces of A-pillar SS trim together and also the 2 pieces of SS Windshield Header trim. The bead is very visible after everything is back together. Is it cosmetic or is it a sealer too?
My pictures show the drivers side A-pillar SS trim. The same material is used on the header. It looks somewhat gray in the pictures but is more silver than gray to my eye.
It looks like it went on at about the consistency of thick tooth paste. It seems to have set up hard, and after 35 years it is brittle enough to easily crack.
My solution involves Michael's Craft Store. I'm curious what other people are using?
Regards,
Alan

I had always thought it was black strip caulk that lost its color with age.
You think it is silver to start with?

Patrick

[Chuck S.]

Re: 70 Windshield and pillar post reveal sealing

Another issue that arises in dealing with the SS windshield trim is the tiny SILVER bead of material that seals the 2 pieces of A-pillar SS trim together and also the 2 pieces of SS Windshield Header trim. The bead is very visible after everything is back together. Is it cosmetic or is it a sealer too?

My pictures show the drivers side A-pillar SS trim. The same material is used on the header. It looks somewhat gray in the pictures but is more silver than gray to my eye...

Interesting...I don't recall seeing any silver sealant material in that area of my car.

Your picture of the weatherstrip retainer being separated from the pillar molding with the black material on the retainer is exactly what I observed on my car. That is what the AIM calls "plastic seam cement (UPC 1, Sheet F10, Material application 57e, View D)

Another sealant is used between the body frame pillar and the pillar molding (UPC 1, Sheet F10, Material application 84k, View D). I observed this material to be a type of "dum-dum" material, kind of a beige-ish gray, and still pliable after more than twenty years.

The same gray sealing compound is also shown used under the windshield header of the T-top center support reveal molding. This is shown in View A, which also shows the foam backing dam. They used this stuff liberally...I found about a half pound of it under each of the cast end caps.

[Alan S.]

Re: 70 Windshield and pillar post reveal sealing

The sealer I'm referring to is most often seen on cars that have their original windshields, and almost never on cars that have had the SS trim taken off at some time in their life. It is silver and different from any other sealer because I believe it was cosmetic. It's the only sealer around the windshield you can still see when the car is completely 'buttoned' up.
You can see it best in the 1st picture in my post. It's at the very top of the 'molding side reveal' It's about 1/4" down from where the SS makes the sharp bend to match the surface of windshield. It's a piece of sealer about 1 1/2" long the rest is stuck to the 'retainer'. It setup very hard and thus cracks when the 2 pieces are taken apart.
The sealer is in the small gap between the SS header molding and the long thin WS reveal molding, and between the 2 parts of the SS A-pillar trim.
It's the small details.....that have made me so wacko.
Regards,
Alan

Please look at original cars... It's there...Honest.

[Patrick H.]

Re: 70 Windshield and pillar post reveal sealing

The sealer I'm referring to is most often seen on cars that have their original windshields, and almost never on cars that have had the SS trim taken off at some time in their life. It is silver and different from any other sealer because I believe it was cosmetic. It's the only sealer around the windshield you can still see when the car is completely 'buttoned' up.
You can see it best in the 1st picture in my post. It's at the very top of the 'molding side reveal' It's about 1/4" down from where the SS makes the sharp bend to match the surface of windshield. It's a piece of sealer about 1 1/2" long the rest is stuck to the 'retainer'. It setup very hard and thus cracks when the 2 pieces are taken apart.
The sealer is in the small gap between the SS header molding and the long thin WS reveal molding, and between the 2 parts of the SS A-pillar trim.
It's the small details.....that have made me so wacko.
Regards,
Alan

Please look at original cars... It's there...Honest.

I know exactly which one you mean.

And, my comment is the same as above - are you sure it's not black sealant with sun damage turned gray?
Forgot to check my 72 when I had it out tomight.

Patrick

[Terry M.]

Re: 70 Windshield and pillar post reveal sealing

Alan is right, and I am pretty sure it is silver from the start. It was much more flexible years ago, but hardens as it ages. I have seen it on original cars, and never on restored cars.

Reverend Mike has his 1971 here -- I'll check and see what pictures I can get tomorrow.

[Patrick H.]

Re: 70 Windshield and pillar post reveal sealing

Hmm.
I've worked on two original 72s in the past week, and should have checked.
I know I saw it on an original 72 two weeks ago, and it was, I'll say, gray. Would you call that more accurate than silver? Or has the silver lost its color with age?

Looks like mine is "sinking" - which is something I often see.

Patrick

[Terry M.]

Re: 70 Windshield and pillar post reveal sealing

It might be gray -- I'll look at the bow tie cars today -- soon as I get breakfast.

[Jim T.]

Re: 70 Windshield and pillar post reveal sealing

The sealing between the trim shown in Patricks two pictures had a silver appearance, but not a true silver color on my original owner 70. I wondered for several years if this was a source of the leaking water off the rear view mirror onto the my 70's console although this header trim sealing looked very good with its aging.
Wrong thought, found out in 1986 when I had my windshield removed/replaced that the water was coming through the steel windshield upper framing because of upper windshield framing rust. Bought a new one from GM and replaced it.
My 70 is a coupe and I had to remove all the trim under the t-tops for this repair.
I used 3M strip caulking putting it all back together. On the front header area in Patrick's pictures I used the 3M strip caulking and smoothed it so that it looked good. I then masked off the edges and painted the strip caulking with Krylon paint. Don't remember if I used semi-flat or gloss black.
The 3M caulk and painting between the trim have aged very good, although the car is the garage most of the time and not exposed to the outside weather.
Just took a look at my original owner 68 convertible. The trim in this area sure is a much tighter, closer together across much of the header with a wider area for caulk on the left and right sides. The material used to seal between the metal trim is black, actually looks like smoothed 3M caulk. It has weathered well, no cracking. The trim is so close together that there is very little application area for this caulking away from the corners and it is just as the factory built it.

[Roberto L.]

Re: 70 Windshield and pillar post reveal sealing

I wondered for several years if this was a source of the leaking of water off the rear view mirrow onto the my 70's console although this header trim sealing looked very good with its aging.

Yes, I have the same problem in my 70, a bit of water through the interior mirror on heavy rain. Probably that sealing compound which is aging... My windshield was replaced too, at least one time previous to my ownership.

A very helpful thread.

Best regards