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Reasonable Expectations on a Sedan Roof (--revisited topic)

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  • #16
    My roof does not leak, and it has been in heavy rain. My brother installed a new roof on my father's town sedan, and when he drove it down here from the Canadian border to attend a New England Meet, he drove the 300 miles in a hurricane, and it never leaked a drop.
    Bill
    http://www.brauchauto.com/

    Comment


    • BRENT in 10-uh-C
      BRENT in 10-uh-C commented
      Editing a comment
      Bill, are both those cars using original mouldings?

      I just tested this one by washing the car with a hose where we washed the top material however we did not intentionally hold the water hose over the top of the mouldings either. We did not get any water inside with a light washing ...however the owner did scrub the top with a steady stream of soap & water and he did get water inside.

    • 2manycars
      2manycars commented
      Editing a comment
      My car has the original side mouldings/drip rails, and repro steel front and back mouldings. I used seam sealer under the material, and under the mouldings. No leaks. My brother used repro mouldings, I think aluminum on the town sedan. Still no leaks.

  • #17
    My Sport coupe never leaked. It was in some hard rains.

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    • #18
      All of the above suggestions and previous Model A roof experiences have lots of merit. Like installing any type of commercial roofs today, the roofing contractor's experience and standard of care is most important along with his knowledge of proper long lasting sealants ....... lots of today's offered sealants fail very rapidly.

      Various specified modern types of sealants offered today in commercial construction or in any professional field can make a World of difference. UV resistance is one major concern; percent elongation and contraction with temperature changes is another, adhesion and cohesion is another.

      If one is really interested, one of the better ways to test sealants is to provide sealant between metal joints located between two (2), twenty (20) feet long copper gutters ....... Wow ..... experience that movement!

      It wasn't until the late 1960's that sealants were manufactured that met Federal Specifications FS TT-S-00230, where said sealants could seal the expansion and contraction that occurred in metal gutter joints.

      Prior to the late 1960's all metal gutter joints were manufactured with metal "Z" shapes and contoured to fit and match the gutter profile. Dust and dirt got into the tight fitting "Z" and prevented leaks like the levees along the Mississippi River.
      Last edited by H. L. Chauvin; 04-25-2018, 05:22 PM.

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      • Mitch
        Mitch commented
        Editing a comment
        With today's modern sealants a roof can be made tight even with inferior moldings.

      • BRENT in 10-uh-C
        BRENT in 10-uh-C commented
        Editing a comment
        You may be right Mitch. The issue is likely going to be that most bathtubs, windows, or roofs do not see the same degree of movement or flex that a Model-A body does traveling down the road. Therefore applying enough sealer while keeping the sealer hidden, --and keeping it stuck to the fabric & surroundings is likely the difficult issue. Not saying it can't be done, ....just saying I have one that appeared to have an issue. All we have done is tapped each of the moulding tacks and it appears it isn't leaking.

      • H. L. Chauvin
        H. L. Chauvin commented
        Editing a comment
        1. Simple today's, modern sealant experiment where, "True Faith follows Facts!" Get a tube of GE clear silicone sealant indicating meeting Federal Specifications FS TT-S-00230 printed on the label.

        2. Get two pieces of sheet metal, may 4" x 6" x maybe 26 gage galvanized or Galvalume or finished with baked "factory" enamel on metal.

        3. Apply clear sealant to metal, press metal together, and next day, get very brave and try submerging these glued metal pieces in a bucket of water for a week.

        4. After one week of being submerged in water, try to see what type of force is required to pull these two pieces of metal apart .

      • 2manycars
        2manycars commented
        Editing a comment
        Black 3M seam sealer in a caulking gun tube works wonders.

    • #19
      Brent I am no expert on the subject if the cars leaked when new or not. I just find it hard to believe that they had a major issue with it. That would involve replacing lots of interior upholstery items in the first 90 days. These posts are just my opinions.
      I would like to see the documentation you have to support if sealer was used or not at the factory. I know they asked the dealers to buy it for doing repairs but that could be unrelated. I did find this entire thread to be very informative
      2 1930 Tudors

      Henry Ford said
      "It's all nuts and bolts"


      Mitch's Auto Service ctr

      Comment


      • George Miller
        George Miller commented
        Editing a comment
        If they leaked from new the interiors would have showed it. Some of my better A,s showed no sign of leaking.

    • #20
      H.L. is on to something. We use the GE silicon as mentioned in other posts to help hold the outer running board trim on as well as hubcaps.The non paintable silicon doesn't accept paint but there is a paintable version but that also may not hold up to automotive paints. A good paintable sealant is the 3m Ultrapro 8300 though the working time is quite short. We like the water based version which is the 8500 All Around type, and mouldings can be set in it due to its much longer working time and cleanup, before painting, etc..
      Btw, attached is the orig. '27 Chry. roof. Note the similarity to the '28 Ford sport coupe and fabric, trim, etc. Couldn't find sealant under lower metal trim.
      Attached Files

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      • #21
        Hell would freeze over before I would ever use any type of RTV silicone rubber for this application. Only single stage moisture cure urethane sealants. 3M has a slew of them. Just ask your paint/body supplier for a cut sheet. Yea, I'm very opinionated about this. To each his own!

        Comment


        • H. L. Chauvin
          H. L. Chauvin commented
          Editing a comment
          I like Mr. MikeK's suggestion of asking if ever in doubt: "Just ask your paint/body supplier for a cut sheet."

          For step one (1) in trying any new product for automotive work, seeking advice from well experienced professional paint/body guys is a step in the right direction for doing something correctly and doing something once.

          Many new products tested today by professional are later found to have entirely different advantages and even more specific limitations.

      • #22
        I cannot imagine them leaking when new, so they should not leak when rebuilt - repo or original stylle parts. I have put tops on a dozen cars in the last ten years and so far none of them leak. If done rightand carefully no stickum, messy glue or sillycone or urethane is necessary. Yes, on some of my cars I have used the urethane sealant. kenp

        Comment


        • BRENT in 10-uh-C
          BRENT in 10-uh-C commented
          Editing a comment
          Hey Ken, then let's discuss what is 'do them right'. What do we feel is the right way in this?

      • #23
        Originally posted by MikeK View Post
        Hell would freeze over before I would ever use any type of RTV silicone rubber for this application. Only single stage moisture cure urethane sealants. 3M has a slew of them. Just ask your paint/body supplier for a cut sheet. Yea, I'm very opinionated about this. To each his own!
        I agree with Mike. Years ago a windshield installer from Canada posted that silicone next to metal promotes rust, so you should only use good windshield setting urethane sealers. After reading that it dawned on me that that's why I was seeing so much rust around windshields in the junkyard cars that used silicone as a sealer.
        Last edited by Tom Wesenberg; 04-27-2018, 04:16 PM.

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        • #24
          Am in agreement with Tom and Mike and not a fan of RTV except in a few circumstances.. I was not suggesting using silicon except in the couple of areas we've tried (post 20) successfully so far where it has not attacked the zinc trim or over powder coat. If it smells like acetic acid, then it can be corrosive and / or incompatible with some finishes and materials.

          Comment


          • #25
            Our '29 Tudor was real watertight. I never drove it in the rain on purpose but the few hard downpours I got caught in, it was always dry as a bone. A previous owner had put a new top on, I think, in the late 60's. Maybe they had better material then. Still had the original rain gutters.

            And like Brent stated, people today are not only big bitchers but whiners. That wasn't really the case in the Model A era. People today are not as 'tough' as our grandparents were. My generation included and I'm 63.

            Comment


            • #26
              What to do?

              PO did full restoration some 20+ years ago. Paint is showing age with chips, cracks, rust bubbling, fade and rough areas. Not interested in effort or expense to do it right, now. Perhaps I will have time in a decade to make it fresh for the century celebration.

              However, I do not want it to get too bad between now and then.

              The roof is in good shape except for the Hideum welting having rotten thread and it separating. Looks like PO hit a few spots with sealant on exterior.

              How hard is it to replace just the welt? And, how much more to do the top?

              The interior is in great shape so I do not want to mess it up.

              As a minimum, I am thinking of removing welt, reseal, tape off and paint, then install new welt.

              What do you think?

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              • #27
                Brent: If I was paying you what I think you're getting for a complete restoration I would EXPECT the roof NOT to leak ! ! !
                Paul in CT

                Comment


                • #28
                  Never did a top, but I was looking at how they seal up stuff on boats not long ago.

                  I suggest a visit to a boat yard or marine place and ask around about what they use.

                  They make some sealers that go between fittings and the hull that keep water out. It looks like a tape of sorts. They also point out for a better seal when you drill holes put a little counter sink so the sealer has a place to go.

                  Comment


                  • #29
                    2 words.."DRIP CHECK" use it all the time and it works great..Seals, primed and painted what ever color you want...

                    Comment


                    • BNCHIEF
                      BNCHIEF commented
                      Editing a comment
                      Please elaborate Mark you have my attention.

                  • #30
                    Forgot to mention that most of the closed cars were designed to drain water, especially the windows,doors and trunks had weep holes. The '27 Chrysler posted earlier has mohair interior and surprisingly no stains at the top headliner. Most of the sealants back in the day were oil (alkyd), alcohol, or asphalt based, and zinc chromate primer (can be toxic) is a good primer for aluminum moldings. As stated, and having spent decades in the construction industry, today's sealants are complex chemistry and designed for specific applications and materials compatibility.Most of the common big box store sealants are designed to be used with foam backing rods in joints, so automotive types may be better suited , available from commercial auto body paint suppliers, etc. The vendors sell a model A club's replacing Roofs videos with some good techniques on how to improve closed car roofs performance while maintaining the stock appearance.
                    Last edited by plyfor; 06-14-2018, 02:11 PM.

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