The original seal was what the autobody people call a "dew wipe" for a car window, the part that is supposed to squeegee off film of dew when you roll the window down. As Mike described, they had a "felt" or "flocking" on them. I suspect that this has long since warn off even the newest of the factory original installations on SMs. With the "flocking" intact, on the hard, smooth varnish we don't see "chattering" of the rubber on the moving slide.
Right now, our seal is getting old again, and the flocking has worn off--in spots. Those bare rubber spots are starting to "grab" a bit. Time for a new seal...
Wax helps a lot on the smooth operation of the whole system. Helps the varnish last longer, and look better too.
P.S. It has been pointed out to me that I screwed up... forgetting to move from radius to diameter. The equivalent round hole to a 2mm x 750 mm gap is 22mm in radius, so 44mm in diameter. Four times the area, and water flow for your calculations. I really doubt there is a condition where it would ever sink anybody's boat, but the "box" the slide goes down into on my boat is lined with a pile fabric. I just don't want any drips in there so things can grow.
Annapolis, MD, USA
---In amelyachtowners@..., <lokiyawl2@...> wrote :
You make some very good points. A 22mm hole at a 1' head could flow around 615 GPH if my calculations are correct so there could be conditions where this could allow a lot of water into the boat. I certainly hope to never encounter the conditions that Eric has. One of the primary functions of a boat imo is to keep water on the outside and this seems to me to be a good way to reduce intrusion. I second your concerns about silicones which can be impossible to finish over if they soak into bare wood. Customers have brought boats to us to refinish the interior varnishwork and some where furniture polish was used were impossible to recoat, nothing but fish eyes no matter how much cleaning we did. On the other hand some boats that also had furniture polish used on them were fine to refinish and I never determined which products had silicone or in them and which were safe so I just revarnish when needed.
The varnish on the slider I imagine gives you a nice sealed and fairly hard surface for the wiper to rub on. Does the wiper ever chatter as you raise and lower the slider? I need to reface or replace my door and will go with varnish as well.
Have a safe trip back South.
SV Sueno, Maramu #220
La Maddelena Island, Italy