Thursday, March 15, 2012

Rebuilding the Fixed Ports

When doing our refit on Last Affair, we decided to rebuild the large glass fixed ports in the boat.  There is a story behind why, but for the purpose of this blog, lets just go with “we decided to”.
This blog and subsequent videos are not going to be about how to rebed the window and frame to the fiberglass hull, but rather once removed, how to actually remove the glass from the frame and rebuild that.

This started innocently enough, it was to take the ports home and clean them up (They had a bunch of residual silicone on them from years or caulking by the PO (Previous Owner).  Once home, I started thinking that I really didn’t know if they leaked from the bedding into the hull or between the glass and the aluminum frame.  One way I thought to check was to lay the port down on a flat surface glass side down.  On these ports, the frame is about an inch thick and the glass is on one edge almost making it like a 1” deep bowl when laid flat with the glass down.  So, I poured a quart or 2 of water into that little 1” bowl.
In about 20 minute almost all of the water had leaked out from between the glass and the frame.  The majority of that was from the spot where the rubber sealant that goes around the glass was sealed back together at the bottom of the port (the bottom, that doesn’t seem like good planning either come to think of it).

These windows are rectangular (about 9” tall and 23” long but they have angles on both the leading and trailing end of the window forming a parallelogram (?) with rounded corners.  The point is that there was not a replacement out there that you could just go find easily to fit this size and shape.
I removed the screws holding the upper and lower halves of the frames together and pulled them careful away from each other exposing the edges of the glass and the rubber spline that was around the glass and pushed into the slot on the aluminum frame to hold it in place.

This part turned out to be a challenge.  I have looked at many places on line and local custom glass shops and can’t find the same shape spline.  While searching for sources for the spline, I decided to clean up the frames.

I was able to get some supplies (from Home Depot) so you can likely get it from your local hardware store to refinish the aluminum frames.
I started with a wire wheel on a lathe (a drill would work, this was just easier for me).  I used the wire wheel to brush, scrape and scratch away all of the old silicone, and gunk that was in the grooves of the aluminum.  I also used the wire wheel on the facing side of the aluminum in the areas that had scratches.  The wire wheel actually sands down the surface and removed the scratches.

I then lightly sanded these with a sanding disc in the same drill/lathe.  I used 400 and then 600 grit to remove the scratches that the wire wheel left.  This got it fairly smooth and confirmed that there was not more silicone caulk left. 

After the sanding, I installed the first buffing wheel (I used a denim buffing wheel) with “Tripoli” that is the brown buffing stick.  You rub it on the buffing wheel and then buff the aluminum.  After that was complete they were really starting to look good.  I then put on a loose cotton buffing wheel and used the “White Diamond” that is the white buffing stick.  I rubbed some on the cotton pad and ran at high RPM’s (3000 or so) and brought the surface up to a nice shine.  These are not as shiny as stainless steel, but pretty darn close.

In this video, you can see the before and after, but also can see the construction of the window, and how the glass gets put into the frames.  Where the spline came together is where mine were leaking.

NOTE UPDATE:  I have read a few posts on the internet about being cautious in using a wire brush on aluminum window frames because small amounts of the steel from the bristles can lodge on the softer aluminum and while not seen by the naked eye, could cause issues with corrosion due to dissimilar metals in a salt water environment.  I will update this blog over time if there seems to be any negative results from this method described. 

Now that the frames are complete, lets get back to the assembly of the glass into them.  I tried for a week, Rubber Mallet, Clamps, Tie down straps, bench vise and even the lathe to try to compress the frame together.  Long story short, I was defeated.  I couldn’t get the frames all the way together (1/2” gap could not be closed).  I called a local glass glazier and brought the 2 ports (or parts as it were).  He was able to rebuild both of them for $175.  Money well spent because comparable sized ports were $700 each.

I did the same leak test mentioned above and all was good.  We took them back to the boat and rebedded them back into the fiberglass and tested for leaks. 

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