In 2013, I started refurbishing the (hateful) aft stateroom portholes. The paint was falling off, letting aluminum oxide form under the coating on the frames. Most of the aluminum latch dogs had locked up on their stainless steel machine screws because most of them don’t get opened very often, water gets in, and aluminum oxide fills the gap between the stainless screw and the aluminum latch. The coating had also failed on the dogs because the aluminum was painted even in the rough contact areas where the latch dogs lock onto the openable window frames to clamp them closed. And then there were the gaskets…rock hard rectangles of old rubber that long ago had compressed and taken a set. Because they were hard and had taken a set, water would stream in past the gasket and get into the cabinetry as well as the stainless and aluminum screws (yes…aluminum screws) that held the glass and screen frames in the porthole frame. The whole time I was dealing with the messes caused the OEM’s approach, I vowed to take different approaches when I put them back together.
I started with having them completely stripped then coated with Awl Grip aluminum primer, Awlquik, 545 primer, then top coated with Matterhorn white for the main frames and Awlcraft 2000 Navy Blue for the exterior screen frames, to match the blue accent stripe. In 2016, I got the screens installed in the portholes, and later that year I installed the new tinted glass. While the original screws that held the screen frames in place were stainless machine screws, the window frames were held in place with aluminum panhead screws (without washers), most of which had turned to AlO3 powder from water intrusion into the threads. None of them appeared to have been installed with grease. So when I put them back together I used stainless screws and washers for the panheads. I also used Tef-Gel, a terrific teflon product that seals the threads and isolates the screw metal from the frames. So, I had beautiful portholes, and the materials I was using should resolve most of the problems with the OEM build. But there were still those old gaskets…
I’d been pondering on what approach I should use there since 2013. Late in 2019, after looking at all of the currently available options, I decided to make my own gaskets out of super soft and durable silicone. I made the gasket molds and waited for the silicone kits to arrive. Once the kits arrived, I made my first gasket and tried it out on a porthole…it worked great! The last step was to finish assembling the portholes.
Found it!!!
I mentioned a few posts back that I took some time off of the project to do some things around the house, which included cleaning my garage and basement. That wasn’t entirely truthful. I had been trying to find the box of porthole hardware, and I was getting frustrated that I couldn’t find it. I thought I’d turned the boat upside down already. Cleaning the garage and basement came next (upside: I put lots of stuff on ebay and they’ve been selling like hotcakes!). I was organizing the sandpaper stash in the aft stateroom when I found the box! Booya!
Aluminum latch dogs still had aluminum oxide inside the bore
I picked up these stainless brushes in various sizes years ago…finally got to use them!
Nice and clean
I smoothed the contact surface of the dogs, too
My ShopSmith 12″ sanding disc with 220 grit made them nice and smooth.
The stainless screws for the latch dogs had been painted, but they polished up nicely
Putting the screws in a drill and spinning the head and shaft on 220 grit sandpaper cleaned them up pretty quickly.
Can you say tedious? I live it…sometimes
I had a bunch of 1/4″ nylon washers but none in the dimension for the latch dog screws. I’d looked for them online, but the only ones I found in the right ID had a bigger OD that wouldn’t look right. So I drilled out the 1/4″ washers to 3/8″. I had to do it in 1/64″ increments, and there are 36 of the dogs. Anything more aggressive than 1/64″ bigger, and the drill bit would bite into the washers and just spin them. It was tedious, but these are mission critical parts because they’ll isolate the lock nut from the painted frame.
Engine assembly lube is great stuff
Assembly lube coats the stainless latch dog machine screw and the bore hole
Almost ready to install
Chase the threads with a tap
Generous application of Tef-Gel inside the threaded hole and on the screw threads
Super important step: avoid paint-to-paint contact in high stress areas
I’ve used this product in other places, including when I rebuilt the bow deck hatch. It’s called Slick Strip–an adhesive-backed ultra high molecular weight polyethylene tape that’s available online in different thicknesses. I used the thinnest– 1/32″. After wiping down the contact areas to remove dust, I pulled off the blue backing and applied the Slick Strips to the window frames and latch dogs.
The adhesive is pressure sensitive, so you have to press all of it into 100% contact with the substrate
I cut off another little strip for the latch dog
Not bad!
It was around this time that I realized I might need an intervention…
Yes…I was beveling the edges of the Slick Strip on the latch dogs. I don’t want them to pop off when the two straight edges impinge on each other. But maybe this is a bit over the top? I eventually decided it was worth the effort…only took an additional five minutes to trim all of them.
Contrasting the OEM approach and mine
In the picture above, from lower left to right, are the stainless screws and washers (with Tef-Gel) I’m using to hold the window frames in place. I’m also using new #18 stainless flathead screws to secure the portholes to the mahogany surround panels instead of the corroded aluminum screws you can see next to it. Next is the stainless undercut flathead screw (with OEM aluminum oxide dust clogging the threads!) and one of the few aluminum panhead screws I was able to remove from the hateful portholes back in 2013. And finally, unpainted aluminum latch dogs and polished machines screws, with Tef-Gel, assembly lube on the bolt, a nylon washer to keep the locknut off the paint, and Slick Strips to protect the paint in the clamp area.
Sikaflex 291 LOT from a small syringe goes in the gasket slot
New 00-50 Shore, super soft silicone gaskets go in next
Looking good!
That’s a good looking gasket!
Set the center latch dog…the gasket compresses really well!
Left-side latch dog goes in next
That Slick Strip-to-Slick Strip contact is super smooth, and it clamps the frame nice and tight.
One porthole assembly done…11 more to go!
Next up in our 1969 Chris Craft Roamer 46 Refit: Aft Stateroom Headliner Prep IV
1969chriscraftroamer46 