Teak deck outer rails

One of my outer teak rails is separating from the hull. I am using the term “outer teak rails” however in case it’s the wrong name, I mean the teak board which is affixed to the outer part of the hull and runs fore and aft. The teak board is not yet in any danger of falling off but it needs secured. It looks like these boards are screwed on. I was wondering if any of the other owners have considered using bolts with an external flat head to secure these rails and if anyone can advise of what bolt type was used?

Teak toe rails and hand rails – what to do about caring for them? John brought this question back up to me via email, so I thought I would answer here.

When we bought Rainshadow in 2009, all deck teak was varnished with MANY layers from years of touchup. In about 2012, I carefully used a heat gun to remove all the thick varnish – amazed that I neither burned myself or the boat. Then I started on the quest for how to maintain the teak without varnish.

First I tried an off-the-shelf teak oil product. In the Seattle climate, it turned to black mildew in short order.

Then I tried Teak Guard. The result was an odd color teak with limited durability.  I didn’t stay on top of recoating areas where bare teak was exposed by wear (as in, the place we always step when getting on/off, etc.). The result was the bare teak would go grey, and the coated stuff would be too orange-tinted to look real. So I would scrub it all off with a green scotch brite pad and start over once a year.

Once we made the passage from Seattle to Hilo, Hawaii, I decided to let the teak just weather naturally. After a few years of tropical sun and ample rain, the teak is very weathered with severe surface ridges. Many of the plugs that cover the screws are popping out, exposing the end grain of the teak.

This year, I decided to use Tung Oil. Following  common recommendations, I started by cleaning with a detergent/mild bleach wash using a stiff brush, then several coats of tung oil cut with turpentine to help it soak in. Turpentine stinks, so I think I’ll change to cutting with odorless mineral spirits next. The teak soaked up the oil, but as expected within a week of tropical sun, the oil oxidized and went dark. I decided I don’t care.  I can easily see where the wood can soak up more oil because it’s lighter. I’ve touched up those areas with more oil, not bothering to scrub first.  Also, for the first week-ish after coating, the wood feels a little sticky like oxidized oil. It doesn’t rub off or wash off.

I chose to use tung oil rather than an off-the-shelf teak oil product because I had the tung oil on hand, and my past experience with expense “teak oils” indicated they don’t stop the darkening as promised. Besides, we had a sample piece of teak scrap that we coated with tung oil and left it outside in the weather for about a year, after which time it was dark but not dried out with ridges like our boat teak has become.

Lots of people recommend cutting together tung oil, mineral spirits, and little varnish like Epiphanes, with the varnish acting as a sealer. I don’t like the idea of varnish build-up again, so have not tried that.

Does my teak look good? Beauty is in the eye of the beholder. The weathered-gray teak look is fine, but I just got worried about the screw plugs popping out and exposing the end grain – that’s a good way to promote rot in most woods.

Does the Tung Oil actually do any good? Many folks pontificating suggest my efforts to restore oil to the weathered teak are pointless (or worse, detrimental). Instead a sealer is needed to seal-in the teak’s natural oils.

Does anyone know of a sealer that has some durability? And can be reapplied without removal/sanding?  Is it even worth trying to seal in the natural oils on teak that is 50+ years old and badly weathered?