Railing Stantion Inserts?

Helicoil makes titanium inserts that can be used with the aluminum.


http://www.helicoil.com.sg/HeliCoil-Screw-Thread-Insert-Materials-Platings.htm

I've removed the toe rail entirely on the boat I'm bringing back to life. What I found upon removal was that two conditions generally proved to be the case: 1) the epoxy barrier coat was sticking well to the aluminum and the underside of the toe rail was rotten, sometimes extensively; and 2) the barrier coat had failed and the wood was pristine, but the aluminum was covered with oxidation and in some places was quite pitted. If you're serious about doing the toe rail, I recommend that you spend a day carefully removing it. Then have the entire area blasted clean. Call in a welder to fill the screw holes that are no good, then drill and tap new ones in the same spot. Then barrier coat with modern epoxy and flood the toe rails with CPES on the underside where they will almost certainly be rotten. Dutch in new wood where necessary, then make them pretty on the topside and remount with good bedding compound.

I know, it's a lot of work. But you'd be surprised what's hiding below pretty toerails on 40yo aluminum Roamers.

To q240z - An easy method, if you have access to the back side of the bolt 0 machine screw, put on a nut and washer! However, Murphy (writer of laws) makes sure that the stripped holes are not accessible short of torching a hole in the side of your boat.

Stanchions/Helicoils.

Haven't had this problem (yet)*. Have you seen this kit:
http://www.emhart.com/products/helicoil/repkit.asp
More general info here:
http://www.roadstarmagazine.com/modules.php?name=News&file=article&sid=233
Helicoil tips (Google):

"Just be sure to drill it straight and don't wallow it out; clean the hole with alcohol use plenty of the red locktite to hold the insert in place, and always always ALWAYS use silver anti-seize on the bolt!!"

"Helicoils are fine repairs for infrequently swapped hardware, but for items that require frequent removal over a very long lifetime the keyed inserts reign supreme. Helicoils are less expensive though."​

To ELIMINATE crevice corrosion:
http://www.tefgel.com/contain.php?param=tefgel_infor
(Really).

* Notably, CC used two types of foundations for side rail stanchions: (i) Open-ended - which allows water to pass thru; (ii) Fixed or closed end caps - causing water to collect at bottom. In the latter case, water (especially salt water) facilitates crevice corrosion which generally attacks the (less noble) aluminum/steel structure into which the SS stanchions are screwed into. Santa is not happy.

More notes from the internet:
"HOW TO INSTALL Heli Coil® INSERTS: The following comments are intended for installation into steel and aluminum. The installation of the inserts is a four-step process. First you have to drill out the old thread, then TAP the hole using an STI (screw thread insert) tap, install the insert with the appropriate installation tool until it is approximately ½ to ¾ of a pitch below the surface and finally break off the driving tang. If you purchase a Heli Coil® kit from either an automotive parts store or an industrial distributor, it will contain all of the tools that are needed. The tapping process is not complex since the tap wants to follow the predrilled hole and is removing relatively little material - just keep it parallel to the center line of the drilled hole. You will require only minimal forced to achieve the desired results. NOTE: The taps used, regardless of the style of tap, MUST be marked with the STI identification because this tap is cutting a hole that is larger to accommodate the extra thickness of the insert. DO NOT use roll form or forming taps. Use of this type of tap to prep a hole for a Heli Coil® installation will cause problems virtually all of the time especially when using fine threads. A Heli Coil® Brand tap will carry a marking consisting of a part number, size, fit and the STI notation. Breaking off the driving tang can be accomplished in a number of ways. In the smaller threads, the easiest way is to obtain a piece of drill rod slightly smaller that the ID of the insert, insert it until it comes in contact with the tang and then tap it with a hammer. The tang will break off. In larger inserts, it may be easier to grasp the tang with pliers or gripping tool and then work the tang up and down until it breaks off. GAUGING OF FINISHED HOLES: The mil spec that governs the installing of wire inserts states that gauging of the tapped hole prior to installing the insert defines whether or not the hole is properly prepared. Attempting to gauge a hole after the insert is installed renders useless data and can cause problems since the insert is not seated until the installation of the mating fastener and if the fastener is removed, the insert will attempt to return to its original state. "
http://www.airheads.org/content/view/213/49/

On mine, all of the stanchion bases bottomed out in the toe rail. None of them went all the way through to aluminum originally. But since they never got rebedded, water eventually found its way to the bottom of the hollow cutout in the rail and rotted many of them out. From there, water fell directly on the epoxy barrier coat, which also failed (generally starting at the screw holes for the toe rail and stanchion bases, but growing far and wide from the point of origin). When we remake the toe rails, we'll fill the hollows and treat all sides of the toe rails with CPES (cold penetrating epoxy sealer) before installing. Once it's plasticized, the mahogany should be water tight for a very long time but still retain its natural beauty.

Toerails REDUX

From the archives:
"Roamer owners may note corroding from around the wood to metal area of the deck... hard stop unless the wood is removed and replaced. The best product to bed the wood is brown Sikaflex,..., remains pliable, slow to dry and does not "goo-out" like the originl Dauphinite. Correct number to follow,..
As far as the wood, if it is not replaced, do not Epoxy as water seeps up from the bottom around the screw plugs and always will unless the wood is removed, epoxied underneath and plugs epoxied as well. Epoxy is a bear to get off so only recommended with a "start from scratch" job.
The best epoxy product to use is MAS, thinned with 10% laquer thinner. Build three coats, sand smooth as baby’s ass,..., you will not remove all pocks, so do not sand down that far.. go back and fill pocks and re-sand.
The highest quality finish is to spar Sterling/ DETCO clear acrylic (which is rubbable,...., several coats,..,. 3 then sand with 220,..., and then 3 more coats. If you want glass,...., wet sand. Long stroked with flat block; then spray 3 more coats, dry, lightly sand and one more finnish coat,..., then rub out to car-like finish and it will make a varnish job look like a non-skid deck."

See, you aint the first.
Cheers!
Eric

I wouldn't hesitate to use CPES and then refinish on an old toe rail as long as it wasn't as far gone as mine. Unfortunately, whether new wood or old, the only way to do it right is to remove the rails and treat all sides.

What else are you gonna do in your spare time? lol