Repair of Loose Screw Fasteners

[otter]

Q1: what is the best method to restore the purchase of loose screw fasteners on the "grab bar" and on the base of the "pole holder" on a 1998 Outrage17 II boat"?

Q2: is an acceptable method to [restore the grip of loose screw fasteners] to

• remove screw fasteners;
• insert wood slivers into hole; and
• finish off with epoxy covering the screw threads?

The above method seems to me to be the most workable.

Have 1998 Outrage II 17ft and was wondering the best method for screws that won't tighten up on the grab bar and a few in the base of pole holder. Is the acceptable method still to remove screws, insert wood slivers into hole and finish off with epoxy covering the the screw threads. This would seem to be the most workable. Thanks

[jimh]

Advice on restoring the purchase (that is, the advantage of a firm hold or grip) of loose screw fasteners is a frequently asked question. The FAQ at

https://continuouswave.com/whaler/reference/FAQ/#Q7

gives one approach where the load on the fastener will be particularly highly stressed and where a very strong repair is needed.

If the screw fastener can be given better hold or grip by adding some wood splinters, and if the load on the fastener is not particularly high, augmenting the screw's hold or grip or purchase by adding some wood splinters can be a temporary solution.

For example, on the helm console of my boat there are a dozen small screw fasteners that hold the metal instrument panel in place on the laminated helm console. The load on any individual fastener is very small, and in several locations the screw fasteners were no longer getting much purchase. I used a small knife to cut off slivers from soft pine wood, and I put those slivers into the holes for the screw fasteners. This much improved the hold or grip or purchase of the screw fastener in the existing hole, but, again, the load on those screws was minimal, and that load was was being spread over a very large number of fasteners.

In your proposed method, I do not understand your instruction to "finish off with epoxy covering the screw threads." Please elaborate on what you mean. It sounds you want to coat the steel screw fastener threads with an epoxy adhesive and then try re-installing them in the original hole. The process of threading-in the screw fastener would tend to shed most of the epoxy off the screw fastener. Also, bedding screw fasteners with epoxy resin may inhibit future removal of those screw fasteners without causing damage to the laminate around the hole, as the epoxy resin will produce a very strong secondary bond to the cured laminate and added wood slivers and the screw fastener--unless you were to coat the screw fasteners with a wax to prevent the fastener from being bonded to the wood and laminate by the epoxy adhesive.

Also, your descriptions of a "grab bar" and a "pole holder" are not very clear.

Perhaps you are trying to describe the railing that surrounds the windshield as the "grab bar." On boats there are often tubular structures that are provided as places for the crew to hang onto for stability and safety, and these devices are called "railings" as in names like "bow railing" or "side railings" or "cockpit helm console railing" and so on. The term "grab bar" is not in the nautical vocabulary.

As for what is meant by the "pole holder" I will need a better description to understand your meaning. On a boat a "pole" is usually a called "mast" or a "boom" or a "sprit". Or perhaps you are using "pole" as in "fishin' pole." Please clarify your intended meaning. Thank you.

[otter]

When I was referring to the "grab bar" I was referring to the railing that goes around the windshield on the center console.

Also, the "pole" holder is referring to a fishing rod holder that exists on each side of the hull toward the transit area. It obviously is capped with a small chrome or stainless plate to finish off.

I will probably insert wooden slivers while injecting epoxy into the fastener holes then after the curing process will reinstall screws.

[jimh]

When I was referring to the "grab bar" I was referring to the railing that goes around the windshield on the center console.

A better name is the center console windshield railing.

The only use of "bar" in nautical expression is in reference to sand bars, or possibly to units of pressure in Metric dimensions, or to shore establishments that sell alcoholic beverages, such as "the Anchor Bar" or "the Sailor's Bar."

Also, the "pole" holder is referring to a fishing rod holder...

Those tubular attachments that are designed to hold fishing rods are generally always referred to as "rod holders."

I will probably insert wooden slivers while injecting epoxy into the fastener holes then after the curing process will reinstall screws.

If you instill epoxy resin into a hole that was used to retain a screw fastener that was a self-tapping screw, and you let the epoxy resin cure, you will need to carefully drill a pilot hole for the screw fastener so that when the self-tapping screw is trying to cut its own threads it will only be removing the minimal amount of material. Cured epoxy resin is very hard and it will not be easy to use a self-tapping screw fastener to thread into it. For this reason, if you use epoxy resin it should be mixed with a filler. You can use sawdust as a filler. You do not really need the wooden slivers.

Also, when I am restoring the diameter of a fastener hole to improve the bite or grip it will have for a certain size fastener, and I have filled the existing with epoxy resin mixed with filler, then when I am cutting new threads for the self-tapping screws I use ONE screw over and over to cut the new threads, removing that screw, and then installing a different new screw as the permanent fastener. In this way the initial screw or "threading screw" is doing all the work, and the finishing screw is much easier to thread into the hole. You will find that the process of cutting new threads in epoxy resin--even when mixed with a filler--will generate a lot of heat, and the "threading" screw will get quite hot in the process.

I always use screws with a Phillips head drive, and typically the "threading" screw head will get a bit deformed from the screwdriver slipping out of the Phillips head. The tool coming out of the screw head is actually somewhat intentional in the design, as it prevents the screw from being over-tightened and stripping its own threads. It was adopted initially by automobile manufacturers who were using power-screwdrivers to install screws, and did not want the workmen to be able to over-tighten the fasteners. My "threading" screw head will usually get a bit deformed after it has been used to create threads in many epoxy-lined holes, but the next Phillips-head screw that follow in the somewhat pre-threaded hole will have no deformation of the screw head--as long as you insert it so it picks up the prior threads and does not try to cut its own new threads.

Also, because the diameter of the screw fastener shank grows larger toward the head of the screw, you MUST relieve the upper part of the hole that is in the gel coat so that the screw fastener is NOT cutting away and part of gel coat layer. If you do NOT do this then you will produce a big crack in the gel coat resin. Old gel coat is particularly brittle and prone to cracking.

ASIDE: there is another cross-head screw design called the JIS (Japanese Industry Screw) screw head, which is designed to NOT shed the tool when the torque increases. I first encountered use of JIS screws when working on electronic gear made in Japan. Loosening these JIS fasteners with a Philips-head screw driver was very difficult, as the tool did not fit properly into the cross-head slots. In some expensive professional grade gear made by SONY, a special screwdriver was included. Using the SONY screwdriver the fasteners could be loosened and tightened much better than using the similar-but-different Phillips head screwdrivers, which often would just spin off the screw head or damage it. You may see screwdrivers that will fit the JIS screws marked with a PZ designation, but they are not Pozidriv (or Posidrive) tools, which are for another cross-head design.