Q1: what is the best method to fasten the Z-leg of a Reversible Pilot Seat to the cockpit deck of a 1986 MONTAUK 17 so it forms a tight connection to the deck?
BACKSTORY
I am nearing the completion of my first phase of the renovation of my 1986 Montauk 17. When reassembling and remounting the Reversible Pilot Seat (RPS), I noticed the top surface of the Z-legs tops were not in intimate contact with the bottom surface of the (new) Specialty Marine seat (cushion).
The Z-leg on the Port side was leaning toward Starboard. The port mounting holes in the deck--and probably starboard holes, too--are overlarge from age and use; they are "wallered out."
My plan is to removed the RPS from the deck, and enlarge the existing screw holes in the deck; then clean out the holes and fill them with G-Flex epoxy (or similar). When the epoxy is fully cured, I will drill new holes of diameter "body size." Then I will re-install the Z-legs and RPS to the deck.
--Glen
Fastening RPS Z-leg to Deck
Re: Fastening RPS Z-leg to Deck
Referring to the wood locating diagram for the 17-foot hull (which is listed and is available from the REFERENCE section List of Drawings), the area of the cockpit deck where the RPS Z-legs would be attached should be reinforced by an embedded sheet of half-inch plywood. That material was probably what originally gave the mounting screws enough purchase to hold the self-tapping screws that fastened the Z-legs to the deck. Here are the linksglen1941 wrote:Q1: what is the method to fasten the Z-leg of a Reversible Pilot Seat to the cockpit deck of a 1986 MONTAUK 17 so it forms a tight connection to the deck?
List of Drawings
https://continuouswave.com/whaler/refer ... wings.html
Wood Locating Drawing 17-foot hull
https://continuouswave.com/whaler/refer ... 0x743.jpeg
To regain a strong attachment, your plan to create a circular pocket of thickened epoxy resin is a good approach. This same method has been suggested and used to restore the base mounting fasteners for railings. See the FAQ on this topic at
Q7: How are loose railing anchor bases repaired
https://continuouswave.com/whaler/reference/FAQ/#Q7
Additional advice: do not drill the new holes too large or too deep.
Also, you may want to begin with non-thickened resin to wet the plywood and seal the foam material below the wood, before using a much thickened epoxy to create a new material for holding the screw fastener.
Also, you may be able to thread and tap the thickened epoxy, and then be able to use a machine screw as the fastener instead of a tapered self-tapping wood screw.
As for your plan to use G-Flex, I don't have any experience with that product as a means to create a new material for holding screw fasteners. According to the manufacturer of G-Flex (West Systems), that product is described as:
West Systems wrote:G/flex 650 Toughened Epoxy
G/flex® 650 is a toughened, versatile, liquid epoxy for permanent waterproof bonding of fiberglass, ceramics, metals, plastics, and damp and difficult-to-bond woods. It is a bit more flexible than standard epoxies and polyester but much stiffer than adhesive sealants. This gives it the ability to make structural bonds that can absorb the stress of expansion, contraction, shock, and vibration. It is ideal for bonding dissimilar materials. It can be modified with WEST SYSTEM® fillers and additives and used to wet out fiberglass tapes and fabrics. This system is simple to use with its 1:1 mix ratio by volume.
I think you could use a West Systems Repair Kit. That will come with resins (in pre-measured foil packets) and filler materials. There should be enough filler material and resin to create several reinforced holes. The $50 repair kit will be handy to use, and the resin and hardener won't be spoiling in the unopened foil packets you didn't use.
West System Repair Kit
https://www.westmarine.com/west-system-105-k-fiberglass-boat-repair-kit-12954095.html
Also, avoid using sawdust as a filler material.
Cf.: https://epoxycraft.com/trade-secrets/three-reasons-not-to-thicken-epoxy-with-sawdust-and-what-to-do-instead/
You should not need to color the epoxy as it should never be seen as long as the Z-legs are in place.
Re: Fastening RPS Z-leg to Deck
Glen—if you are over six feet tall, you might consider increasing the height of the RPS by fabricating wood risers to place between the Z-legs and the deck. See
RPS Seat Height
https://continuouswave.com/forum/viewtopic.php?t=5854
RPS Seat Height
https://continuouswave.com/forum/viewtopic.php?t=5854
Re: Fastening RPS Z-leg to Deck
Jim, Thanks for the great advice. Exactly what I look for in CW over the years. Am following through with the West repair kit, and will use the West G-flex as suggested to establish a good bottom in the holes. Again, thanks. Glen
Re: Fastening RPS Z-leg to Deck
Hello all, removed Z legs and rps, drilled out holes in deck to 1/2", filled with West Repair Kit epoxy. Tomorrow will sand down the places on the deck where the epoxy was overfilled, drill holes to body size of screw, and put it all back together. Observation. The previous owner had installed the Z legs onto 3/4" thick teak pads. The result was that the screws only had 3/8" purchase into the deck. As engineer, am thinking of all the different loads on the rps when under weigh. What were these people thinking? Suggest that anyone who obtains an older Whaler where the Z legs have been raised with a pad, should determine how much screw is holding the seat to the deck.
Re: Fastening RPS Z-leg to Deck
Consider drilling and tapping the holes in the cured epoxy resin in the deck. Epoxy resin can cure to be very hard, and using self-tapping screws may be a challenge.