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Fitting hardware - Gougeon Brothers

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  • Fitting hardware - Gougeon Brothers

    I've a separate thread on my little outboard cruiser I've been building (Selway Fisher Clyde 18), and I'm now fitting hardware to it. Last night I was reading the Gougeon brothers document online about their suggestions of fitting hardware. A search on here showed builders liked some of their suggestions but not all. The main concerns I saw were that using epoxy could make future removal difficult or that the epoxy could crack, and the resulting seam would allow moisture in.

    (1)At the basic level, drilling a pilot hole and coating the inside of the hole and screw thread before screwing up. Removal might not be too hard - solder iron on the head of the fixing to heat the screw and soften the epoxy would likely be ok. Probably for light duty.

    (2) For fittings which would be held in with screws and not subject to too much stress, they suggest drilling a pilot hole, and then an over sized hole - pilot+6mmto 3/4's of the depth, coat the inside of the hole with unthickened epoxy, and then fill the hole with thickened epoxy - the last 1/4 can hold the screw until the epoxy cures. A countersink provides a bit more strength and then screw it all up. Again a solder iron would likely get the fixing out. They suggest bonding the fitting to the timber of the boat would add additional strength, but might cause more paint repair than necessary in the case of future replacement of the fitting.

    (3)For fittings with through bolts (eg cleats) they suggest to drill and oversized hole as above and coat the threads with unthickened epoxy, fill the hole and the threads of the fitting with thickened epoxy and assemble it, until a small amount of squeeze out. In practice, I found it easier to drill the oversize hole, fill with thickened epoxy and wait until it cures before drilling it out for the bolt/machine screw. Thickened epoxy can be put on the thread/base of the fitting to take up any gaps before assembling the fitting on the boat.

    There is ways of creating a threaded bush in the epoxy using release wax/oil, or drilling and tapping etc so the fitting can be threaded into the epoxy.

    The don't (as you would expect) suggest using a sealant (Sika 291/3M4200 etc)/ butyl tape etc.

    On my boat, I've got the sole hatches screwed to the sole and sealed with arbomast, my cabin vent is fitted the same way. Nav lights and all the other light duty bits and pieces I'll do this way

    I've fitted two cleats on the quarter knees on my boat - I've fitted them using method (3) above. If they crack and water gets in, it's not a huge job to make new ones.

    I've a few left to do - some grabrails for the cockpit - they're 900mm long and 200m high, with three fixing plates with 4 holes each. Because my boat has a self draining cockpit, the sole and side benches are raised, which means there isn't much height between the top of the seat and the gunwale, I wanted something on the gunwale. I'm thinking to use method (2) above. I can't really through bolt because of access and the shape of the inwale. I wasn't going to bond the underside of the feet to the top of the gunwale.

    The bow roller - I have a central spine with timbers either side on my boat so can't through bolt. I have got 6x M8x60mm coachscrews which I'll fit using (2) above. I wasn't going to bond the underside of the roller to the deck. I'll probably keep the anchor in the foredeck locker when it's not in use.

    Samson post - I'll through bolt this- probably using method (3).

    When I looked through here and videos online (most were fitting to FG boats), there was nearly always a tube of sealant, rather than thickened epoxy around the threads.

    How have you all attached fittings to your boat?

  • #2
    Re: Fitting hardware - Gougeon Brothers

    only epoxy
    epoxy only
    well okay, a wee bit of butyl
    but mostly epoxy
    no devil sperm
    404 thickened is good n strong
    no sika goo
    yes, epoxy


    • #3
      Re: Fitting hardware - Gougeon Brothers

      5/16" X 2 1/2" stainless chainplates passing through a cored fiberglass deck. Seal them with what?


      • #4
        Re: Fitting hardware - Gougeon Brothers

        The Gougeon brothers aren't always the last word, but they will not lead your project to ruin either.
        ​​♦ During times of universal deceit, telling the truth becomes a revolutionary act
        ♦ The further a society drifts from truth the more it will hate those who speak it
        ♦ If liberty means anything at all, it means the right to tell people what they do not want to hear
        ♦ George Orwell


        • #5
          Re: Fitting hardware - Gougeon Brothers

          Originally posted by willin woodworks
          5/16" X 2 1/2" stainless chainplates passing through a cored fiberglass deck. Seal them with what?
          two things i wont have, ss chainplates and a cored deck


          • #6
            Re: Fitting hardware - Gougeon Brothers

            Some of the Gougeon methods seemed to me to take extra time and depend on epoxy not cracking. For permanent screws I drilled a pilot hole, dry fit the screws and hardware then removed, made a small countersink at each hole to make a well for epoxy, soaked the holes with straight epoxy, added thickener to the mixed epoxy and stored on ice, after an hour or so filled the holes and dunked the screw in thickened epoxy and final assemble.

            For removeable screws I would put the screw in again after the straight epoxy, wait until the epoxy started to set, remove the screw and wait until full set. Then assemble with toilet ring wax in the hole and on the screw.

            For through bolts I found the drill-fill-drill again method too fussy. It was difficult to fill the hole unless the part could be placed horizontal, and re-drilling right down the center was not always successful. Instead I epoxied in some kind of tube or bushing. For pivoting high stress things like kick up rudder pivot I used a bronze bushing. For holes that just needed to be sealed I used garolite tube. G10 garolite is expensive, but the cotton/phenolic tubes are cheap and easy to cut to length. McMaster has all the tube and bushings.

            Removeable fittings got butyl tape. It seems to seal well, but the butyl does continue to squeeze out even a year later and looks a bit messy. I keep going round and cleaning off the extra.


            • #7
              Re: Fitting hardware - Gougeon Brothers

              For most parts I drill the oversized hole, fill with epoxy, let it cure, then drill to fit -- through bolted whenever possible. I bed the fitting with something, Dolphinite being my preferred goop of late.


              • #8
                Re: Fitting hardware - Gougeon Brothers

                Thank you for this timely thread- at least, timely for me! I am finishing the interior of my sail-and-oar boat and have not yet addressed the screw holes used to retain the thwarts, benches, CB case cap, and some of the floorboards:

                I guess I was hoping that some paint would get in there and magically resolve things. It sounds like I'd be wise to do a bit more. It sounds like tonight I'll be treating all the holes for removable screws as described by Rick above.

                If the wooden boat hive mind would weigh in on these questions for a trailer-sailed boat I'd be obliged:

                1) Is it ever OK to just put a screw into the wood, without any kind of epoxy prep? Say I'm arranging gear storage by attaching footman's loops to the interior underside of my gunwale using 1/2" stainless screws- would you still dip those screws in epoxy, or swab the pilot holes?

                2) When people say they bed everything - what about oarlock sockets? Wooden cleats? If so, why? (and thank you).

                3) The OP mentions bedding hatches in Arbomast. My hatches, and some others I've researched, specify silicone bedding. Silicone is bad around varnish and paint. What do you all use?

                Sorry if this is a thread hijack, and thanks!

                - James


                • #9
                  Re: Fitting hardware - Gougeon Brothers

                  The main thing is not to let water lurk anywhere, it will cause rot. Either seal it so water cannot get in, or put limber holes so it drains. Even wood screwed to wood, water can be trapped between.


                  • #10
                    Re: Fitting hardware - Gougeon Brothers

                    Never overlook the basic truth that the business of the Gougeons is to sell epoxy.It is a very useful product,but it isn't the only solution to every problem.It does seal holes well.If I had to have s/s chainplates passing through a cored deck,I would be hoping the builder placed a solid piece of 10G40 Tufnol or G10 in the area.I would be a lot less enthusiastic about having to put a bent nail in a drill chuck and opening out a void to fill with thickened epoxy before removing enough of it to pass the chainplate through-but if it had to be done......


                    • #11
                      Re: Fitting hardware - Gougeon Brothers

                      I have just fitted metal strips on the 'keel' of my dinghy as it will sit on a beach, and used the 2nd option. Time will tell how successful that is....


                      • #12
                        Re: Fitting hardware - Gougeon Brothers

                        Totally agree that the Gougeons want to sell epoxy. I agree that the drill, fill and drill is a bit fussy. I have done 4 holes tonight this way and does need care taken to avoid air traps, making sure the tape on the underside doesnt come unstuck (don't ask how I know this!!!)

                        I fitted the side grabrails tonight to my boat using method 2. I hope it'll be OK, and I'll keep an eye out for any movement which might let water in.

                        I've never used silicone- Arbomast is much nicer to use, and I think better. Was recommended to be by John on here- seems a very good product and at a good price.

                        I havent got any screws on my boat that don't have something round them. Arbomast if I want to get them out, dipped in epoxy if light duty, and the oversize hole and thickened epoxy for heavier duty.


                        • #13
                          Re: Fitting hardware - Gougeon Brothers

                          Well, after admonishing James to seal everything I realized my oarlock risers are not bedded (ahem). The through bolt holes are not sealed either. I will say that the deck and its holes are epoxy sealed and lined, and that the risers get removed and oiled a couple of times a year.


                          • #14
                            Re: Fitting hardware - Gougeon Brothers

                            Originally posted by Woxbox
                            For most parts I drill the oversized hole, fill with epoxy, let it cure, then drill to fit -- through bolted whenever possible. I bed the fitting with something, Dolphinite being my preferred goop of late.

                            I would add that you consider where the strain may come upon the assembly: is it a shear load, a pull-out load?? My hull is strip-built western red cedar: the crush strength of this is not infinite. The naval architect I hired schooled me that 4 bolts, 3/8" diameter in a chainplate acting in sheer would exceed the crush strength of the cedar as the chainplate was pulled upwards. So I basically took the advice above and bored a larger hole, filled with high density epoxy, so that there were more square inches of epoxy bearing on the soft wood, and the strength of the high density epoxy resists the load per square inch that the fasteners are able to exert in sheer. Does this make sense? In engineering terms it is not enough that a 3/8" bolt will take the shear load, the wood that it bears against must be able to take the same sheer-load when it is applied as compression per cross-section of the bolt on the wood fibers. someone help me make this clearer, I don't feel I have done a good job.



                            • #15
                              Re: Fitting hardware - Gougeon Brothers

                              For the most part experience is making the same mistakes over and over again, only with greater confidence.