{"id":20866,"date":"2025-11-13T13:45:54","date_gmt":"2025-11-13T13:45:54","guid":{"rendered":"https:\/\/manuals.seakeeper.com\/seakeeper\/seakeeper-18-installation-manual-90672-2-s-n-18-234-2475-to-current-copy\/1-0-mechanical-installation-2\/1-6-saddle-installation\/"},"modified":"2025-11-13T14:43:25","modified_gmt":"2025-11-13T14:43:25","slug":"1-6-saddle-installation","status":"publish","type":"page","link":"https:\/\/manuals.seakeeper.com\/seakeeper\/seakeeper-18-installation-manual-90672-3-s-n-18-254-2135-to-current\/1-0-mechanical-installation-2\/1-6-saddle-installation\/","title":{"rendered":"2.5 Saddle Installation"},"content":{"rendered":"\n

Seakeeper<\/span> provided mounting hardware is intended to apply to typical installation arrangements. However, each installation, especially custom aftermarket foundations, should be thoroughly reviewed to ensure the provided hardware meets the required thread engagement for the Seakeeper<\/span> unit being installed. The mounting bolt thread engagement requirements are outlined in the Installation Manuals and Installation Details Drawings for each Seakeeper<\/span> model. This also applies to Seakeeper<\/span> model adapter kits and OEM built frames where the bolt hole depth should be checked to ensure the bolts will not bottom, preventing the bolts from achieving the intended preload.

When the Seakeeper<\/span> provided hardware is not appropriate, the bolt specification (diameter and thread pitch) and grade should be matched in the required length and used with the Seakeeper<\/span> provided washers. Mounting bolts should always be torqued to the Seakeeper<\/span> specification. All Seakeeper<\/span> provided bolts are metric course thread. Hardware specifications are also listed in the Installation Manuals and Installation Details Drawings.<\/p>\n\n\n\n

See Sheet 6 of Seakeeper<\/span> drawing No. 90545 for loads information and recommended adhesive properties.<\/mark><\/strong><\/p>\n\n\n\n

2.5.1 Preparation of Hull Structure<\/h2>\n\n\n\n

Refer to Seakeeper<\/span> Drawing No. 90545, Seakeeper<\/span> 18 Installation Details \u2013 Bond-In Method<\/em><\/strong>. Important dimensional and load information is given in this drawing that will impact the design details of the structure that will receive the Seakeeper<\/span> as well as selection of the adhesive to bond the Seakeeper<\/span> into the hull.<\/p>\n\n\n\n

The foundation \u201csaddles\u201d of the Seakeeper<\/span> are designed to be bonded directly to the composite hull structure of the vessel to effectively distribute Seakeeper<\/span> loads.  A complete bond is required between the inside surface of the saddles and the hull structure<\/strong>.<\/span> An estimate of adhesive volume required should be calculated for each installation based on gaps between saddles and structural members. There is some adhesive waste as a part of the process, so a good rule of thumb is to purchase up to 50% more adhesive than estimated volume to ensure a complete bond. Depending on conditions and adhesive used, two workers may be required to apply the adhesive at the same time to finish the installation before the adhesive starts to cure. To aid in determining the quantity of adhesive required, the interior surface area (bonding surfaces) of each<\/strong> saddle is 164 in.2<\/sup> (1,058 cm2<\/sup>) for a total bonded surface area for all four saddles of 656 in.2<\/sup> (4,232 cm2<\/sup>). <\/p>\n\n\n\n

The hull structure supporting the Seakeeper<\/span> should be arranged so the Seakeeper<\/span> is parallel to the waterline in the transverse direction and within 2 degrees longitudinally.  The four areas on top of the beams that the saddles will bond to need to be co-planar within .13 in. (3 mm) for consistent adhesive bond gap.  In addition, the four areas on top of the saddles on which the feet of the Seakeeper<\/span> foundation will rest need to be co-planar within .06 in. (1.5 mm) to minimize potential distortion of Seakeeper<\/span> support frame when installed.<\/span><\/strong><\/p>\n\n\n\n

Note that any paint or gelcoat present in bond area should be removed so that adhesive will bond directly to laminate fibers and resin. <\/strong> <\/mark><\/p>\n\n\n\n

Seakeeper<\/span> provides an installation fixture template, P\/N 90282 that locates the saddles at the proper spacing both in the fore-aft direction and the port-starboard direction. See Figures 14, 15, & 16. Once assembled with the provided saddle fittings, the fixture can be used to check clearances and alignment of the hull structure. The fixture will allow the builder \/ installer to lay-up and adjust the foundation dimensions to create a low-clearance fit between the Seakeeper<\/span> foundation saddles and the hull structure. Shear strength of the adhesive will be maximized if the cured thickness between the vessel structure and Seakeeper<\/span> saddles is at the thinner end of the adhesive manufacturer\u2019s recommended range. Therefore, the fixture should be used to confirm that the overall dimensions of the foundations are square and level and that the adhesive gap is within Seakeeper<\/span>\u2019s recommended range of .04 to .13 in. (1 to 3 mm).Note: \u00a0 Do NOT use the installation fixture to establish Seakeeper<\/span> envelope dimensions.\u00a0 Refer to Drawing No. 90545 for envelope dimensions.\u00a0\u00a0 A 3-D model of the Seakeeper<\/span> is available on the Seakeeper<\/span> Technical Library (<\/strong>www.seakeeper.com\/technical-library\/<\/strong><\/a>) to aid in designing the Seakeeper<\/span> foundation and the space around the Seakeeper<\/span>.<\/strong><\/p>\n\n\n\n\n\n

NOTE: MAKE SURE NO OBSTRUCTIONS FROM THE HULL STRUCTURE CAN BE SEEN WITHIN THE INSIDE OF THE INSTALLATION TEMPLATE KIT (INSIDE THE MARKED RED LINES). REFERENCE SEAKEEPER DRAWING NO. 90545.<\/mark><\/p>\n\n\n

\n
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Figure 14<\/em> – <\/strong>Exploded view of saddle installation fixture<\/em><\/figcaption><\/figure>\n<\/div>\n\n
\n
\"\"<\/figure>\n<\/div>\n\n
\n
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Figure 15<\/em> – <\/strong>Saddle installation fixture on notional hull structure<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n

2.5.2 Fiberglass Hull Preparation<\/h2>\n\n\n\n
    \n
  1. Position installation fixture (Figure 16) on hull girders noting recommended clearances for maintenance from Figure 3.\u00a0 Check that the screws fastening the saddles to the installation fixture are tight (Figure 18).<\/li>\n<\/ol>\n\n\n
    \n
    \"\"
    Figure 16<\/em> – <\/strong>Installing fixture on hull<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n
      \n
    1. Mask hull area (Figure 17) around foundation saddles for easy clean-up and to create outline of surface area to receive adhesive as (Figure 16).\u00a0 Ensure that the bond gap is within Seakeeper<\/span><\/span>\u2019s recommended thickness, or 3 mm if using Plexus MA590.<\/li>\n<\/ol>\n\n\n
      \n
      \"\"
      Figure 17 <\/em>– <\/strong>Masking perimeter of saddles<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n
        \n
      1. Raise fixture clear of foundation.\u00a0 Check all four mounting areas are co-planar to within 0.13 in. (3 mm) to each other, as well as parallel to the water line plane, as shown in Figure 18.<\/li>\n<\/ol>\n\n\n
        \n
        \"\"
        Figure 18 <\/em>– <\/strong>Coplanar properties of foundation<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n
          \n
        1. Thoroughly clean with alcohol or acetone all areas of girders to be bonded to remove any contaminates. Use new paper towels for cleaning, not shop rags.<\/li>\n\n\n\n
        2. Remove any paint or gelcoat from bond surfaces so that adhesive will bond directly to laminate fibers and resin as shown in Figure 17.<\/li>\n\n\n\n
        3. Thoroughly sand hull girder bond surfaces with 80 grit sandpaper.  (IMPORTANT \u2013 BOND STRENGTH MAY BE REDUCED IF THIS STEP IS SKIPPED.)<\/strong><\/li>\n\n\n\n
        4. Wipe surfaces clean from dust with alcohol or acetone using new paper towels, not shop rags.<\/li>\n\n\n\n
        5. Re-position installation fixture on girders and double-check that the adhesive gap is within the adhesive manufacturer\u2019s maximum recommended thickness. Seakeeper<\/span><\/span> recommends a maximum gap of 3 mm if using Plexus MA590.<\/li>\n<\/ol>\n\n\n\n

          Note if bonding saddles to a metal structure, contact Seakeeper<\/span> for<\/strong> hull preparation instructions.<\/strong><\/mark><\/p>\n\n\n\n\n\n

          2.5.3 Seakeeper<\/span> Saddle Preparation<\/h2>\n\n\n\n
            \n
          1. Ensure that screws fastening saddles to the installation fixture are tight (Figure 17).<\/li>\n\n\n\n
          2. Check that each saddle contains 2 plastic screws which will ensure an adhesive gap of 0.080 in. (2 mm) on top surface of hull as shown in Figure 19. Do not remove these screws.<\/li>\n\n\n\n
          3. Thoroughly sand all saddle inside surfaces with 80 grit sandpaper in cross-hatch pattern. (IMPORTANT \u2013 BOND STRENGTH MAY BE REDUCED IF THIS STEP IS SKIPPED.)<\/li>\n\n\n\n
          4. Thoroughly clean with alcohol or acetone the inside surfaces of Seakeeper<\/span><\/span> foundation saddles to remove any contaminates as shown in Figure 19. Use new paper towels for cleaning, not shop rags.<\/li>\n<\/ol>\n\n\n
            \n
            \"\"
            Figure 19 – <\/em><\/strong>Saddle cleaning<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n
              \n
            1. If using Plexus MA590 adhesive, apply one coat of Plexus PC-120 surface conditioner to inside surfaces of Seakeeper<\/span><\/span> foundation saddles in accordance with manufacturer instructions.  These instructions are located in the following section.  If using an alternate adhesive, check with manufacturer if any surface conditioner\/etch is required for the aluminum saddles.<\/li>\n<\/ol>\n\n\n\n

              2.5.4 Bonding Saddles to Hull<\/h2>\n\n\n\n

              Note: This is a sample if using Plexus, if using another adhesive follow manufacturer\u2019s<\/p>\n\n\n\n

              recommendations. If using Plexus MA590 adhesive, the Seakeeper<\/span> saddles should be installed when PC-120 is confirmed dry.<\/p>\n\n\n\n

                \n
              1. Assemble Plexus cartridge into either the manual or pneumatic gun as shown.  Remove cap on cartridge and attach mixing tip.  For pneumatic gun, start with low air pressure and increase until desired flow rate is achieved.<\/li>\n<\/ol>\n\n\n
                \n
                \"\"
                Figure 20 – <\/em><\/strong>Manual adhesive gun (left) and pneumatic adhesive gun (right)<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n
                \n
                \n
                  \n
                1. Cut tip of mixing wand as in Figure 21.<\/li>\n<\/ol>\n<\/div>\n\n\n\n
                  \n
                  \"\"
                  Figure 21 – <\/em><\/strong>Trimmed mixing wand tip<\/em><\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n
                    \n
                  1. Prepare a second mixing wand as shown in photo below by attaching the simple flexible nozzle to the end of the mixing tip. Set aside for now as this will be used to inject adhesive into the sides of each saddle after the fixture \/ saddles are in position.<\/li>\n<\/ol>\n\n\n
                    \n
                    \"\"
                    Figure 22 – <\/em><\/strong>Mixing tip with flexible nozzle<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n
                    \n
                    \n
                      \n
                    1. Install provided rubber plugs in six holes of each saddle. The plugs will limit the adhesive being forced out of the injection holes in step 6 below. Refer to Figure 23.


                      <\/li>\n\n\n\n
                    2. Apply large bead of Plexus adhesive to the hull structure per Figure 24. Apply approximately 2<\/sup>\/3rds<\/sub> to 1 cartridge at each of the four locations.\u00a0 Work deliberate and fast as it takes some time to apply the adhesive to the structure. MA590 has a 90-minute working time at room temperature (73\u00b0F \/ 23\u00b0C).\u00a0 This working time can reduce to 40-50 minutes at elevated temperatures. Two workers should apply the adhesive at the same time to finish the installation before the adhesive starts to cure.<\/span><\/li>\n\n\n\n
                    3. Lower fixture and saddles over the hull structure and apply light downward pressure to each of the four saddles until the two nylon screws rest on the hull structure (Fig. 24). The adhesive will be forced towards the forward and aft ends of each saddle and partially down the sides of the foundation beams.<\/li>\n\n\n\n
                    4. Insert full adhesive cartridge along with mixing wand \/ nozzle assembled in Step 3 above into gun.<\/li>\n\n\n\n
                    5. Begin to inject adhesive into the three holes provided on each side of each of the four saddles. Follow the numbered sequence shown in Figure 25 until the adhesive pushes out the edges of the saddle perimeter. The intent is to pump in the adhesive working from the top down and from the middle to the ends to fill the gaps and displace any air.<\/li>\n<\/ol>\n<\/div>\n\n\n\n
                      \n
                      \"\"
                      Figure 23 – <\/em><\/strong>Rubber plugs <\/em>
                      placed in saddle<\/em><\/figcaption><\/figure>\n<\/div>\n\n
                      \n
                      \"\"
                      Figure 24 – <\/em><\/strong>Adhesive applied to stringers<\/em><\/figcaption><\/figure>\n<\/div>\n\n
                      \n
                      \"\"
                      Figure 25 – <\/em><\/strong>Image showing adhesive application order<\/em><\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n

                      A complete bond is required \u2013 excess adhesive will be needed to make sure all bond gaps are filled.<\/mark><\/p>\n\n\n\n

                        \n
                      1. Repeat above step for remaining 7 sides of the saddles.<\/li>\n\n\n\n
                      2. When gaps have been completely filled, clean off excess adhesive, remove plugs, and remove masking tape.<\/li>\n\n\n\n
                      3. Allow adhesive to cure per manufacturer\u2019s recommendations.  Follow adhesive guidelines for curing time versus temperature prior to removing the fixture.<\/mark><\/li>\n\n\n\n
                      4. Bonding of Seakeeper<\/span><\/span> saddles onto the hull is now complete.  Remove installation fixture.<\/li>\n<\/ol>\n\n\n\n

                        2.5.5 Installation of Seakeeper<\/span><\/h2>\n\n\n\n
                        \n
                        \n
                          \n
                        1. The four areas where the feet of the Seakeeper<\/span><\/span><\/span><\/span> will rest should be coplanar to within 0.06 in. (1.5 mm). See Figure 26<\/strong>.<\/mark><\/li>\n\n\n\n
                        2. Rig the Seakeeper<\/span><\/span><\/span><\/span> for lifting and lower it into position onto top surface of four saddles.<\/li>\n\n\n\n
                        3. Apply a small bead (approximately 4 mm wide) of sealant or caulk to the mating surfaces between the saddles and the Seakeeper<\/span><\/span><\/span><\/span> foundation.  Adjust position of the Seakeeper<\/span><\/span><\/span><\/span> until alignment is achieved for the 16 fasteners that will attach Seakeeper<\/span><\/span><\/span><\/span> foundation frame to saddles.<\/li>\n<\/ol>\n<\/div>\n\n\n\n
                          \n
                          \"\"
                          Figure 26 – <\/em><\/strong>Co-planar tolerances shown<\/em><\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n
                            \n
                          1. Install the Seakeeper<\/span><\/span> supplied Grade 10.9, M14-2.0 x 90 mm fasteners or alternative Grade 10.9, M14-2.0 bolts to maintain a minimum thread engagement of 0.83 in (21 mm).<\/strong> Apply a moderate coat of nickel-based anti-seize (e.g., SAF-T-EZE nickel grade anti-seize, SBT-4N or equivalent) to the threads<\/mark> of each bolt and include a small bead of marine grade sealant (e.g., SILI-THANE 803 or equivalent) under each bolt head and washer before installation.<\/li>\n\n\n\n
                          2. Torque all fasteners to 100 ft-lbs (136 N-m).<\/span><\/strong>
                            \n
                              \n
                            1. New bolts, matching the Seakeeper<\/span><\/span><\/span><\/span> specification, must be used for each installation and reinstallation that meet the requirements listed above.<\/mark><\/li>\n<\/ol>\n<\/li>\n\n\n\n
                            2. Proceed to electrical and cooling portion of the installation.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

                              Seakeeper provided mounting hardware is intended to apply to typical installation arrangements. However, each installation, especially custom aftermarket foundations, should be thoroughly reviewed to ensure the provided hardware meets the required thread engagement for the Seakeeper unit being installed. The mounting bolt thread engagement requirements are outlined in the Installation Manuals and Installation Details Drawings […]<\/p>\n","protected":false},"author":9,"featured_media":0,"parent":20856,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"manual":[369],"model":[],"document_type":[],"hidden":[],"class_list":["post-20866","page","type-page","status-publish","hentry","manual-seakeeper-18-installation-manual-90672-3-s-n-18-254-2135-to-current"],"acf":[],"_links":{"self":[{"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/pages\/20866","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/comments?post=20866"}],"version-history":[{"count":2,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/pages\/20866\/revisions"}],"predecessor-version":[{"id":20924,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/pages\/20866\/revisions\/20924"}],"up":[{"embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/pages\/20856"}],"wp:attachment":[{"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/media?parent=20866"}],"wp:term":[{"taxonomy":"manual","embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/manual?post=20866"},{"taxonomy":"model","embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/model?post=20866"},{"taxonomy":"document_type","embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/document_type?post=20866"},{"taxonomy":"hidden","embeddable":true,"href":"https:\/\/manuals.seakeeper.com\/seakeeper\/wp-json\/wp\/v2\/hidden?post=20866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}