Seciton 6 Bonding and Fastening

601. Arrangements

1. Details of arrangements and building tolerances are to be laid down in the Builder’ production plan.

2. Particular attention is to be given to the accurate arrangements of the following:

(1) girder abutting single skin bulkhead;

(2) girder webs with tank sides;

(3) frames with beams;

(4) deck/bottom girders with bulkhead stiffeners;

(5) tank baffles with floors;

(6) longitudinals where broken at tank ends; and

(7) transom stiffeners with bottom/deck girders.

3. To ensure efficient transmission of shear loads, the alignment tolerance of intercostal ‘top hat’ stiff- ener webs is, in general, to be within half of the web thickness.

602. Bonding 【See Guidance】

1. Bonding is to be executed after making effective preparation such as sanding the surface to be bonded and thoroughly removing oils and sanding dusts.

2. If a laminate subject to secondary bonding has cured for more than 5 days the surface should be ground. If resin containing wax is used grinding is required if the curing time exceeds 24 hours.

3. If peel strips are used in the bonding surface the required surface treatment may be dispensed with.

4. Bonding is to be executed paying careful attention not to cause spring back of fibre reinforcements.

5. Bonding is to be carefully executed so as not to cause any deformation due to excessive exother- mic effect.

6. Bonding is to be carefully carried out so as not to cause strength discontinuity at the joint.

7. T-joints and L-joints are to be laminated at the site.

8. The lamination may be bonded by using polyester resin or epoxy resin, and the joint part of resin connection is to be located at the position that shear force acts. The butt joint by resin connection is not to be used at the position that tensile force acts.

9. The lapping connection is to be lapped 38 mm or more for glass fiber lamination of 3600 g or less and the lapping breadth is to be increased 6.5 mm per 1200 g excess of glass fiber reinforcement.

603. Mat-in connection

1. The structural members are to be connected with main structures using angles made of laminations before that angles are cured completely.

2. The scantlings of mat-in angles are classified as following two types based on flange breadth per weight of reinforcements.

Table 4.1 The Flange Breadth based on Types

604. Bolts and Rivets Fastening

1. Where laminates are connected each other or where metallic fittings are fastened to laminates, me- chanical fastening such as bolts and rivets may be applied. However, mechanical fastening is to be carried out at a right angle to the laminates as far as practicable and the fastening holes are to be well coated with resins.

2. For the end parts or edges of holes, the exposed ends of glass fiber reinforcement are to be cov- ered or bonded by resin.

3. The weight of lamination is to be increased 25 % or more at the location of connections, flanges and outfitting installation.

4. The distance between the centre of bolt hole and the edge of laminate is not to be less than three times the diameter of the hole. The distance between the bolt holes is not to be less than three times diameter of the hole.

5. For lamination of chopped strand mat, the lamination panels are to be connected at the position which the distance from edge to center of bolt or rivet is to be 2.5 times of bolt diameter or more, and the distance is to be increased in accordance with the kinds of reinforcement.

6. Where bolts are used, washers are to be used on the surface of laminate.

7. The laminations may be connected with steel, alloy or copper rivets and the washers or strips are to be inserted to avoid damages on lamination when making a rivet head after inserting rivet bolts.

8. The bolts, rivets, screws, etc. are to be of the seawater corrosion resistant metal or to be the prop- erly protected against corrosion.

9. Where bolts, screw, rivets, etc., are used, penetrating sandwich laminates with cores of hard plastic foams, timbers or plywoods well seasoned are to be inserted in such parts of the cores in advance.

10. Where mechanical fastening such as bolted joints, etc. is used in way of a location where water- tightness is required, suitable measures are to be provided to maintain watertightness.

605. Attachment of metal equipment

1. In case of attaching equipment by bolts penetrating hull lamination, the large diameter washers are to be used to avoid damages of lamination. The washer is not to be less than 2.25 ᾘ in outer di- ameter and 0.1 ᾘ in thickness, where, ᾘ is diameter of bolt and the material of washer is to be

that of bolt.

2. The poromeric metal panel with rough surface treatments to be inserted in the lamination panel

where heavy loads act and that metal inserted plate are to fiber by epoxy resin or polyester resin.

3. The contact surfaces of metal outfitting are to be finished after cleansing chemically and they are to be moulded on resin.

be bonded with rough surface of glass

by sand blasting or wire brushing and lamination by epoxy resin or polyester