Any owner of a boat, whether it is lightweight PVC catamaran Or a solid aluminum mottor, sooner or later, faces the need for minor repairs or redesigns, and water does not forgive mistakes, and even a microscopic hole in the bottom or a loose can mount can turn a pleasant walk into a dangerous adventure. rivet universal fasteners, ensuring tightness and strength of the connection.
Unlike screws or bolts, these elements create a seamless connection that is not afraid of vibration and constant contact with moisture, but the market offers many options, from simple aluminum rivets to complex systems with EPDM seals. The right choice It depends on the material of the boat, the thickness of the parts connected and the operating conditions.
Don't underestimate the importance of this seemingly simple element. Using the wrong metal can lead to electrochemical corrosion that will erod the board faster than you can get back to base. In this article, we'll take a look at all the nuances to make sure your repairs are done. professionally and forever.
⚠️ Warning: Never use steel or galvanized rivets to repair aluminum boats without insulation. The aluminum-steel galvanic pair in salt water will cause instantaneous oxidation and destruction of the fastener.
Classification and materials of manufacture
The main task of any rivet is to ensure reliable mechanical connection of two or more layers of material. corrosion resistanceMaterials are divided into several main groups, each of which has its own advantages and limitations.
The most common option is aluminum rivetThey're lightweight, cheap, and great for connecting aluminum profiles or attaching accessories to the sides of inflatable boats. But pure aluminum is soft, and when you're under heavy loads, the hat can deform or float.
For more responsible units, such as fastening of transoms or keel profiles, products from stainless steelThey have high tensile strength, but they require caution when you put them in soft aluminum, and there are also combinations where the body is made of steel and the cap is made of aluminum, which is a compromise solution.
- 🔩 Aluminum / Aluminum (Al / Al) - a universal option for light work and repair of PVC, does not cause corrosion on soft metals.
- 🛡️ Stainless steel (A2/A2) – maximum strength, ideal for transverses, but heavier and more expensive.
- 🔒 Steel/Zinc is a budget option for temporary repairs or dry areas, subject to rust during prolonged contact with water.
- 💧 With EPDM seal - specialized products with a rubber washer under the hat for guaranteed waterproofing.
Table of dimensions and decoding of markings
When buying fasteners in the store, you will encounter a marking of the species 3.2x8 or 4x10Understanding these numbers is necessary to avoid buying a rivet that is too short that will not close, or too long that will hang around inside the profile.
The first number represents the diameter of the body (legs) in millimeters, and the second is the maximum length of the package of materials to be fastened. 1.5–2 mm beyond the thickness of the materials.
For boatworks, the most running diameters are 3.2 mm and 4.0 mm. fine 2.4 mm are suitable only for fine plastic or temporary fixation, and 4.8 mm and 5.0 mm are used for power units and thick aluminum.
| Marking | Drill diameter (mm) | Body length (mm) | Recommended packet thickness (mm) | Applications on the boat |
|---|---|---|---|---|
| 3.2 x 6 | 3.3 | 6.0 | 2.0 – 4.0 | Fixing of leer arcs, small fittings |
| 3.2 x 10 | 3.3 | 10.0 | 5.0 – 7.0 | Repair of holes, laying of patches |
| 4.0 x 10 | 4.1 | 10.0 | 3.0 – 6.0 | Can firmening, stitching |
| 4.0 x 16 | 4.1 | 16.0 | 8.0 – 12.0 | Installation of transpanel plates, kilsons |
| 4.8 x 12 | 4.9 | 12.0 | 4.0 – 8.0 | Power units, engine compartment attachment |
What do the letters in the label mean?
The letters indicate the material: 'A' is aluminum, 'S' or 'St' is steel, 'Cu' is copper. The combination 'Al/St' stands for an aluminum cap and a steel rod.
Specifics of repair of PVC boats
Inflatable boat repairs require a special approach, as classic metal rivets are rarely used here and only in specific cases. hot-glue However, metal elements may be needed for the installation of reinforced hinges, handles or for the repair of rigid elements (plywood floorboards, transoms).
If you install fittings on the soft side, it is absolutely impossible to use conventional hood rivets, since the sharp edge after rupture of the rod can damage the fabric during pumping. squirrel Or petal rivets that distribute pressure over a larger area.
For sealed plastic or composite inserts in PVC boats often use rivets with a wide hat and mandatory use sealantBefore installing the place around the hole, it is recommended to degrease and treat with a primer.
A common mistake is to try to stick a soft element to a hard one without taking into account elasticity. When the pressure in the cylinders changes, the material walks, and a hard metal fastener can tear out a piece of fabric. Here, you better use a combined method: adhesive joint plus a neat rivet around the perimeter to fix the shape.
Installation on aluminum boats
Aluminum boats, such as popular models Kazanka, Wind Or modern welded boats, which require more powerful fasteners, where vibration and dynamic wave loads come to the fore, and the rivet can become unwound during the active season.
For aluminum, the preparation of the hole is critical, it must be strictly perpendicular to the surface and have no barbs, and should be drilled with sharp cobalt drills at low rpms, so as not to overheat the metal and not to fold the thread (for special screw rivets) or deform the edges.
Installation technology includes mandatory use sealantEven if the rivet has a rubber seal, an additional layer of polyurethane or thiokol sealant (for example, 3M 4200 or Sixflex.The sealant is applied to the rod and around the hole.
☑️ Arrangement for installation of aluminium
⚠️ Warning: When working with aluminum, avoid using copper rivets. The aluminum-copper galvanic pair has enormous electrochemical potential, which will lead to rapid destruction of the boat side around the fastener.
Safety tools and techniques
The quality of the connection depends on the tool used. For a home craftsman, the best choice is a lever rivet with a rotary head. Mechanical tick-types are suitable for one-time work, but they are difficult to ensure uniform force when installing large amounts of fasteners.
Professionals often use the pneumatic rivetBut for a garage craftsman, a high-quality hand tool with a set of interchangeable sponges for different diameters is quite enough.
Don't forget your personal protective equipment, because when you pull off a rivet rod (especially steel), it can fly away at high speed, glasses are mandatory, and you should also keep your hands away from the sharp edges of freshly drilled aluminum.
- 👓 Safety glasses are required to protect the eyes from flying debris of rods.
- 🧤 Gloves – protect against sharp edges of metal and contact with chemical sealants.
- 🔧 Ringing rivet with a rattle - provides control of the force and prevents the tool from turning.
- 🧴 Degreasing agent – acetone or alcohol to prepare the surface before installation.
The main secret to durability is not to skimp on sealants. A sealant-free rivet is a ticking bomb that will start flowing in a season or two.
Frequent mistakes and how to avoid them
One of the most common mistakes is to miscalculate the length, and if the rivet is too short, it will not be able to form a full-fledged response head, and the connection will be weak, and if it is too long, there will be a long tail inside the profile, which will rattle and create an extra vibration.
Another problem is the "failure" or the tightening, and when you squeeze it, the hat doesn't fit tightly to the surface, leaving a gap for water, and if you push it too hard, you can crush the thin aluminum or break the sealing ring if you have one.
Ignoring surface preparation is also fatal: placing rivets on a dirty, oxidized or wet surface ensures corrosion under the hat in no time. Always clean the installation site until it is metallic.
Finally, many people forget about finishing. The sticking piece inside the boat is not only an aesthetic defect, but also a risk of injury or tearing equipment. Always remove the remnants of the rods and, if possible, grind the hats level with the surface (if the design allows).
What to do if the rivet scrolls?
If the rivet is twisted with the tool when tightening, the hole is too large or the material is too soft, the solution is to drill the hole to the next size (for example, from 3.2 to 4.0) and put a larger rivet, or use a rivet with a larger cap.
Frequently Asked Questions (FAQ)
Can I replace a broken rivet with a screw with a nut?
Theoretically, it can, but it's not recommended for the underwater part, because the screw joint tends to be self-unwrapping from vibration unless you use special carving fixtures, and the nut inside the boat creates a traumatic protrusion, and the rivet is more robust and compact.
Which sealant is best used to rivet on a boat?
Polyurethane is best suited (for example, 3M 4200, Sikaflex 291) or thiocol sealants: they remain elastic, not afraid of water and UV radiation, acid silicones can not be used, they can cause corrosion of aluminum.
How to remove an old rusty rivet?
Carefully drill the center of the rivet with a drill of a slightly smaller diameter, then carefully select the remains of the body, trying not to damage the edges of the main hole. If the hat interferes, it can be cut with fork cutters or weaned.
Will the rivets be suitable for repairing the bumper of the car for the boat?
No. Car rivets often have a plastic or soft head and are not designed to be in constant contact with water and the high mechanical loads that characterize the operation of boats. Use specialized marine fasteners.
Do I need to remove the stains before installation?
You can't lubricate it with oil or solidol, it will break the sealant's adhesion, but you can dip the rod in the sealant before inserting it into the hole for better waterproofing the inner cavity.