How to Install a Clamp On Seat on Aluminum Bench

If you are working out how to install a clamp on seat on aluminum bench, the process is simple. Measure the bench, clean it, bolt the seat to the swivel base, then clamp the mount across the bench and tighten it evenly. Drilling into that bench leaves holes you have to seal later. A clamp on mount avoids that.

If you are comparing jon boat seats for an aluminum bench, the Better Boat Clamp On Jon Boat Seat with Swivel fits flat benches from 9 to 20.5 inches wide with no drilling into the bench. The rest of this guide walks through each step, the mistakes that cause a loose seat, and the checks that keep it tight all season.

The right tool for this job

Clamp On Jon Boat Seat with Swivel

Adds a swivel seat to a flat jon boat bench without drilling into the bench. Fits benches 9 to 20.5 inches wide, with a 360 degree swivel and PVC coated legs.

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The Better Boat Clamp On Jon Boat Seat with Swivel

The Clamp On Jon Boat Seat with Swivel grips a flat jon boat bench and turns a full 360 degrees, so you add a swivel seat without drilling the bench itself. The listing details are the specs that matter during installation.

• Bench width fits flat benches from 9 inches to 20.5 inches wide.
• No drilling into the bench is required.
• Swivel turns a full 360 degrees on a 7 inch by 7 inch swivel base, so you can turn to cast, steer, reach gear or face passengers.
• Seat bolt pattern accepts seats with a 5 to 6 inch bolt pattern.
• PVC coated legs help grip the bench while reducing scratches and dents.
• Tightening tool is included to help you reach under the mounted seat during setup.

If you plan to mount a seat you already own, confirm its bolt pattern falls between 5 and 6 inches before you start. For replacement hardware, cushions and related parts, browse the Better Boat boat seat parts and care collection.

Measure and Check the Bench Before You Start

The bench must be flat and measure between 9 and 20.5 inches from front edge to back edge where the mount will sit. Checking this first helps prevent a mount that never fully grips.

Measure straight across the top of the bench at the exact spot you want the seat, not at the ends. Some benches are narrower near the hull sides or have a rolled lip that changes the usable width. Then look at the surface itself and note anything that would keep the legs from sitting flat.

• Rivet heads and seams can lift one leg and create a rocking point.
• Ribs, braces or curved tops can prevent even contact along the clamp.
• Bent or dented sections may concentrate pressure when tightened.
• Clearance underneath matters, since the clamp needs room to wrap the bench lip.

Before you choose between clamping and drilling, check how your bench is built. If your boat manual shows the bench as part of a sealed or hollow compartment, follow its guidance before putting any hole in it. A clamp on mount does not require drilling into the bench.

Step by Step Installation

Installing a clamp on seat takes basic hand tools and the included tightening tool. Clean the bench, assemble the seat on the swivel, center the clamp, and tighten both sides evenly. Follow the instructions packed with the product for the exact assembly order.

1. Clean the bench. Wash the top and the underside lip where the clamp contacts the metal. Sand, grit and old fish scales trapped under the legs can scratch the aluminum and let the mount shift. A soft brush and boat soap from the Better Boat deck cleaning collection handle this quickly. Let it dry fully.
2. Attach the seat to the swivel base. Line the seat bolt pattern up with the 7 inch by 7 inch swivel base and bolt it on. Tighten the seat hardware to the seat maker's guidance, then confirm the seat turns freely.
3. Set the clamp close to the bench width. Adjust the mount to roughly match your measurement so it slides on without forcing.
4. Position the mount. Center it front to back on the bench so the PVC coated legs sit flat on the top. A mount hanging off one edge may tilt under load.
5. Tighten evenly. Use the included tightening tool to reach under the seat. Snug one side, then the other, and alternate until both are firm. Even pressure helps keep the mount square.
6. Test before you trust it. Sit down, lean forward and back, and swivel a full circle. Any rocking or sliding means the clamp needs another round of even tightening or the bench spot is not flat.
7. Recheck after the first trip. Run the tightening tool around once more after your first outing.

Clamp On vs Drilled Bench Mounts

A clamp on mount suits a flat bench within its width range when you want a swivel seat without putting holes in the bench. Bench shape, width, condition and your boat manufacturer's guidance all affect whether it is the right fit. A drilled mount stays bolted in place and suits benches that are not flat or do not fit a clamp's width range.

Better Boat pick

Boat Seat Pedestal

Low 6.8 inch fixed pedestal with 7 inch by 7 inch plates. Bolt slots fit 4.5 to 6 inch spacing for jon boats, skiffs, and fishing boats.

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If you are switching from an old drilled seat to a clamp on mount, seal the leftover holes so water stays out of the bench. The Marine Sealant & Adhesive Caulk is a fit for that sealing step.

Common Mistakes That Cause a Loose or Damaged Seat

Clamp on seat problems often come from uneven tightening, a dirty or uneven bench, or skipping the recheck after the first trip. Each one has a simple cause and an easy fix.

• Measuring at the wrong spot. A bench that tapers near the hull can measure inside the range at the center and outside it at the ends. Measure where the seat will actually go.
• Tightening one side all the way first. This can pull the mount crooked and leave the other side loose. Alternate sides in small turns.
• Overtightening. Excess force can dent a thin bench top. The PVC coated legs help reduce dents, but firm and even is the goal, not maximum force.
• Clamping over a rivet or seam. A raised point can become a pivot. Slide the mount a few inches to a clean, flat section.
• Skipping the cleaning step. Grit trapped under the legs can let the seat creep.
• Using a seat with the wrong bolt pattern. A seat outside the 5 to 6 inch pattern may not bolt squarely to the swivel base.

Safety and Season Long Upkeep

A raised swivel seat raises your center of gravity, so stay seated, keep the load within the boat's capacity plate, and follow your boat manufacturer's guidance for seating while underway. Never stand on the seat to cast or reach gear.

Small jon boats react quickly to weight shifts, and that effect grows as you sit higher. Check the capacity plate for your boat's person and weight limits, and wear a life jacket that meets US Coast Guard and state rules. Rules for seating while the boat is moving vary, so defer to your boat manual and local regulations.

For upkeep, run a quick check at the start of each trip.

• Grab the seat and rock it. Retighten if it moves.
• Swivel it a full turn and listen for grinding from trapped sand.
• Rinse the mount and bench with fresh water after saltwater trips.

If the boat sits in a yard or on a trailer between trips, loosening the clamp and storing the seat indoors keeps the cushion out of the sun and the mount free of debris.

Frequently Asked Questions

Can you put a swivel seat on a jon boat bench without drilling?

Yes. A clamp on mount grips the bench, so no holes go into the bench. The Better Boat Clamp On Jon Boat Seat with Swivel fits flat benches from 9 to 20.5 inches wide and turns a full 360 degrees.

Will a clamp on seat fit every aluminum jon boat bench?

No. The bench has to be flat and fall within the mount's width range, which is 9 to 20.5 inches for the Better Boat model. Curved, ribbed or heavily riveted benches may not allow even contact, so measure and inspect the exact spot before you buy.

Why does a clamp on boat seat slip or rock on the bench?

A clamp on seat can slip when it was tightened unevenly, the bench was dirty, or the legs sit on a rivet or seam. Clean the bench, move to a flat section, and tighten both sides in alternating turns, then recheck after your first trip.

Do clamp on seats scratch or dent an aluminum bench?

Clamp on seats can mark a bench if grit is trapped or the clamp is overtightened. The Better Boat mount uses PVC coated legs that help reduce scratches and dents, and a clean bench plus firm, even pressure keeps the surface in good shape.

Is it safe to sit on a raised swivel seat while the boat is moving?

It depends on your boat, its capacity plate and local rules, so check your boat manual first. A raised seat lifts your center of gravity, so stay seated, keep weight centered, wear a life jacket, and never stand on the seat.

Can you add seats to a center console boat?

Often yes, as long as there is a solid, flat spot to mount a seat and the added people and weight stay within the boat's capacity plate. Check the boat manual for seating guidance, and keep seats from blocking the helm view or walkways. A clamp on mount only works on a flat bench within its width range, so a boat without a bench usually needs a bolted seat base instead.

Are pedestal boat seats universal?

No. Pedestals differ in height, plate size, and bolt spacing, so match them to both the seat and the mounting surface. The Better Boat Boat Seat Pedestal is 6.8 inches tall with 7 inch by 7 inch plates and bolt slots that adjust from 4.5 to 6 inches apart, which covers many common patterns. A swivel bracket is sold separately if the seat needs to rotate.

The Bottom Line

Installing a clamp on seat on an aluminum bench comes down to four things, a flat bench in the right width, a clean surface, a centered mount, and even tightening with a recheck after the first trip. Skip the drill and keep the bench sealed. The Better Boat Clamp On Jon Boat Seat with Swivel fits flat benches from 9 to 20.5 inches wide, swivels a full 360 degrees, accepts 5 to 6 inch seat bolt patterns and includes the tightening tool you need to reach under the seat. Measure your bench today and turn that hard aluminum plank into a seat you can actually fish from.

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