What are float drums made of?

TechniDock float drums are rotationally molded from virgin polyethylene with UV inhibitors. The seamless one-piece shell resists oil, gas, marine organisms, salt water, and fresh water. The interior is filled with steam-pressured expanded polystyrene (EPS) foam, which provides buoyancy even if the outer shell is ever punctured.

How much weight can a float drum support?

Buoyancy varies by drum size. TechniDock float drums range from approximately 100 lbs to over 2,000 lbs of buoyancy per drum depending on dimensions. The full size chart on this page lists the rated buoyancy for each of our 102 available models. As a general rule, plan for 50% of rated buoyancy as your working load to maintain adequate freeboard.

How long do float drums last?

TechniDock float drums carry a 15-year warranty to the original owner. With proper care — including seasonal removal in freeze-prone climates, correct vent plug installation, and avoiding prolonged UV exposure when out of the water — float drums routinely last 20–30 years or more.

What is the difference between standard and long-slot float drums?

Standard float drums (FF prefix) have fixed mounting slots on the top surface for attaching to a dock frame. Long-slot float drums (FFLS prefix) have extended slots that run a greater portion of the drum length, giving more flexibility in frame attachment positioning. Long-slot drums are useful when frame spacing is non-standard or when precise positioning is required.

Can float drums be used in salt water?

Yes. TechniDock float drums are manufactured from virgin polyethylene with UV inhibitors that resist salt water, oil, gas, and marine organisms. They are suitable for both fresh and salt water applications including marinas, tidal waterways, and coastal installations.

What happens if a float drum gets punctured?

A puncture in the outer polyethylene shell is not a catastrophic failure. The EPS foam interior continues to provide buoyancy even if the shell is breached — this is why encapsulated foam fill is so important. A properly manufactured drum made from virgin resin may be punctured by a severe impact but will not shatter or crack around the hole. An improperly cured shell or one made from off-spec resin will shatter on impact, which is an immediate and complete failure. TechniDock float drums are tested to the ASTM D1998-04 Falling Dart Impact Test standard — shell coupons are frozen at -20°F and subjected to a 90 ft-lb impact without cracking or shattering.

What testing standards do TechniDock float drums meet?

TechniDock float drums are tested to three key standards: (1) ASTM D1998-04 Falling Dart Impact Test — shells must withstand a 90 ft-lb impact when frozen at -20°F without cracking or shattering; (2) 7-Day Hunt Water Absorption Test — EPS foam must absorb no more than 3.0 lbs/ft³ of water; TechniDock actual results range from 0.71 to 1.98 lbs/ft³; (3) Ultrasonic wall thickness testing — every completed shell is tested at 20 or more spots, with no reading permitted below the 0.125" industry minimum. The EPS foam also conforms to ASTM C578, UL-94, ASTM E84, and NFPA 259. Factory test results are available on request.

Float Drums

Home/Float Drums

TechniDock distributes a full line of high-quality dock flotation products. Our float drums provide reliable buoyancy for floating dock systems in commercial and residential applications.

Float drums are a critical component of any floating dock system. TechniDock supplies durable, UV-resistant float drums engineered to maintain consistent buoyancy over years of use. Our flotation products are compatible with a wide range of dock frame systems and are available in multiple sizes to meet your specific load requirements. Contact us to discuss the right flotation solution for your project.

TechniDock float drum — rotationally molded polyethylene dock flotation

Jump to Size Chart

Built to Last

Every float drum we supply is engineered for long-term performance in fresh and salt water environments.

One-Piece Seamless Shell

The plastic exterior is rotationally molded as a single seamless unit — no joints or seams that can leak or separate over time.

Virgin Polyethylene Construction

Drum walls are made from tough virgin polyethylene with UV inhibitors to resist sun damage, debris, oil, gas, marine organisms, and both salt and fresh water.

Nominal .150" Wall Thickness

A thicker-than-standard wall provides superior impact resistance and durability compared to thinner-walled alternatives on the market.

EPS Foam-Filled Interior

Steam-pressured expanded polystyrene foam fills the interior for maximum buoyancy. The foam also provides flotation if the outer shell is ever punctured.

Molded-In Mounting Slots

The flat top surface features molded-in mounting slots for easy, secure attachment to any standard dock frame — no special hardware required.

15-Year Warranty

Backed by a 15-year float drum warranty to the original owner, reflecting the manufacturer's confidence in long-term performance and durability.

Float drum cross-section diagram showing EPS foam fill, polyethylene shell, and mounting slots

Float Drum Types

With over 70 sizes available — from 1 to 4 feet wide, 3 to 8 feet long, and 8 to 36 inches high — there's a float drum for every application.

Standard Float Drum

The most versatile option for new or existing dock systems. Available in the widest range of sizes and suitable for private dock builders and large commercial marina contractors alike.

FFLS

Long Slot Float Drum

Features extended mounting slots along the top for greater flexibility in frame attachment. Ideal for dock systems that require more precise positioning or non-standard frame spacing.

FF…RND

Cylindrical Float Drum

Round-profile drums designed for wave attenuation applications such as breakwaters, barriers, and booms. Provides effective protection in exposed or high-traffic waterways.

FF…LF

Log Float Drum

A compact, lightweight option designed for log float and similar low-profile applications where minimal freeboard is required.

Float Drum Sizes & Specifications

Over 70 sizes available. Dimensions shown as Width × Length × Height (inches). Buoyancy in lbs. Click any part number to expand details.

Part No.	Description	Wt (lbs)	Dimensions (in)	Buoyancy (lbs)
Click any row to expand details
F-1420	Float Drum	27	12 × 48 × 20	359
F-1428	Float Drum	31	12 × 48 × 28	472
F-1.5420	Float Drum	33	18 × 48 × 20	542
F-1.5436	Float Drum	54	18 × 48 × 36	966
F-1.5616	Float Drum	45	18 × 72 × 16	620
F-1.7608	Float Drum	34	20 × 72 × 08	360
F-1.7610	Float Drum	38	20 × 72 × 10	450
F-1.7810	Float Drum	50	20 × 96 × 10	592
F-2308	Float Drum	21	24 × 36 × 08	211
F-2312	Float Drum	27	24 × 36 × 12	318
F-2316	Float Drum	30	24 × 36 × 16	436
F-2320	Float Drum	33	24 × 36 × 20	540
F-2412BM	Float Drum	30	24 × 48 × 12	409
F-2416BM	Float Drum	35	24 × 48 × 16	546
F-2408	Float Drum	27	24 × 48 × 08	288
F-2412	Float Drum	33	24 × 48 × 12	433
F-2416	Float Drum	39	24 × 48 × 16	581
F-2418	Float Drum	39	24 × 48 × 18	628
F-2420	Float Drum	44	24 × 48 × 20	729
F-2424	Float Drum	50	24 × 48 × 24	866
F-2428	Float Drum	55	24 × 48 × 28	979
F-2436	Float Drum	72	24 × 48 × 36	1,297
F-2612	Float Drum	44	24 × 72 × 12	629
F-2616	Float Drum	57	24 × 72 × 16	796
F-2808	Float Drum	53	24 × 96 × 08	562
F-2812	Float Drum	64	24 × 96 × 12	866
F-2816	Float Drum	75	24 × 96 × 16	1,155
F-2820	Float Drum	84	24 × 96 × 20	1,420
F-2828	Float Drum	88	24 × 96 × 28	1,956
F-2.5412	Float Drum	33	30 × 48 × 12	514
F-2.5416	Float Drum	38	30 × 48 × 16	712
F-2.5616	Float Drum	56	30 × 72 × 16	1,051
F-3408	Float Drum	37	36 × 48 × 08	429
F-3412	Float Drum	45	36 × 48 × 12	650
F-3416	Float Drum	51	36 × 48 × 16	874
F-3418	Float Drum	54	36 × 48 × 18	990

Part No.	Description	Wt (lbs)	Dimensions (in)	Buoyancy (lbs)
Click any row to expand details
F-3420	Float Drum	62	36 × 48 × 20	1,088
F-3424	Float Drum	66	36 × 48 × 24	1,280
F-3432	Float Drum	82	36 × 48 × 32	1,644
F-3512	Float Drum	58	36 × 60 × 12	783
F-3516	Float Drum	61	36 × 60 × 16	1,017
F-3520	Float Drum	74	36 × 60 × 20	1,328
F-3612	Float Drum	62	36 × 72 × 12	999
F-3616	Float Drum	78	36 × 72 × 16	1,313
F-3620	Float Drum	87	36 × 72 × 20	1,638
F-3624	Float Drum	99	36 × 72 × 24	1,951
F-3632	Float Drum	107	36 × 72 × 32	2,553
F-3812	Float Drum	90	36 × 96 × 12	1,331
F-3816	Float Drum	103	36 × 96 × 16	1,735
F-3820	Float Drum	112	36 × 96 × 20	2,172
F-3824	Float Drum	132	36 × 96 × 24	2,597
F-3828	Float Drum	135	36 × 96 × 28	2,928
F-3832	Float Drum	149	36 × 96 × 32	3,349
F-3.16.512	Float Drum	76	38 × 78 × 12	1,133
F-3.5612	Float Drum	70	42 × 72 × 12	1,166
F-3.5616	Float Drum	81	42 × 72 × 16	1,555
F-3.5620	Float Drum	98	42 × 72 × 20	1,934
F-4412	Float Drum	55	48 × 48 × 12	878
F-4416	Float Drum	67	48 × 48 × 16	1,182
F-4420	Float Drum	75	48 × 48 × 20	1,480
F-4424	Float Drum	83	48 × 48 × 24	1,738
F-4432	Float Drum	108	48 × 48 × 32	2,231
F-4436	Float Drum	114	48 × 48 × 36	2,480
F-4512	Float Drum	73	48 × 60 × 12	1,101
F-4516	Float Drum	80	48 × 60 × 16	1,497
F-4520	Float Drum	92	48 × 60 × 20	1,851
F-4524	Float Drum	106	48 × 60 × 24	2,199
F-4532	Float Drum	130	48 × 60 × 32	2,815
F-4612	Float Drum	78	48 × 72 × 12	1,369
F-4616	Float Drum	98	48 × 72 × 16	1,823
F-4620	Float Drum	111	48 × 72 × 20	2,225
F-4624	Float Drum	123	48 × 72 × 24	2,701

Part No.	Description	Wt (lbs)	Dimensions (in)	Buoyancy (lbs)
Click any row to expand details
F-4628	Float Drum	141	48 × 72 × 28	2,940
F-4632	Float Drum	154	48 × 72 × 32	3,457
F-4636	Float Drum	166	48 × 72 × 36	3,800
F-4712	Float Drum	89	48 × 84 × 12	1,510
F-4716	Float Drum	105	48 × 84 × 16	2,056
F-4812	Float Drum	109	48 × 96 × 12	1,803
F-4816	Float Drum	131	48 × 96 × 16	2,396
F-4820	Float Drum	145	48 × 96 × 20	2,996
F-4824	Float Drum	163	48 × 96 × 24	3,578
F-4828	Float Drum	172	48 × 96 × 28	4,017
F-4832	Float Drum	193	48 × 96 × 32	4,631
F-4-1012	Float Drum	124	48 × 120 × 12	2,118
F-4-1016	Float Drum	143	48 × 120 × 16	3,020
F-4-1020	Float Drum	177	48 × 120 × 20	3,692
F-LS1420	Long Slot Float Drum	23	12 × 48 × 20	289
F-LS2420	Long Slot Float Drum	44	24 × 48 × 20	602
F-LS2424	Long Slot Float Drum	50	24 × 48 × 24	756
F-LS3420	Long Slot Float Drum	62	36 × 48 × 20	967
F-LS3620	Long Slot Float Drum	74	36 × 72 × 20	1,474
F-LS3624	Long Slot Float Drum	82	36 × 72 × 24	1,756
F-LS3820	Long Slot Float Drum	99	36 × 96 × 20	1,978
F-LS4416	Long Slot Float Drum	67	48 × 48 × 16	1,115
F-LS4420	Long Slot Float Drum	77	48 × 48 × 20	1,367
F-LS4424	Long Slot Float Drum	86	48 × 48 × 24	1,639
F-LS4432	Long Slot Float Drum	108	48 × 48 × 32	2,129
F-LS4508	Long Slot Float Drum	51	48 × 60 × 08	720
F-LS4620	Long Slot Float Drum	96	48 × 72 × 20	2,002
F-LS4624	Long Slot Float Drum	108	48 × 72 × 24	2,396
F-LS4632	Long Slot Float Drum	130	48 × 72 × 32	3,305
F-LS4820	Long Slot Float Drum	145	48 × 96 × 20	2,894
F-LS4824	Long Slot Float Drum	163	48 × 96 × 24	3,134
F-LS4832	Long Slot Float Drum	193	48 × 96 × 32	4,438
F-2323-24RND	Cylindrical Float Drum	22	23 × 24	330
F-2308LF	Log Float Drum	21	24 × 36 × 08	194

* Cylindrical float used for wave attenuation as breakwaters, barriers, and booms. Contact us for ordering information.

Ready to spec your project?

Not sure which float drum is right for your dock?

Our engineers have been sizing floats for docks, marinas, and waterfront structures since 1986. Tell us your project — we'll spec the right drum for the load.

Get a Free Quote

Not All Float Drums Are Equal

Before a float drum ever touches the water, it has already been through a lot. Drums are loaded and unloaded at the manufacturing plant, transported to the job site, attached to dock frames, and bounced around while the dock is floated into position. Once installed, they face decades of ice, floating logs, boat impacts, and wave action.

A float drum made from off-spec resin, regrind material, or improperly cured shells may look identical to a quality drum on the outside — but it will fail years earlier, often without warning. The difference is in the material and the manufacturing process, and the only way to know what you are buying is to ask for the test results.

U.S. Army Corps of Engineers Requirement

Encapsulated flotation is required on any floating dock project that requires a shoreline use permit. TechniDock float drums — with their sealed polyethylene shell and fully encapsulated EPS foam interior — meet this specification.

The Shell: Where Cheap Floats Fail First

The outer polyethylene shell is your first line of defense. Not all shells are created equal.

The Out-of-Spec Resin Problem

Float drums made from off-spec resin, regrind material, or improper mixes of resin and UV black can result in below-minimum wall thickness. Improper shell curing leaves air bubbles in the top third of the wall — causing premature failure when the drum is stressed by impacts and loads.

All float shells have some water permeability that might appear over 40 years of service. But improperly cured shells or shells made from off-spec or regrind materials begin absorbing water many years earlier — leading to excessive damage during transport and handling, and premature failure once installed.

Puncture vs. Shatter — Why It Matters

The ASTM D1998-04 Falling Dart Impact Test freezes shell coupons at -20°F for a minimum of 2 hours, then subjects them to a 90 ft-lb impact. A properly cured shell made from virgin resin may be punctured at this level — but will not shatter or show cracking around the hole.

An improperly cured shell or one made with off-spec resin will shatter — not just at 90 ft-lb, but at lower test levels too — because of air bubbles in the upper third of the shell wall.

PUNCTURE

Acceptable — float still supports load; EPS foam provides backup buoyancy

SHATTER

Immediate and complete failure — dock section loses buoyancy

Wall Thickness: The 0.125" Minimum Standard

TechniDock float drums are manufactured to a nominal 0.150" wall thickness — but the critical standard is that no spot on any completed shell can fall below 0.125". This is the industry and regulatory agency minimum.

Every completed shell is tested sonically at 20 or more spots. Any shell with a reading below 0.125" fails. Our factory QC records show an average wall thickness of 0.218" — well above the minimum. Test results are available on request.

EPS Foam: Your Second Line of Defense

EPS (expanded polystyrene) represents 99.9% of foam used in float drums today. When properly encapsulated, EPS is unaffected by freeze/thaw cycles — a common misconception that leads buyers to accept inferior polyurethane foam alternatives.

TechniDock float drums use a single-piece shell with EPS beads injected directly and steam-expanded to fill all voids. Fewer voids mean less water absorption if the shell ever leaks — and a more stable dock section over the life of the installation.

The Difference Is on the Inside

The quality of the EPS foam fill is just as important as the shell. These cross-sections show the difference between properly and improperly steamed foam.

Inferior Foam — Incomplete Steaming

Loose, visible beads indicate an incomplete foaming process. Large voids between beads will absorb far more than the 3.0 lbs/ft³ test threshold — and some areas may have no foam at all. This leads to unstable dock sections and premature replacement.

TechniDock Foam — Properly Steamed

A smooth surface with no visible beads indicates a complete steaming process. Minimal voids mean minimal water absorption. TechniDock foam consistently meets or exceeds the 7-Day Hunt Water Absorption Test at well under 3.0 lbs/ft³.

Ask for the Test Results — We Will Show You Ours

Most float manufacturers test. Few will show you the results. TechniDock provides factory test documentation on request — because buyers who have been burned by cheap floats deserve to know what they are getting.

PASS

ASTM D1998-04 Falling Dart Impact Test

Shell coupons are frozen at -20°F for a minimum of 2 hours, then subjected to a 90 ft-lb impact. Must not crack or shatter. TechniDock shells: Passed.

Standard:90 ft-lb — no cracking or shattering

TechniDock result:Passed

PASS

7-Day Hunt Water Absorption Test

Foam cubes taken from random production floats are submerged for 7 days and weighed. TechniDock actual results range from 0.71 to 1.98 lbs/ft³ — well below the 3.0 threshold. Results near or below 1.0 lbs/ft³ are considered the work of a foaming artist.

Standard:3.0 lbs/ft³ maximum to pass

TechniDock result:0.71 – 1.98 lbs/ft³

PASS

Ultrasonic Wall Thickness Testing

Every completed shell is tested sonically at 20 or more spots. No spot may register below the 0.125" industry and regulatory minimum. TechniDock factory average: 0.218". Heavier walls can be manufactured for specific project requirements.

Standard:0.125" minimum at every test point

TechniDock result:0.218" avg (factory QC)

Tank-Tested Buoyancy Ratings

Buoyancy ratings have historically been calculated based on shell dimensions alone — not actual tank testing. A published calculated rating can be up to 21% higher than the actual tank-tested rating. If you based your float purchase on calculated buoyancies, the freeboard and load-carrying capacity of your dock could be 21% lower than your design goal.

TechniDock buoyancy ratings are tank-tested. Always ask for tank-tested ratings when comparing float drum suppliers — and ask to see the documentation.

Real-World Example: 14-Slip Pier

A 14-slip pier design with a combined live and dead load of 92,070 lbs. Same float size (36x48x12), same quantity ordered — very different actual buoyancy delivered.

Manufacturer	Published Rating	Floats Ordered	Tank-Tested Rating	Actual Buoyancy Delivered	Variance
TechniDock	656 lbs	140	656 lbs	91,840 lbs	0%
Competitor	679 lbs	136	542 lbs	73,712 lbs	-21.4%

The competitor's customer ordered 136 floats expecting 92,244 lbs of buoyancy. They received 73,712 lbs — 18,358 lbs short of design capacity, or 79% of the load the dock was designed to carry.

Always ask these questions before you buy:

→Are these buoyancy ratings calculated or tank-tested?
→Can you provide tank test documentation?
→For large projects: can independent testing be arranged?

Quality Tested. Installation Ready.

Every float drum is continuously tested to meet or exceed the Hunt Water Absorption Test standard of 3 lbs per cubic foot. The "Falling Dart" impact test and ultrasonic wall thickness testing are standard quality procedures to ensure long service life. Detailed installation guidelines cover storage, vent plug insertion, frame support, attachment methods, and seasonal removal.

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Common questions about dock float drums and flotation products.

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