Total Boat Epoxy Calculator
Calculate the amount of mixed epoxy resin and hardener needed for a boat project using surface area, number of coats, target epoxy coverage, and the manufacturer's resin-to-hardener mixing ratio.
Boat Epoxy Results
How much epoxy do I need for a boat?
The amount of epoxy needed for a boat depends on the surface area, application thickness, number of coats, and the epoxy system being used. Fiberglass wet-out generally requires a different material usage rate than a thin sealing coat.
The simplest calculation starts with the surface area and the coverage rate supplied for the chosen application.
$$Epoxy = \frac{Surface\ Area} {Coverage\ per\ Coat} \times Coats$$
How does the epoxy waste allowance work?
Some epoxy is commonly lost during mixing, transferring, spreading, rolling, brushing, and cleanup. A waste allowance can therefore be added to the calculated theoretical requirement.
$$Total\ Epoxy = Required\ Epoxy \times \left(1 + \frac{Waste\%}{100}\right)$$
How are resin and hardener calculated?
Once the total mixed epoxy volume is known, it can be divided according to the manufacturer's resin-to-hardener ratio.
For example, a 2:1 ratio contains three total parts, with two parts resin and one part hardener.
$$Resin = Total\ Mix \times \frac{Resin\ Parts} {Resin\ Parts + Hardener\ Parts}$$
$$Hardener = Total\ Mix \times \frac{Hardener\ Parts} {Resin\ Parts + Hardener\ Parts}$$
What is epoxy coverage?
Epoxy coverage describes how much surface area a particular amount of mixed epoxy can cover at a specified application thickness. Coverage is not a universal constant because a thicker coat consumes more material than a thin coat.
Surface roughness, wood absorption, fiberglass weave, temperature, application tools, and spreading technique can also change actual epoxy consumption.
How much epoxy is needed for fiberglass wet-out?
Fiberglass wet-out is different from applying a simple protective coating. The amount of epoxy required depends on the fabric weight, weave, resin content, substrate, and application technique.
For fiberglass work, the manufacturer's recommended resin-to-fabric ratio or a known wet-out coverage rate should be preferred over a generic coating estimate.
How many coats of epoxy should I use?
The required number of coats depends on the purpose of the epoxy. Sealing porous wood, building a protective coating, encapsulating material, and preparing a surface for later finishing can require different application schedules.
Should I calculate epoxy by weight or volume?
The mixing ratio must be followed exactly as specified by the epoxy manufacturer. Some systems specify resin and hardener ratios by volume, while others specify them by weight. These are not automatically interchangeable because resin and hardener densities can differ.
This calculator therefore asks you to specify whether your ratio is based on volume or weight. The calculation itself uses the supplied ratio as a parts relationship.
How much extra epoxy should I buy?
A modest waste allowance is useful because some mixed epoxy remains in mixing containers, rollers, brushes, pumps, and transfer equipment. Larger allowances may be appropriate for difficult surfaces, heavy fiberglass work, or inexperienced application.
Can this calculator calculate TotalBoat epoxy specifically?
It can be used with a TotalBoat epoxy system when you enter the coverage and mixing ratio specified for that particular product. Different TotalBoat products can have different application characteristics, so the product instructions should take precedence over generic calculator assumptions.
Does this calculator account for epoxy density?
No. The main calculation is volume-based unless you are using a manufacturer's weight-based mixing ratio. Resin and hardener density varies between products, so a weight calculation should use the manufacturer's actual density or weight-ratio instructions.