Combustion Boats

Quick Answer: Combustion boats are small, shallow, boat-shaped trays, usually of porcelain or another ceramic, that hold a weighed sample while it is slid into a combustion tube or tube furnace and heated, often in a stream of gas such as air, oxygen, hydrogen or nitrogen.

Carrying a Sample Into the Tube

A crucible will not go into a narrow tube, so samples heated in a tube furnace are carried in a combustion boat: a long, narrow, open tray with rounded or squared ends. The boat is loaded outside, pushed into the hot zone of the tube with a rod, heated, then drawn out again with the product still in it for weighing or examination.

Shape matters mostly for fit. The boat must slide freely inside the tube without jamming against the walls. Porcelain is the traditional material for general work, while alumina, quartz and metal boats are used for higher temperatures or special atmospheres. The listing does not state the material, length or width, so compare these with the bore of your tube before ordering.

In teaching labs, a boat of this kind holds copper(II) oxide in the classic experiment to find the formula of copper oxide by reduction, with the boat weighed before and after. In analytical and materials labs, boats carry samples for ashing, oxidation or heat treatment in a controlled gas.

Applications

• Reducing copper(II) oxide in a stream of hydrogen or natural gas to find its formula.
• Ashing small samples in a tube furnace.
• Heating metals in air or oxygen to follow their gain in mass.
• Heat-treating small solid samples under an inert gas.

Specifications

Care & Handling

• Pre-heat new boats and cool them in a desiccator before their first weighing, so the mass is steady.
• Slide boats gently into hot tubes; a sudden push into the hot zone can crack them.
• Withdraw the boat with a hooked wire and let it cool on a heat-resistant tile.
• Keep separate boats for different sample types to avoid carry-over.

Why Choose LabEquip

College chemistry departments, metallurgical labs and research groups with tube furnaces buy these boats in sets, since they wear with repeated heating. LabEquip lists them in General Lab Products alongside the combustion tube; ask for sizes through the contact page.

Frequently Asked Questions

What is a combustion boat used for?

It holds a sample inside a combustion tube or tube furnace, so the sample can be heated, often in a stream of gas, and then pulled out again for weighing or further work.

How do I choose the right boat size?

Measure the inside diameter of your tube. The boat should slide freely with a little clearance on each side, and be long enough for the sample while still fitting within the furnace’s hot zone.

What materials are these boats made of?

Porcelain is common for general heating. Alumina tolerates higher temperatures, quartz is used where purity matters, and metal boats such as nickel or platinum serve special methods.

Why pre-heat a new boat before use?

Heating to the working temperature and cooling in a desiccator drives off moisture and anything volatile, so the boat reaches a constant mass. Weighings made with it afterwards are then reliable.

Can the boats be used in a muffle furnace?

Yes, a boat can sit on the floor of a muffle furnace like a small tray, although crucibles are more usual there. Boats are chosen mainly when the sample must go into a tube.

How should a boat be cleaned?

Let it cool, tip out the residue, and soak it in water or a suitable dilute acid to loosen deposits. Rinse, dry and re-heat it before weighing again.

Last Updated: September 2026