I need to buy 100% carbon fibre tubes 26mm inner diam x 31mm outer diam x 110 cm long to built custom made spearguns . 

Hi Albert,

To help people understand which type of tube is better for a specific application, it's helpful to understand the differences between the two manufacturing procedures.

Pultruded tubes are made by pulling continuous strands of carbon fibre through a ‘die’; as they are pulled through they are coated in epoxy resin and as they come out of the die the epoxy resin is cured at high speed. Tubes (or rods, or strips) made in this way have all of their fibre running length-ways down the tube which means that they are very strong along their length (very stiff if you try to bend them) but very weak in any other direction (very easy to crush for example).

Roll wrapped tubes are made by pre-preg wrapping carbon fibre (a combination of unidirectional and bi-directional) material around a ground steel mandrel. When the fibre is layered onto the mandrel it is orientated such the some of the fibres are aligned lengthways down the tube but others are aligned at 45° degrees and some at 90°. Once the fibre has been layered onto the mandrel in this way the tube is wrapped tightly with a shrink tape before being loaded into an oven to contract the shrink-tape and cure the pre-preg. It is the shrink tape that leaves the tubes with their characteristic slight ribbed texture on the outside. Tubes made in this way are not quite as strong, down their length as an equivalent pultruded tube would be but they are much stronger in other directions and so will resist crushes, fractures and torsional load (twist) much better.

For an application such as a speargun, instinct tells me that a roll wrapped carbon fibre tube would be the most suitable. A part like this would be vulnerable to getting knocked/crushed and so needs more 'real world' strength than a pultrusion can offer.

Therefore, for a 100% carbon fibre tube that's roll wrapped and also has a great woven carbon fibre appearance, our Woven Finish Carbon Fibre Tubes would be perfect.

The only think I'm afraid we can't help with is the specific ID and OD that you're after. We don't have anything at the 31mm(26mm) mark, in fact the closest we come to this combination would be 25mm(22mm) or a 40mm(37mm).

Anyway, I hope the above explanation helps with your understanding of these excellent tubes.

All the best, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

I too am looking at Pultruded vs. Wrapped.  Yet for me, this is no speargun.  It is for Foam Fighting, a full contact full force game that uses weapons made from foam, but not nerf foam, we would break and blow out those weapons in seconds. We use a mixture of 2, 4 lb and volara foam to put around a 'core' which is the backbone of the weapon. No core = no strength.  PVC cracks and is dangerous because of the way it shatters and leaves jagged edges.  Steel and wood is too heavy and leads to monster strikes and can lead to unnecessary injuries.   We have used fiberglass in the past, and now carbon fiber rods are the new norm as they are strong, fast, and ultimately safe. I was just looking to purchase some rods for making some foam weapons.  What would be best for the type of force of say, axe swings, sword swings and the like?  Pultruded or Wrapped? 

Thanks!

The rods are only pultruded.  If you are looking for tube, roll wrapped is the better all round choice as it has better hoop strength.  I would still be concerned for failures as composite splinters into pieces.  You may need to ensure your designs have a large safety factor in them to ensure that does not happen. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant