29 Roselle Street, Milford, CT 06461, US

(203) 877-4339

Welcome to Nor'Easter Yachts, fiberglass composites

Filament Winding

8" mandrel and first run tube for Navy drone firing tube

Design

There are many characteristics which can be customized in the design and manufacture of your tube.


Helical winding: 

Wind angle can be set for helical wound layers. We generally use a 56 degree angle.  The longer the wind angle, the more strength may be found from bending, whereas a shorter angle will yield better burst strength.  Each layer, approximately ,06" thick, could be customized, although we generally simply copy layers to achieve the desired wall thickness.


Hoop Layer:

In hoop winding the band of filaments is spun at almost a 90 degree angle, yielding a strong burst strength, and a relatively smooth finish.  Whereas a helical layer actually builds two layers of filaments crisscrossing each other, a hoop layer lays down only one layer, and thus builds only an additional .03" of wall thickness.


Resin:

Different types of resin can be used to achieve desired properties of the tube.  We generally use an ISO polyester resin, and glass filaments in our tubes. An iso resin has better chemical resistant properties than a general purpose ortho resin, and is better for direct contact with the marine environment. We colorize our resin white, to match our products in coler

Mandrels

The mandrel determines the inside diameter of the tubing. The lengths of our mandrels and the limitations of our machine provide a maximum length of approximately 9' in most cases.


The OD, outside dimension, is approximated by how many layers of filament are wound.  This controls wall thickness. By a combination of helical and hoop winding we can achieve dimensional control to approximately .03" increments.

Current Mandrels

2" X 108"

2.25" X 100"

4" X 96"

8" X 96"

10.75" X 96"

12" X 96"

Inventory

We generally do not carry much in inventory.  The filament winder is mostly used to build tubes for our needs in building stabilizer fins.


Tubes are built to order.  It is a somewhat labor intensive process, as set up and cleaning generally take up as much time or more than the actual spinning of the tubes.


Shorter lengths may be available from inventory. Best to email with  requests.


The tube lengths we use in our production are:


2"ID by 2.5"OD

2.25" ID by 2.5" OD

4" ID by 4.25"OD

Limitations

We do not have facilities for centerless grinding of the OD on the tubes.  They are "as wound". We generally end the filament winding process with a "Hoop" wind, where the bands are laid side by side, rather than the helical wind, which gives a much stronger cross hatch finish.


We do not use ovens, but run a "hot Pot", resin catalyzed ahead of time, giving us a limited amount of work time, and a limitation on production to one or two tubes a day.  Definitely not high production.