Spin Weld Fittings

AU$1.06 - AU$3.80

Spin Weld Fittings

For most applications, we recommend protruding female threads. 1/2" is ideal for fresh waster lines. 1-1/2" is ideal for gray water lines, fresh water fills, and vent stacks. 3" is used for toilet fittings and black tank drains. Membranes are a thin polyethylene wall in the fitting opening that is watertight. It is drilled or cut out of the fitting after it is installed but before tank is used. It can stay in place if the fitting is never put in service.

When selecting location for fitting, it is best to have a flat spot on the tank where the entire flange is on the flat surface and the fitting and tool can spin freely.

First, cut a proper size hole with a hole saw. Drill a hole in the tank that is slightly larger than the pilot on the fitting so that it is not binding but also not sloppy in the hole.

Choose the proper size router for the job. On fittings up to 1/2", you can use a 1 HP router. On fittings measuring 3/4'' to 1-1/2'', a 1-1/2 HP to 2 HP router is acceptable. On fittings 2'' and larger, you'll need a beefy 3 HP router of at least 14 amps. Drivers for 1/2" fittings will have 1/4" shanks. Drivers for all other fittings have 1/2" shanks. Do not use a pneumatic router. Use an electric router capable of 18,000 to 25,000 RPM's. Do not attempt to spin weld with a drill press or hand drill because you cannot reach the proper speed.

Place the fitting pilot in the hole of the tank. Holding the router in your hands and having the driving tool attached to the fitting, turn on the power and apply slight pressure so that molten plastic starts to flow around the entire outside diameter of the fitting. You will develop a technique as to how to apply pressure. The melting process will only take 2-3 seconds. When you have a good 1/4" bead of molten plastic around the perimeter, turn off the power and keep the driver in position with applied pressure for another 5 seconds. This will ensure a good bond.

After 1 full minute you can apply testing procedures, such prying with leverage.

These polyethylene fittings are spin welded into polyethylene holding tanks and fresh water tanks. They are made of low density polyethylene and can be used on either low density or high density polyethylene tanks.

To install the fittings, you will need a special drive tool inserted in your router. You will carefully cut a hole in the tank using a hole saw. The fitting is then placed in the hole. The driver tool holds the fitting and spins it at very high speed until it melts into the plastic. Once installed, it cannot be removed. 

We stock only a limited number of drivers, but we are happy to special order any size for you. Each size fitting may require a different size driver. Drivers typically cost between $70 and $120 each. Smaller fittings can be installed with a mid-size router. Larger fittings (2" and up) must be installed with big heavy duty router. A power drill will not spin fast enough to do the job.

Spin welding requires some practice. We highly recommend you let us do it when you buy a tank from us.