Roger Bisby: Fixing with Fischer

Roger Bisby: Fixing with Fischer

I am always interested in looking at new fixings. It seems to be one of those Dragons’ Den type products that every Tom, Dick and Harry thinks they can improve, and in the end most of these bright ideas seem to be variations on the same theme rather than radical departures.

At first glance Duotec from Fischer is no exception – there is nothing here that we haven’t seen before until you take a closer look. Then you see that this is a dynamic duo.

The Duotec toggle fixing is a simplified (and we hope therefore cheaper) version of other toggle fixings you may have used.

The strap is one-piece and part of the wrap around. The red glass fibre component making up the duo is the toggle which has a metal insert to grip the screw thread and prevent stripping as you tighten.

This works best if you use the correct size screw, which is 4.5 to 5mm diameter. The screws are not provided.

You can get an incredible amount of purchase on this fixing but in plasterboard you are only ever as good as the board.

The toggle fixing, however, is only half the story. The second option is to use the fixing without the toggle going all the way through into a void. This is basically using the toggle as a conventional expanding plug. It has a hole in the end to take a screw.

The illustration shows the fixing being used in a timber stud, and you have to ask why you wouldn’t simply screw into the timber and save yourself a plug.

I suppose you would prefer the plug in chipboard or similar materials, which do not always take a screw that well, but softwood studs are perfect, and I don’t see much point in this product for that application.

Where I think it does win is in insulation boards and other boards where you are uncertain if you will find sufficient void for the toggle to spring flat.

The second product I tried is a Duopower plug. Again this employs nylon with wings to help prevent rotation and a harder closed end to expand in the hole and provide a secure wedge fixing.

I tried a pull out test in dense concrete with a claw hammer and it was fairly easy with a smaller screw to pull them out. If you want them to be really secure in a hard host material you need to go for the maximum permissible screw.

Again this is a two function fixing and the second idea is to use it as a plasterboard or cavity fixing where the red end of the plug is in free space and can be drawn up into an expanded stop. This is an ideal fixing for Porotherm clay blocks.

For more information click here.

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