how to stiffen up plastic desk lamp joints

[therustyone]

I put a 3W 240 v. LED MES bulb in a desk lamp but, as it's a tad on the heavy side, the lamp's plastic joints don't hold the arm up as required and it sags. This is a half size version of an anglepoise without balance springs and the arms are held up by tightening wing nuts on the joints. What sort of friction material could be put in the joints to stiffen them up while still allowing adjustment. The plastic material is fairly hard and glossy, a bit like the keyboard I'm typing on.

rusty

[NT]

A picture would help

NT

[Brian Gaff]

I think more to the point, how big are the surfaces that grip, if they are quite small I suspect you are not going to get it to work.

One might break the material before you could get anything to grip.

Brian

[Andy Burns]

Roughen it up a bit with course sandpaper?

[therustyone]

Here's a pic. with a 20p for scale (if it all works). Not enough space for a sandpaper shim.

[Chris J Dixon]

you accommodate?

Chris

[therustyone]

sliding a cigarette paper in would be a struggle. I think I'll try the fine sandpapering idea and maybe spread some superglue in the process so that bits of the grit stick on the plastic surfaces.

rusty.

[djornsk]

Two possibilities are firstly a bolt through the frame a couple of cm above the hinge bolt to pinch the frame slightly and thereby increase the friction, and another might be to lock the thing in position with a small screw.

j

[Dave Liquorice]

use that as a template for a bit if cartridge paper, put this paper washer between the two bits of plastic and replace the handle. Might need two of the paper washers.