Thread: Lid Strength

It would probably need to have battens at the very least, otherwise it's likely to warp. I'd be inclined to reinforce it across the front and sides as well, seeing as it will be supported only at the corners.

Maybe it needs a frame. Or you could make a curved (coopered) lid. I'm making one at the moment. The skin of the lid is 15mm but it has ribs and a stringer up the middle to support the weight.

Thanks SilentC.
So your saying that an unbraced panel wouldnt cut the mustard.
I'm at the post-inspiration stage now where I just want to get it finished and move on

The frames are all glued up so it would be a really major rework to support the lid across all rails. The reason I've done it like this is that lid supports and softclosing hinges are so fiddly and trial&error to install that I decided to avoid them.

Not sure what you mean by a "frame" surely a frame and panel lid would not be as string as a full panel.

What I meant by a frame was like a shallow box or tray, for want of a better word, with the panel sitting in it. The strength would be in the frame members being on edge, rather than on the flat like a normal frame and panel. I would then put some ribs underneath the top to provide the support. The panel can still float in a groove. You make the frame strong enough to support the weight and the panel is just there to keep out the dust. Sort of like a torsion box if you get what I mean.

no idea sorry

Have a look at this: http://www.diynetwork.com/diy/shows_..._26946,00.html

That is a torsion box. The idea is that it has a strong frame and a lightweight skin. It means you can have a strong lid without the weight. The frame members are on edge so that they can carry a heavier load. You make the four perimeter frame members deeper and put in a rebate or a groove to take your panel. The internal frame members are flush with the rebate so that the panel rests on them, but is not glued to them. This allows the panel to float. It is the internal frame that is taking the weight. If you want you could skin the bottom of it as well to hide the frame when the lid is up. You could do that with ply.

I think that even with battens you are still going to have problems with a flat top because the front of the lid is resting on the corners only. If you make it as a frame then it is more likely to take the weight across the one metre span without bowing.