Low budget build - H3 lids

Built some lids for our two H3's from cheap ply left over from other projects and some catches salvaged from an old flight case.

I wanted to make the long sides of the lids locate precisely onto the edges of the cabinet, and the catch positions needed to be dead on so it required a bit of thought and a lot of fiddling to make sure everything lined up.

First I cut the two top panels from 12mm ply, 10mm oversize so they could be flush trimmed at the end. Stacked the panels and cut the first two catch openings with a jigsaw then flipped one and used a bearing guided router bit to cut the second pair.

The sides would be made from a sheet of far eastern 18mm ply which had been stored in my damp shed for a few months so it was quite bowed. I attempted to reverse the warping by wetting the concave side and lying that face down and weighting the top. Repeated the wetting a few times over a couple of hours and this worked surprisingly well. 

I cut the side pieces - First one with basic handheld circular saw and straight edge, the rest were cut slightly oversize then used the first piece as a template to route the others to make them all identical.

Finally I profiled the edge to mate nicely with the cabinet, using a bullnose router bit and parallel guide to route a shallow groove down the centreline, then added a 3mm roundover either side of the groove.

There was still a bit of bow to the side pieces which would have made it difficult to get them straight enough to fit nicely onto the cabinet. To force the sides straight and add strength to the lid I decided to add some strips inside each corner. Found a chunk of mouldy 18mm birch ply and attacked it with a belt sander to remove the worst of the mould then cut the strips.

You can see where these fit in this picture from a bit further along in the project:

To ensure the sides fit the cabinet perfectly I screwed on the catches and did a test fit so I could mark where the side rails of the lid would need to be.

Next I made the lid end pieces. I made a really nice template (lots of sanding to get the curve just right) and then discovered it was too small to use - couldn't clamp it down to route as the clamps get in the way. Tried double sided tape but the stuff I had left residue that was really hard to remove.

After a brief experiment with the router clamped upside down in the workmate (do not do this, it really is as dangerous as you would imagine, didn't loose any fingers but it quickly became evident that would be the outcome) I resorted to cutting them out with the jigsaw then cleaning up the curves with belt sander clamped upside down.

Finally added a roundover to the inside edges as this would be tricky to do once assembled. Used a random collection of offcuts to hold the pieces steady while rounding over. A router table would have made this so much easier.

Another test fit then drilled pilot/clearance holes and countersinks for the side rails

On the home straight now. Glue up and clamp

Filled and sanded all screw holes then flush trimmed the top and rounded over all the edges.

Final test fit before drilling the holes to bolt the catches on.

Painted with the remnants of a very old tub of aldcrofts (10 years?!) from the shed (after fishing the lumps out with a spoon). Smells a bit odd but hopefully it won't fall off, end result looks quite nice.

Cost of materials: a few quid for screws, everything else was leftovers or salvaged.

Cost of time: Err.. quite a lot. I enjoyed myself which is the main thing.

Added bonus: more space in the shed as it's not cluttered up with loads of leftover crap ply