Hi, I am trying to join two sheets of 18mm hardwood ply together with a 6' piano hinge for a sofabed. There are about 30 ~3.5mm holes on each side of the hinge for some sort of screw. I was wondering how best to attach the hinge. My thoughts were to use 3x16mm screws (eg https://www.screwfix.com/p/turbogol...k-multipurpose-screws-3-x-16mm-200-pack/16957) - though I'm not sure if this is the best option. Any thoughts would be much appreciated
That should be fine, I presume you're butting the 2 sheets together and laying the piano hinge on top.
I'd be inclined to think about a 20mm screw, rather than 16... the added strength all along will be considerable, for just a few pence more; https://www.screwfix.com/p/goldscre...multipurpose-screws-3-5-x-20mm-200-pack/12591 If they don't protrude... and I suspect they wont. Cando
Yeah the hinge is about 0.5mm While we're here, I'm planning to screw and glue some other sheets of 18mm ply to 44mm birch legs to make the box underneath. I was thinking regular wood glue, but that I would need a fine rather than coarse screw as it's going into hardwood - is this right? And also, what length of screw would be suitable for this? I heard a rule of thumb that was along the lines of 1.5x the length of what you're screwing through...
Just use soft wood 44x44 legs, if you've bought Birch then take it back or burn it, you will regret using it if you do. Use 45/50 x 4 screws, countersink the heads, PVA if you like.
Ah ok, I was sold them as being the best for the job - what's the problem with it? I'll see if they have anything different in any case. Thanks
Going back to the screws for Piano Hinge - do not use normal Csk screws, buy the specific versions designed for Piano Hinges - they have a slightly smaller head and sit flush: https://www.isaaclord.co.uk/reisser-r2-countersunk-yellow-hinge-screws
When I was in shopfitting, we used a special technique to screw thin hinges or metal to wood: drill a CSK hole in hardwood or steel, place the hole of the hinge over the CSK (or drill pilot holes in the sheet metal and place over the hole) get a big centre punch and hammer the thin sheet into the CSK. This is known as "coining" you will need to CSK the ply to allow for the coined metal to be let into the surface. If done carefully, you can get a flush surface. By the way, Screwfix turbogold screws are pretty good, I use 1000s of them. Maybe not the best quality, but ok for most jobs (like screwing floorboards to joists with 5mm x 50mm). Kevin
The point being that you can't CSK thin metal. you'll just make a big hole. I will up load a picture of some thin steel angle "coined" so that the screwheads are flush or slightly below the surface.