Pilot Holes

[dad needs a hobby]

Hi Guys
Im going to be building the tub out of 12mm MR MDF so Ill need to drill pilot holes in it before screwing on the battens, Can anyone tell me what drill size and depth to go in. I will be using the recommended 4mm x 30mm screws and pre drilling my battens with 4mm holes.

Also is it possible to round the long top edge of the side panels without using a router?

thanks Peter

[Jason]

You can purchase an inexpensive countersink bit that will drill the pilot hole and countersink the screw head at the same time.  Some even have a stop that will make the countersink the same every time. Generally, the bit diameter should be about the same as the screw shank. The depth should be a little deeper than the screw is long. The router is the best tool for rounding the edge but if you dont have one, a belt sander could do the job if you haveone of those. It will take a keen hand to make it uniform.

[dad needs a hobby]

thanks got the drill bits with adjustable countersink bit attached, not expensive £9.95 from screwfix for a 3,4,5 &6mm set.

Got my woodworker mate doing the routing for me.

[Ant-G]

Hi
If you are drilling a hole through a piece of MDF it is better to hold a scrap piece of wood behind. THis stops the back surface 'blowing'.

Anthony

[toys4me]

I have the same set of drills and countersinks. Good enough for what we do, but I sugest you change the drills before they bend and snap, as mine have. Keith

[dad needs a hobby]

thanks Kieth, Did they last long enough to get your tub finnished?

Peter

[toys4me]

I use these quite a bit for work. They broke very early in use. The countersink seems OK though, not had any trouble from them, another 120 holes today !! Keith