Picture rail sprung out at corner.

JohnB47

Eldi_Dos said:

If its a Lath and Plaster wall we may need to come up with another plan.

I vote for a thin spring toggle bolt , would 3/8 be small enough?

No, 1930s plaster over red brick. 

FreeBear

JohnB47 said:

Eldi_Dos said:

If its a Lath and Plaster wall we may need to come up with another plan.

I vote for a thin spring toggle bolt , would 3/8 be small enough?

No, 1930s plaster over red brick. 

Sod's Law says where ever you drill a hole, you'll hit a mortar joint with zero holding power. And if you do go in to a brick, it will be darned hard - Have the same kind of luck with my late 1920s semi.

If the plaster is sound, a squirt of grab adhesive behind the picture rail might be enough to hold it in place along with a thin panel pin tapped in at 45 degrees in to the adjoining piece.

ThisIsWeird

JohnB47 said:

Eldi_Dos said:

If its a Lath and Plaster wall we may need to come up with another plan.

I vote for a thin spring toggle bolt , would 3/8 be small enough?

No, 1930s plaster over red brick. 

A photo would help to give an idea of the shape and size out the rail, and how far out it's springing.

In such situations, tho', your best bet is most likely to be a smallish wall plug - a 'red' one - and a suitable screw, probably size 8 x  2" or 2.25" long.

The plug will give the associated drill size - quite likely 6mm dia - but since it's red brick, I'd be tempted to first try 5.5mm. 

Drill through the thickest - and easiest to fill - centreish part of the picture rail with a sharp wood bit to leave a clean hole. Swap to masonry to drill in to the wall. Make sure you go at least a quarter-inch deeper overall than the screw length, allowing also for pulling in the springiness and the screw head burying itself in a countersunk hole; the screw must not bottom-out! Add a small countersink to the screw hole so the screw's head will go slightly below rail surface level, and can be filled in afterwards. Test-fit the screw for depth before tapping in the plug.

Next is to extract all the dust and debris. If you have a straw, tape it to the end nozzle of your hoover, and insert it all the way in. Or, insert straw but instead blow - but cover your eyes...

Also remove any dust and debris from between the rail and the wall - check and make sure the rail will go back flush.

Insert the plug into the rail, and you should be able to use the screw to tap it right into the wall with a hammer. The secret is to first tap the plug flush using the hammer, then place the screw in the plug and continue to gently-but-firmly tap the plug in, but unscrew the screw every couple of taps, so it doesn't keep embedding into the plug. This should work - you should be able to get the plug nicely in below the wall surface.

Finally, squirt some PVA into the hole and refit the screw - get it to push a good dollop into the plug and wall hole. This will lubricate the thread making it much easier to screw, and also help to bond everything together. Press the rail in firmly and hold it as you tighten the screw. Just before the rail makes contact with the wall, run a nice bead of PVA down along and behind that 400mm to glue the rail to the wall. Fully tighten down, and wipe away any excess PVA with a damp cloth.

Allow to dry fully.

John_the_Boy

If you have an adjustable paint roller handle - the sort that allows you to do ceilings when standing on the floor, I have found these very good for holding a rail against the wall when grab adhesive didn't hold it properly. Alternatively a broom handle that unscrews will work.