Bodged up plasterboard fixings when trying to put up a shelf

NorthernKitty

Thanks everyone. Don't have the money to buy anything else at the moment, (nothing on the packet that suggests you need a tool to insert the things!) so will just have to put up with two large holes in the wall and two shiny metal circles for now until I can sort it out! Appreciate all your comments, I will look for the stud detector (lots of things are missing since the house move so may take me a while to find it!) for putting up other shelves and fixings. 

ThisIsWeird

NK, the wall space is around a metre? How wide is the shelf?
Not that I'm anticipating this making any difference - most likely there will only be a single stud available there, just off centre where it's no use to you. 
There's a good chance there's one right in the corner - coming out around 2" - so that's a possibility, tho' doesn't look aesthetically pleasing. If you look at the pic of the shelf, the brackets are towards the ends, but not at them.
How many extra fixings do you have? I fear the solution will require starting again, as the existing holes will be damaged and cannot be reused with the necessary strength, even if filled.
How to start again? Either by filling the holes and moving the brackets to new positions, or possibly without filling the holes but hiding them by moving the brackets either up or down an inch or so to hide them. Bear in mind the shelf thickness can also hide, if you move the brackets downwards.
A tub of filler should be had for a few pounds in a B&M type store if you chose this route.
So, I think first step is to work out whether you can keep any of the existing fixings in place, and move the rest.
Although the fixing tool is really useful, I don't have one but have used these fittings lots of times - they are my fav p'board fixing type.
1) Drill the hole snugly, with zero unnecessary clearance.
2) Drill the hole cleanly - don't tear or burst through the pepper layers on either side. Ie, try and use a wood drill - the type with the edge cutting bit. (What's they called?)
3) pre-start the fixing before fitting. Ever so slightly, a half-turn or so. The starting torque is huge, but once it moves, this drops off significantly.
4) Gently wiggle the fitting into the interference hole without turning it. It's meant to be a snug fit. The 4 side tangs will form 4 light grooves into the edges of the hole, and this, too, will help to prevent the fixing from turning. 
5) Press the fixing fully home with no turning.
Sometimes you can also use a pair of pliers to help prevent the fixing from turning; on the exposed round collar of the fixing, you'll see mising pie-slices where the tangs were. Place the edges of the plier jaws, at a roughly 45o angle, into these spaces, and press and hold gently - this will bite into the p'board surface, and will help a lot to prevent the fixing from turning during the first starting screws. 
Once the tightening begins, it becomes easier - the very start is the tricky bit.

NorthernKitty

Thanks, I have cut and pasted relevant information for future reference! I haven't had a chance to attempt any more shelves but have 2 days off at Christmas so will attempt another one then. 
Managed to get the first shelf up by keeping the 2 fixings that had worked, and using normal brown rawl plugs and the circular wet plaster bodgedholeinthewall fixings in the holes,  and it has stayed up with 2 lightish boxes on it. Seems strong enough not to fall on anyone's head. 
Thanks everyone for your help, I will be careful to figure out where the stud things are before attempting the next one!

ThisIsWeird

Thanks for the update, and well done.
I've used that technique myself in the past - pushing a screwed wall fixing into wet filler, and allowing it to set in place!
To work at its best, the plug should be embedded in the plaster/filler with the screw already in place in the plug, to its finished depth. That sounds like what you've effectively done.
Although fixing into the timber studs is by far the easiest and strongest method, rarely will you be lucky enough to find two in the right place! So, likely you will need these wall anchors again. They are good fixings, my preferred method, but how they are installed is critical. Really worth investing in a tool if doing more shelfie work.

Postik

ThisIsWeird said:

 So, likely you will need these wall anchors again. They are good fixings, my preferred method, but how they are installed is critical. Really worth investing in a tool if doing more shelfie work.

The tool is about £15 from Screwfix I think (I appreciate £15 is a lot to pay for two fixings if you're on a tight budget). I'm glad I got it for future use. I practiced on a bit of scrap plasterboard and the tool generally makes a much nearer and more reliable job of sprawling out the fixings legs. Manually screwing them was hit and miss so I'd prefer not to leave it to chance, since when doing it for real you can't see inside the wall.

For what it's worth a couple of people have told me that even these fixings can come loose over a long period of time when mounting things like shelves. I think the constant putting items on and off the shelf gradually causes the legs to dig into the plasterboard over a long period of time. I think they're good for things like heavy mirrors or pictures which rarely get touched or moved.

ThisIsWeird

Postik said:

ThisIsWeird said:

 So, likely you will need these wall anchors again. They are good fixings, my preferred method, but how they are installed is critical. Really worth investing in a tool if doing more shelfie work.

The tool is about £15 from Screwfix I think (I appreciate £15 is a lot to pay for two fixings if you're on a tight budget). I'm glad I got it for future use. I practiced on a bit of scrap plasterboard and the tool generally makes a much nearer and more reliable job of sprawling out the fixings legs. Manually screwing them was hit and miss so I'd prefer not to leave it to chance, since when doing it for real you can't see inside the wall.

For what it's worth a couple of people have told me that even these fixings can come loose over a long period of time when mounting things like shelves. I think the constant putting items on and off the shelf gradually causes the legs to dig into the plasterboard over a long period of time. I think they're good for things like heavy mirrors or pictures which rarely get touched or moved.

Yes, 'dynamic' loads in p'board will always be a problem.

I gave a list of the things to watch out for on an earlier post, but how crisply and snugly you make the holes will have a big bearing.