Is there a plug or do I have to fill the holes?

[snowjim]

Hello,

I have decided to replace the bracket for a center speaker in the basement. The wall seems to be some type of cinder block and the holes from the existing bracket are unfortunately quite large.




Here you can see the screw that the new bracket requires



Here we can see a comparison between what the previous bracket used (left) and what the new one (right) requires.

Here you can also see the actual mounting for the bracket.

This is the instruction for 1 bracket. It comes with 2 screws, but I will only use 1 and instead use 4 brackets. We can also see that the drill hole should be 6 mm and the current one is unfortunately much larger (I guess 11-12).


Here I tried to construct my own plug by inserting the bracket's supplied plug into a slightly thicker one. The plug goes in and if you screw in the screw a bit, you can get a mount that seems to hold pretty well for pulling straight out, but unfortunately, there is quite a bit of spring in the screw up and down which is not so good for the mount.

I guess the hole in the wall is maybe 11-12 mm.

Now I'm wondering if there might be a simple solution to this? Some form of screw or plug that could fit?

Or do I have to buy a fix that I inject with a syringe into the wall and then drill new holes? Will it be sustainable without cracking when I drill nearby?

 

[A-Man_08]

What is the dimension of the screw around 4.5?

Fill the hole and drill a new one next to it if possible. It usually gives good results if you use a 1mm smaller drill than what is recommended; for 6mm, I usually use 5.5 and 7mm if it should be 8mm. Then tap in the plug, and it usually holds well.

 

[huggan]

Do not use regular spackle, use something like husfix. This will be much more durable.

 

[Thomas_Blekinge]

Why not use a 12 mm plug?
Using just one screw for each bracket seems a bit unsteady.

 

[snowjim]

What is the dimension of the screw around 4.5?

Patch the hole and drill a new one next to it if possible. It usually gives good results if you use a 1mm smaller drill than what is recommended for 6mm, I usually use 5.5 and 7mm if it should be 8m.m., then you tap in the plug, it usually holds well.

I guess 5 mm since it's the same as the largest screw in the IKEA screw set.

From what I understand, you're not supposed to use regular filler in the basement but fix that you mix yourself, the tricky part, however, is getting it into the hole. If you could inject the fix, you could fill it well, for example, if you had the fix in a sort of syringe that you otherwise have for sealants.

However, I don't understand why I should choose a smaller screw? If you fill in the hole correctly, shouldn't it not matter?

 

[snowjim]

Do not use regular filler, use something like husfix. This is much more durable.

That sounds good! Does it come in a cartridge? Can it be used in the basement? I.e., it breathes just like regular fix? Otherwise, I've heard that you should only use fix in the basement for repairs.

 

[snowjim]

Why not use a 12 mm plug?
Using just one screw for each bracket seems a bit unsteady.

The problem is that a 12 mm plug requires a thicker screw, as thick as the one I've used before. Such a thick screw can't be used in the bracket, unfortunately. I don't know if there are plugs that are 12 mm where you can use a smaller screw, like 6 mm. The risk with such a plug might be that it becomes quite unstable?

I have a similar bracket upstairs mounted in a drywall with molly screws. Admittedly, that bracket is from Biltema and of clearly cheaper quality, but one screw works perfectly there and it holds the same weight that this one will in the basement. Placing two screws so close together in concrete seems risky; cracking is a considerable risk, I would think.

 

[Stefan1972]

If it's a soft stone, I would buy longer wall plugs instead. There are wall plugs with screws like nail plugs that are intended for soft materials. It's better to get the screw in deep so it has more to rest on than to use larger and shorter plugs.

 

[snowjim]

If it's a soft stone, I would buy longer plugs instead. There are plugs with screws, like nail plugs, that are intended for soft materials. Better to get the screw in deep so it has plenty to rest on than to use larger and shorter plugs.

From what I understand, it's hollow brick, which makes it a bit complicated to handle. So if you could inject something to fill everything up and then drill new smaller holes, that would've been great, but maybe it's not that easy?

Nail plugs might sound reasonable if they are a bit longer, but the problem remains that the holes are so large that it's hard to find a screw that fits both the plug and the bracket.

 

[snowjim]

If it's a soft stone, I would buy longer plugs instead. There are screw type plugs like nail plugs intended for soft materials. It's better to get the screw in deep so it has much to rest on, rather than using bigger and shorter plugs.

What does a nail plug mean, by the way?

 

[Stefan1972]

type:
http://www.bauhaus.se/spikplugg-11.html

note that despite the name, it is a screw that can be dismantled. It is suggested that you fill the old holes and drill new ones in a different place and use drill bits with carbide tips then, no hammer drilling. That way you can get relatively neat holes without them becoming too large.

 

[snowjim]

type:
[link]

note that despite the name, it's a screw that can be dismantled. I suggest you fill in the old holes and drill new ones elsewhere and use only a drill with carbide cutting edges, no hammer drill. That way you can get relatively nice holes without them being too large.

Hmm why is it called spikplugg? I see that it's longer and also seems to have less material, is this the difference?

Yes, there were a few problems drilling these holes, firstly the drill tended to wander in some direction and additionally, the hole ended up being quite a bit larger than the drill itself. So what you're saying is that I should buy a regular drill bit that's not made for hammers and instead has carbide cutting edges? Can you link some example? Can you run such a bit in a regular drill or is it okay to use in a hammer drill where the hammer function is turned off?

 

[Thomas_Blekinge]

In a plug joint, it is not the "up and down" stability of the plug that bears the load. Instead, the screw is tightened properly so that the bracket carries the load through friction against the wall. Therefore, the pull-out strength is more important than how a screw wobbles in the plug.

 

[snowjim]

In a plug connection, it's not the plug's "up-and-down" stability that bears the load. Instead, you tighten the screw properly so that the bracket bears the load through friction against the wall. Therefore, the pull-out strength is more important than how a screw wobbles in the plug.

The problem here is that the hole is perceived as slightly larger at the outer edge. Additionally, I don't have a plug that fits the hole (12-13 mm) but at the same time fits a 6 mm screw (does such a thing exist?), so I tried constructing one on my own with plug in plug. The problem there was that the plug became thick in the middle, which made the screw hold well for pull-out (could not be pulled out) but it moved a lot up and down.

If one could get hold of a plug that fills the hole but at the same time works with the screw, then it would certainly have been possible to reuse the holes. This would have been by far the most convenient solution, but I'm not aware if such a plug exists.

It's relatively important for the bracket to sit close to the wall, unfortunately I found that it was relatively easy to jiggle it up and down when I tried the homemade plug.

 

[A-Man_08]

I guess 5 mm since it is the same as the largest screw in the IKEA screw set.

From what I understand, you should not use regular putty in the basement but rather fix that you mix, the tricky part will be getting it into the hole. If you could inject the fix, you could fill it well, for example, if you had the fix in one of those syringes that you normally use for sealants.

However, I don't understand why I should choose a smaller screw? If you fill the hole correctly, shouldn't it not matter?

A screw as large as you used before won't fit into the new bracket's hole, and you need a 6mm plug, therefore you should drill a new hole. That will hold if you use the right plug. But putting a smaller plug into the old hole won't be good.