SDS Drill/Physics Question?

[bobfog]

Background:

Old bungalow, interior, non load bearing walls in slightly poor condition owing to being built shortly after WW1 and Portland cement being in short supply so Ash cement being used as a substitute. Walls aren't dangerous, but maybe a little more delicate than would be ideal.

Question:

When drilling holes with an SDS drill, would a drill with 4.5j of impact energy taking say 5 seconds to drill the hole cause more or less potential damage/shock force to the wall than a drill with 2.0j of impact energy taking say 10 seconds to drill the hole. Or is the amount of energy required fixed/absolute and there is no difference?

I'm thinking Newtons 3rd law about equal and opposite reactions is the key factor and the answer being there's no difference, but I'm not a physicist so conformation would be nice.

Thanks

 

[Kevin McConville]

big difference

if someone strokes the back of your head 1000 times with one unit of force, or they hit you once with a baseball bat with 1000 units of force - do they cause the same damage?

 

[bobfog]

big difference

if someone strokes the back of your head 1000 times with one unit of force, or they hit you once with a baseball bat with 1000 units of force - do they cause the same damage?

But isn't that a slightly different scenario?

Would this be more akin to someone driving a spike into your hand with either one sharp motion or a slower driving motion, is the amount of energy in which your skin/bone/muscle is penetrated still the same?

 

[Kevin McConville]

Your analogy is flawed. Go whichever direction you feel is best. Hope it works out for you.

 

[bobfog]

Your analogy is flawed. Go whichever direction you feel is best. Hope it works out for you.

It's not my analogy, I'm just asking questions to try to get my head around it. Appreciate your input.

 

[Kevin McConville]

The spike analogy is flawed because it's perspective is the hole that the spike creates. Your concern is not with the hole the drill produces but instead with the material around it. Energy is not the physics you need to consider but instead the force component of that. The rest of the delicate wall may not be able to withstand the sds level force applied a relatively few times but may well be able to withstand half that force applied many times

 

[bobfog]

The spike analogy is flawed because it's perspective is the hole that the spike creates. Your concern is not with the hole the drill produces but instead with the material around it. Energy is not the physics you need to consider but instead the force component of that. The rest of the delicate wall may not be able to withstand the sds level force applied a relatively few times but may well be able to withstand half that force applied many times

Yeah I see where you're coming from. Maybe reverting to a percussion drill instead of SDS would be a wise move for this job.

Thanks.

 

[windmill man]

How many holes and what diameter, what material is the wall made of? What country are you in ? [smile]

 

[Simon (UK)]

Too many unknown variables to be able to make a definitive decision but if it were me I'd be opting for the softer but longer approach. Not the same application but when recently braking up my old tiled kitchen floor, less unwanted damage was done to the substrate when I used a small lump hammer and a chisel rather than a 2kg rotary stop SDS impact drill. When the drill caught on a lump it removed far more than was ideal. Less energy produced less damage but took longer. A lot lot longer.

Chemical bonds are normally associated with bond breaking energy not bond breaking force. Keep the energy below a certain level and the bond holding atoms/molecules together should not break. This could imply a lower energy drill is likely to less surrounding damage to the OP's wall.

Analogies are great. They are extremely useful in putting across new ideas. I use them a lot. However because they are analogies and used to model a situation they do have limitations. No harm, just be aware. Stroking, poking or punching in the face are all analogies that help visualise. They are not the same situation as being discussed but still help move the thread on.

A crane with a sodding great mass attached is used to demolish a wall rather than a crane with a ping pong (table tennis) ball attached.  [scared]
Simon.

 

[AlexThePalex]

It is simple.

The harder you hit something, the more energy you transfer TO the material.

The harder you hit something, the more energy gets propagated THROUGH the material, away from the point of impact.

So if you just want a neat little hole and not damage anything around it, use the smaller drill.

 

[Holmz]

It is energy, momentum, and force... Which to use depends on a few things.
I am not a materials science guy, but energy over a short time will have a higher amplitude resonance, and a higher force.

Either way (force or energy) one is busting off chunks and not the 1/2 the wall. Like a woodpecker does not may the hole in one blow... So should you.

 

[No Skills]

If you can get one the right diameter use a multi purpose drill bit in a standard non sds/percussion drill.
Saves any physics questions and vibration damage to the wall.

 

[Cheese]

If you can get one the right diameter use a multi purpose drill bit in a standard non sds/percussion drill.

I'd go along with this suggestion, it has the potential for causing the least damage, it will just be more time consuming.

In the past, I've used a conventional metal drill bit in a conventional drill, to bore some holes in a plaster wall for plastic anchors. This combo allowed me to drill holes without possibly having the finish coat of plaster separate from the brown coat. The drill bit would only last for about 6-10 holes though before it needed to be replaced.

 

[mwahaha]

If you can get one the right diameter use a multi purpose drill bit in a standard non sds/percussion drill.
Saves any physics questions and vibration damage to the wall.

What he said...

And if the hole is bigger than 13mm (the largest size multi-purpose bit I have seen in the local hardware shop) then go for a diamond core bit in a standard drill with a squirty bottle full of water for coolant

 

[oldie]

Agree with last three posts. 
Would add that if holes need to be precisely positioned, I like to drill a pilot hole
for a couple of inches. 
Sometimes will drill the pilot hole the full depth required - then use a slightly larger
diameter bit, before finishing with correct sized bit.  Just depends on how it seems to
be going. 
As far as possible would avoid percussion or sds if wall fragile - even if takes more time, and needing
to have more bits available. 
The aim, of course, is to minimize disturbing the surrounding material as much as possible. 

Richard (UK)

 

[Jak147]

Good lord, if a wall is too weak to drill a hole into it with fear of damaging it,  then it should come out.
Cinder blocks whilst beings soft are still much harder  than modern lightweight blocks, you can't cut then with an old handsaw for instance.
Just pick up a drill a make a hole, thou make sure to have an extracter involved the dust is on par with red bricks if not worse

 

[oldie]

Jak147.  Lol when read your post. 
Can't disagree with what you wrote. 
Not familiar with a wall constructed as OP described - nor why wanting to drills holes. 

(Off topic - apologies to anyone who thinks shouldn't have been posted) 
But I tell you what - in the UK, some of the old, turn of the last century, terraced properties can
have, by modern standards, appalling build quality. 
Something you really have allow for, cost wise, when being renovated, or anything else come to that. 
For eg, can literally just lift bricks off - really sandy crap mortar; with some internal walls being
built with bits of brick, large stones - whatever. 
Reckon you could 'demolish' whole houses by just lifting the bricks off.
Ditto wrt foundations - for any practical purpose, can barely be said to exist. 
One property worked on, the third bedroom had been previously converted for use as a bathroom.  But, decision
made to move the toilet - which meant everything had to be brought up to latest reg's.  New stack, manhole (access chamber), new pipework to communal sewage pipe running along the bottom of back yards etc - a nightmare! 
And yes, there was subsequently some settlement of building - which fortunately was predicted, and, contractually noted. 
Another eg was one property where, after plaster removed, surveyor warned to 'not touch' one party wall - was just
very gingerly plastered over...
Last eg - honest: Adjacent properties, where external wall, round the back, bulged out about 4 inches. 

Right or wrong - no harm in taking it easy if, say, drilling hole for overflow pipe or whatever. 

Just saying.  [smile]

Richard (UK) 
(Edit:  added "Off topic - apologies to anyone who thinks shouldn't have been posted.)

 

[No Skills]

Ha  [big grin]  I live in a house like that, built 1890.
Buy an old house they say, do it up it will be cheaper...  pah!  Never again  [big grin]

 

[demographic]

Good lord, if a wall is too weak to drill a hole into it with fear of damaging it,  then it should come out.

That^.

All the rest is like trying to work out how many angels can dance on the head of a pin.

 

[RuhiA]

Only in a public forum you can fit so many wrongs in one page...  [eek]

Drill it, if it breaks, fix it. You are welcome.