How to avoid breakout when rotary hammer drilling?

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I was drilling a weephole :'( in the garden wall using a borrowed SDS drill and suffered my first breakout. Research has yielded the term 'breakout' and that it can be avoided by drilling from both sides but drilling from both sides isn't really practical, in this case at least. Would it also have sufficed to switch off percussion as I neared the exit? Drilling without percussion is so very slow, though :/
 
Drill a pilot hole through from the most important side, then put the full size hole through from both sides.

Ahh, very clever. Would you use percussion for the pilot hole or not (maybe start with percussion and switch off in proximity to exit)?

The wall I was drilling through was 240 mm thick, but, since I was drilling at an angle, and because the drill couldn't approach the hole (it's body touched the ground about 10 cm from the hole), I used a 400/460mm drill bit (I don't know what the "twirly bit" (mum's words) is called - that's 400mm). But drill bits of that length don't seem to get much, if any, narrower than the 10mm hole which I drilled, so I don't know what I'd pilot with.

Am I right then, that your advice is more useful when drilling larger holes (whereupon you'd use such a drill bit as I used originally to make your pilot hole)?
 
Indeed, 8mm or 10mm would be the pilot hole for a 16mm or 20mm hole. You can try drilling without the hammer but it'll go really, really slowly, and you'll probably end up overheating the bit.

Next time try drilling more slowly, don't push the drill in, just hold it and let it work its way through. Less likely to break out that way.
 
I was drilling a weephole :'( in the garden wall using a borrowed SDS drill and suffered my first breakout. Research has yielded the term 'breakout' and that it can be avoided by drilling from both sides but drilling from both sides isn't really practical, in this case at least. Would it also have sufficed to switch off percussion as I neared the exit? Drilling without percussion is so very slow, though :/
My understanding of your question is you wish to avoid the large chunk that can pop off as the drill breaks through the otherside?
The pilot hole from both sides is good but very difficult to achieve correct lineup. Another good way to avoid the inevitable damage is to clamp a simillar material to your predicted exit hole and drill into that, don't get anyone to hold it in place, it won't work and is probably stupidly dangerous, it needs to be jacked on, wedged on, with something pretty substantial.
 
Sky fitters drill into the wall to fit the dish, but through the wall to feed the cable running from the dish into the property.
 
Sky fitters drill into the wall to fit the dish, but through the wall to feed the cable running from the dish into the property.

Ok, correction: How do they manage breakout with such a tiny pansy drill?
 
And they have to dress like Village People " construction Guy" :roll: I hate them more than Gas Fitters :evil:
 

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