Fixing bolt to wall

[DiyNutJob]

I could sit down and use basic trigonometry to calculate the lowest rung that could be used, but I really don't see the point.

I couldn't. I relied on gut when I lowered the stand off. The gut then said too high, too low etc. I think the center of gravity is usually around the gut level - a muscle guy builder would be higher; a flabby DIYer would be lower.

 

[noseall]

clearly didn't understand your point (hence his comment about seesaws).

I could sit down and use basic trigonometry to calculate the lowest rung that could be used, but I really don't see the point.

Precisely. It's ok securing a ladder at the top AFTER one has secured it at the bottom. To do what that clown is saying just above the centre of gravity is downright dangerous.

 

[opps]

No more talk of sds. I have just committed to these for under £5. Although the tips look blunt as bricks! I already have some of the other sizes between these two.

View attachment 271836

I can't see how blunt they are but Heller make very good drill bits.

 

[DiyNutJob]

I can't see how blunt they are but Heller make very good drill bits.

Blunt enough to be useless without hammer action. Even adding water won't do a thing. The multi-purpose bosch blue painted flutes are better. Those are sharp enough to drill metal - meaning drilling without hammer action is possible even if not perfectly effective. Those are beyond my price range.

 

[DiyNutJob]

Hole done. It was drilled from 4mm up to 10mm in 2mm increments, then a big jump to 16mm. The jump was a lot more challenging, the rest was easily piecely. The brick was ground into a very fine powder. It would have been a lot easier if I was able to extract the powder. In my impatience, I didn't bring any water, nor did I switch off the hammer action. I did ease off hand pressure as I approached the punch through. Using a proprietary blowout gauge, I estimate the blowout to be 5mm deep. I could probably do better if I used water and had 12mm and 14mm drill bits.

I drilled into the brick's center cavity that was filled with mortar. Behind the brick was rock wool insulation. The wool kept the blowout pieces nearby and I was able to vacuum them out. The wool will likely help me keep the resin nearby when I come to fill the hole.

 

[DiyNutJob]

Anchor completed with vinylester resin. The resin had crazy short working time. Even keeping it in the fridge overnight didn't extend the time by much. The wire looking thing is just a proprietary stick-out gauge to help setting the correct depth for the bolt.

 

[opps]

Blunt enough to be useless without hammer action. Even adding water won't do a thing. The multi-purpose bosch blue painted flutes are better. Those are sharp enough to drill metal - meaning drilling without hammer action is possible even if not perfectly effective. Those are beyond my price range.

I was in the pub the other day and some guy came along to remove the old condom machine so that the could fit a new one. He just drilled through the lock mechanism using a SDS drill bit.

I would never have thought of doing that. I have carbide tip metal drill bits which I use for drilling through (hardened) screwheads. His option was noisy, but probably faster and cheaper.

I do carry a set of the blue bosch drills in my bag but I find them so slow that I also have a set of Heller cobolt drills for dealing with wood and metal.

Anywho, well done for drilling your holes.

 

[DiyNutJob]

The heller I have didn't drill but ground the brick to powder. The tip edge was so unsharp, it was round. But, I don't care, as long as it works and cheap.

 

[noseall]

We'd have moved onto the third job by now. Don't ever attempt building work for a living.

 

[Deleted member 174758]

The heller I have didn't drill but ground the brick to powder. The tip edge was so unsharp, it was round. But, I don't care, as long as it works and cheap.

True masonry drills aren't designed to cut in the same way that twist drills are - in fact they don't drill at all, they are specifically designed to be hammered against the masonry, creating chips or dust which is then removed by a combination of the rotary action of the drill and the spiral flutes of the drill bit body. That's why the carbide tips aren't sharp, and never will be. Using a masonry drill without hammer action means that you are converting it, in effect, into a scraper - and it will get very hot. Throwing water onto a hot brazed carbide tip can cause the brazing which holds the tip in place to fail, and the tip will simply fall out, so it isn't conducive to long drill bit life.

The blue Bosch Construct drill bits are a composite design which are designed to work passably well in a wide range of materials, but the hole quality with them in metal and wood is only just acceptable for many purposes (put it this way, you wouldn't try to drill engineering grade holes in steel with them) and they drill fairly slowly in compoarison to mor specialised drill bits

The resin had crazy short working time. Even keeping it in the fridge overnight didn't extend the time by much. The wire looking thing is just a proprietary stick-out gauge to help setting the correct depth for the bolt.

Most resins used these days are 2-component types which are mixed in a spiral nozzle. With those you don't need to chill anything because it makes no difference. The resin only starts to go off after you've mixed the two compounds in the nozzle, but at the end of each session you do need remove the mixing nozzle sharpish and cap off the resin tube. These nozzles are 50 to 70p a pop and each time you do a job they are obviously toast, so you try to do as many anchors as you can in one session. I haven't seen the old glass vial type anchors for years.

The points made earlier about blow-outs at the back of brick is very valid - the one thing you don't want with resin anchors is to drill straight through a brick or masonry so that there is a void at the back. Do that and with gun resins and you'll just end-up pouring expensive resin into the void - so you should always stop short of drilling through. If your rod sticks out too much at the front once the resin has set you thread a nut onto it, cut the rod short with a grinder or hacksaw, file a chamfer on the edges of the cut then wind the nut off (to reform the thread).

And a minor point to make about resin anchors - whilst they can be used with threaded bar, the thread ideally needs to be a course pitch. The hole in the masonry should also be 2mm larger than the thread - so for an M12 thread you drill a 14mm hole. Bigger than than and you just waste resin, smaller than that and you run the risk of a "dry hole", where there is insufficient resin to bond the bar in place adequately. Lastly, resin anchors don't always "take", so once they have set fully (24 hours) it's always a good idea to test them before you depend on them

Posted as additional information and as there are a few points in the thread above which I feel are not informative

 

[RandomGrinch]

In addition to the very comprehensive information above, when you mention:

An anchor fixed to a full brick is 4x more safe than fixed to half a brick. Not everything in life is about looks.

Do you have a source for the '4x more safe'?

I've found chemical fixing manufacturers are reticent to give pull out forces for masonry walls; given the unknown quality of construction - the chemical anchor may not budge an inch, but it doesn't mean that the brick won't be pulled straight out of the wall!

Example from Hilti:

 

[DiyNutJob]

Do you have a source for the '4x more safe'?

No, I made it up. But, my antagonist is no wiser. A half blown out brick will certainly pullout a lot easier than a full brick. This is something the quick job cowboys don't understand.

My proprietary gut gauge says the anchor is adequately installed. No doubt someone will ask me if I could withstand a nitpick session in a court of law after I have fallen off the scaffold from the failed anchor.

Most resins used these days are 2-component types which are mixed in a spiral nozzle. With those you don't need to chill anything because it makes no difference.

That's not correct. The Rawlplug hybrid resin I used was temperature dependent. At 15C ambient, the working time was 5m, at 25C was 2m. The temperature at the moment of application was around 17C. Miraculously, the pre-cooled resin probably gave me 5m. I had not a second to spare when I was surprised it had gone off. But fortune favoured me because I had completed what I needed just in time for the surprise.

 

[Deleted member 174758]

A half blown out brick will certainly pullout a lot easier than a full brick. This is something the quick job cowboys don't understand.

What a professional installer understands is that for resin installation you try to avoid drilling through the back of the brick, unless you are aiming to inject resin into the skin behind that - a rare occurrence. You invariably try to avoid having a void at the end of the hole, because you can end up pumping a lot of resin down that hole and still not getting a reliable fixing. So there should be no blow-out, because if you are doing the job properly you wouldn't drill through the back of first skin in the first place

My proprietary gut gauge says the anchor is adequately installed. No doubt someone will ask me if I could withstand a nitpick session in a court of law after I have fallen off the scaffold from the failed anchor.

For your information scaffolders actually use a special calibrated pull-out gauge to test each and every eye bolt and anchor they install. It happens to be a legal requirement for them to do so The problem with the way you have approached this is that you potentially weakened the resin bond by drilling through the back of the front skin because you didn't understand how resin anchors are normally installed

Most resins used these days are 2-component types which are mixed in a spiral nozzle. With those you don't need to chill anything because it makes no difference.

That's not correct. The Rawlplug hybrid resin I used was temperature dependent. At 15C ambient, the working time was 5m, at 25C was 2m. The temperature at the moment of application was around 17C. Miraculously, the pre-cooled resin probably gave me 5m. I had not a second to spare when I was surprised it had gone off. But fortune favoured me because I had completed what I needed just in time for the surprise.

As I stated it, with reference to 2-part resin anchors, the most commonly used in general construction, what I stated is correct. You install one resin anchor, seemingly badly, and that makes you the world expert?

To my mind selecting a resin which goes off so rapidly, when you have never installed a resin anchor before, then having to ****** it by fridging the product, smacks of you having not got hold of the product sheets and read them before commencing the job. Because if you had maybe you'd have chosen a different product. But then you drilled through the back of the brick and argued with an(other) experienced builder that he didn't know what he was talking about when he told you that was wrong.

 

[Harry Bloomfield]

True masonry drills aren't designed to cut in the same way that twist drills are - in fact they don't drill at all, they are specifically designed to be hammered against the masonry, creating chips or dust which is then removed by a combination of the rotary action of the drill and the spiral flutes of the drill bit body. That's why the carbide tips aren't sharp, and never will be. Using a masonry drill without hammer action means that you are converting it, in effect, into a scraper - and it will get very hot. Throwing water onto a hot brazed carbide tip can cause the brazing which holds the tip in place to fail, and the tip will simply fall out, so it isn't conducive to long drill bit life.

The very first masonry drills, did actually need to be sharp, because the drill action was mostly like a conventional steel or wood bit, but they were very slow to make holes, mostly suited to softer masonry and hardly faster than an entirely manual Rawdrill and hammer, except they produced a cleaner hole. Then along came drills with hammer action, where the drill bit was a compromise between a drilling action and a hammer / powder the masonry to dust action and much faster, until they came up against hard concrete, or a tough pebble in the concrete - then what was needed was a decent hammer action - often it was quicker to resort to the manual Rawdrill and hammer, to get through the tough bits. These drill bits did all need to have an edge, but a flat faced edge, so the suppliers would sometimes offer a 'return for sharpening' service for them, as the bits were quite expensive - at least until green grit grinding wheels became more common.

Finally, along came the very much faster SDS, which relies almost entirely on a good hammer action, with just enough rotation to clear the debris out of the hole.

I agree, you should never use water on the tips.

 

[noseall]

No, I made it up. But, my antagonist is no wiser. A half blown out brick will certainly pullout a lot easier than a full brick. This is something the quick job cowboys don't understand.

My proprietary gut gauge says the anchor is adequately installed. No doubt someone will ask me if I could withstand a nitpick session in a court of law after I have fallen off the scaffold from the failed anchor.



That's not correct. The Rawlplug hybrid resin I used was temperature dependent. At 15C ambient, the working time was 5m, at 25C was 2m. The temperature at the moment of application was around 17C. Miraculously, the pre-cooled resin probably gave me 5m. I had not a second to spare when I was surprised it had gone off. But fortune favoured me because I had completed what I needed just in time for the surprise.

Says mr slow and safe, whilst promoting putting a dangerous pivot (ladder stand-off) just above a ladders centre of gravity. Downright dangerous.

There's nothing to not understand. So long as the stand off is not below your center of gravity, it's fine. This then allows the ladder to be closer to the wall. This kind of thing is either obvious or it isn't. Another option is to mod the stand off by cutting it shorter. If it needs to be very short, then it's no worst off just to use your own beam of some kind. With that, you have got to have a feel for what size beam is needed.

FFS.