54 minutes ago, Gus Potter said:

It's a thing you can recycle.. to light the fire with when the kindling has run out or the pages when there is no toilet roll.

 

Just kidding.

 

 

Just kindling?

We used stainless steel Rawl bolts with Larsen resin, worked a treat. The larsen comes in a standard silicone sized tube with a mixing nozzle. Dead easy. Couldn't get hilti locally but they more than did the job.

Edited September 10, 20215 yr by Conor

2 minutes ago, Conor said:

Just kindling?

Conor.

 

I'm left handed so went to check my spelling.. kindling.. these are the small sticks you use to light the stove say. Kidding is just friendly banter..

2 hours ago, saveasteading said:

Just remembered with a shiver...no it wasn't the worst.

 

The worst was when a truck hoist fell over (with 5 tonnes of truck) because a base anchor pulled out of a slab.

 

My slab but the client's hoist installer. They had only used 12dia expanding anchors 75mm deep into the floor slab. Should I think have been 16 dia, 200 deep.

By the time I got there the client had realised not to blame me.  I got the chance to see a genuine (not lab) failure, with the perfect cone shapes of concrete attached to the bolts that had pulled out.

A demonstration of how the depth makes a disproportionate benefit to the strength, as the surface area of the cone increases.

 

I didn't ask about the state of the truck in their time of stress, but nobody was hurt, very  luckily, as the mechanic had heard the creak and dived for cover.

 

Hoping not to dream of any other horrors.

We had an aerator in a sewerage plant work loose.

 

cause- the mechanical fitter didn’t blow the dust out properly and overtime it worked loose and vibrated itself to death- site closure, drive from middle England to Fife, Scotland for repair 

local crane hire on-site redrill and fix

3 days in total.

all at the contractors cost!

 

expensive repair cause the fitter  thought he knew what he was doing.

A proper Rawlplug puffer is far, far better than blowing out the holes with a compressor or using a vacuum.

 

https://www.screwfix.com/p/rawlplug-hole-cleaning-pump/6995F?

 

You can get a special brush too. 

I have used water from a hose to clean out holes for baseplates on a foundation.  It seemed to work well.

I have been subconsciously thinking about resin anchors.

3 more bits of advice, for big jobs really.

 

1. Do not use a diamond drill as they make a beautifully smooth surface. You need a rough face to the hole, as created by an impact bit.

2. If outdoors, fitting foundation bolts for example, then the holes may fill with water. That is when a stick and rag can work, when a puffer will not, but this is not mentioned by Hilti et al.

Check that a damp surface is ok for that resin.

3. The resin is very temperature sensitive. After mixing it can go hard in minutes in a hot summer's day. This can be very difficult to control as there are seconds to do the whole thing. Also you may end up using a nozzle for every bolt.

The reverse is that it may not be set next day in winter, and there are low temperatures when it should not be used at all.

The instructions are usually good on this, so do follow them.

 

I think that now makes 12 points of concern/control. That does not mean that I don't like resin anchors: I do, but instruction and supervision is important, as the consequences of any big anchors failing are worrying,

One other point is that I have seen it recommended that you wind the studs in anti-clockwise, which seemed a bit counter intuitive to me but I guess it is to prevent the resin being dragged up out of the hole.

Drill all the holes in one go!

 

Just read all of the feedback, thanks everyone. Hope this will be good for others who investigate resin anchors in future.

17 hours ago, Mr Punter said:

wind the studs in anti-clockwise

Hadn't heard of that one, so not adding it to my list...yet.

On the contrary, if winding very slowly clockwise, the thread gets well filled.

Perhaps it depends on the material and the amount of stuff between stud and concrete.

2 hours ago, saveasteading said:

Hadn't heard of that one, so not adding it to my list...yet.

On the contrary, if winding very slowly clockwise, the thread gets well filled.

Perhaps it depends on the material and the amount of stuff between stud and concrete.

 

The threaded stud is clean and has an excellent key and unlikely to fail due to lack of bond, so I think it may be to do with the resin bonding properly to the substrate, with the anti clockwise action forcing the resin against it rather than pulling it out.

On 11/09/2021 at 17:10, saveasteading said:

think that now makes 12 points of concern/control

Has anyone mentioned degreasing the studs/bolts?

 

If the resins is a polyurethane based one, moisture be of less of a concern.

Often with epoxy resins it is hard to get a new mix to adhere to a fully cured mix. 

Many a long night I have spent in a workshop waiting for epoxy to cure enough to apply a new substrate.