Expanding bolts into concrete...

[Adrian]

This type...

I've been whaling away on the pin, and it's just not going fully in. They're big buggers - the hole is 19mm - and, yes, it's the right size drill bit for the fasteners, which came with a (new) two-post hydraulic lift that I'm installing into the new garage.

I'd say they're probably 50% of the distance between gently resting in the bolt, and fully home. They feel solid - I don't think there's any way I can get 'em out again to run the drill down again. They all just dropped straight home, no resistance. I'm using a decent size lump hammer, nothing massively heavy, but the biggest I've got.

Are they OK like that, so long as they are PROPERLY belted?

Do I need to just man up a bit, and make sure I get 'em fully home and expanded, come what may, no matter what size hammer it takes...?

[Andy Burns]

Their installation video shows they should be hammered flush, doesn't seem to take excessive force, did you clean the dust out of the hole fully?

[Adrian]

Yeh, and in the immortal words of Haynes... "Reassembly is the reverse of the removal procedure"...

As fully as I could. Running the drill up and down a few times, still running, cleared a lot of dust out until no more came. But I'll admit I didn't get the vac on it...

[Tim Lamb]

Not used those but surely you need to get them fully inserted before whacking the expansion pin?

Short length of suitable tube?

[Adrian]

Indeed.

I put the plain washer/spring washer/nut onto the top of the thread, then dropped it all down into the hole (a few times, because I needed to get the position of the pillars and the cross-piece containing the hydraulic pipe and steel wires right)

Then I reached for the FBH...

[F Murtz]

Blow it out with a straw.

[Adrian]

Bit tricky now the bolts are partially expanded.

[Peter Parry]

They seem to rely entirely upon the pin expanding the fitting along its whole inserted length. Pin not fully in = fitting not fully secure. With the use a vehicle lift gets and the sideways forces you can expect with some work I'd be very unhappy about working under one supported by some half fixed bolts.

I doubt if a bigger 'ammer is going to work, the risk is you snap the hardened pin and if that happens you really are in trouble.

[Adrian]

That's about what I feared...

Any thoughts on the best way for'ard?

[RobertL]

I would think that is the problem. Look at the flutes in the drill bit - w hat proportion of the cross sectional area do they occupy? 20% perhaps? That means up to 20% of the depth of the hole will be filled with unlifted dust that was stuck in the flutes.

[RobertL]

what proportion of the cross sectional area do they occupy? 20% perhaps? That means up to 20% of the depth of the hole will be filled with unlifte d dust that was stuck in the flutes.

Sorry, I was assuming the holes were vertical. perhaps they weren't.

R

[Adrian]

But surely the bolts wouldn't have dropped in their full depth?

[Adrian]

A VERY big pile of dust came out of each one.

[JimK]

/That's about what I feared...

Any thoughts on the best way for'ard? /q

If the bolts are on the ends if the threads as you said, what happens if you tighten them? Might this lift the partly expanded section up in the holes, possibly clearing any remaining dust and allowing you to hammer the pins in ?

Jim K

[Andy Burns]

New set of holes 6" away from current ones?

[Peter Parry]

Well, angle grinder obviously. Use it to cut the pin off and smooth the top flush with the floor.

Before doing this -

If you can move the verticals 200mm I'd make new holes and put some very large rawlbolts in there. (Confast recommend putting other fixings at least 10 diameters away from existing ones).

If you can't alter the position you could try pulling the fixings out (if you can extract the pin) by drilling a thick steel plate to the bolt size and then putting packing pieces either side of it and seeing if it will pull itself out vertically.

[Adrian]

Trouble is, it wouldn't just be 200mm, it'd be 200mm from the furthest right holes to the new position for the furthest left holes. Since the holes are spread over 300mm of base plate (2 at front, 3 at rear), we're looking at 500mm movement. And that would be Much Less Than Ideal.

I've had a measure up.

Three pins have withdrawn with little effort, and the bolts have pulled out. All these are on one column. The pins are 8mm diameter, with an 8mm long taper on the end. The gaps in the cross at the end are 2mm. The hole size required is 19mm, the bolt is 18mm diameter...

Of the 7 pins that are still in place, two have gone in 12mm, two 14mm, one 14.5 and two 18mm. They need to go in 29mm, which will leave 10mm out of the end of the bolt...

So - two are _VERY_ near to going through the base of the bolt. They're both on the column that the other three have come out of...

The head of the pin isn't huge - there's not a lot to grasp with a slide hammer or similar, and my crowbar won't fit the root diameter.

[JimK]

/The head of the pin isn't huge - there's not a lot to grasp with a slide hammer or similar, /q

Weld something on to pull on?

Jim K

[Muddymike]

/The head of the pin isn't huge - there's not a lot to grasp with a slide

Just what I was about to suggest.

Mike

[Adrian]

fx:

Hmm. I wonder.

THEY ARE ALL OUT!

Thanks, all, for the suggestions.

Just spoken to the suppliers of these, and they reckon they're just fine for the job.