Remove wooden fence post 'stub'.

That will take out the concrete too, if you use enough.

I was going to suggest bashing a Metpost spike into the remains of the wood. Post shoe is probably a better idea. But, I wouldn't do rawlbolts (the concrete block probably doesn't have a nice flat square top). I'd drill four holes as deep as possible, 12 or 15 mm diameter with pitch to suit the shoe, then inject polyester resin and set lengths of 10 or 12 mm zinc plated studding into them, ensuring that they are all more or less vertical and that the post shoe still fits over them. Or stainless, if you want to be posh. When it has all set, you can make a level "platform" for the bottom of the post shoe with four nuts and large washers, add a bit more concrete up to the platform level and, while it is still wet, bolt the post shoe down into place.

That's what I did (and have another to do).

I fitted a 20mm Forstner bit to a long extension (or two) and then chain drilled a row of holes across the middle of the stub.

Then I did the same across the stub to form a cross.

Then I drilled diagonally though each hole to break each hole into the next (the Forstner bit seemed less keen to bind than most and could be 'steered' easier, even when fairly deep in a hole and were quite strong in general), and the Henry used to keep the wood chips out so you could see what you were doing.

I think I finished the breaking though off with a long Saber then panel saw and was then was able to compress the sides in and pull the stub out (a screw eye, rope and a long lever over the old post top laid over the hole).

That's probably how I'm going to do the remaining one (to be replaced by steel posts in the same holes).

Cheers, T i m

You can buy a short "repair" spike for this very purpose intended to be hammered into the wooden remanants.

My 2p's worth of advice would be to drill into the wooden stub and screw in the largest eye bolt you can find (something like a shield anchor perhaps which will expand). Then after loosening the soil around the concrete as be st you can use the broken post with a hole at one end with a rope through t he hole/eye bolt to act as a lever to pull out the concrete stub. Might nee d some jigging but this worked for me (I did have a few inches of broken po st above the concrete so I was able to drill a hole to thread the rope). Ot her advantage is that your hole isn't much bigger than the original as you' ve not had to dig out the concrete.

I haven't looked all that recently but it is usually next to ammonium, ferrous and magnesium sulphate. Along with other specialist feeds.

You have to grind it (and all the other components) very fine to make gunpowder. By comparison sodium chlorate was trivial to make a bang.

Pyrotechnics are very unforgiving - as one expert once told me "all the best fireworks makers in the world are missing precisely one finger".

I think you are thinking of ammonium nitrate. That is a bit harder to get for home users but there are big sacks of it sat around on farms. One of the big brands is my name backwards Nitram.

It's usually in the form of pellets (called "prills") and unsuitable for making ANFO.

Also, you need a high explosive to initiate ANFO - it isn't just a case of light blue touch paper and run like f*ck.

Why not I have always found them to be stronger than the wooden post.

I have often broken the concrete with an sds and then levered it out but if the concrete is as good as you say why not use the metpost with a square base and resin bond the fixings to the existing concrete.

I have also removed the wood and hammered a modified met post into the socket. I have not been successful burning the wood out but it may be possible with a cheap hot air gun like the Einhell I light my fire with.

Personally I would never concrete or postfix a wooden post in, they seem to rot faster.

AJH

My thoughts too but wonder if the concrete would stand the rawlbolt compared with a resin fixing.

I didn't know they were called shoes

AJH

On Tue, 27 Feb 2018 09:05:55 +0000, Martin Brown wrote: .

Ah yes, you're right. Thanks for the correction.

FWIIW my idea would be to drill a large diameter hole in the centre of the post say a 1" auger or the like and use a coarse threaded rod which cuts only into the sides of the timber because the shaft of the threaded rod is loose within the hole. Put a couple of nuts on the rod for grip and pull i t out with a jack or the like. Wait till a dry day and put in a hair drier for a few hours first to get the MC down as much as possible . Alternatively, if time is not of essence, drill lots of holes and introduc e a bit of dry or wet rot on a bed of malt agar. It will only take a year o r so! If time is of essence the idea of burning out with an oxidising agent is pe rfect. When putting back the timber replacement soak the pointed end grain to go i n the hole in an organic solvent borne fungicide for a day two, let it dry, sleeve it with plastic and then drypack with 1:1 fine sharp sand and cemen t around the perimeter of the new wood which should be slightly smaller in diameter to allow for this. Alternatively, use the same size, coat it in a n epoxy resin and ram it home !

Bite the bullet, dig it out from one side and break it up. When you replace it use heavy gauge steel box section with a rain cap. If that gets damaged it can be straightened/repaired or cut off and a new piece welded on.