Anyone used a "mortar raker"?

[Eric The Viking]

I've got an urgent problem: I need to rake out deeply and crack-stitch, then re-point some brickwork. It's old "black mortar" high cinder content, etc. so it will come out fairly easily, but using a grinder (a) isn't deep enough and (b) is way too messy (it's indoors and there is a limit to what a female human can stand, so she says).

I desperately need to know if these mortar raking things work, and if anyone knows if 14mm is the standard thread on a 110mm (small / 4") grinder (and if that's how you're supposed to use them. Any/all thoughts appreciated!

Many thanks to anyone who can advise with experience

E.

PS: I mean this sort of thing:

 

[marcros]

My 5" metabo grinder has an m14 thread on it. Not sure it is much help but it will also take the smaller disks so I assume it is pretty standard.

 

[kostello]

Never used one but I think you would have more luck drilling it out and then using a chisel in an SDS drill.

http://www.screwfix.com/p/armeg-sds-plu ... isel/18218

M14 is the thread on a 115 mm grinder....I've never used a mortar rake like you show but reckon that it would be messy inside.
Mortar dust clogs VAC filters very fast so you would need a drop box or cyclone....


Depends on how much you have to do.

 

[dc_ni]

https://www.youtube.com/watch?v=PQZLI9Oqirs

 

[Peter Sefton]

I have used one of the cutters some years ago, I didn't find it particularly good or quick to use. From memory its difficult to see whether you are cutting mortar or brick, I think a bought a few and wore them out before reverting to the dusty job of a a angle grinder. Another option to keep the dust down and the traditional way is either using a plugging chisel or a cut nail in a block of wood a bit like a scratch stock.
I believe commercially they use a small hand held Kango, I remember renovating my first house with my grandfathers help and how he told me the enjoy the process as every brick is an individual!
Best of luck Peter

 

[MARK.B.]

Only problem with using a hammer/ chisel or sds drill is that the constant knocking can cause more harm especially in a older property where the structure may be fatigued (knackered) by age. I used a diamond cutting disc and cut a slice each side of each joint and snap out the remainder its reasonably fast and does create a fair bit of dust but nowhere near as much as a mortar rake. I found that each blade would cut around 1 square metre before it needed changing,and it takes a bit of getting used to and can run away if you let it.It worked well for me and i had almost 70 square to do.Not a professional so be it at your own risk.
Usual mask n goggles and dont forget a decent pair of gloves.

Disclaimer from Bob Hoskins - On your ead be it then son :twisted:

 

[Eric The Viking]

One of the reasons I thought this was worth a try is that it is soft mortar - at least it's old black mortar (cinders mixed in, etc.). I also have to go quite deep. Otherwise I'm going to have to splash out on a 9" grider and make a horrid mess.

Opinion seems sharply divided in that video, though. Given the problem (the plasterer was all lined-up to start tomorrow - until I discovered how bad the cracking was), I'll get one tomorrow and try it.

I do have a good, if a bit elderly now, SDS (Makita 2400). I've been using it with a wide, cranked chisel to hack away at the dreadful re-rendering job that's in the way of getting at the core of the problem.

I think the thin chisel would be fine for just repointing, but it won't go deep enough for stitching - I need about 2 1/2 - 3" in order for the stitch to be strong enough.

It's Edwardian jerry-building - the opening below should have had a shallow arch in the brickwork - but they were in a rush or saving money, and because it doesn't...

Thanks all,

E.

 

[Kieran62]

Morning Eric,
Go to your local hire shop and ask for "ARBORTECH AS170 ALLSAW BRICK & MORTAR SAW"
It uses two reciprocating blades to cut out the brick joints, and because the blades are slow moving they don't produce the plumes of dust that grinders do.
Used one last week to cut through an internal thermolite wall and the dust was in a heap uder were I'd used the saw, I paid £35 for the days hire.
HTH
Kieran

 

[Eric The Viking]

Thanks Kieran - they look amazing.

Sadly, hire rates here are twice what you paid (cheapest I can find is 50 plus consumables, etc.). Have got a rotary raker - worth a try to start with but will go the Arbotrech route if I can't get it to work.

Really appreciate all the advice,

E.

 

[RogerS]

IMO the Arbortech is the ONLY way to go especially when you factor in the minimisation of dust. An angle grinder creates a huge huge huge amount of dust - not helped by air disturbance caused by the rotating blade.

No consumables to consider if the mortar is as soft as you say. For £50 it is a no-brainer.

 

[flying haggis]

HSS do the arbortech for £120 a week! + vat

 

[Kieran62]

Eric, do you not know anyone in the building trade?
With a TP trade card, I got the Arbortech for the day for £35 including the dreaded.
There should be two sets of blades in the bag, one for mortar and one for cutting brick and block.
I repointed a listed town house which was 9 metres wide by 6 metres high, took three days and there was no wear on the blades.

Kieran

 

[Wuffles]

Another "Go for the Arbortech" here.

Unless your angle grinder has a variable speed, you'll be lucky to come out of the house alive let alone in one piece if your Wife is anything like mine.

The dust will limit you being able to see any kind of mortar line so it'll be inaccurate and my cyclone performed less than well on a similar task so you'll clog your vac's filter very quickly indeed.

I could make a few calls and see what price I can get you the hire for if you like (I'm in the building trade), and you're just up the road so PM if I can help at all.

 

[Eric The Viking]

Sorry for the delay getting back to everyone.

Thanks for all the kind offers. I had to make a few sub-optimal choices yesterday, limited in part by not having my own transport at the moment. I get to use the family car before 0745, which allows a trip to Toolstation, but not much else (except at week-ends, and this wasn't one).

So I got a couple of mortar rakers (one long, one short) and they did the job, although they were a lot slower than I hoped. I got the worst of the two cracks properly stitched, but then ran out of polyester resin!

Plasterer came today and did an excellent job. The skirtings are tall, so I can still cut in down low, out of sight, and do the second crack if it's necessary.

On the mortar rakers, I'm not sure how long they would last. The two I have seem to have worn down a lot faster than I'd expect.

Next time: very probably an Arbortech!

Thanks everyone.

E.

 

[Peter Sefton]

Good to hear it all worked out Eric

 

[Waka]

Just to add my experience on mortar raking. I did the weather sides of my house this year, quite a big job and searched around for tools to make the job easier, it that's possible.
I did try some of the spindle rakes, but really found them inadequate for the task. A long search on the net and I found that De-Walt do a specific motor raking machine with dust extraction, a bit expensive I thought coming in at £200, but anything for a easy life.
So took the plunge and bought the thing, also got some 6 mm raking discs from tool station.
I fixed and old vac up to the dust extraction port and away we went. I have to say I was very impressed with the machine and the dust extraction, it collected about 80% of the mortar dust and that's with cutting a depth of 1 inch.
Yes I know it was a big outlay for a machine that I'll only need to use once, but it will go on the Bay, so I should get some money back on it.

 

[Peter Sefton]

Waka it sounds like a good bit of kit that probably saved you days of laborious work.