Feltwell
Member
- Messages
- 6,377
- Location
- Shropshire, England
The mammoth task of repointing Feltwell Towers, with accompanying brick repairs, is well underway - chimneys and rear of house done, the front & side is work in progress.
One of the points that's been discussed here before is how to rake out old pointing. An angle grinder is very effective with a diamond disc but is very, very easy to inflict damage with. Used carefully & with skill and it can be very effective though leaving no damage. It is a filthy job, the clouds of dust generated are unbelievable. I've seen horrendous examples of irreparable damage done with grinders though.
I've heard folks talk about using hand tools only, taking it all out with a plugging chisel, to avoid damage. That's all very well in theory but in practice with cement repointing to remove especially it's very easy to do damage - blows with a plugging chisel can take both the pointing & the edge of the brick to which it is adhered off, a grinder used carefully will leave the brick alone. It's *very* hard work doing extensive pointing removal with hand tools, very easy to get repetitive-strain type injuries.
There are other powered mortar removal tools out there, I've not come across any so far that are anything less than hopeless. But, I have discovered something myself that is working rather well for us here that I thought I'd share. The problem came when getting to the front elevation of the house - close jointed brickwork, no way to use a grinder without causing damage, so the grinder was banned!
An air hammer is more commonly used for car body repairs, I've got one with a needle scabbler attachment as it's great for rust removal on cast iron rainwater goods. Anyway, I thought I'd try it on pointing - so I modified one of the chisels to be like a plugging chisel, and gave it a go. It works a treat - the air hammer delivers hundreds of tiny blows, as opposed to a lump hammer & hand plugging chisel delivering much fewer, much larger blows. Those tiny blows seem to be better at loosening the pointing but leaving the brick well alone.
Now there are drawbacks - it's noisy, and I'm using two compressors linked together, as it's an air hungry tool. The chisel rotates in the tool which isn't ideal, holding it with a gloved hand to stop rotation is possible though. Use it for too long and the vibration will get to your hands. But, it is doing a very good and fairly rapid job of removing the old mortar. I'm slightly surprised there seems to be no one producing chisels to do this, bar one Canadian firm, who are very much aiming at the professional stonemason market with a dedicated tool. Similar chisels are available for use in SDS drills with roto-stop but there is no way I'd want to use one, the blows would be far too heavy and I'm certain would inflict damage.
One bonus is if you have or can borrow a compressor then an air hammer is cheap - mine was £20. I modified a chisel using a bench grinder.
One of the points that's been discussed here before is how to rake out old pointing. An angle grinder is very effective with a diamond disc but is very, very easy to inflict damage with. Used carefully & with skill and it can be very effective though leaving no damage. It is a filthy job, the clouds of dust generated are unbelievable. I've seen horrendous examples of irreparable damage done with grinders though.
I've heard folks talk about using hand tools only, taking it all out with a plugging chisel, to avoid damage. That's all very well in theory but in practice with cement repointing to remove especially it's very easy to do damage - blows with a plugging chisel can take both the pointing & the edge of the brick to which it is adhered off, a grinder used carefully will leave the brick alone. It's *very* hard work doing extensive pointing removal with hand tools, very easy to get repetitive-strain type injuries.
There are other powered mortar removal tools out there, I've not come across any so far that are anything less than hopeless. But, I have discovered something myself that is working rather well for us here that I thought I'd share. The problem came when getting to the front elevation of the house - close jointed brickwork, no way to use a grinder without causing damage, so the grinder was banned!
An air hammer is more commonly used for car body repairs, I've got one with a needle scabbler attachment as it's great for rust removal on cast iron rainwater goods. Anyway, I thought I'd try it on pointing - so I modified one of the chisels to be like a plugging chisel, and gave it a go. It works a treat - the air hammer delivers hundreds of tiny blows, as opposed to a lump hammer & hand plugging chisel delivering much fewer, much larger blows. Those tiny blows seem to be better at loosening the pointing but leaving the brick well alone.
Now there are drawbacks - it's noisy, and I'm using two compressors linked together, as it's an air hungry tool. The chisel rotates in the tool which isn't ideal, holding it with a gloved hand to stop rotation is possible though. Use it for too long and the vibration will get to your hands. But, it is doing a very good and fairly rapid job of removing the old mortar. I'm slightly surprised there seems to be no one producing chisels to do this, bar one Canadian firm, who are very much aiming at the professional stonemason market with a dedicated tool. Similar chisels are available for use in SDS drills with roto-stop but there is no way I'd want to use one, the blows would be far too heavy and I'm certain would inflict damage.
One bonus is if you have or can borrow a compressor then an air hammer is cheap - mine was £20. I modified a chisel using a bench grinder.
My technique was to use a thin diamond disc in an angle grinder to cut through the cement, then to chip the cement off the bricks into the gap the disc had created. Trying to get underneath the cement and push it outwards tended to damage the faces of the bricks. 