Hi Tony,
I had a play around with black coloured mortar a few days ago so I'll be to ready to finish off the paving when we have a stint of 'fine weather'. I made up a small batch suitable for normal use, and pointed a false joint between two bits of flag. It looked terrible, very black mortar and it stained the paving very easily. I'll have another go, and use less dye than recommended and see what that looks like, but the thought of buggering up the paving by trying to point with black mortar concerns me. Any suggestions/advice re. this would be great. I used Travis-Perkins black dye if that helps in any way.
cheers
Richard
Pointing flags with coloured Mortar
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84-1093879891
Hi Richard,
did you use silver sand for your black mortar? Using silver sand means that you need less of the messy dye to get a dark mortar than you would with a traditional red or yellowy building sand.
I'm afraid mortar work is, by nature, a messy job. Don't make your mix too wet; remember that many dyes incorporate a plasticiser, so you don't need much added water, and try working with two trowels - a larger brick trowel to hold the mortar and a smaller pointing trowel to feed it into the joints.
You might find it useful to 'mask' the edges of the flags as you work. You could use a bit of tin plate (a flattened baked bean tin, f'rinstance) or a piece of plywood, or even just a polythene bag (such as sand comes in) that you can move along as work progresses.
Although the mortar might stain at first, it soon weathers away to nothing. Don't expect to achieve a perfect, stain-free fionish - it's just not possible. However, keep the staining to a minimum, and, if you do get a bit messy, wipe off as much as you can as soon as you can, then rub over the stained area with dry sand and, if necessary, wipe down with a damp cloth.
And most importantly, take your time! :~)
did you use silver sand for your black mortar? Using silver sand means that you need less of the messy dye to get a dark mortar than you would with a traditional red or yellowy building sand.
I'm afraid mortar work is, by nature, a messy job. Don't make your mix too wet; remember that many dyes incorporate a plasticiser, so you don't need much added water, and try working with two trowels - a larger brick trowel to hold the mortar and a smaller pointing trowel to feed it into the joints.
You might find it useful to 'mask' the edges of the flags as you work. You could use a bit of tin plate (a flattened baked bean tin, f'rinstance) or a piece of plywood, or even just a polythene bag (such as sand comes in) that you can move along as work progresses.
Although the mortar might stain at first, it soon weathers away to nothing. Don't expect to achieve a perfect, stain-free fionish - it's just not possible. However, keep the staining to a minimum, and, if you do get a bit messy, wipe off as much as you can as soon as you can, then rub over the stained area with dry sand and, if necessary, wipe down with a damp cloth.
And most importantly, take your time! :~)
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richard
- Posts: 4
- Joined: Fri Feb 22, 2002 6:20 pm
- Location: Cambs-ish
Thanks for that Tony,
I used a red building sand. Will the intense black colour I saw on my practice run tone down at all, or does it stay "black"?
I'll may have another go with less dye and see how that looks, and will certainly try some of your masking tricks when I start the main job.
cheers
Richard
I used a red building sand. Will the intense black colour I saw on my practice run tone down at all, or does it stay "black"?
I'll may have another go with less dye and see how that looks, and will certainly try some of your masking tricks when I start the main job.
cheers
Richard
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84-1093879891
I find that if a red building sand is used, what starts out as a black mortar weathers to a dark brown in 12-24 months. Some red sands are so loaded with iron oxide (the technical name for rust, which is responsible for most of the reddy colouration in these sands, and, coincodentally, the base compound for most concrete/cement dyes) that they weather to a distinct reddy-brown in 12 months or so.
Just another reason to use a washed silver sand rather than the red building sand. :)
Just another reason to use a washed silver sand rather than the red building sand. :)