Which sand?

[Rtony]

Like a lot of people on here I've got loads of pointing to do. Can anyone advise me on which grade of sand to buy? I've bought a couple of cartridge guns which are a bigger version of a mastic gun.The cartridge is filled with mortar and squirted out between the stone with mortar. These require a very soft sand, any grit and they just compress it and nothing comes out the end. Also, a cream coloured mortar would be good (not the bags of ready mixed, too expensive).

Our house is near Fontenay le Comte, if anyone can recommend a place that supplies & delivers at a fair price I'd be grateful.

Thanks,

Tony

 

[Théière]

Your pointing guns won't work as you need a mix of course to fine sand, (0.4)

There are a couple of options that will work, The Pointmaster, now available at B&Q

Or the Pnu Point

The colour comes from the sand (try your pages jaune for sablier) and is lighter because of the chaux (from a brico shed) once dried.

Use no cement.

[Rtony]

I've used the guns in England, (they're called Durguns), with no problems. I've used a soft sand and lime.

Where's 'your pages'?

Thanks

 

[Théière]

Yes I have Durguns and I too use them in the UK but lime work requires a blend of course to fine sand and as you have stated they jam. By contrast the Pointmaster can handle course stuff, only occasionally jamming up.

You're pages jaune= yellow pages to look for your local sand pit that way your pointing should match in with the local area colour and sand pits are much cheaper than Brico's who buy form the same pit and sell it back to you at +50-100%

[halfblind]

I have done a lot of pointing over the years (pierre apparente) and using a chaux/sand mix of about 1:6 seems to work well. Never used any applicator, just some large rubber gloves from the Brico and hand pressed it in, then rub down with a scrubbing brush before it goes too hard. Sand from local quarry is preferable but you will have to buy about 8 tonne to make it worth their while. You can also get powder colourant from the Brico if you want to play with shades.

[BIG MAC]

What's the accepted wisdom re mixing using a cement mixer? I have shedloads to do and am thinking that if entire walls are raked out I could repoint larger areas ...Its a question of how much chaux to sand and will the mix go off too quickly?

[Théière]

I guess everyone has their own ideas but all the suppliers I know would use a ratio of 2.5-3:1 sand to chaux. If possible get a forced action mixer as these really do the job compared to a cement mixer.  Good thing with chaux is you can wet down unused mortar and liven it up again to re use so far less waste.

[Yonner]

I’m with Thiere on the gun thing. I’ve tried a couple bought

from the UK and used here, and they are more trouble than they are worth (

although the Pointmaster was the better of the two).  Firstly, the mix has to be perfectly fluid and

“grit free” to get a continuous flow out of them, and secondly unless the mix

bonds immediately on application to the wetted cavity, there’s regular drop out

– although you can re-liven

it as T says, it’s a pain. 

I used the” gloved technique” mentioned by halfblind in the

end, in all but the deepest cavities  -

where I used the pointmaster or trowel and finished with a glove – it’s

effective, with least drop out and certainly quickest.

Mix-wise, I went with the instructions on the Chaux bag –

about 5-1 I think for joints. 

And at risk of stating the Bl***ing obvious, once you pick a

sand supply and mix ratio stick with it religiously or you’ll get a patchwork.

[Rtony]

Just returned from France.

I bought a Pointmaster and took my Durgun too.

Using 0/2 jaune sand and lime the Pointmaster was absolutely useless, even with plasticiser. The Durgun was good for half a tube.

With deep areas to fill, these would have been very useful. Had to resort to a trowel and a stick (and raw finger tips). 

Not to worry, there's only another 18 walls to go (inside).

Very disap'point'ing.

Tony

 

[Théière]

Sadly and there is no easy way to say this, it was your mix that was wrong. I have used and still do use the pointmaster for pointing with chaux and I use 0.4 sand (course stuff). proprietary plasticiser will not improve the mix (it's meant for cement not chaux)  getting the mix right is critical and adding some shredded soap or calcium stearate will help but you have to let things sit for a while and soak. You don't mix it as you do cement mortar (adding the dry ingredients first) you mix the water and soap flakes and then add the rest and let it sit for a while, mix and let it sit some more before using. 

[Rtony]

Thanks for the reply Théière.

I did buy a 40kg bag of coarse mortar sand, mixed that with lime & that didn't work either.

I have in the past used 16 sand 5 lime & 1 cement in the Durgun with varying degrees of success.

0/2 was the sand recommended by Point P (couldn't remember yours). If you're right about needing 0/4, and I'm sure you are, then I've got a problem, I've bought a tonne of the 0/2 (so I'll have to use it).

I have generally mixed 2/3 of a 10 litre bucket at a time and used c2.5 sand to 1 lime and added I think about 1 litre of water.

Where do you think is the best place to get the calcium stearite/shredded soap and how much would need to be added?

Tony