What Tape To Use With Ashlar Pointing

[chuckalicious]

I am about to repoint the fine joints in my architrave (non-red sandstone) using ashlar mix. I know I should put tape on either side of the joint in order to keep it nice and neat, but can anyone tell me what tape I should use?

I stupidly forgot to get some from the masons and it's flippin miles away, so thought I might be able to get the tape closer if I know what to get

Thanks

 

[stuart45]

Use a good quality wide masking or carpet tape.

 

[chuckalicious]

Cool, so in other words, just anything that will stick to the stone?

Oh, lastly, how long a dry spell does ashlar mix need after application before it can be rained on?

Thanks

 

[stuart45]

It depends on what type of lime used.

 

[chuckalicious]

It's the stuff at the bottom of this page, MM120

http://www.masonsmortar.co.uk/site/natural-coloured-ready-mixed-mortar.htm

 

[stuart45]

That one is the weakest hydraulic lime, so it needs to be protected against the sun and wind to prevent it drying out too quickly, as well as the rain. Keep the sheets back 4 inches to prevent staining. Have a look at how its doing after a week, but it will probably still be quite soft.

 

[chuckalicious]

Sorry to sound stupid, but what do you mean by "keep the sheets back 4 inches"? What sheets?

I was advised by the Scottish Lime Centre that this is the mix I should use as it's for the fine 3-5mm joints around my sandstone architrave. I hope they are right!

 

[stuart45]

If you use hessian sheets to cover the new pointing keep it back because heavy rain may cause some staining.

 

[chuckalicious]

Ok, tried my first bit of this today, using Duck tape, which I thought would be strong enough to put either side of the joint allowing me to point without getting it on the stonework, however, the tape isn't quite strong enough and so I made a wee bit of a mess Problem was that the very edges of the tape didn't stick well enough and the mortar got down the sides.

Can anyone suggest a stronger tape I could use to stick to sandstone? Doesn't need to be on long, just long enough for me to point.