Renew mortar between the bricks of the basement ceiling

Hello,

I need to renew the mortar between the bricks of the basement ceiling and between the sandstone blocks of the foundation (inside and outside) because the old mortar is already very washed out and crumbled (house built in 1821).

An experienced mason probably has the right swing and the appropriate technique with a pointing trowel down to a fine art, but I definitely do not.

On Ebay, there is a "mortar gun" for such joint work (sometimes overhead or vertical) that looks like a mixture between a New Year's Eve rocket and a silicone cartridge (but bigger). There are, for example, models in yellow/black with a simple handle, and others in black/orange with a pressing mechanism. Are such devices suitable for me as a layman?

I have also tried filling pointing mortar into an old silicone cartridge and working like that, but nothing came out of the spray nozzle.

Or does anyone have another tip on how to improvise?

Thanks, Peter

Or does anyone have another tip on how to improvise there?

Improvising in an area that affects the structural integrity of your entire building?

Improvising in an area that affects the structural integrity of your entire building?

Oh no, a forum troll – my partner warned me about that :o Is the joint spray part of the structural integrity? Did I want to improvise with rice cakes or whipped cream stabilizer? So please read what I wrote first, and then feel free to give a factually appropriate answer. Don’t just take individual words out of context. It’s like investigative journalism.

I'm out then