I have 4 foot brick built pillar that's been hit by a car and has a clean break on the mortar about half way down. I know I have to take it off, clean off all the old mortar and replace it. My question is, are there any kind of wedges that can be bought to keep the gap in the mortar, or is there another way of doing it? If I just put the half pillar, which is very heavy, back on fresh mortar, will it just flatten it out and lose the gap?