In the last post i described i ended up with gaps in the bricks of the arch, in this post you will find out what i did about it.
Firstly I used an angle grinder to remove any loose mortar and excess mortar so I had a flat arch interior surface, I also used a chisel and hammer to dislodge alot before grinding and also to scrap the small mortar off the bricks, thats the thin "wash" that happens.
I angle ground into the gaps as well tho make sure anything loose was fully removed. most of the gaps were only a few cms deep but 1 was almost a full brick deep !! so i don't know how that occured?
So now i have a clean area to refill, please note the obvious.... I haven't done any burning of the interior yet.
So i now mixed a small amount of "fondue" and started at the back of the oven systematically filling in the gaps, i used a thin pointed tip trowl and a fatter round tipped trowl for the big holes. For the small gaps it was easy to just push some mortar into then using the pointed trowl for the larger gaps i used the rounded trowel and HEAPED it with mortar and pushed it into the gaps, and again and again and again to make sure it was filled up, THEN i pushed my finger into the gap to push the mortar in and you'll be surprised that the mortar does move in, THEN once again trowl pushed more mortar again and again.
The theory is that if you leave a gap (air pocket) that that can expand and explode/damage your oven THUS my now reasoning that its better to make sure your mortar is complete and angle grind it off later.
Having said all that I have seen MANY oven insides that the maker hasn't bother bout it and is using it successfully so this is purly my opinion.
This whole process to took me 7 hours ! (just so you know there is 33 bricks in my arch, [ 3 rows of 11] just so you can calculate it to your dimension)
THEN, yes its not finished yet, then i let the mortar filling set a little and THEN went back in and with a scraper, scrower and sponge scraped the excess mortar off then scrowed then sponged to end up with a clean smooth fully mortared internal surface. This took me another hour+
I will now let it dry for a week and then do some (very little) cosmetic work on the inside with a chisel and angle grinder.
SOOOOOO, In conclusion you can see that perhaps making sure all joints are fully mortared is much better then trying to do "mortarless" joints.
DISCLAIMER: my bricks are square thus i of course have to have gaps, if you are using tailored angled bricks then i haven't a clue wats best, but i do think if you are using ANY mortar at all then making sure it reaches the inside is vital in my opinion.
The whole day was full on and i finished in darkness so now photo on this post but it does look GREAT, I'll put a photo of the end result into the next post next week.
