Laying down mortar

[jcg31]

Hey folk,
This is my first experience working with any sort of mortar, or masonry for that matter. I am reading the posts about waiting for the mortar to set before removing the shims and suggestions that folk have multiple shims in place with multiple brick while the mortar sets, making me wonder if I am on the right path. I am using Refrax and it is setting within seconds of placing the brick. I have gotten to the point where what I am putting down is almost soupy in consistancy. I am wetting the lower brick, and soaking in a bucket the one I am placing. Even with this consistancy I am not able to tap (with rubber hammer) the brick and get any downward movement after about 30 seconds. Am I doing something wrong or missing something?
Thanks,
Jim

[dmun]

Re: Laying down mortar

I don't think you want your mortar anything like soupy. Peanut butter is the idea. Too-wet mortars are weaker. Your bricks may not be wet enough.

I used heat-stop, someone who used refrax may jump in here.

The tendency for bricks and blocks to absorb some mortar moisture and set up quickly make them much easier to lay. i laid up nine glass blocks in the course of my project, and boy was that hard. They stayed loose and wiggly until the mortar set up by its self.

[christo]

Re: Laying down mortar

The refrax firms up quickly. It was frustrating at first as I was so slow....

Soaking the bricks before use is important. Makes a world of difference.

After I got the hang of placing bricks right the first time, it was a nice feature to hold it in place for a few seconds and move on to the next brick.

Christo

[asudavew]

Re: Laying down mortar

After I got the hang of placing bricks right the first time, it was a nice feature to hold it in place for a few seconds and move on to the next brick.
Christo

I bet that it is nice to have them hold in place. Maybe I should of went this route...I'm using cheap-guy mortar, and it takes quite a while for it to set up.

I'm fixing to move on to some upper courses where the angles might start to get me.....I can here them hitting the oven floor now.


Might be time for some sticks to hold em up.

[Dutchoven]

Re: Laying down mortar

Asuda
You just have to find the right balance between the stickiness of the mortar and the wetness of the bricks...could give the bricks less time to soak. What kind of mortar recipe are you using? 3:1:1:1 sand:cement:lime:fireclay? Could add a bit more lime?
Best
Dutch
P.S. Your oven is looking good!

[asudavew]

Re: Laying down mortar

Asuda
You just have to find the right balance between the stickiness of the mortar and the wetness of the bricks...could give the bricks less time to soak. What kind of mortar recipe are you using? 3:1:1:1 sand:cement:lime:fireclay? Could add a bit more lime?
Best
Dutch
P.S. Your oven is looking good!

Yeah, 3-1-1-1

How much extra lime should I add?
I am fixing to start the 5th course past the soldier course, and the angel of the dangel.....
I did cut my bricks into thirds .... maybe that will help.

And thanks for the compliment! I've been doing my best on a budget.

[Unofornaio]

Re: Laying down mortar

I don't know where this mix came from but with equal amounts of cement lime and fire-clay if your bricks are not sticking then your mix is too wet or the bricks are too wet. With that ratio how the heck do you get it off the trowel and on to the brick? Where did this come from?

[asudavew]

Re: Laying down mortar

straight off the plans... i believe

i dont have a copy at home

[Unofornaio]

Re: Laying down mortar

Dave- I just looked over the plans and I cant find a recipe for mortar anywhere, except for the hearth bricks. Do you or anybody know what page?

[Hendo]

Re: Laying down mortar

Appendix 6 - p67 on mine!

[asudavew]

Re: Laying down mortar

Yeah,

Just about the last page.

[Dutchoven]

Re: Laying down mortar

FYI guys! Uno is right on. With that mixture it is important to be able to adjust for your particilar working conditions to make it workable. It took a lot for me to get the hang of it. Some mortar recipes would increase the sand to 4 or 5 parts as well.
Best
Dutch

[Unofornaio]

Re: Laying down mortar

Thanks guys I found it. Here is my thing with that mixture. Lime in mortar really only serves a workability function as in water retention to increase board life and stickiness. I don't see any need for it AND fire clay. Fire clay adds both these elements to mortar and while you can use SOME fire clay in place of lime for brick laying (never as full a replacement for lime) we have always used lime and never used it for heat applications. Interesting..

I'm not saying its is a bad mix just different and I would assume VERY VERY sticky. What we have always used is 6 sand 2 cement and 1 fire clay and this is more than sticky enough. My dad and I built my bakery oven with this mixture and I never had a problem. As a matter of fact when I dismantled the bakery oven (in use for 5 years) this summer I had to use a rotor hammer to get the chamber down and Id say about 70% of the brick broke in the field and not at the bond which to me was surprising. The other 30% were probably the ones I laid my father is a true master. A huge part of laying fire brick is to get the moisture in the mud and the brick just right. Although for the new oven I will use a true refractory mortar and this oven will serve double duty as my tomb because I am NOT taking another one down.

I remember a post now with that recipe being suggested by a furnace builder or something like that somewhere. It would be interesting to know the rational behind the lime addition.

Anyway Dave you are going to have to play with the mix to get it right to hold the brick and not slide off, I'm sure you will be just fine. And you can always use forms or sand there certainly is no shame whatsoever doing it this way.

[asudavew]

Re: Laying down mortar

6 2 1

I wish I would of know this sooner............


Should I finish with this formula or continue with the one I have been using?

BTW. I hate the lime... Nasty stuff... I would love to avoid it!



Thanks guys!

[Les]

Re: Laying down mortar

Guy's

I've been working with the Forno receipt and find that it's a pretty good mix - granted it hasn't stood the test of fire yet The heat stop I was using had to be shipped (crazy expensive) and I find the two pretty similar. In fact, the Forno flavor allowed me to pull my shims quicker. The lime does add a workability factor, but I never seen that as an issue (until you clean the tools).

Les...