Partially fill joint between dome fire bricks with steel wool before refractory

[ined]

Doing a little maintenance on my 5 year old WFO (built from Alan Scott's book). One of the joints between dome fire bricks has lost its refractory mortar (Heat Stop).

I tried to fill it with refractory mortar, but it was too deep, and the
mortar fell out.

I think if I partially filled the joint with something like steel wool(or some
other recommended material) it would form a base that I could finish with Heat Stop.

Anyone have any experience with this problem or any ideas that might help withthe repair.

Thanks in advance.

[Tscarborough]

Re: Partially fill joint between dome fire bricks with steel wool before refractory

The deeper the better. Mix some heatstop and put it in a heavy duty ziplock bag. Cut one corner out so that it is about the size of the crack and squeeze it in. You may have to make the mix a tad wetter than normal.

[david s]

Re: Partially fill joint between dome fire bricks with steel wool before refractory

Filling cracks is usually not particularly successful, but you can improve the success rate with this method.
1. Take some of your Heatstop and sieve out the aggregate.

2. Wet the area to be filled and leave for 10 mins so it is damp not wet.

3. Mix some water with the sieved heatstop to form a thin slurry and paint this into the area to be filled. Then wait 10 mins again to allow the stuff to penetrate into the cracked surfaces.

4. Mix up some unsieved Heatstop to a peanut butter consistency and apply.

5. Leave for a few days before refiring.

This method creates a better bond with the surfaces to be filled. Calcium aluminate cements do not require the extended curing times like Portland cement. 24 hrs and it's done, but you do need to then wait until it's properly dry.

[ined]

Re: Partially fill joint between dome fire bricks with steel wool before refractory

Thanks for your replies. I will incorporate both methods and give it a try. The joint in question is a mortar joint between two fire bricks in the dome.

thanks again