Meeco's Red Devil 610 Refractory Cement - Pre-Mixed Fiber-Reinforced High-Temp Silicate Mortar for FireBrick & Masonry Joints - Withstands Temperatures Up to 3000°F (0.5 Gallon) - Made in The USA

I bought this refractory cement to use for constructing a home made gas fired smelting oven. The cement is a dark gray color and has the consistency of warm peanut butter. It spreads nicely onto fire bricks and is easy to work with. When it dries, it has the same gray color, but slightly lighter. The cement air dries in 1/2 hour or so, good enough to handle something that was cemented together, but to really CURE the cement needs to be heated. For example, cementing one fire brick to another, after an hour of drying time, the two bricks can be (with considerable force) pulled apart. However, if the same setup is heated (I baked mine in the home oven at 500F. for a few hours) the same bricks will crack elsewhere before the joint fails. In summary, this cement works great, it's easy to use, easy to apply and cleans up with water. It dries "well enough" to handle assembled items, but for a full strength cure, the cement must be heated. (Added info 23 September 2014): One important thing to know: Do not "scrape off" excess, partially dried cement from a trowel back into the container. The scraped off pieces will cure even with the cover on the tub, resulting in hard chunks mixed with good cement. I suggest using a sheet of plywood or some other inexpensive, disposable item and scoop out the cement you need, then immediately cover the tub of cement. When you need more, scoop out more and re-close the tub. Never put any unused cement back into the tub, or it will ruin the whole batch. Another important thing: When this cement is not used for a while, the solids and liquids will partially separate, leaving tiny puddles of brown liquid on top of the gray cement. Do not dump this liquid out! Thoroughly re-mix up the cement and it will be fine. Yet another important thing: This cement is highly alkaline (caustic - like lye or drain opener) when wet (uncured). If you get some on your hands and it stays there for a few minutes, you will know it because it will start to sting. This will not cause any injury, it just hurts a bit. So if you do get any on your skin, immediately wash it off with a lot of cool running water (or better yet wear gloves when working with the cement). Note that the cement is NOT caustic and it is COMPLETELY safe once it is cured (dried). The fact that wet cement is caustic is not unique to this brand or item. Almost all "cement" type products (grout, concrete, etc...) are caustic when wet.

I needed to tuckpoint my fireplace, and rather than pay hundreds of dollars I decided to git it a DIY try. This stuff really works. The tricks are to chisel out all the old mortar and wire brush all the soot and ashes away so you have a solid base for it to stick on. Then put it on in _thin_ layers, like 1/8 inch and let each layer dry for 24 hours before the next one. When you make your first fire, build a small one. Low heat lets it cure slowly. Yes, it takes a few days but this process worked very well for me. The cement is easy to use--buy a smaller cheap trowel and a tuck pointing tool at a big-box store--and there's lots of it. I've been using my fireplace for two months now. I build big, hot fires from oak and hickory wood and have had no problems.

I wish I did a bit more research before buying this stuff to line my forge with. The stuff is still a good product, but for a mortar. I coated my kaowool with it, let it dry for quite a few days, then heated it super slowly, over the course hours. Once it started getting to forging temps, it bubbled up like crazy. Now.... it turns out the bubbles can be busted off and there is still a thin layer of this material on the other side of the bubble, over the wool.. so it's usable. Ive been using it that way for a while now, but it's starting to break down. You want "castable" refractory cement, for your forge, btw. I still use this stuff to cement firebricks back together that have broken and if i'm doing a hamon.

Arrived in a sealed plastic tub inside of a tied plastic bag. I assume for freshness. The product warnings are a little scary, but the product is a wet paste. No fine particles were flying around. It did require a little mixing, but that was expected and addressed on the packaging. It sealed up the small gaps between the fireplace brick panels very easily. Once it was mixed, it went on like a thick paste. It did not slide down the vertical gaps. It stayed in place quite easily. Once the panels were squeezed together, the gaps were less than 1/8” just like the instructions recommend. Even though the product says it doesn’t need to cure, I let it sit for a day to dry. The next day I lit a fire with a duraflame log and let it burn out. There was no bubbling or anything else like some have complained of. I suppose reading directions prior to use helps. 🤷🏻‍♂️

I'm using this, some old firebrick from a kiln, and a hacksaw to construct a pair of forges with arched ceilings. It's working great to repair broken bricks and hold the bricks together. Of, course I won't know how well it works till I've fired them up a few times: I'm sure it'll hold, but it's not porous, so I'm being careful not to seal up too much of the brick faces, so I don't trap air that could burst out. It is also very susceptible to water, even after it has set, but that may allow me to smooth out rough spots, since it easily forms little dingleberries that are hard to remove dry. My last thoughts are that this is not really an insulator, and it would be expensive to apply thickly.

So a buddy of mine had a fireplace base (floor) that was chipping and eroding. He wanted my help with removing it and recasting it… weekends are for beer and fishing so I didn’t really didn’t want to get myself in way over my head and spend a whole damn month there just getting deeper and deeper. Bought this item item while sipping on some Tito’s thinking this will stop him from bothering me to help him. Followed directions and got down to cleaning the debris. Holy cow. His base was worse than I thought. When we pulled out the shop vac and started to vacuum everything out, we were pulling out chunks of the base that was just loose. I’m talking about the center of the base was almost 3/4" gone. That’s how deep the chipping went. In my mind I know he’s freaking out as his wife is somewhat of a complainer. Hell if she can do better, roll up them sleeves, put down the fancy bag and do better. Anyway, I digress, but skeptically we got the trowel and prepared for failure… opened the container and realized it was like mortar, sandy and all… not a paste like some people say. He kept bothering me to add water to thin it out so it’ll pull better, so I sent him on a beer run… took my time and coated the fireplace base even, filling all the cavities and ruts… probably added 1/4" coat to the areas that were fine… now mind you the direction says only do 1/4" coat max and we went 1" on the eroded areas so we both were expecting to get out the sledge hammer in a week… he let it dry for a few days and when it did get cold I brought some oak logs from my place and we burned for a good few hours well. He would use to poker to clear out the center and just take a peek to see if it’s bubbling… couldn’t tell…. Next day he swept out the fireplace and what do you know. This thing is solid as a rock and smooth as factory. Now every time he burns I tell him to send me a pic when he cleans out the fireplace. Now I always tell him he can thank me for the warmth. This item is great. I actually called a fireplace supply house and told them what we did and the sales rep said that’s what they would of done if they came out too… hope this review makes you smile.

I did not know that it was pre-mixed. I cleaned out my fireplace, scraped off all the loose mortar that was willing to come off and I use the 610 to fill in the holes where the mortar was missing and where some of the brick had cracked off. It went on like putty (with some sand) and if you are use to working with drywall mud, this should be about the same. I tried to improve the finish by pushing a flat piece of plastic against the mortar and leaving it there. That was a mistake. It needs to be air dried so when I remove the plastic, the mortar had not set. I smoothed it out and let it air dry for a few days and then started a fire in the fireplace. Best I can tell, all the repairs stayed in place and nothing had cracked off.

Exactly what was needed and held consistency for several years