Rutland Castable Refractory Cement 25 Pound - High Temperature Fireplace & Woodstove Fire Cement - Cast Custom Fire Brick, Refractory Panels & Fire Pits, Pizza Ovens

I had the back slab develop a 4" hole. Shut down the FP and scurried to find out how I could access it and find a replacement. Found both, placed an order and then worked on disassembling to get the slab out. A week or so later, I hadn't received shipping information so I contacted the vendor and found the slab was back ordered and would be shipped on Feb 5th. Not trusting the actual date supplied, I started searching for possible repair solutions and found the Castable Rutland product. I'd used other Rutland products but was a bit concerned due to my lack of cement knowledge and some of the reviews I read. I decided to take a chance as the coldest part of the winter was upon us and I burn 24 x 7. I planned my approach and in a couple days I had the cement (left input in questions about getting the top off), had a board to sit it on and some wax paper that I planned to put between the 4 " hole in the slab and the board I was putting it on. I used another stick to define the edge of the hole to be filled and a couple of bar clamps to hold everything in place. Now I was ready to go. I brought the slab to the cellar and realized that this might just not work. The slab not only had the hole but fractures that were threatening to break the entire slab in half. I started doubting my entire approach. I gingerly set it onto my board and got it stabilized with the bar clamps. Mixing the cement was easy as long as you didn't add too much water. I just mixed it comparing the final product to a too thick pancake batter. With a trowel, I started picking up gobs and let them run into the holes until it was filled but left it about a quarter inch lower than needed. There was another two to three inches below the hole that was crumbling and I hoped filling that area in as well as a second coating over the hole might stabilize the slab. I waited 24 hours but the patch was still wet, probably due to the 55 degrees in the cellar. I took the bar clamps off and carried the slab upstairs on the board and let it dry another 24 hours. Totally dry, down stairs I went again. Mixed up a second batch and put that second layer over the hole and the crumbling area and immediately took it back into the warmer house to let dry. 24 hours later it was all but completely dry. It was dry enough to check the backside that I was concerned about due to the cracks. It still looked fragile but didn't feel at all "loose". I made a third batch, this time more syrupy. Caution, it quickly goes from syrup to watery. I had to add cement to get it right. I filled small holes on the back and a very thin layer over the bad area and let it sit for another day and a half when I finally had time to reinstall. All of the looseness of the slab was firmed up and it felt solid. My hope initially was that I could get it to hold up until the new one came in. After seeing how well it felt, I thought maybe I could get to the end of the burning system and after a few fires, I'm thinking that if it holds up thru the rest of the winter I'll just leave it alone. If it starts crumbling, I'll have the replacement here and it will be an hour or so project to put the new one in. I loved this stuff!

Definite learning curve here. Not nearly as forgiving as mortar for brick and block, but a with little practice and a little experience, anyone who can get good results with masonry mortar can enjoy success with refractory cement. Very important to read and follow the instructions, which make it sound like working with this stuff is easier than it really is. For my purposes, which involve building arches from fire bricks to make the roof of a wood stove fire box, I have found it wise to work in small batches. A small batch is so easy to mix it makes no sense to race the pot life clock with a big batch. Note that the bigger the batch the faster it gets hot and sets up. Heat is your enemy here. One thing that really helps is to keep your cement in a cool location before mixing and to use ice water, without the ice cubes. I have found that I can mix equal volumes of sand and cement to get excellent results in terms of bonding and compression strength. No doubt some loss of tensile strength, but perhaps better shear strength. So. Save some good money with a little clean mortar sand. Best if damp enough to hold the shape of a tennis ball size sphere, but if dry, just add a little more water. Avoid really wet sand because this cement really works best if quite dry. Have since done a heat test. Stays hard and strong when heated to glowing yellow. Which is around 2000 degrees Fahrenheit. My small batch recipe is one quart sand, one quart cement, and one and a quarter cups of water. This uses about five pounds of cement. Using cool materials and cold water the pot life is a comfortable 25 minutes from when the water is added to the previously mixed sand and cement. Best to use a mixing tray rather than a bucket as this mixes much more easily and being spread out, is not prone to self-heating. I like the ten gallon tough tote. Which has also proven to be easier to work out of than a bucket. Follow up report: I made a test batch of equal volumes of mortar sand and cement, using the suggested water to cement ratio. After curing and slow heating with a heat gun, I used a propane torch to heat a quarter of a 1 1/4 inch test ball to glowing yellow for a minute. During which time, I poked at it with a utility knife. Could detect no softening and saw no indications of failure. A good idea to test, but go ahead. Be creative.

The directions on the tub are very specific, but mixing 1 quart of water with 12.5lbs of product will not result in the dry consistency required. This mix also sets extremely quickly. They advertise 20-30 minutes working time. In reality, I has 15 minutes from the time water hit the mix until it started setting up. Recommend using a mechanical mixer and working as quickly as possible.

So I like the performance and I like the container if comes in which can be used for various other things afterwards like cleaning my tools and doing the sponging of the brick. I’m not a professional mason but the consistency seems on par with what I’ve worked with before. It’s like a very fine fluffy concrete powder. It does dry rather quickly and it is super easy to over water which can also loosen it up. It sponges off great. It dries incredibly hard. The only fault I have with it is it took a while to arrive. I didn’t realize I needed as much as I did so I had to place multiple orders and ended up taking three weeks from start to finish to complete my pizza oven because I had to keep waiting for more to arrive. I was hoping it would be done in a day or two but ended up taking three weeks overall but six days to build and six orders. Unfortunately this product isn’t stocked anywhere else either so I was stuck with this process. And because of the weight of the product, over ordering and then returning it wasn’t a practical option.

If you want to get into a simple forge this stuff is unbeatable. I have created two separate forged with this product now and gotten great results. It’s simple to use but if you have never worked with concrete before, don’t just dive in and add water to the bucket (I feel that should be obvious but you can’t know what you don’t know). The recipe calls for one quart of water per 12.5 pounds of mix (half the bucket) so add one half quart water and mix in the refractory mix slowly until you get a cookie dough mix and pour that section then start mixing again. It’s easy to blame the mixing instructions if you don’t know how to trust your own eyes are telling you and take it slow. This stuff doesn’t set up right away so don’t be in a huge hurry. Set aside an hour for each bucket you want to use up and you will be happy with the results. If you don’t have anything to vibrate the mix with simply tap the sides of your cast for a few minutes with a rubber mallet and the air bubbles should not be any issue. This stuff does not have to be thick to perform diligently. An inch and a half of wall thickness is more than enough for anything you are going to do in your garage. DO YOUR MATH! The volume of what you are casting is something you need to know before you start. Have a plan before you order and be detailed in your setup. All the issues folks had with this stuff could have easily been remedied by putting a bit of brain muscle in before hand. I know how exciting it can be wanting to get into the mix as fast as possible but pace yourself so you don’t end up regretting your final product. I used this alongside some one inch thick kaowool to reduce my materials cost for this build and was able to cast a full size stainless steel keg using a Lowe’s 5 gallon bucket and a well insulated lid along with it with one roll of kaowool and three buckets of refractory.

I'm happy with the outcome of the cement. I made 4 refractory panels for a wood burning fireplace insert. 1) 16.5" x 17" 2) 16.5" x 17" 3) 18.5" x 18" 4) 16.5" x 31" x 20" x 16.5" (trapezoid shape) Thickness of each panel was 1/2". I added 1" refractory needles (stainless steel) to each panel, about 3% of weight of the panel. These are suppose to prevent cracking. I used a total of 75lbs of the RUTLAND Castable Refractory Cement. I made molds from wood, sprayed cooking oil on each, laid down plastic, placed the mold over the plastic, mashed half the cement into the mold, spread the refractory needles, added the remaining cement and covered with plastic. Rutland customer support said to cover all sides of the mold for 24-hours. This is to keep the moisture from evaporating so the cement sets properly. The cement drys a very, light grey....almost white. The panels are solid and heavy.

Great product. Mixes easily, dries rock hard, impervious to high temps. I was tempted to remove a star for the adult-proof shipping container, but the final product works so well I had to give it five stars. Like others, I had problems removing the top from the 25 pound pail. Why such a great product would ship with a medieval torture device for a lid is beyond me. I suppose it prevents accidental opening during transport, but unfortunately it also prevents access to the contents without nuclear-powered jaws-of-life. I twisted off and completely removed the red “safety” tab with a pair of pliers. There is no way to hold the pail securely and simultaneously twist the lid to remove it, so I slid a large flat blade screwdriver under the lip of the lid and carefully lifted a section upward just high enough to pry it away from the pail. Once a section was freed, I inserted a large paint stick horizontally between the pail and the lid to prevent the lid from re-attaching as I worked on the next section. Eventually the lid came off, but not before the air turned several shades of blue from my vigorous commentary. Despite the abuse, the lid sealed the pail securely (I hope) after I was done, but time will tell whether I’ll need a band saw to open it next time. The manufacturer states 25 pounds makes 432 cubic inches (12 x 12 x 3) and requires 2 quarts of water. I needed only 150 cubic inches, so I did some calculating. In hopes it will help others, I used a kitchen scale to weigh the water. I had great success combining 11 cups of (well-stirred) powder and 668 grams of water. That level of precision may seem like overkill, but the mixture changes texture dramatically in response to tiny amounts of water, especially when mixing small batches. I still had to fine tune the final ratio achieve a thick but not crumbly mixture, but I ended up satisfyingly close to the amount needed with only minor adjustments. All in all, a great product if you need a high-temperature refractory for repairs or to create heat-resistant panels -- provided you can get the lid off.

We bought this to coat out outdoor fire pit( cinder block). The mixing directions are inaccurate and makes a slop that is too wet! Thankfully we had only mixed half the bucket, so we had to add more mix to dry it out. It will not stick to vertical concrete blocks. Does not go on smooth. Dips off and wastes half of what you are working with. It does not create smooth surface as it just slides and falls off. . It barely covered one wall of our 12 inch x 3 foot square fire pit. Didn't like the result as it was so uneven and not at all what was expected. And didn't want to buy more as we were so unhappy. We scraped it off and will take the loss on this expensive waste of time and money. Do not buy! There has to be a better option

As I couldn’t find the original refractory boards for my fireplace, I decided to give a try to this product. I used two buckets (50 lbs) of this refractory cement to fabricate four panels. I followed precisely the instructions to have an optimal mix. Poured it into the molds and 24 hrs later the result was pretty awesome. I did a couple of minor cuts with a diamond saw for a perfect fit and it didn’t cracked or chipped off. It feels rock solid. Yes, it is time consuming but for me it was the only solution and probably at a fraction of the price of the original panels. Now the time will show if it was worth it.

Like that this sets up fairly fast and holds up pretty well under high fire conditions. Worth the cost.

Does not come with any mixing instructions and I couldn't even find any information online either which is strange. But I've used it for two different applications (a small tin can forge, mixed dry for easy packing and for a skim coat over my kaowool insulation for my gas forge mixed quite wet) and both have worked well. The one instruction you do get is to not fire cure the cement. Listen to that. If you add too much heat to quick it blows chunks out of the surface from steam escaping.

This is the perfect cement for replacing fire brick

Very good. Though it would go farther. Dried pretty fast which is handy.