Refractory Mold

Here is a picture of the mold I made. Mike

What would be the outside diameter of that mold if all the bricks completed a circle?

nice job mike, I have an old mold looks a lot like what you made,its made out of wood. it was for old boilers and furnaces, still use it for some stoves
wilson

Thank you Wilson, Now I will have to get it in service ,make 3 bricks and allow the last brick in the stove to tell me just what I did. It was a fun little project . Mike

Nicely done. A description of your design and building technique would no doubt help others.

Mike, it looks like the flat bar ends slide out, so you can make other slots for a smaller brick . is that what I see?
Wilson

That mold looks almost the same as the ones dcrane shows in the thread "Replacing refractory bricks in a Crane 44"

WH ,It is a matter of the old line "form follows function". There is not much of a way around it , It almost has to look like those of Doug. I know the original patterns will work , I have yet to try mine . I will go out this afternoon and order the refractory cement and then we will see what is what. Mike

Wilson, There is no doubt that one could cut additional slots into the sideplates as required. The bars slide out easily, I made it a loose fit which can be shimmed tight from the backside at pour time and then have the tiny shims pulled to easily get the end bars out. Mike

stovepipemike wrote:Wilson, There is no doubt that one could cut additional slots into the sideplates as required. The bars slide out easily, I made it a loose fit which can be shimmed tight from the backside at pour time and then have the tiny shims pulled to easily get the end bars out. Mike

Good job, Mike.

No need to pull the bars if you first spray-coat the inside of the mold with vegetable spray such as PAM. Then brush it out evenly over all the surfaces that the refractory will be in contact with. Quick and easy mold releasent that does not affect the refractory cement. I used the local supermarket's house brand of spray. Less expensive than PAM and it worked great.

Once the refractory is in the mold, you'll need to cover the open parts of the mold with something like Saran warp to keep the refractory cement from starting to dry out too soon. It can't be allowed to dry out for the first 24 hours or the bricks will be weak and crumbly.

After about 12 hours the bricks should be set up enough that just turning the mold upside down, the vegetable oil will let them fall out of the mold. Then wrap them in Saran Warp to keep them damp to finish that 24 hour curing time.

After that 24 hours of keeping them wet, unwarp and let them air dry slowly to reduce chances of small stress cracks forming inside the bricks.

In case you didn't see it, here's more about working with refractory cement in this thread.
The Refractory Thread!

Paul

scalabro wrote:What would be the outside diameter of that mold if all the bricks completed a circle?

Bueller..... Bueller

Thank You Paul, that sounds like good advice to assure the strength factor is in range. I was just now at the masonry supply house and the kind of refractory I want to try is not in stock. I am told that if I want it in 2-3 days it will be an expedited shipment from Ohio and in the $150.area for shipping costs alone. OUCH! They said they will call around to see if any is in the area, they do not get too much call for it. I am anxious to try a pour to see if all measurements are accurate before I can say it is O.K. to copy etc,so I may try a sakrete look alike to see if it fits perfectly. All measurements are taken directly from an actual stove so that part is straightforward. Mike

Yeah, shipping that stuff is expensive because of the weight.

I paid $58.00 for a 25 pound bucket of Rutland's #601. I ordered it directly from Rutland. $30.00 of that was the shipping. That was plenty to make two rows of bricks, all one inch thick, for the 15-1/2 inch diameter x 10 inch deep fire pot of my Glenwood #6.

Wilson told me he has a bunch of #6 and #8 base heaters and other Glenwood base heaters and oaks to reline to get ready to sell. So he's picked up bags of fire clay, sand, and Portland cement, and he's mixing his own refractory using equal portions of each.

He might be able to give you a lead on where to get the bags of fire clay. Wilson Mull 508-763-8941.

The sand and Portland cement you can get at Lowes, or Home Depot.

Here's a pic of his first batch of #6 fire bricks that he made in molds I gave him.

Paul

Paul, The bricks came out beautiful and the stove deserves them. If I do not hear in a few days from the concrete supply yard, I will go with an alternative. Your mix sounds a lot better than sakrete, even to test the fit. I took the grate and warped slide by the local foundry to see what the thinking was. He said they cut the slide completely thru to make it lay flat and can get a straight final product from the mold. Just as a curiosity I asked about another grate and slide[a complete spare set] he said about $80 range. still thinking on that . You have got to like jigsaw puzzles to enjoy this for sure. Thanks , Mike

stovepipemike wrote:Paul, The bricks came out beautiful and the stove deserves them. If I do not hear in a few days from the concrete supply yard, I will go with an alternative. Your mix sounds a lot better than sakrete, even to test the fit. I took the grate and warped slide by the local foundry to see what the thinking was. He said they cut the slide completely thru to make it lay flat and can get a straight final product from the mold. Just as a curiosity I asked about another grate and slide[a complete spare set] he said about $80 range. still thinking on that . You have got to like jigsaw puzzles to enjoy this for sure. Thanks , Mike

$80.00 to have spare grate parts on hand? I'd go for it. In fact I have.

I had Tomahawk make an extra grate bar when I had new ones made.

Since the pattern grate was the longer of the two grates, I had all the recasts made from that one. Being longer, it can easily be cut shorter to use as the short bar. And, I figured it would only added a bit more to the shipping cost to have an extra.

That way, if anything bad happens to either grate bar, I then have a spare to get the stove back into action as soon as possible. That also buys me time to resend the pattern to have more spares made and not be without the stove while I'm waiting.

As for the jigsaw puzzles, yeah, I guess I do like them. I restore cars with over 10,000 parts in them, for a living. And you should see the jigsaw puzzles Scalabro works on.

Paul