refractory cement

R

Rey

Well-Known Member
I recoated my forge with a can of rutland refractory cement last night. When I purchased the forge the layer of cement was cracked and falling off. I mixed a small amount of water to make it smoother to apply. After I finished let it dry with a fan to help the dryness. It is humid here in south Texas but, continued in drying process. I proceeded to use my torch and gradually apply heat inside the forge. It started to bubble, anyway kept up the heat slowly. Will the bubbles effect the burners or should I scrape the ugly bubbling effect and apply the cement again?. This is new to me so, please gentlemen comment and advise needed. Thanks,............Rey:confused:
 
I read on the instructions of rutland cement need to dry completely because, during heating processs moisture may be trapped between the wall of the old layer and the newly applied cement thus, causing a bubbling affect. Comment and advise needed since, this is new to me, thanks.............Rey
 
Rey
On my forge I used Satanite as a coating,so I don't know about the rutland but you should have let it air dry for 12 hours or so before starting heating,then fire up the forge for a couple of minits let it cool fire it up again a little hotter, and about the third heating take it on up to forging temp.
Hope this helps
Stan
 
Rey , i just put some in my forge and they put my heatgun in front of it on low and everything come out great
vern
 
Thanks guys for the advise next time I will let it dry overnight before heating to cure. Thanks SBuzek and Vern, greatly appreciate it. Rey
 
low and slow

v-6 said:
Rey , i just put some in my forge and they put my heatgun in front of it on low and everything come out great
vern
Click to expand...

I believe it best for any cement product to be allowed to dry slowly for strength and durability. The heat gun is the best way that I have heard yet to cure the stuff though. The Idea is to raise the temp. above the boiling point to drive out the moisture (212 degrees in most places) but below the superheated steam temps (above 400 I think). If the moisture tries to escape to quickly you will get the bubbles and that will reduce efficiency at least a little. When all moisture is gone you can run several short heats of increasing temps. This will give you a surface with as little porosity as possible. Hope this helps.
 
If the cement starts to bubble, then your pushing the drying process too hard. If bubbles occur, its likely that your also applying it too thickly. I've found that its much better and quicker if you reduce the consistency to that of approximately latex paint, brush it on with a cheap paint brush, and allow that coat to dry a day or two, then apply another coat.

If you apply this type of cement without thinning it down considerably, it can take a week or more to dry. Anything short of letting it dry naturally will reduce its life span considerably. I always ensure that when I have to re-line one of my forges, its planned that it will be out of commission for at least a week. By allowing that much time for things to dry, it greatly increases the times between re-linings, and in the end reduces overall down time. Take the time to let refractory and/or cements naturally, and although it might take longer than you would like at the moment, it will payoff in overall durability.
 
Thanks JR and Ed for the advise, I will let it dry for more time and apply it thin. Do you gents use satanite or what? I used rutland refractory cement, do you apply another additive over satanite, or use it as the same as refractory cement?. Rey
 
The main product that I use is ITC-100, but I also keep typical refractory cement around the shop in case a forge needs some actual patching. If I must do a "patch job" that requires a thick layer of refractory cement, I will use the standard refractory cement, let it dry, then overcoat it with a slurry mix of ITC-100.

Any time I do a re-line, it gets a slurry coat or ITC-100, and then its usually 3-5 days in my climate for it to dry.
 
I use Kast-0-Lite 3000 degree when I make a forge. It is light weight, is insulating, and hold up well to flux. I usually build a forge from a 20# propane bottle using 1" of Insowool with about 1" of Kast-0-Lite over that, then a coat of Plistix. This makes a very strong, durable forge that is light weight. I use 18# of the Kast-0-Lite so the finished forge weighs about 20#.
The Plistix is a similar product to ITC 100 but costs a lot less.
I have a convection oven in my shop, mainly for tempering blades. After I have cast the forge I let it cure over night, then put it in the oven a 500 degrees for about 2 hours. This has cured all of my spalling problems.

I built a forge like this for one of my students using one of Larry Zoeller's Modified Side Arm Burners. I fired it off and after it had time to come up to heat I timed heating a piece of 1" square to forging temperature. It took 11 minutes. After it cooled off I painted the inside surface with 1 pint of Plistix and again timed heating the 1" square to forging temperature. It took 6 minutes. I therefore recommend that anybody coat the inside of their forge with an IR reflective product, like Plistix or ITC 100.

I sell the Kast-0-Lite in 6# bags for $15.00, Inswool for $7.00 per running foot 2 feet wide and Plistix for $9.00 per pint.
You can contact Larry at http://www.zoellerforge.com/index.html
<);-)>
Wayne Coe
WayneCoe@Highland.net
http://www.WayneCoeBlacksmith.Etsy.com
423-628-6444
729 Peters Ford Road
Sunbright, Tennessee 37872
 
Rey, I just checked on my Pay Pal account. To send money you can just go to www.paypal.com. Log in, click "send money", put in my e-mail address and the amount you want to send. They then send me an e-mail telling me that you have sent the money and that it is there. I then instruct them to deposit it into my bank account. That easy.
Wayne Coe
WayneCoe@Highland.net
http://www.WayneCoeBlacksmith.Etsy.com
423-628-6444
729 Peters Ford Road
Sunbright, Tennessee 37872
 
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