Usage directions for Plastic Refractory (Blu-Ram HS)

Discussion in 'Furnaces and their construction' started by Melterskelter, Jun 30, 2020 at 3:31 PM.

  1. Melterskelter

    Melterskelter Silver

    After much unsuccessful searching online and a couple of emails and a phone call to my foundry supply house I was provided installation and drying instructions for Blu-Ram HS plastic refractory. I am posting that information in a separate thread rather than burying it in my build thread to make it easier for someone seeking that information to find it. Most likely the information for this brand of plastic refractory is similar for other phos bonded plastic refractory.

    The original file was a PDF, so I am posting it as images.

    F36E877E-C2FA-4182-9CDD-9894DF59E81A.jpeg 0E26B547-C389-4B95-BBD2-7E459D86B877.jpeg ADFBC4F1-C33D-453D-AE07-757B8A92A630.jpeg ADC297B5-2E21-4380-8019-FD12CD7AB6C8.jpeg ADE46648-71FE-4304-9A16-BB3B8BFCE684.jpeg F30BDB28-ED6D-44D3-AFA3-FB8DFD246C03.jpeg 1EAD13D9-994D-48C0-BAFE-E8165EA6C3DE.jpeg E8A4B703-8A2C-4667-A20A-BB73205B299F.jpeg 019D9BEA-AF21-4971-BEB2-757E5CC42F53.jpeg D9E55C82-25A7-4172-9A6E-B7CB14BADDBE.jpeg 57BCEA10-F79C-453D-BAE3-AE57A49A1BA9.jpeg 8C71CB14-F3CD-457F-8C19-EAF1DF2440E8.jpeg BA87EDBB-8D8C-42C2-8D65-60D12D311597.jpeg D73ADB28-3860-4828-8812-E9CB37ECD9C5.jpeg 16C997DB-0705-49B9-B14D-926DB54DF4DD.jpeg 0F0A453E-520E-4541-8E3F-8882FA3393EF.jpeg 2049B99E-75AF-4EB5-B4D8-AD7F880B3B62.jpeg CFFDA74C-6631-4A82-98AC-7A7B1E091EFA.jpeg CD617E6C-385E-445F-B0C6-868259F72238.jpeg

    Denis
     
    Last edited: Jun 30, 2020 at 3:39 PM
  2. Melterskelter

    Melterskelter Silver

    Drying instructions:

    784A4465-9551-489B-9AA5-C8354E3598FF.jpeg 1A9CD3B2-36F2-41D1-ADEE-F75876066DD8.jpeg 53FDB4B2-DEB0-4ADF-96D0-8B54F4C4918F.jpeg 512C39B3-8651-4C5D-A609-A8AF45473BCC.jpeg A19AF485-1FC9-4B5F-9A03-1C8FF5A7B28F.jpeg

    Denis
     
    Bentation Funkiloglio likes this.
  3. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Don't know about you Denis but I find the content of all that to be a bit disappointing. I bet if you asked 5 professionals about the placement methods you'd get 5 different variation and they'd all work just fine. For the drying instruction, about the only useful information is the references to the tendency to skin, and the recommendation to proceed immediately to heat curing, and possibly adding vents to help avoid steam entrapment. Your use of a pounce wheel seems to be a clever adaptation for this if penetration is sufficient.

    The one thing that is surprising absent is any recommended variation in curing cycle that corresponds to the refractory thickness. In many castables the ramp can be increased as thickness is reduced. In most cases for us, drastically increased ramp rates and reduced curing schedules are possible due to typically 1" or less thickness. I would think the same would apply for your segments since they are so thin, and obviously because you want them to have enough strength to be demolded. I know when Phos-bonded plastics are used for patching by my professional friends, they pay no attention to any firing schedule.......they just put the heat to it. Same thing with all the cupola guys.

    Best,
    Kelly
     
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  4. rocco

    rocco Silver

    That seems like a pretty typical experience, most of us here that have used commercial refractories aren't really equipped to rigidly follow a recommended firing schedule, we do the best we can and most of the time, that's good enough.
     
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Not saying nor advocating for uncontrolled full heat cure to castable refractory, just that the manufacture's recommendations are usually formulated around much more massive commercial structures and those schedules can be inordinately conservative for things like our hobby furnaces. Patchwork by it's nature is usually minor so not surprising that just gets the wick turned up.

    I still think one is well advised to follow a more gradual ramping in heat to cure thin castable refractory structures just more on the order of a handful of hours rather than 30hrs!

    Also, I think plastics start out with less water than castables, especially the typical user here which will tend to mix wetter for ease of placement.

    Best,
    Kelly
     
  6. Melterskelter

    Melterskelter Silver

    I was neither surprised nor disappointed that the instructions were aimed at more industrial users than probably anyone here on the forum except maybe the guy from Logan. But, I did find some very useful nuggets. For instance I now recognize that I had some steam spalling on one of my segments. I did form my plastic on metal shutters (I learned that term in the handouts) and likely did not vent deeply enough. I did use a pounce wheel and avoided almost completely bubbling or spalling on the air side of the layup. But, on one segment there was a sort of oblique separation of the plastic on the shutter side. That was probably due to my greatly accelerated drying "schedule" and lack of through-vents that they recommended. Had the instructions not come after I had completed forming and cooking the segments, I would have done a better job of venting. Also, it was informative to see that there curing plan maxed out around 1750 indicating, most likely, that full vitrification occurs at that temp. As it was I warmed my panels to 650 to 700 using a weed burner. My sections were only 1/2" so they undoubtedly dried much much faster than a 6" or 12" thick wall. But still, I am sure the 20 mins or so of gently applying the burner was not optimal and I did directly apply flame to the plastic which they said to avoid. Once steaming stopped (and that seems to agree with an endpoint they recommended following) I turned the burner to half power or so for perhaps 5 to 7 mins and watched for steaming backing off it any was seen. My spalling probably occurred because I was overly aggressive with heat as I gained confidence (it was the 3 panel) in heating the material. Once steaming seemed to be gone completely, I then went full bore with the burner and got the panels up to 650 to 700. That dried them thoroughly and they were fairly strong at that point. But vitrification occurred yesterday when I again warmed them in stages but finished at white heat held for only 10 minutes or so. I was impressed that bits of plastic I crammed into small spaces survived just fine with no preheat, just the furnace warm up followed by full heat.

    Other areas covered that I felt were useful were admonitions to not smooth the surface and to actually roughen it with a curry comb. Management of openings without "boring" them but actually packing them to forms was useful as well. There are more, but no need to list them all. Each person can now read through them if they wish and extract what may be useful to their particular circumstance.

    Comment:
    1) It seems odd that the documents are not easily found online. My supplier grumbled a bit that he had to reach out to someone at the manufacturing facility to actually get his hands on them. I don't get that, but that is the way it is.

    2) A better way to cure these panel would likely have been to build a temporary oven from blanket and chicken wire and to have been a bit more patient.

    3) At one point I was toying with using wood shutters and burning out the panel from the shutter. Based on my reading of the papers, I think that is not a great idea.

    Denis
     

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