My Attempt at an IFB Domed Furnace Lid

Discussion in 'Furnaces and their construction' started by Melterskelter, May 6, 2019.

  1. Bubble alumina is not bad, $64 for 5 lbs. 3,300F rating. It is highly flux resistant.

    Satanite is cheap, $46 for 20 lbs. 3,200F rating. It is flux resistant.

    My furnace is firebrick and Satanite and it heats quickly. I have wool around the outside of the firebrick just to cushion them against the steel shell.

    Both Satanite and bubble alumina are recommended for coating wool.
     
  2. Tobho Mott

    Tobho Mott Gold Banner Member

    On hightemptools.com, it lists a rating of 3200F for satanite.
     
  3. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    >$12/lb not bad? Wow, with pockets like that farming must be pretty good. When I looked at BA I thought it was the 4 Vs. Very: high refractory, insulating, flux resistant, and high priced........but, if it does the job.

    As for Satanite: SDS It has an interesting composition. Lot's of different materials in the mix.

    https://thinkhwi.com/products/satanite/

    You have to hunt hard for the tech data sheet but here it is. It was originally intended as a firebrick mortar. Interesting as it lists a water addition for dipping!

    Best,
    Kelly
     

    Attached Files:

  4. No, the big money is in home casting.

    I think it's a pretty good price compared to brick or refractory for a long lasting furnace. Denis will prove it soon.
     
  5. Melterskelter

    Melterskelter Gold Banner Member

    This is a mixture of coarse and fine material. The larger bubbles are 1/8" or so.



    I don't think there is a practical way to spray it. I mixed it with water to a consistency that would not quite form a ball and then troweled it onto the horizontal surface (added later: AFTER spraying the surface to make it wet wet using a hand-pump sprayer and spraying small areas, applying to that area and so on. The brick soaks up water so fast it does not stay wet long). Troweling it onto a vertical surface would be very challenging as near as I can tell as it just is not a cohesive paste (like Satanite which can be so easily applied) when mixed as the bubbles are so coarse. After sort of troweling it on, I used a weed burner to heat the BA until it was glowing in high spots. I did this immediately after application without waiting for it to dry. The heating made it adhere quite firmly. Is this the right way to do it? Dunno. But it seemed to work. When I talked to a bubble alumina manufacturer's tech guy he said this was the first application as a surface treatment that he knew of. It is intended to be used as a formed refractory. Hearing that from him did nothing for my confidence in this surface-applied usage.


    I think it might be possible to coat the inside of an IFB furnace with BA if you tipped the assembled furnace on its side and troweled on BA to the lower 1/4th of the furnace lining, hit it with a weed burner, rolled 90 degrees, repeat etc. If the BA proves durable that might be a good alternative and might be an especially good coating for the floor given the very high resistance to chemical attack (I'm thinking iron drips and aluminum drips) of the BA.

    I bought a Large Flat Rate Box of BA for about 100 dollars. that would be enough to coat the inside of a decent-sized furnace. I bought mine from High Temperature Tools.

    Denis
     
    Last edited: May 28, 2019
  6. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    MS, applying coatings to IFBs can be affected by the IFB's propensity for wicking water out of the coating. My local tech guy told me this makes coatings hard to spread and can actually adversely affect the cure of mortar or castable. Wetting the IFB prior to application helps. He mentioned he had even used concrete water seals, or a very dilute coat of mortar first........might make BA application easier next time.

    I know you are aware of this site, just wondering what you thought about the BA and Corundum Brick. Not sure about the brick size/shape shown at the link.

    http://ktrefractories.com/Refractory-Bricks.cfm

    I have no idea how it cuts or how much it costs. I suspect it is tough expensive stuff so may not be practical. -Dunno. If it could be cut, the corundum might be a candidate to tile the furnace floor.

    Best,
    Kelly
     
  7. Melterskelter

    Melterskelter Gold Banner Member

    OOOOPS, Forgot to mention above that I did spray the brick with a pump sprayer to moisten the surface immediately prior to spreading the BA.. The cementatious "setting" of the refractory I thought was hopeless in this thin application. So, I just skiped that went immediately to fusing it with heat. By default the fines did form a sort of skim coat of BA and then the coarser stuff (and I do mean coarser) stuff started to sort of adhere. The heat was the definitive factor I THINK. Don't know about corundrum bricks (are they like conundrum bricks?:D)

    Denis
     
  8. PatJ

    PatJ Silver

    I just found a source for "Plastic A".
    55 lbs for $94.00 including tax, but not including shipping.

    It seems like this could perhaps be used for a hot face depending on what its rating is and how it holds up.
    I will open my furnace today and see what my patches look like.
    But at this price, I could do some serious hot face patching every time I use the furnace.

    Compared with ITC100 at $64.95 a pint (yikes !).

    They used Plastic at to repair the interior of the cupolet at the Metal Museum, and just slapped it on and hand-packed it out flat, one area at a time.
    So I am thinking either hand pack or water down and spray on a coat of Plastic A over some IFB's, and omit the cast refractory altogether.
    With this method, you could literally make a furnace in a day, using simple tools.

    Edit:
    The sprayer would have to be able to spray some very coarse material, and I am not sure if this is possible or not, although I have sprayed on some bubble stuff on an interior ceiling in a house, so maybe possible.

    Edit02:
    And here we have it, ESC has already been there and done that with the IFB furnace with a coating on the interior.
    I figured somebody had already tried it.
    I somehow missed that thread. I had a big work project going for about 8 months and was not following.
    http://www.alloyavenue.com/vb/showthread.php?11532-1914-Indian-V-twin-heads/page7&highlight=Indian


    Edit03:
    The last page of the thread:
    "The insulating firebrick did not hold up to the temperatures I needed to pour cast iron."
    http://www.alloyavenue.com/vb/showthread.php?11532-1914-Indian-V-twin-heads/page8&highlight=Indian

    And that is what I have experienced also, but I was using an IFB rated at perhaps 2250 F, so that is to be expected.
    Perhaps with a 3,000 F IFB's it may work.
    .
     
    Last edited: May 28, 2019
  9. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    It may or may/not be any better than a high alumina mortar. Sort of depends on what it is but plastics come in all formulations and are only plastic for ease of placement. Most manufacturers vary their formulas for different methods of placement by ie: hand, vibed, gunned, rammed etc.

    If they are using Plastic A to patch a couplet, besides refractory, it probably bonds well, is low permeability, and resistant to metal contact..... but that may not necessarily make it a superior hot face covering for IFB. The key for these coated wool furnaces may be getting a very high refractory zirconia wool for the first 1/2" so it doesn't breakdown. MS' IFB dome will definitely provide some more structural support but the IFB isn't any higher refractory than 2600F wool.....probably will be just a matter of how much it degrades at service temp.

    Since Satanite was originally developed as a heat setting IFB mortar, it's probably reasonably well (as possible) matched in thermal expansion to IFB, and based upon it's popularity in use in forges, it apparently is fairly resistant to chemical attack......and at 3200F seems like some pretty good for qualities for a fuel fired iron furnace.

    I can say with a fairly high confidence that Vesuvius Super 3000 (another high alumina Mortar) will eventually peel and lift the surface of IFB with repeated cycling.....even at <1800F. Dunno about Satanite but I'm guessing the denser the IFB the lesser this tendency with any dense coating.

    Best,
    Kelly
     
  10. Melterskelter

    Melterskelter Gold Banner Member

    The bottom line, the reason for all this foolishness:

    4CB8A892-B253-49FD-8D14-43526BC820B4.jpeg D2B2A4EE-43A9-48A6-A739-D3D2F6D09D01.jpeg B03463FB-051B-4CF5-AE43-62AF6DE99D90.jpeg
    One of the two 18’s I cast yesterday. 20 to 22 pounds including riser,sprue, oversized pouring basin(which makes life so easy.)

    Denis
     
  11. PatJ

    PatJ Silver

    I am interested to see if you can pull of that big one you mentioned previously.
    I guess with a large enough crucible, just about anything could be poured.
    Scavenger was up to a #70 before he retired.

    The Satanite seems like a good product.
    I guess I will try Plastic A first since it is cheap and locally available.

    .
     
  12. ESC

    ESC Silver Banner Member

    None of these coatings are rated for the 3600* F of the oil flame, so in that sense they are another consumable. That being said I will take a shot of the lined shell from the link Pat referred to. It has been in use since 2016. My lid is the original from the early '90's when I first built it. The material was ShastKast I believe, a 2800* dense castable.
     
  13. Melterskelter

    Melterskelter Gold Banner Member

    I agree that Satanite may be a good choice for IFB. What I shoulda done is coat half the lid with Satanite and the other half with BA! I guess the really attractive thing about BA was it’s high resistance to corrosive materials/atmospheres.

    But Satanite is certainly easier to apply and it has been pretty resistant as the hot face on the vertical faces of my wool furnace. I suspect it would work well on IFB. Hasn’t OIF used it in IFB successfully?

    Denis
     
  14. Melterskelter

    Melterskelter Gold Banner Member

    The 48” SE will weigh about 50 pounds or a bit more with basin, sprue etc. There are a few things that have to be done prior to the pour.

    1). Make the pattern
    2. Make the larger flasks
    3. See if the hoist fits the 25 crucible. Currently using a 20. Make whatever needed hoist changes
    4). Make a new ring for the trolley
    5). Make new runner and sprue patterns

    I am not worried about the size of the pour. I just need to fairly soon start on all of the above.

    Denis
     
  15. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Good for you MS....all a means to an end.

    Best,
    Kelly
     
  16. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Assuming the furnace atmosphere ever reaches the max flame temp...right? ....and then assuming the hot face surface temp ever reaches the furnace temp. You have to have temp differential in order to conduct heat through the wall......with some fine tuning you might get within 100-200F at each transition zone which may explains why 2800F refractory survives.

    So per your old AA thread, after the mortar coated 2600IFB gave up, the furnace wall ended up being about an 1" of Mizzou over (2"?) 2600IFB and the lid is what? Solid ShastKast or?

    Best,
    Kelly
     
  17. I've been using Satanite on IFB with great success melting aluminum and occasionally brass/bronze/copper but only two iron melts. The Satanite is holding up very well and is hard at the flue opening where I bump it with tools during charging and skimming.

    Precisely, Kelly. The only place you'll have temperatures approaching flame temperature is at the flame impingement areas. I've been measuring flue gas temperature while I'm waiting for a melt and often see 1,100F when the melt is at 1,500F. Even at higher temperatures it is interesting to put a thermocouple into the flue and watch the temperature go up, pulling it back at 2,000F. It doesn't get there melting aluminum bronze.
     
  18. PatJ

    PatJ Silver

    This seems odd.
    Wouldn't the flame temperature have to be some differential above melt temperature? else you would never reach melt temperature?

    Edit:
    I dug out my Pyro iron-rated optical pyrometer, and will put a new batteries in it (I converted it to alkaline).
    I feel confident enough with iron to try it again, and will get the melt hot, and then open the lid, skim, and take a reading.
    Edit: The early iron melts I did use to terrify me.
    I was not really sure if something (burner, iron, spill, whatever) was going to jump up and bite me (it did once, but I got better and the skin grew back on my finger).
    Now days, melting iron is much more routine, although not without its little hazards.

    I guess to get an accurate comparison, I should also pull the crucible and close the furnace, and then take a second reading, to be sure the IR/UV from the furnace wall is not throwing off the reading.

    3-$_122.jpg


    Edit02:

    I put some poop on the Pyro optical pyrometer here:
    http://forums.thehomefoundry.org/index.php?threads/optical-iron-pyrometer.466/

    I have no idea who the Egyptian man in post #4 is. :D

    .
     
    Last edited: May 28, 2019
  19. ESC

    ESC Silver Banner Member

    Yes, this is the original lid. Its over 20 yrs old and was on the furnace when I cast the first iron smallblock. I have used a grinder on the sealing surface when I cast a new furnace body.

    IMG_20190528_150402.jpg

    This is the body from the AA thread. It has had multiple cast iron melts plus the aluminum melts I've done since then. I use the IR thermometer and when I get a outer skin temp of 300* the interior is around 2500* and I will start to check temps with the optical pyrometer. When it was dense castable the skin temp reading was around 700* and I had difficulty getting the superheat I needed for the thin parts. I usually aim at the back wall for the first ones and if I slag off and return the crucible to the furnace I will try to get the reading from the surface of the melt. The seal at the lid surface needs repair, It was a leveling patch of some furnace cement.

    IMG_20190528_150353.jpg
     
  20. Melterskelter

    Melterskelter Gold Banner Member

    What you are reporting here squares very well with my observations on vent gas temperatures. “Back in the day” before I had to dream up and make a muffler for my furnace, I welded up a SS grill that resided over the vent full time and on which I preheated chunks of iron prior to adding them to the melt. I noted then (and reported here) that the grill itself never got over a fairly bright cherry red. That was an inch or two above the vent opening. That would correlate with about 1600 deg while I was melting iron at 2500 and still climbing. I am thankful for the cooling of exhaust gases. Otherwise my chimney—a sheet metal duct lined with one inch of rigidized 2600 deg wool would be long gone.

    There is much to understand about this furnace business. Maybe we should all get together somewhere nice and hire an expert on flame and furnace to teach us. Or maybe we should just keep on pooling our observations and keep on trying to tease out the meaning.

    Denis
     

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