Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Metal strips back of steam radiator?

franzsf
franzsf Member Posts: 5
edited November 2021 in Strictly Steam
Long time listener, first time caller. Really appreciate all the advice on this site; we moved into a house with one-pipe steam last year and I've spent that time tweaking the system. Almost runs like butter now.

Has a question about (a) the function of these metal "strips" attached between the backs of the columns on most of our radiators and (b) if its a bad idea to remove them if we're intending to repaint and then rotate a radiator 90 degrees during a bathroom remodel.

I suspect the answer has something to do with trying to keep heat away from the wall? Or maybe something to do with convection.

Pictures of the rad in question. The rad will be rotated 90 degrees towards the bottom left of the frame of the first picture, so the metal strips will be on the new front.

Thank in advance for any insight.


Comments

  • Jamie Hall
    Jamie Hall Member Posts: 17,829
    That's a new one for me... but that's a pretty ordinary radiator otherwise, and I expect you can remove those...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,560
    edited November 2021
    Another inventor has left his mark on the world. If we only knew what the dead man had in mind when this was done. Perhaps the wall paper around the radiator was being discolored by the heat currents passing by the wall at a different rate than the rest of the wall.

    I think a dead wallpaper hanger asked a dead sheetmetal worker to make them for the dead steamfitter so the dead homeowner would stop complaining about the need to replace wallpaper every 3 years. Is there any wallpaper behind that blue paint?

    OR NOT?

    i agree with @Jamie Hall ... rip 'em out

    Mr.Ed
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
    PC7060
  • franzsf
    franzsf Member Posts: 5
    Nope. Paint is on plaster which is directly applied to the structural clay tile of the exterior wall (with brick veneer on the outside). I'll try prying one off and go from there. Thanks!
  • JUGHNE
    JUGHNE Member Posts: 9,345
    Do they extend down the back of the rad?
    They may have been used as a rear reflector to push more radiant heat out the front.

    It seems like they would cut down on the convection thru that back part, maybe to save the wall above?

    It looks like they just snap in place.
  • mattmia2
    mattmia2 Member Posts: 4,360
    Maybe the radiator is oversized for the room and someone was trying to reduce the output. Do they go all the way down the back?
  • franzsf
    franzsf Member Posts: 5
    edited November 2021
    Yep, they go all the way down the back, in these grooves on either side of each column. After attempting to remove one from the top, I think it'll be easier to tap them out from the bottom, with the rad on its side.

    Edit: I should note these seem to be on all our rads, so its not a one-off.
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 15,633
    They’re meant to block the radiant heat toward what is probably an uninsured wall. You can remove them. 
    Retired and loving it.
  • motoguy128
    motoguy128 Member Posts: 389
    Radiators are in reality primarily convectors. I would be negligible I suspect, the reduction in the amount of radiant heat going to the wall by radiation as those metal strips are also metal themselves and there’s no air gap between it an the radiator. It encloses the radiator partially mike some recessed wall convector radiators. They mainly would reduce vertical air flow out of the radiator and therefore reduce its capacity. I’d guess about 25% or so.
  • franzsf
    franzsf Member Posts: 5
    Thanks to everyone for their thoughts. I managed the get the strips off pretty easily by starting cuts at the bottom with a Sawzall. 95% slid out within seconds due the vibrating action of the saw alone.

    I did have a followup question about the type of radiator construction, and whether or not power-coating would be a bad/good idea.

    All the radiators in the house are Crane, likely 1930s, manufacture. The only documentation I can find online is this promotional pamphlet: https://www.historicnewengland.org/explore/collections-access/gusn/314219/ which isn't very helpful.

    Since there are no threaded rods going down the length of the radiator, I am assuming these aren't push-nipple construction? Are they threaded together? Gasketed? If I go the powdercoating route, are there any issues there? Any tips on how to handle the rad so as to not have it leak?

    Thanks in advance! 

  • Jamie Hall
    Jamie Hall Member Posts: 17,829
    Well... I'm a conservative sort of person, and I wouldn't care for heating up something for powder coating unless I knew for certain what, if any, gasketing was used.

    In fact, if I could get them out of the house, I'd have them sandblasted, sprayed with a good primer, and then sprayed with a top of the line acrylic (such as Benjamin Moore Aura) in whatever colour was wanted.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • franzsf
    franzsf Member Posts: 5
    Definitely considering, and there are a lot of good threads here on the refinishing issue. 

    I wish I had time to wire brush and paint myself, but as you might gather from the picture, I have skim coating, trim carpentry and finish painting to do on the room itself ... and all on my vacation time ... :)

    Anyway, just not sure if there are additional risks here with this kind of radiator construction.
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 3,046
    edited December 2021
    @mattmia2 said:
    Maybe the radiator is oversized for the room and someone was trying to reduce the output.
    ..........and I agree. Either the radiator was oversized, they added more insulation or someone made a mistake on the heat loss calc's. You may end up putting TRV's on some of those radiators, especially if you are adding insulation and/or replacing the windows.

    I think moving those radiators around too much for powder coating would torque them and then you've got a leak that's hard to fix.
    Often wrong, never in doubt.
  • mattmia2
    mattmia2 Member Posts: 4,360
    If there are no rods then there are left-right nipples that screwed in between the sections with a spud wrench through the core.
    Hap_Hazzard
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,643
    These should clean up fairly easily because there's plenty of space between the sections. Harbor Freight sells a wire brush that's perfect for radiators. I have a bunch of these, including one that I adapted to work on my reciprocating saw.

    You don't need to get the surface pristine. As long as all the loose paint, dirt and rust is removed, the paint will stick. The most important thing is to wipe the surface with a damp cloth to remove all the fine dust.

    I've had very good luck with Rust-Oleum High Heat paint. It's good to 1,200°F, doesn't give off a paint smell when it gets hot, and it doesn't require a primer. Just don't use the stuff that's made for engines—I've heard it smells terrible.

    Maybe I'm just biased because the previous homeowners slopped multiple coats of interior house paint all over my radiators that I found peeling off in huge flakes, but I'm not a big fan of using house paint on radiators. To me it just makes sense to use a paint that's formulated for hot metal and resists rust.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
    PC7060wlgann