Any experts on Silicone Tubing Heat Resistance | FerrariChat
Buy

Any experts on Silicone Tubing Heat Resistance

Discussion in 'Technical Q&A' started by robertgarven, May 27, 2013.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. robertgarven

    robertgarven F1 Veteran
    Owner

    Feb 24, 2002
    5,294
    Ventura, California
    Full Name:
    Robert Garven
    #1 robertgarven, May 27, 2013
    Last edited by a moderator: Sep 7, 2017
    Friends,

    I have the original aluminum heat shields on my exhaust system. They are in pretty good shape and thank goodness I have not had to remove them yet. The rear on hangs down low as it has about 1/4" of play. Fortunately the curved heat shield in the pic below rest against it and pushes it up a bit which is good, as when it hangs down it touches a few other bits. I cannot figure how to cinch it up(the header cover).

    There is a notch which has been in the shield since I had the car for 20 years and it wore a bit into the header shield so I put some JB weld there and that seems fine. It does rattle a bit and I was wondering if there were any experts on silicone here.

    My idea was to find some silicone tubing about the size of aquarium air tubing and cut a piece so that it slips over the sheild where it touches the header shield. I know it get very hot so just trying to figure out something that would keep it from rattling and rubbing.

    I think some silicone take high temps but not sure how hot that gets. Since my car is all apart I cannt get it hot and measure it.

    Knowing the variety of experts here i figured one of you is a silicone /heat/material engineer!

    Thanks in advance for any suggestions,

    Rob
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  2. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    3,373
    #2 vincenzo, May 28, 2013
    Last edited by a moderator: Sep 7, 2017
  3. robertgarven

    robertgarven F1 Veteran
    Owner

    Feb 24, 2002
    5,294
    Ventura, California
    Full Name:
    Robert Garven
    #3 robertgarven, May 28, 2013
    Last edited: May 28, 2013
  4. smg2

    smg2 F1 World Champ
    Sponsor

    Apr 1, 2004
    16,329
    Dumpster Fire #31
    Full Name:
    SMG
    #4 smg2, May 28, 2013
    I'm not following where the tubing or isolation material is needed. that said, JB weld is good to a MAX 500*F at 600*F it'll breakdown and fail. given that you've put JB weld on the shield I'd say that 350* high temp silicone would work fine. mcmaster-carr is worth surfing thru, you'd be amazed at the number of materials that may work for you.
    McMaster-Carr
    McMaster-Carr
    filter for high temp.

    the material is called polysiloxane.
     
  5. andyww

    andyww F1 Rookie

    Feb 7, 2011
    2,775
    London
    #5 andyww, May 29, 2013
    Euro 328s have a foam material on the bulkhead which is just a few inches from the front manifold and is in direct contact with the front heat shield.
    When I replaced this I contacted some manufacturers for advice and the outcome was silicone foam was the right stuff.

    It has been fine. I would think silicone tubing would work here. I dont think the heatshields get that hot, relatively speaking.

    BTW your curved heatshield is in such good condition! Never seen one that nice before!
     
  6. 2dinos

    2dinos F1 Rookie

    Jan 13, 2007
    3,024
    #6 2dinos, May 30, 2013
    I used silicone tubing as EZ conduit for emission testing. I was impressed how well it worked -AND- that the heat really did destroy it.
     
  7. ElastomerGuy

    ElastomerGuy Karting
    Rossa Subscribed

    Feb 25, 2007
    126
    N.W. PA
    #7 ElastomerGuy, May 30, 2013
    robertgarven:
    There are a number of ways to improve the heat resistance of silicone rubber. One of those ways is to put a little bit of iron oxide into it. You can tell if it has iron oxide in it by its color. Iron oxide imparts a kind of orange color to it. With a little bit of iron oxide in it, it should be good for continuous use at 200 to 225c and typically you will see specifications for the material written that call out testing at those temperatures. You should also find that materials with iron oxide in them are pretty common. Keep in mind that the 200 to 225c temperatures are for continuous use. The material will tolerate short periods of exposure to 250 and 300c and still remain elastomeric. The higher the temp, the shorter the exposure time and serviceability will be. Anyway, I think silicone is a good choice. In the eighties, our company made silicone rubber tubes that slipped over throttle and emergency brake cables that ran in close proximity to exhaust manifolds and catalytic converters. They provided protection from heat for the cables so what you're trying to do should work. Send me a PM with some dimensions for what you need. We might have something that I can send you to play with. I'm put of the plant til next week but ought to be able to get you something next week if we've got something in stock.
     
  8. robertgarven

    robertgarven F1 Veteran
    Owner

    Feb 24, 2002
    5,294
    Ventura, California
    Full Name:
    Robert Garven
    #8 robertgarven, May 31, 2013
    Elastomerguy,

    Thanks so much the heat shield is about 3mm thick I was thinking of getting some tubing as large of a OD as I could with a small ID slice the tube and slip it over the lower shilled. It pushes up the the header shield about 1/4" and is in constant contact not sure if that would be too hot. I have JB weld there for a few years and it never melted.

    Rob
     
  9. autowerks9

    autowerks9 Formula 3
    BANNED Rossa Subscribed

    Sep 1, 2009
    1,161
    North Wales, Pa.
    Full Name:
    David S.
    #9 autowerks9, Jun 1, 2013
    Last edited by a moderator: Sep 7, 2017
    We apply a self adhesive "lava shield" heat shield material to some of our carbon fiber items that need added protection and heat shields for some of our exhaust ( pic is of a set of 355 a/c-Alternator heat shields). If you are looking to protect just the area where the 2 overlap and impact each other. Its is only .025 inch thick and has a 800 deg. direct and 1200 deg. Indirect temp rating. It is easily trimmed with scissors. I would be more than happy to send you a strip to insulate between the 2 shield.

    David
    Image Unavailable, Please Login
     

Share This Page