Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by rhc

  1. rhc

    I seek a more durable plastic material

    As I recall Phenolics decompose around 300 deg C. Regardless of their excellent mechanical properties at elevated temperatures, when burnt, they give off a characteristic "Bakelite odour". The barest trace (I believe parts per billion)is easily detectable by smell or taste and that...
  2. rhc

    I seek a more durable plastic material

    Look at marfotd's original spec:"To keep the inner stainless steel wall free of the burned food residu, we use ptfe(eriflon) scrapers (l=162mm,b=50mm,d=20) The scrapers are pressed against the wall with a spring construction." The key word here is burned. PTFE is great stuff but in...
  3. rhc

    I seek a more durable plastic material

    Hi nbucska I agree with your sentiment but it woodn't do because you wood end up with a lot more fibre than you wood bargain! Try hitting wood with high pressure steam at 180 deg. C. As an engineering excercise my choice would be to use a fully cross-linked high molecular (novalac) phenolic...
  4. rhc

    Oily Water Separation On Board Ships.

    Look at www.quickwater.com.au & go to "about us"
  5. rhc

    Making "permanent" plastic bubbles

    sciguyjim I think you got on to something with your "long lasting non permanent bubbles" glycerine comment. It made me think how would gelatine or room temp setting agar agar go. Being such a thin film one of them might emulate a rapid set polymer. Has anyone tried either?
  6. rhc

    Hardening Of Aluminium Threads

    Dave, this is way out of my area but could you punch the holes with a special forming punch - you might "extrude" a longer hole for more threads.
  7. rhc

    boron carbide as cut glasses fore decors((ASAP)

    Tessa, What exactly are do you want boron carbide for. You mention cut glass. Do you want to make "glass" shapes with boron carbide?
  8. rhc

    Hardening Of Aluminium Threads

    Thanks CoryPad I was not reccommending socket head cap screws only stating that we use them. We have space & streamlining issues that overide bearing area. The device is made of 316L stainless steel and fastened to aluminium with M10 316L socket head capscrews. It is my experience that during a...
  9. rhc

    Convoluted stainless steel flexible hose

    Stainless steel if continually worked hard becomes stiff & brittle. We have tried ss springs but they did'nt last as long & were unpredictable. We went back to conventional spring steel.
  10. rhc

    Small Vacuum Mixer

    For what its worth I remember seeing a laboratory mixer which employed an external geared revolving magnet as the driver. A self centering magnetically attactive material was placed in a glass jar with the solution to be mixed and it worked a treat. Sounds like you will need strong magnets! Hope...
  11. rhc

    Hardening Of Aluminium Threads

    We have an application which requires a device to be "permanently" fastened to an aluminium base with M10 coarse thread ss scocket head cap screws. If the screws get loose the device fails. In operation it is always underwater and subject to constant vibration and occaisional severe...
  12. rhc

    General question!!

    There are two strengthening mechanisms present. IRstuff is right ......"A rule of thumb is that stiffness increases as the cube of the thickness, so 6 folds works out 24^3 increase in stiffness, which explains why the difficulty in folding does not go linearly."...... But DVD is also...
  13. rhc

    To seal or not to seal We are in

    To hero123 If you have direct experience and can provide practical information about a high rpm seal that will work in the 100mm x 120mm x 50mm space we have available we would appreciate. The shaft rotates, the carrier does not
  14. rhc

    To seal or not to seal We are in

    To seal or not to seal We are involved in an R&D project. Part of the project requires that a seal isolates fluid from the inner chamber to the outside. Fluid = water + fine abrasive particles Shaft dia = 100mm Carrier = 120mm Len = 50mm rpm = 1000 ~ 6000 Fluid pressure = 100 psi We were...
  15. rhc

    Lubricating a chromed bearing surface

    I need to correct a typo ........."Fast rotating shafts are the Achilles heel of this group of materials . We sometimes come across marine"....... Should read ......" Grease and fast rotating shafts are the Achilles heel of this group of materials . We sometimes come across...

Part and Inventory Search