What is CABOSIL ??

[Van - E-Mail LIST]

I have got to tell you, from the e-mails I have read from Gray and Lance in the last few weeks as I ready to build my Entropy. I have learned a TON about glass and gear. this is VERY VERY cool.

Thanks guys,

Van
________________________________________________

Van Flowers
AMA: 6216 IMAC: 2229 
IMAA: 26019 NSRCA: 2778
www.rc-aerobatics.com




  ----- Original Message ----- 
  From: Gray E Fowler 
  To: discussion at nsrca.org 
  Sent: Friday, September 06, 2002 12:37 PM
  Subject: RE: What is CABOSIL ??



  Mike 

  Neither cabosil nor microballoons are structural and they way you are using them is correct. Cabosil does not change the strength of the epoxy much at all and is used just to increase the thixotropic index -to make it not flow. 6% cabosil by weight when mechanically mixed will turn a low viscosity resin into jelly. Microballoons do reduce the strength of the epoxy but most of the time this is okay becuase it is still strong enough for our airplane applications. And as you know microballoons greatly increase volume and reduce the density of the epoxy. 



  Gray Fowler
  Principal Chemical Engineer
  Composites Engineering 


       "Baiano, Mike [HCS]" <MBaiano2 at HCSUS.JNJ.com> 
        Sent by: discussion-request at nsrca.org 
        09/06/2002 11:08 AM 
        Please respond to discussion 

               
                To:        "'discussion at nsrca.org'" <discussion at nsrca.org> 
                cc:         
                Subject:        RE: What is CABOSIL ?? 



  HI Verne, 
    
  So does micro-balloon expoxy mixtures have any structural strength? I have both micro-balloons and cabosil - and I'm never quite sure when I should use one as opposed to the other. I generally reserve the cabosil when I just want to thicken epoxy into a paste, and weight isn't a huge issue. How do you decide which one to use for a particular application? 
    
  Thanks, 
  Mike 
  -----Original Message-----
  From: Verne Koester [mailto:verne at twmi.rr.com] 
  Sent: Thursday, September 05, 2002 11:41 PM
  To: discussion at nsrca.org
  Subject: Re: What is CABOSIL ??

  Cabosil is fumed silica sand. It's extremely light weight. When mixed with epoxy finishing resin, it creates a paste that won't run on vertical surfaces. It's also frequently mixed with epoxy in a thinner mix and brushed into a mold to create the external gel coat on a glass part which prevents pinholes from making it to the surface of a part. On a clear epoxy-cloth piece, the epoxy/cabosil mix can be seen in all the 90-degree corners to bridge the radius the cloth can't make. It'll show as an opaque white as opposed to the clear epoxy/cloth you see everywhere else. Down side is that it's much tougher to sand than micro-balloons and has virtually no structural strength. Good stuff to have around, though. I use it a lot. 
    
  Verne 
    
    
  ----- Original Message ----- 
  From: Van - E-Mail LIST 
  To: Pattern LIST 
  Sent: Thursday, September 05, 2002 8:32 PM 
  Subject: What is CABOSIL ?? 

  Don't think I know what this is ? 
  ________________________________________________ 
    
  Van Flowers
  AMA: 6216 IMAC: 2229 
  IMAA: 26019 NSRCA: 2778
  www.rc-aerobatics.com 
    
    
    
    


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