jscott.pi...@juno.com wrote:
> >On Tue, 16 Jan 2007 17:09:54 -0600 Larry&Sallie Flesner ><fles...@verizon.net> writes: > > >>At 03:39 PM 1/16/2007, you wrote: >> >> >>>But I thought peel ply left a skin of silicone on the epoxy???? I >>>thought you had to remove that before you laid another layer on?? >>>Fred Johnson >>> >>> >>+++++++++++++++++++++++++++++++++++++++++++++++++++++ >> >>I've not heard of that before. Most of my use of peel ply was on >>the >>top or finish coat and only had finishing materials applied. No >>problems that I've observed. I'm sure I used peel ply and then >>later applied epoxy / glass over that area after removing the peel >>ply but again, I've not observed any problems. Several areas on >>my KR are over 10 years old since construction and with 270 now >>on the KR I've just not seen a problem. >> >>Larry Flesner >> >> > >There is a type of peel ply that is typically only used with synthetic >pre-pregs that has a silicone release agent sprayed on it. If you use >that particular type of peel ply, you need to clean the glass before >attempting to bond to it. Having said that, you would only have that >type of peel ply if you went out of your way to order it from a >composites supply house. You won't be buying it through Wicks or Spruce >and it's not cheap. > >Most peel ply is plain old dacron fabric just like you would use to cover >a fabric airplane and has NO release agents. It works well with wet >layups leaving the surface ready for sanding or bonding. Check the part >numbers in the Aircraft Spruce catalog. Their peel ply has the same part >number as their light weight uncertified dacron cloth. > >Jeff Scott > > > I saw the head manufacturing guy at Columbia Aircraft talk about quality controls at the plant. He said due to the drastic failures silicone can cause for composite bonding, there is not a single can of silicone in the plant... -dave
