Spoken like a man who know his stuff also might add that to stay away from anything that has varnish in it or reference to it. Happy Flying, guys.
Wood, Sidney M. wrote: > Type A epoxy resins contain a small amount of wax. The curing epoxy is > hydroscopic: The resin draws moisture from the air; this will interfere with > the polymerization process and drastically slows down the curing process to > the point of staying tacky for months. The wax film prevents the hydroscopic > action. Type B epoxy resins (so called laminating resins) do not contain the > wax. Their intended use is for multiply lay-ups in quick succession before > the first or under laying lay-ups have cured. The final lay-up would use > Type A resin for open air room cure. Vacuum bagging would use Type B > throughout. Unless the label says otherwise, you can assume the resin is the > Type A containing the wax. The resins used in polyester and vinyl ester tend > to dissolve the surface of cured epoxy, which then resets in the curing > process to effect a tighter bond. Do not confuse this ester to epoxy bond as > a true polymer bond. These are totally different families of chemicals. It > wou ld be like saying lizards and birds lay eggs, so they should be pretty much the same animal. As stated in the previous post, it's not a good idea to mix systems. > Sid Wood, Tri-gear KR-2 N6242 > Mechanicsville, MD, USA > sidney.w...@titan.com > > -----Original Message----- > From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On > Behalf Of cartera > Sent: Monday, August 09, 2004 12:13 PM > To: KRnet > Subject: Re: KR> Epoxy Varnish on Spars > > Good Morning > This is a misconception, cured epoxy does not leave a waxy residue only > in the esters does this happen. That is why one if necessary can put > polyester on epoxy but not epoxy on any polyester. Furthermore, it's not > a good idea to mix systems. Suggest that a > thorough research be done on resins before this misconception is thrown > out. This is why it is not a good idea to use varnish on the inside for > sealing, but epoxy diluted with alcohol then one does not have to sand > out varnish in the event that further gluing has to take place. However, > it should still be roughed up before gluing for adhesion. > Happy Flying! > > patrusso wrote: > >>Cured epoxy leaves a waxy residue that must be cleared off from surfaces >>that will be reglued to attach other parts. You may find it easier to finish >>you rib and other attachments to the spar before epoxying. >>----- Original Message ----- >>From: <rick...@comcast.net> >>To: <kr...@mylist.net> >>Sent: Monday, August 09, 2004 1:48 AM >>Subject: KR> Epoxy Varnish on Spars >> >> >> >> >>>I have some epoxy varnish left over from painting the inside of the fuse. >> >>Is it OK to use it on the spars? They're closed, but I haven't begun to >>assemble the wings yet. >> >> >>>Rick Coykendall >>>KR-2 >>>rick...@yahoo.com > > -- Adrian VE6AFY Mailto:cart...@spots.ab.ca http://www.spots.ab.ca/~cartera
