Quick building question

[wgalligan]

I'm with "U" PatternDUDE!!!!
I have experienced the shrinking qualities of the epoxy in some fill areas of a now departed airplane that was thinned with alcohol.   If it was shrinking in a fill area imagine what would happen in a critical area like a joint or in the glass seam... could it shrink enough to pull on the center joint casueing problems... I dont know but I wouldnt want to find out.
WG

 Hey epoxy cutters,
> This may be obvious, but I've seen some statements that can be misleading. 
> When anything is added to epoxy, it either evaporates out or stays in the 
> mix.  When you add alcohol or acetone to epoxy the mixture will be thinner, 
> but these solvents will severely weaken the epoxy.  When we paint it on balsa 
> (as in glassing wings) the solvent evaporates off, but if you use thinned 
> epoxy on other applications (where the epoxy is inside a joint) the solvent 
> molecules will be bound into the epoxy matrix and the result will be weaker 
> epoxy.
> 
> You can prove this by leaving the epoxy/alcohol mix 1/4 inch deep in your 
> epoxy mixing cup.  When you come back the next day, it will be cured,but 
> rubbery.
> 
> The best way to get thin epoxy is to start with a thin epoxy.  Don't start 
> with thick epoxy, unless you don't care about strength.
> 
> --Lance
> > Use denatured alcohol (ethanol) to cut epoxy and be real careful how much 
> > you use.  Usually a few drops will thin it down a lot, and adding it will
> > take the cure time from whatever it might have been to overnight or longer.
> > You can buy it at Walmart in 1 quart cans.
> > 
> > Adding acetone may thin epoxy, but it will attack foam.  The only thing I
> > use it to thin is Aerogloss Dope.
> > 
> > ----------
> > From: Bill Mears <bill at mears.com>
> > To: discussion at nsrca.org
> > Subject: Re: Quick building question
> > Date: Wed, May 7, 2003, 9:54 AM
> > 
> > 
> > Can  acetone ne used to cut epoxy ?
> > 
> > Terry Brox wrote:
> > The view was certainly proof of that  LOL
> > ----- Original Message -----
> > From: "wgalligan" <wgalligan at cnbcom.net> <mailto:wgalligan at cnbcom.net>
> > To: <discussion at nsrca.org> <mailto:discussion at nsrca.org>
> > Sent: Wednesday, May 07, 2003 9:12 AM
> > Subject: Re: Quick building question
> > 
> > 
> > 
> > I think he os leaning more towards the "something" thing.
> > WG
> > 
> >  > Are you an epoxy expert or something?  LOL
> > 
> 
> > BTW, Your new contest mate sure has a cute, um, shoe. LOL
> >   ----- Original Message -----
> >   From: Gray E Fowler
> >   To: discussion at nsrca.org <mailto:discussion at nsrca.org>
> >   Sent: Wednesday, May 07, 2003 8:41 AM
> >   Subject: Re: Quick building question
> > 
> > 
> > 
> >   Steve- Rubbing alcohol is a mixture of isopropyl and and water. Water
> > 
> > bad. Epoxy hate water.......Plus amines (the epoxy hardener) really do >
> > 
> > not dissolve well in isopropyl. You are better off with methanol or >
> > denatured alcohol which is ethanol with a nasty taste killer so you > won't
> > drink untaxed alcohol.I do not know what epoxy you are using, but > that
> > center reinforcement is easy without cutting the viscosity. Bring > it to my
> > house I have lots of low viscosity resins.
> > 
> > 
> > 
> >   Gray Fowler
> >   Principal Chemical Engineer
> >   Composites Engineering
> > 
> > 
> >        "Steve Barlow" <stevebarlow at attbi.com> <mailto:stevebarlow at attbi.com>
> >         Sent by: discussion-request at nsrca.org
> > <mailto:discussion-request at nsrca.org>
> 
> >         05/06/2003 10:10 PM
> >         Please respond to discussion
> > 
> > 
> >                 To:        <discussion at nsrca.org>
> > <mailto:discussion at nsrca.org>
> >                 cc:
> >                 Subject:        Quick building question
> > 
> > 
> > 
> >   Guys,
> > 
> >   I'm doing the fiberglass reinforcement over the balsa sheeting where >
> > 
> > the main wings are joined on a .60 size kit.  Can I use rubbing alcohol > to
> > cut the epoxy with to thin it just a bit?  Do you think that would > cause
> > me any problems?  It sure would make it easier.
> > 
> >   Thanks,
> >   Steve
> > 
> > 
> > 
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> > 
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> > 
> > 
> > 
> 
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