Lloyd,
Excellent tips. Thank you. I wasn't running any heat source near the layup,
but I do have the shop at 23 Centigrade (75 F.) However, I only use one batch
of epoxy per layup so there's less chance of "old" epoxy getting tossed into
the mix.
BTW, as I look back I'm thinking I may have caused the cloth to pull away while
I was repairing two small raised areas. I wasn't sure how long it took to heat
up the cloth to get it plastic, so I had my heat gun (read: hair dryer) on the
area for several minutes. I may have transferred so much heat to the area that
I raised the forward section of glass without noticing it. That would explain
why neither my wife nor I noticed the "long" run of raised glass until this
morning.
As for the fix, I went really low tech. I used about a dozen wide rubber
bands, arranging most along the width of the piece and the rest stretching from
TP-6 to the leading edge of the core. (Think of Gulliver being tied down by
the Lilliputians; same image.) I hit the area with some heat and watched the
high spots pull down under the tension of the bands. Once I get my replacement
syringes from Aircraft Spruce, I'll inject some epoxy into the area to fill the
small void space left behind. It ain't perfect, but it looks like it'll fly.
Regards,
Steve "Does all this rebuilding count as putting together 2 aircraft?" Genotte
GERAINT L OWENS wrote:
> >Has anyone else had a similar problem? I'm keen to hear any suggestions
> >you may have concerning repair.
>
> Hi Steve
>
> Not sure about how to repair, but I caused the same problem to my own work
> in the early (and not so early!) days by 'force drying' lay-ups with too
> strong a heat (ie. a 3kW fan heater). What happens is that the air under
> the lay-up expands with the heat and causes the kind of problem you
> describe. I am now careful_not_to use too strong a heat, or to position
> the fan heater far enough away so as to not cause the problem. This may,
> or may not, be what caused your problem; but this advice may save you (and
> others) learning the hard way. Other glassing tips:
> 1 don't keep working the epoxy once it starts to get warm or go thick.
> Throw it away, and mix up some more. Fresh epoxy is so much less viscous
> than 10/15 minute old epoxy and is _much_ less likely to cause bubbles in
> your lay-up.
> 2 once you've been using your brush for 10/15 minutes, don't squeeze
> excess epoxy from the brush into your current epoxy cup. This 'old' epoxy
> will cause the fresh epoxy to go off quicker.
> 3 for the same reason, don't keep using the same brush on a long lay-up.
> Brushes are cheap compared to your kit; so keep a handful by your side each
> lay-up ... and throw them away once they start to get a bit gunged-up with
> epoxy.
> 4 don't do lays ups in conditions hotter than 20/22 centigrade (68/72
> fahrenheit?). Your epoxy will go off prematurely if you do and make the
> work much harder. Turn the heat up in your workshop just as you're coming
> to the last ten minutes of your lay-up ... then keep the heat up. Just a
> few of my own tips, learned the hard way, and not found in the Europa
> manual. Regards.
>
> Lloyd Owens (Bu. 097) - possibly one of the slowest kits being built!!!
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