Message-ID: <186ED3F9DB0AD311A34B00A02462185817BFD6@OEINT_LAF1>
From: "Westphal, D. (Dana)" <Dana.Westphal@Oceanenergy.com>
To: "'lancair.list@olsusa.com'" <lancair.list@olsusa.com>
Subject: Re: Lead Weights
Date: Tue, 27 Jul 1999 09:52:03 -0500
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
I submitted the words below to LNN sometime during 1995.  The procedure
worked fine, so I thought I'd go ahead and send it to LML as well,
especially since there has been a lot of discussion on this subject lately.
The plumbers lead method described in the recent LML digest sounds
interesting and worth further investigation.

Previous LNN Submittal:

I read with great interest Chris Toms' tip on elevator counter balancing in
the June/July 1995 LNN, especially since I was about to begin this stage of
construction.  It seems that counter balancing before close-out is a growing
trend among builders in order to get the lead as far forward as possible and
thus minimize weight.  I basically used Chris' technique, but would like to
share my experience on this subject.
	
I was not quite brave enough to pour molten lead into my MKII elevator
halves, so instead I built a mold by creating a "dam" with a tongue
depressor (~1-2" back from the LE of the CB), lining with release tape and
then applying a 1 BID lay-up into the area formed.  After cure, the
mold/lay-up was popped out, coated on the inside with Permatex* Ultra
Copper(tm) Silicone (good to 700 *F, 371 *C) and sunk into a pail of sand to
offer additional support and for insulation purposes.  I then put some lead
into an old non-stick saucepan (please clear this with your significant
other first) and then started heating it over a propane stove (outdoors of
course).  Using a portable torch (Mapp gas and oxygen), I melted the lead
and then poured it into the mold.  The stove may not be necessary, but it
helps keep the lead in a molten state prior to pouring.  After cooling, the
lead weight simply pops out of the mold and can be potted into the elevator
half using an epoxy/flox mixture.  I found that one mold for the lower and
one for the upper skin was sufficient.  The true perfectionist, however,
will want to make four molds since the parts do vary slightly.  Since I'm
trying to keep my building time to under 10 years, I opted to do a little
filing instead to fit the weights into the two halves that didn't have
molds.  Of course you will need more lead for the left side to offset the
weight of the trim tab and servo.  I was very happy with the end result -
the elevators hung about 1/2-3/4" below level after close-out as suggested
by the manual.  Final balancing will be performed after primer (as per the
manual) by drilling out some lead starting at the aft end first to achieve
the greatest weight reduction.  Don't forget to mark the lead positions on
the outside surface of the CB arms for future, post close-out reference.

Another tip: During the bonding of the elevators, I squeezed the TE between
the jig and some angle iron in order to achieve as straight of a TE as
possible (no "wavies").  Note that I used screws that passed through the
angle iron, TE and into the jig (remember to appropriately apply release
tape).  I was very pleased with the result.  In addition, I used an "angle
iron squeeze" technique on the TE of the HS during application of the 3 BID
close-out on the aft spar.  This was a bit more challenging, and I'm not
really sure if it was worth the effort. However, the TEs did end up pretty
"wavy-free" and made it easier to attain uniform clearances/gaps with the
LEs of the elevators.

Dana Westphal
(360 MKII)


>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML homepage:   http://www.olsusa.com/Users/Mkaye/maillist.html