Hello All,
Carl and Dot Pattinson.
We have only been wired up for a week so here's our first contribution.
Firstly, loved Doncaster, very interesting meeting everybody. Venue really good
and would certainly go again. Trevor and Helen Jackson did a really superb job
of organising things.
FILLING AND SANDING
We have filled and sanded all our flying surfaces. For the filling we did use a
Kenwood mixer (old one out of the loft) This really made life easy. We used
three mixes per wing side. This consisted of a standard europa mixing pot full
of mixed resin (cant give you weights). This was immediately put into the mixing
bowl and kept moving continuously (slow speed with the K beater). To this we
added 4-5 potfuls of the pink/brown filler for a thick but not overdry
consistency. Incidentally it is very important to do this operation at the same
temperature every time as cold resin takes far less filler than warm resin.
There was no sign of the mixtures exotherming at any point.
This was dumped along a !/3 length of the wing in the spar area and spread out
using a large plasterers scraper (about 24 inches long. After this we adopted
Ron Swindens fishing line technique.
At about 20 C the filler could be sanded after about 36 hours. We used a
combination of long splines and an electric orbital sander with vacuum
extraction (very important). Time taken was about 2hrs to apply each wing
surface and about 6 hrs to sand the filler back. It is surprising that even with
fine fishing line it still takes ages to get back to the glass.
If you do decide to risk using power sanders, (a) be careful (you knew that).
(b) you will use lots of perforated sanding sheets as the grit seems to get
blunt and stop cutting after 10 mins sanding. (c) because the wing is a very
large insulator there are massive static charges generated by the sanding action
and you may get some nasty electric shocks. This can be minimised by earthing
the sanding platen. Dont assume that because your sander motor is earthed that
the orbiting plate will be as it probably is'nt.
We chose this method because it was fast and clean and we think it has made a
reasonably good job. Pinholes were a problem but their frequency did seem to
vary so we dont think its necessarily down to using the mixer. An over dry mix
certainly aggrevates things. We could probably have done with some additive to
reduce this. We have however not got down to painting stage where all our errors
will become more obvious. There is much more we could say but time and space is
short. If anybody would like to chat about this, our work phone no is 01296
432731 or home 01296 738129 (we're not usually home till after 8.00pm but there
is an answerphone)
We do have pictures of the mixing and filling operations and could pass these on
to interested parties.
Hope this is some help.
Carl & Dot (G-LABS)
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