<<Source for Epoxy Pumps: Aircraft & Spruce
Catalogue p.32 Uk Tel. 0462 441 995 info@aircraft-spruce.com
US (800) 824-1930 http://www.aircraft-spruce.com >>
I bought an epoxy pump from them - the one that does 1:4 ratios but discovered
that I still have to weigh the resulting output on my balance and top up the
hardener. I can only put this down to the ratio being measured is volume not
weight. While convenient for small amounts, with hindsight - and as I still have
to use my balance anyway, I don't think it is worth buying one.
For big layups, ie. wing skins, I just used the balance but instead bought
larger mixing pots (pint capacity) which are around 4 inches across at the base
but made of the same polypropylene type material as the factory supplied ones.
I
can put a good load in these - about 1/2 inch in the bottom - and because of the
large surface area (presumably), find I do not have problems with exotherming.
Make sure you stir it a bit longer than when using the smaller factory supplied
pots.
The larger pots are also great for mixing filler. I find that I can really mix
up a good load - enough for a couple of 8 inch wide, 'wing chord long' strips
(using 1.25 mm fishing/strimmer [U.S equivalant = weed wacker] line) before
having to mix up another pot. One wing side took 10 mixes.
For fishing line I use 1.25 mm for the wings and 0.75 mm for the flaps and
ailerons. I used the factory supplied filler (SP Systems Fairlite) mixed to a
dryish, sticky consistancy and put on at 65 deg F. It was not so wet that it
glossed over when allowed to stand, not so dry that it rolled up behind the
metal blade running on the fishing lines (roughly the way it is described in the
instruction manual funnily enough - a wet mix can only be heavy - and difficult
to sand I would guess).
Squidge the filler into the weave first between the lines using your squeegee
then use the metal blade (I used a drywall finishing knife with a 12 inch wide
blade). Once you move the fishing lines along for the next run just make one
pass with your squeegee - curved slightly so the corners don't dig in to close
up the gap.
Hope you find my experiences useful.
Regards
Martin Tuck
#152
Wichita, Kansas
U.S.A.
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