Hi All,
May I add my bit to the discussion on resin pumps. I started
building a year ago and have been using a Michael Engineering adjustable
ratio pump from AS&S from the start.
I can't fault it - operation is mindlessly simple,
[essential with my brain] eliminating all calculation errors. You can mix
just as much as you need, cutting down on what you throw away [ or worse -
put on your plane so you do'nt think your wasting it]. It seems very
accurate - doing one of my calibration checks to-day, while pumping thro'
142.5 gms of hardener, 566.5 gms of resin went thro'. Just 3.5gms, or approx
0.62% out. I have never had a greater error, or ever adjusted the pump in
the year.
On the 'bubbles in the hardener' issue, I have only had a
couple of small bubbles during the first stroke when using the pump after a
bit of a break - maybe a week or so. It seems the hardener may drip out of
the tube below the bend just above the nozzle. I just throw away the result
of that stroke - less than 20 gms. I've never experienced any of the other
problems.
Of course you still need accurate scales, not least to check
the pump, and the cost is a bit daunting, especially at the start. However
every time I make a mix I become more convinced it's money well spent.
Best Regards, Paddy Clarke, [ builder 404]
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