Model 2 - fuel tank weights

[Smiffy]

Probably a bit of a strange request but, does anyone have a list of weights for the different size wing tanks in both fiberglass and aluminium?

We have a KF2 here with aluminium wing tanks, 1 x 6gal and one 13gal

The aeroplane is quite heavy and we are trying to work out where the extra weight is.

[motortommy]

maybe no real match to your request, but my 13gal fiberglass tanks weight 6,2kgs each.
(Kitfox IV - Skystar era around `93)