Wednesday, May 14, 2008

Dont trust digital scales

I have had a cheap digital scale in the garage the last couple of years for measuring epoxy by weight. This weight went "bananas" some weeks ago and started incrementing its values by itself. Not something you want to happen when measuring epoxy and hardener.

Frode got the mission to buy a new digital weight to measure epoxy. First weight he got did not count one by one gram but jumped from zero to 6 or 8 grams instead of incrementing by one as we added epoxy. We thought this was just a one-time problem and had the weight replaced. Tonight we was supposed to glass the outside of #3, but the digital weight was not reliable! Bugger!! Shop will have the weight returned as it was supposed to be a high quality and very accurate product, OBH Nordic in stainless steel. For the next scales we will do some tests in the shop before we accept the product. Will bring a cup and a bottle of water and check both how it updates and how accurate it is. The shop staff will probably not like it, but if they want us to buy an accurate product we have to test it first. All good things are three is a norwegian saying. Hopefully weight number three is good.A clear wood finish is good looking. Too bad about all the knots, even if they give a kind of "rustic" look. Fortunately the knots dont mean anything strengthwise. This hull is sanded, pre-coated, washed and sanded again, ready for glassing. We use 165gsm twill weave for glassing. Light but strong enough. Twill weave reduces the amount of epoxy needed to wet out the weave and "fill" it. Every gram counts in the end :-)

This photo shows how we laminate the gunwhales. We have a stringer running the length of the mould (almost) with notches at each station. The strips are wet out with epoxy, thickened epoxy added and then secured to the mould with screws and a few clamps. Works quite well.

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