The revisionist mythology of Wharram

In the technical data sheet they say the nominal ratio by weight for 105 resin / 205 or 206 hardener is 5.19/1, but you can use 4.83 to 6.2/1 which is acceptable.
So the accuracy of mixing ratio is not critical. But the package contains 5 volume of resin and 1 volume of hardener, wich corresponds in weight to 5.19 / 1 .
If you use 5/1 in place of the exact weight ratio 5.19/1 , you will be short of hardener and you are wasting money ! this can be a lot for a big project !

 

Great explanation.
THAT also explains why I was always running out of hardener in past projects.

 

The best mixing regime is the one that works for you, many home building projects are stretched out over such time and un workman like work hygiene that the pumps are barely recognisable let alone working.
I like working by volume as for me it bares the closest resemblance to the resin required estimate. (from my polyester days)
To facilitate that I make up a chart of volume/ratios to refer to when mixing for a job, the other handy think is having a "spare resin" job on hand to use up any left overs. As for running out of hardener, its small bananas on a boat building project, most largish projects will have several speeds of hardener on hand so its really not an issue.

 

the "running out of hardener" is not the thing that worries me! It is the obviously (slightly) incorrect mixing ratio...-therefore: electronic scale!

 

That's the point of the discussion. Its not "incorrect". Its close enough if the manual says so.

 

...the Gurit manual does not give a "from - to" ratio...

 

There must be an acceptable +- ratio otherwise you are chasing .1 or .01 or .001 in order to get the ratio perfect. There is more resin stuck to the resin container than the catalyst container has that upset the ratio ? No. Get real.