I bought Soltek UV Catalyst+ in the bottle sufficient to make 20L of resin.
Unfortunately the bottle says:**“Add total contents to 20kg of resin. Do not split contents”. **
How do I get around this?
They FAQ section states:
“Soltek UV Catalyst+ comes in two standard sizes for adding to either 4kg or 20kg of polyester resin. This means all you have to do is empty the entire contents of the Solcat+ bottle into the tin (4kg) or pail (20kg) of resin and mix. No weighing or calculation is involved. Once the Solcat+ has completely dissolved it is ready to use. Note that you should NOT attempt to split the contents of the Solcat+ bottle.”
I want to use this for making many small ding repairs and I will not go through 20L resin in 6 months, before the resin expires.
I am making a number of assumptions:
Assumption 1: The Soltek UV Catalyst+ has a long shelf life when not yet mixed with resin.
Assumption 2: The catalyst powder consists of several components that might not be mixed evenly in the bottle, possibly due to stratification resulting from different grain size or weight.
Assumption 3: With a careful approach, splitting of the catalyst should be possible. I hope I can split it into 20 x 1L portions in one session, maybe using small brown medicine bottles or old 35mm film containers (if I can find some in the digital age).
Has anyone tried this before or know if the above assumptions are correct?
The bottle that is meant to be added to 20litres of resin is about 1/4 full with pale yellow crystals. The seller reassured me that this is how the bottles come from the original seller, he has used several before to make batches of UV resin.
The crystals weigh 60.66g.
At first glance (see photos with green plastic cup) it looks like the contents are homogeneous, but on careful inspection one can see that they are not entirely homogeneous, there are a few larger conglomerates of white colour and some larger yellow crystals in the heap.
The white parts can easily be crushed to white powder and then they mix into the rest of it all, but the larger yellow crystals are hard to crush, put possible.
I think the larger yellow crystals (of which there were very few) are probably of the same or of very similar composition to the majority of the crystals, but the white powdery parts are different.
With a few minutes of carefull stirring and crushing maybe about 30 white powder parts and 5 larger yellow crystals, I achieved a mixture that looks homogeneous enought for my liking, e.g I cannot see any more white bits and no more large yellow bits.
Overall, I think that it is unlikely that my actions have made much difference to the effectiveness of the catalyst in this particular bottle, and at this particular age, but it may be that different batches have more or less build-up of white powdery parts and yellow hard larger crystals. Maybe with age, the bottle contents separate from each other and re-mixing becomes more important.
A plastic measuring spoon 1/4tsp works well for breaking up white and yellow conglomerates in the mix, and is aboiut the right size to measure out catalyst amounts for small resin batches.
1/4tsp = 0.68g
60.66g / 20 –> 3.03g needed per litre of resin, or about 4.46 x 1/4tsp per litre of resin.
I’ll mix a slightly heaped 1/4tsp = 0.76g catalyst into 250ml resin and expose some of it to the sun to check if my maths are right…
It seems to work as expected: Gelling in afternoon sun within a minute, it feels fully hardened after 10min.
While I was at it I tried out the UV-B lamp I bought yesterday (before I read that UV-A is what you need for the resin): It does not seem to penetrate deep into a resin drop on the bench, so that a skin form on top which then pulls off when touched. Underneath it is runny resin which then forms a new skin.
'Hopefully they will allow me to switch the globe for a UV-a globe…
