I have some Pactra acrylic that I use and I thin it 2:1 and it works great.
I would try that ratio and see how it works.
Use 2 parts clear flat to 1 part filtered water, or 2 parts clear flat to 1 part of 1/2 water and 1/2 isopropyl alcohol mixed.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon