I’ve noticed quite a few references to cabosil. I have found that cabosil is almost impossible to sand once it is hardened. I use a mixture of 3-4 parts micro balloons to 1 part cabosil. Not only does it sand/shape really well it also makes a lighter mixture. The micros are the filler and the cabo just thickens it up. Does any one else do this? Is there any reason not to?
Cabosil adds thix to a resin, micro-ballons are for sanding and weight savings. You don’t use cabosil for sandability.
We used to use cabosil in the filler, but you had to sand it when it was ready, no later, or it was like rock.
We found it provided a bit of scratch resistance compared to just resin.
I would occasionally put a tiny bit in the laminate as well which helped make the board even tougher.
As for microballoons, it’s a legitimate way to lighten up your filler. But each of those balloons sanded leaves a micrscopic pit, that unless sealed, gets dirty pretty easy. It’s not recommended to use microballoons in the laminate.
If you’re happy with the results then I don’t see any reason to stop.