And apple cider vinegar is even cheaper and seems to work as well. You can even reused a brush although not as good as new.
Another hint, as soon as you finish a batch (make your batches smaller in the heat), pump in a few pumps of resin (no hardener), move your brush around and the resin dilutes the hardener for a while so you can reuse the brush and do not have to clean out the container. Then just remember to add the correct amount of hardener when you are ready for the next batch.
One more hint, lay out your cloth or mat or tape on some thick PE film (I use heavy PE bags). Then when you are ready, just pick up the saturated cloth by the PE film and you can apply it to your workspace. You can "squeegee" the air out and get it smooth with your bare hands. After it cures, just peel off the PE film and you have a reasonably smooth surface to work from. This works especially well for vertical surfaces and saves a lot of sanding
. Although with the really hot temps and thick sections, there is enough heat to sometimes melt the PE film and it rips coming off. I use strips a couple inches wider than the fiberglass
tape and about 2" longer - usually get 3 uses before needing replacement.
One last hint, I duct taped the hose from my small vacuum to the outlet of the random orbital sander with perforated disks and the dust is a fraction of what it was before. While I still wear the respirator, I don't have to wear the Tyveck sweat suit.
Inside is done, finally started painting last weekend !!