On Mon, 20 Feb 2006 22:22:24 GMT, Brian Mahaney
wrote:

Hello,

I've never tried a water-based poly until today, and I have run into a
problem. Admittedly, I am experimenting a bit. The problem is a crackled
finish. Here are the details of what I did.

I volumteered to refinish my parent's kitchen table as payback for my Dad
helping me deliver finished projects to customers. I started out by
sanding the entire table top down to bare wood. I finish sanded it up to
220. I applied a coat of shellac as a seal coat. That dried over night.
Next day I applied a water-based glaze tinted with Transtint dyes. That
dried over night. I was only doing the top, so I was trying to get to the
color of the rest of the table and chairs. I felt that I needed to warm up
the tone a bit, so I tinted the water-based poly with Transtint dyes, and
sprayed a coat. It sprayed great despite being a brushing product. As it
dried I began to notice some issues. Slowly it began to crackle. It looks
kind of cool, but this is not what I was going for. Any clue why this
happened?

Other contributing factors may have been: Temperature in the shop (it was
very cool in the early day, but I had the heat on for hours before I
started). Heating with kerosene. Could that have contaminated the
surface? Anyone experienced this?

I'd suspect the kerosene.

I once finished a piece in water-based poly, and another in oil based
poly. I set them to dry within a few feet of each other, and the
water based piece finish got really messed up. I'm pretty sure it
reacted to the volatile solvents in the air from the oil-based poly.

On other occasions with the conditions in the room the same, the
water-based poly OR the oil-based poly finish turned out fine when
they were drying alone.

Kerosene heaters leave a fine oil film, so this may have reacted with
the water-based poly like the oil-based poly solvents did.

I'm now careful to keep water and oil based poly apart, but wonder if
I just happened to use a formulation of water-based poly that has that
reaction. The stuff I used was Minwax Polycrylic on maple.

YMMV.

....John