Need help with a bubbling deck

[Steve K]

Hello,

A few years back I sanded and then painted a peeling deck with latex paint. It peeled off after a year. I thought that it was due to having been previously covered with an oil based stain which I found out after painting the deck. Last week I applied Behr stain remover and sanded the deck. I next used a Behr cleaner to neutralize the stain remover. I washed the deck with a brush and let it dry for a day. I applied a solid water based stain. Two days later, it started raining and the stain started to bubble with a brownish liquid coming out. Any ideas what the brown liquid is and what should I have done differently? I need help.

Thanks,
Steve