Some of you may remember that I posted a question here about tiling over an existing laminate counter. Well, it's done, and I wanted to report back here in case it might be useful for anyone with similar questions.
The customer (a friend, actually) wanted new tile counters. The existing counters were 60s or 70s-style Formica, complete w/rolled lip, over particle board. After removing the counters, the plan was to either put plywood over the laminate, and Wonderboard over the ply, or, as we realized would be possible after starting to strip the counters, put Wonderboard directly over the particle board.
I say "after starting to strip the counters", as we did start to rip the Formica off the countertop: this, however, turned out to be such a massive pain in the ass that we quickly abandoned the idea. Would have taken many hours to accomplish this. Then I posted my question here, and also did some searching on the Web.
What we discovered was that you can actually put Wonderboard directly over Formica. This was something I wouldn't have believed either, but after a trip to a local tile store with a good reputation, this was confirmed.
The trick is to use the mortar that we already had bought, which was polymer-modified (*not* latex-modified), which will basically stick to anything (well, not sure about glass, but just about anything else). Just to be sure, we scuffed up the Formica with coarse sandpaper.
Everything went on smoothly; the counter is now in use, and shows no signs of weakness.