"Dave Balderstone" wrote in message
news:040420062146159698%dave@N_O_T_T_H_I_Sbalderst one.ca...

Based on your info and the feedback from bambam, I'm thinking at this
point to lift the old formica with heat, scrape the old glue to a
reasonable point, then glue/screw 1/8 inch hardboard or MDF (instead of
the 1/4" bambam suggests) and reapply new formica over that. Not a big
increase in cost, but (it seems to me) a better adhesion on the new
cabinet top.

If you're going to layer additional mdf, then you only need to remove enough
glue to hold the MDF in place with new glue.

Be careful if you screw down the MDF however. The screws have to be counter
sunk and you don't have much thickness for that. If the screws aren't
countersunk you'll get pimpling after you lay down the laminate. The
appropriate stapler/nailer _might_ be better, although you don't want nails
are staples to just go right through 1/8" material.

But if you sand down the original substrate enough the new laminate will
hold

Steve