We have a pretty standard 90s style laminate kitchen counter top. There are cabinets and a dishwasher underneath, and the counter overhangs them by about a half inch. The bottom of the overhang is not covered by laminate and has exposed stuff that looks like particle board. Some of this is right over the dishwasher vent, and the steam is getting soaked up and the counter is starting to disintegrate. It also soaks up random drips off the counter top edge. We tried scraping off loose material and then covering the exposed area with white duct tape (see photo), but it didn't stick very well. Any advice on how we could fix this?
If this is the only area that's being damaged then you could try screwing some stainless steel sheeting beneath it to act as a heat and steam shield from the dishwasher.
You'll need to make sure that the very edge of the steel is not exposed so make sure it doesn't protrude out. And you may need to put some epoxy or similar right to the edge to stop the steam penetrating the wood at that spot. Then sand it all round to make it nice and smooth. It might work, short of replacing the benchtop with something more sturdy.
I'd re-scrape, then smear a layer of white/clear caulk of the tub/tile/sink variety, working it into the 'wood' as much as possible.
The suggestions were appreciated, but we tried something different. First we smoothed it out as best as we could with razor blades and sandpaper (it still wasn't very smooth), then I put on 8 or more coats of Rustoleum protective enamel oil based paint. I'll see how it holds up.
As you can see, it looks pretty ugly from underneath, but you can't see it from above, and I'm hoping it will keep water out.
UPDATE It's been six months, and is holding up well so far.