I've seen a few plans floating around the internet showing various solutions, but I didn't like the way they attached the new bigger top to the old ironing board. Velcro, clips, grips…too bulky, too unsightly, and difficult to store during those rare moments the pointy end of the original ironing board is actually needed for normal laundry.
My wife's ironing board is a fairly new model, so the top is made from plastic…that ruled out the bulky clamping approaches. Using velcro just didn't seem sturdy enough to keep an oversized board in place.
Fortunately, when I peeled back the cover on her ironing board to see what might work, I discovered the plastic top had a great pattern of holes…and a simple solution was inspired! You can see her ironing board, minus its original cover, standing next to the new top in the first picture. The second picture shows the new top in use.
I've made three of these at the TechShop in San Jose. For more info on TechShop, see their website at: http://www.techshop.ws