finish for shelf over kitchen stove?

[Jesse Tutterrow]

A friend wants to add a shelf over her electric stove to hold a microwave (1100 watt). One side and back would attach to drywall the other side to a (big box) cheap cabinet. Since she is short she wants the shelf down low so she can reach it.

The shelf would be 32"wide by 18"deep. I was thinking about making it out of 3/4 oak plywood with a 1/4 oak plywood limanated to form a 1" thick shelf. I would use 1" (to 1 1/4") supports along the sides and back, with a 2" front.

I am concerned, over time that steam and grease splattering on the bottom of the shelf would cause problems. What type of finish would you suggest?

My first thought, just to keep it simple, was to use a wipe on oil finish - General Finishes or Watco Danish oil.

Thanks in Advance

[Howard Acheson]

Things to consider.

Laminating one thinner piece of plywood to another can cause warpage particularly when subjected to moisture.

Because of the highly moist conditions, plywood can delaminate unless made with exterior adhesive. Finish will slow down water vapor transmission but will not stop it. Better to glue on a 3/4" x 1" wood strip to the front edge to give some additional support and to give the appearance of a thicker shelf.

An oil/varnish like Watco would not be a good choice. These types of finishes have very little resistance to water and water vapor (steam). Also, they do not stand up to frequent cleaning with household cleaning chemicals. I would suggest an oil based poly varnish or a good oil based enamel paint..

Finally, there may be fire and building codes requiring a certain amount of space over a range. Check with the building department in your town.

[Jesse Tutterrow]

Thanks Howie,

I was planing on using a 1 1/2 to 2" front edge. I figured the weight of the microwave over a 32" span would need a thicker front edge.

Would you consider using General Finishes Arm-R-Seal Urethane Topcoat (http://www.rockler.com/product.cfm?page=10928&filter=general%20finishes)?

[Scott Holmes]

Most state codes call for no less than 30" clearence above a cooktop.
]
I would cover the bottom with a formica type material. It can still get pretty hot and the steam/splatter is more than most finishes can handle. Ditto for most plywoods from the steam before delamination starts

[Howard Acheson]

I was planing on using a 1 1/2 to 2" front edge. I figured the weight of the microwave over a 32" span would need a thicker front edge.

Would you consider using General Finishes Arm-R-Seal Urethane Topcoat (http://www.rockler.com/product.cfm?page=10928&filter=general%20finishes)?

Almost all the weight will be concentrated along the sides. There is little or no weight concentrated in the center that will be causing the panel to sag. Just make the side attachments strong. Some microwaves need air cirulation pathways up the sided and in the back.

Arm R Seal will probably work as well as any other. But it's a thinned finish so it will need twice as many coats to build a film thickness comparable to a brushed on finish.

Scott makes a good point about plastic laminate on the bottom. It will be impervious to watervapor and should be easier to clean. Be sure to use a solvent based contact cement if you decide to use it.

[Jesse Tutterrow]

Almost all the weight will be concentrated along the sides. There is little or no weight concentrated in the center that will be causing the panel to sag. Just make the side attachments strong. Some microwaves need air cirulation pathways up the sided and in the back.

The microwave is only about 20" wide so there will be 5 to 6" of clearence on each side.


Scott makes a good point about plastic laminate on the bottom. It will be impervious to watervapor and should be easier to clean. Be sure to use a solvent based contact cement if you decide to use it.

If I laminate the bottom wouldn't I also have to laminate the top?

[Howard Acheson]

>>>> If I laminate the bottom wouldn't I also have to laminate the top?

Probably a good idea.