Oak Microwave Cabinet

[Julie Wright]

:confused: :o
Did I already ask this question??
Ok, so I am almost done with the oak microwave cabinet. I have put a couple of coats of watco oil on it and it has been left to dry. What would be the most durrable top coat? Polyurathane or Shellac? This will sitting in the kitchen.

Thanks for your expert input
Julie :) :)

[Bud Duffy]

I built one recently for my mother in law and put 3 coats of wipe on poly on it and seems to be holdin up real well.

[Todd Burch]

Hi Julie - lookin' forward to seeing that cabinet!!

You've asked two questions: 1) What would be the most durrable top coat? 2) Polyurathane or Shellac?

For 1) a conversion varnish would be the most durable.
For 2) between polyurethane and shellac, poly would be the more durable, especially in a kitchen environment.

Todd.

[David Klug]

Hi Julie - lookin' forward to seeing that cabinet!!

You've asked two questions: 1) What would be the most durrable top coat? 2) Polyurathane or Shellac?

For 1) a conversion varnish would be the most durable.
For 2) between polyurethane and shellac, poly would be the more durable, especially in a kitchen environment.

Todd.


What is a conversion varnish?

[Mike Evertsen]

read the can I belive you need to wait 7 days to top coat watco,,,I use polyurathane water over minwax stain not sure if you can over watco you might a solvent base,,,

[Julie Wright]

What is a conversion varnish?
:confused:

[Todd Burch]

If you have the book "Understanding Wood Finishing" by Bob Flexner, Chapter 12 explains conversion finishes in good detail. (If you don't have it - put it on your holiday wish list.)

Excerpting from Bob's book, conversion varnish characteristics (not all) are:

- Excellent wear, heat, solvent, alkali, water and water vapor resistance. ... usually tougher than solvent-based polyurethane.
- Excellent film building properties, using 1/2 as many coats as Nitro lacquer.
- short curing time
- easy spraying and thinning characteristics

Cons are:
- short pot life
- limited application time
- poor rubbing properties
- not as clear as Nitro lacquer
- is nasty solvent based
- repair or touch up is difficult
- poor stripping characterisitcs (due to it's excellent solvent and chemical resistance.)

The theory behind it is different types of resins are mixed with an acid catalyst, and as the catalyst kicks in, cross linking action happens as the resins cure.

I use a precatalyzed lacquer (ML Campbell's Magnalac), which is a conversion varnish that is premixed with the acid catalyst and solvents already in the can - no mixing on my part. Not the best on the market, so I've been told, but still very good. As the solvents evaporate after being sprayed, the catalyst then kicks in and cures the resins. You can most likely get it at a professional finishing store in your locale, or other similar products, like Target (the brand of finish - not the store chain!) and others. If you search the internet on conversion varnish, I'm sure you'll get dozen or hundreds of hits. There is a professional finishers forum on woodweb that has enough info on it and the different brands of "CV" (Conversion Varnish) that it will make your head spin.

Todd.

[Jim Becker]

What is a conversion varnish?

Adding to Todd's excellent comments...conversion varnishes and pre-cat lacquers really require special care when being used for personal safety. They are sometimes best for the experienced or pro finisher as opposed to "us amateurs"! If they are the best finish for a particular project, one can always get them applied by a pro shop for a little financial incentive...