pre cat lacquer or waterlox

[David Hawxhurst]

build a desk out of cherry and at a minimum will be sealing it with waterlox. for a final top coat would a pre cat lacquer like valspar zenith be any more durable/repairable than waterlox?

[Howard Acheson]

Waterlox Original is a top coat. It's a varnish and very durable, water and chemical resistant and abrasion resistant right out of the can. Top coating it with a pre-cat lacquer will not significantly increase the durability of the finish. Also, pre-cat lacquer may not play nice with a varnish that was not fully cured for a few months.

[Sam Murdoch]

I agree with Howard that Waterlox is a very durable finish that requires no top coat. The lacquer would not improve it. I can only recommend the ORIGINAL SEALER FINISH though as I have had mixed results with the new formulas and especially the satin finishes. I have nothing but high praise for the Original. It does not dry any where near as fast as lacquers but that is the only down side.

Sam

[Scott Holmes]

That is not a pre-cat Lacquer as in a pre-cat nitrocellulose lacquer... It's a water-borne "lacquer". Not really a lacquer, as we tend to use the term on this site.

Still it would be either Waterlox or the Valspar not both.

[David Hawxhurst]

the only waterlox product i use is the original sealer finish. i have not tried any of the others.

so is there much difference in the waterborne pre cat lacquer vs real pre cat lacquer? is calling a waterborne stuff pre cat just a marketing thing?

[Scott Holmes]

They're are getting very sophisticated with some of the water-borne finishes; some are now pre-cat. I would say calling it "lacquer" is the marketing stretch...

[Jeff Hamilton Jr.]

Can I ask a dumb question Howard or Scott? What exactly is "pre-cat" lacquer? I've used Deft lacquer in the past with good results, but have wondered what the difference is.

Also, I can attest that Waterlox is a very durable finish. I wiped on the Original on my 4-yr old son's bunkbeds. After a year of hard labor (and I mean HARD) I don't see even as much as a scratch.

[Scott Holmes]

When you add a catalyst to a finish it enhances the cross linking and curing... Lacquer and shellac are evaporitive finishes they don't cure. When the solvent is gone the finish is dry. Varnish is a reactive finish the thinner evaporates then the chemical reaction takes place and it cures (~30 days).

When a catalyst is added to lacquer it now becomes a reactive finish it will cure. Usually within hours not days.

Pre cat means the catalyst is added at the factory product is good for 1 year or more unopened. Post-cat means the catalyst is added just before you use it... pot life after adding the catalyst can be as little as 20 minutes, some are several hours.

There are also blocked or inhibited catalysts, they basically stop the catalyst from working until something happens (for example you spray the finish) then blocker evaporates so the catalyst can start to work. This is a very simple layman's definition, I am not a chemist.

Reactive finishes, e.g. varnish, reactes with oxygen in the air so technically oxygen is the catalyst for the curing.

[Prashun Patel]

+1.

I use the same product as Sam. To put a finer point on it, the one I use is:

Original Sealer Finish (ORIGINAL FORMULATION).

There exists Original Sealer Finish (VOC Compliant Formulation) that (anecdotally) people have had mixed results with.
There also exists High Gloss and Satin Formulations that are full strength and not thinned to wiping consistency. The "OSF" is prethinned which is the ONLY reason they call it a sealer. It is a varnish otherwise - good n proper.

[Howard Acheson]

To add one important piece of information to Scott's reply, a pre-cat lacquer is quite a bit more protective than a NC lacquer. It is even more protective than an oil based varnish. Pre-cat is more abrasion resistant and chemical resistant. The downside is that it is dangerous finish to use. Good respirators and protective clothing are a must. It's also not a good idea to spray it in your house or garage. It can be dangerous to anyone in the house or to neighbors if they live close. Repair of finish damage is difficult if not impossible and most common paint strippers may not remove it.

Get a copy of the manufacturers MSDS before using these products.

Let me also make the point that waterborne cross-linking finishes have some dangers associated with them. Again, get a copy of the manufacturer's MSDS and follow all the cautions carefully.