Comparing Lacquers and Conversion Varnish

Post-catalized lacquers, pre-catalized lacquers, and conversion varnishes — pros compare experiences. July 6, 2005

Question
I've been using Krystal and Magnamax for about a year now, often switching between the two finishes to get a good feel for using both finishes. I typically spray both finishes unthinned. At this point I think it's easier to get a great looking finish using the Magnamax. I'm curious as to how others feel about the look of the finished product using these two products?

Forum Responses
(Finishing Forum)
From contributor P:
I honestly hate Magnamax and I spray a great deal of Duravar. I do spray a lot of Krystal on antique white glazes.

The problem that I keep having with Magnamax is sanding it. I stain a piece, let the stain dry thoroughly, self seal with magna, then let it dry and then sand it. It never sands as easily as Duravar and it seems to clump up on the paper. I don't have these problems with the other topcoats.


From contributor L:
I actually love Magnamax. Contributor P, are you waiting 30-40 minutes before sanding and is your room temp at or above 68º? I find that the finished product (dried overnight) is spectacular. I have only used the Krystal sealer and it was very easy to sand and dried fast. I have not used the Krystal topcoat yet, but I will be using it soon for a tabletop out of curly maple.

To the original questioner: If you can accept the slight amber color of Duravar, you should find it 100% easier to spray and lay out than Krystal. It also dries much faster than Krystal, sands ok - sooner than Krystal, and builds faster than Magnamax.

We switched a while ago to Krystal sealer and then Duravar. Nothing at all compares to the Krystal sealer for dry time and ease of sanding - eg. 4-5 wet mils of K. Sealer, 68 degrees with moving air for 15 minutes and sand to a powder.



From the original questioner:
How does Duravar compare with Magnamax with durability issues? I've been told it's only slightly better, whereas Krystal is way above them both. I do realize we're talking about pre, post and cv.

I have yet to try Duravar, but definitely like the look of Magnamax compared to Krystal. I just don't know if it's really durable enough for kitchen cabinets. I also find that Krystal stinks for too long. How is Duravar for smell?


From contributor P:
My rep did say my problems were temperature with Magnamax. I was spraying directly out of 5 gallon can with Kremlin. The cold from the concrete floor actually dropped the temperature of the topcoat even though the temp in the room was above 70F.

I use Duravar for almost everything. It's very amber in color which I like. I believe Duravar is stronger than Magnamax, yet a finish not maintained will fail no matter what. I did a lot of pre-cat laquer kitchens in the past and I never had call backs for failed finishes. I always let my stain dry overnight, then seal and let dry for a few hours or overnight again, then sand and topcoat. Overall I am very happy with the look and use of Duravar.


From the original questioner:
How is Duravar for off-gassing compared to Krystal and Magnamax?

From the original questioner:
Also, concerning the off-gassing of these products...what exactly is it that is smelling? Is it mostly all formaldehyde?

From contributor D:
Duravar vs Magnamax

Duravar is 85% cross-linked after only 48 hours. Magnamax reaches its useful durability in about 3 weeks time. After three weeks both Duravar and Magnamax have about the same durabilty.

Duravar is higher in solids by volume. That means fewer coats need to be sprayed to get to your maximum dry mil thickness.

Both coatings gum up the sandpaper (corns). This is because the coatings are tough and rubbery. If you want less toughness, you will get less durability, but finer rubbing qualities. If you want all that, then go with shellac or lacquer.

Duravar is a post catalyzed lacquer and Magnamax is a precatalyzed lacquer.

Krystal is about as durable as any of the good conversion varnishes, making it plenty tough (a TR-6 rating). It has a tiny amount of nitrocellulose in it but the coating is known as a non-yellowing coating and this is accurate.


From contributor P:
Have any of you tried Magnasand? It's a precat sanding sealer used below Magnamax.

From the original questioner:
I've always been told that the use of a sealer will weaken a finish, so I self seal with Magnamax. I actually don't find Magnamax that bad to sand.

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