Catalyst Causing Gradual Pigment Change

A cautionary tip: catalysts in catalyzed finishes may cause pigments to change over time in the can ó so a batch may not match itself, if time passes between applications. September 26, 2006

I have been a MLC user for several years. We just learned the following information. We did a kitchen in Magnamax that was heavily pigmented (BM Almond toast). We had problems in the past with color matches on previous jobs, i.e. pieces or extras that were finished later from extra gallons, and we always thought they didnít match well. We now know why. For this job we got a 5 gallon pail, thinking we would be smart. We sprayed the whole job - doors (MDF Conestoga), cab parts, etc. We sprayed all at once. We topcoated with max dull. It was beautiful. We delivered and installed.

Two weeks later, the customer changes his mind on hood style. We cut down upper, reorder doors, and paint doors from the same pail, using the same process. The shades are off. I called the Rep, and he says they are finding out that the catalyst alters the pigments on max over time. Itís now 10PM and Iím not home yet - Iím repainting everything with a new 5 gallon pail at their cost. For my next job I will use Krystal Pigmented.

Forum Responses
(Finishing Forum)
From contributor A:
Are you saying that you painted the job with a Magnamax tinted, then top coated with a clear (dull sheen)? And after the job done, the result was not same as the original paint color should have been before the topcoat with dull clear Magnamax?

From the original questioner:
Before dull clear and after the same there is a color shift. The catalyst changes the color in the pail. The remakes where done on the 45th day of the 120 day stamp. This is not the first time it has happened. We thought on previous lighter color jobs that it was just that the lab couldnít get it right. With this darker color, it really showed.

From contributor A:
The Magnamax (and also Gemini's UL lacquer) does change the color after it's applied to color tinted lacquers, especially whites and lighter colors. Even if everyone says Magnamax is clear, it is not! I recommend using Krystal for the top coat or use another water clear lacquer so it won't change original color.

From contributor B:
There is clear and water clear coatings; on the whites and other light colors you want to use water clear coatings. The clears may show amber after a few coats, or as time goes by it will yellow.

From the original questioner:
Iím not talking about the clear coat. Itís the color in the 5 gallon pail that changes (with the catalyst) over time. MLC rep says he is hearing this more and more and corporate M.L. Campbell is either going to alter the catalyst for color shift or change the labeling.

From contributor C:
Was the color mixed in a clear or a white? Could it be that the clear top-coat has "ambered", thus changing the appearance of the color?

From contributor B:
Can you ask them to ship you the catalyst separately, and you will add it to the lacquer whenever youíre ready to spray? That should solve your problem, and some companies do it that way now.

From the original questioner:
To contributor C: It was white but it doesnít matter. I now know why my white jobs were off also, just not as dramatic. Magnamax doesnít amber up greatly, especially not in 2 weeks. To contributor B: The M.L. Campbell distributor adds the catalyst on Magnamax. Thatís why I am going to Krystal tinted for color jobs - topcoated with Krystal dull.

From contributor D:
If you add the catalyst you're still going to have trouble matching when you add a piece in the future. I went to MLC spray school and did a whitewash door using Magnamax. We stained with white stain, then shot a white toner coat. The door looked great when done. I looked at it a few months later and it yellowed a fair bit. Glad I didn't sell that to a customer.

From contributor E:
Forget resistant CV. It's a fantastic product but Campbell has introduced a new conversion varnish (clear only at the moment) that is called CV200 that is the same solids content and durability of Krystal but is smells a lot less hideous. It works wonderfully! It seems thin but has the same solids content and is less viscous than Krystal.

My rep tells me they are coming out soon with the pigmented version. Call them and bug them to get some of this for you. It's worth it. Uses Care Catalyst like all their other post-cats.

From contributor A:
I asked my MLC distributor about this CV 200.They knew nothing about it and didn't want to know anything about it.

From contributor F:
CV 200 does not have the same solid content as Krystal. As a matter of fact Magnamax has a higher solid content then CV 200. I have the PI sheets for the CV 200. My distributor had the same problem Ė the product didn't exist, until I got the can #'s from another poster and gave the #'s to them. Then all of a sudden they found it. They don't plan on getting any for distribution but they admitted it does exist.

Product Information (PI)
Weight/gal: 7.8 lbs

Viscosity Ford #4 @ 77ļF: 13-19 sec
Solids by Weight: 39.1 +/- 3
SOLIDS BY VOLUME: 32.0 +/- 3
1 mil coverage 5 gal (100% transfer): 513 sq ft +/-5
Flash Point: +65ļF
Color: Clear
Sheen: (60ļ Glossmeter) Dull:17+/-3, Satin: 35+/-3, Soft:45+/-3, Gloss:>80
VOC: 550g/l or 4.25 lbs/gallon
Photochemically reactive: No
Dry to touch: 15-25 minutes
Sanding Dry: 30-45 minutes
Stacking Dry: 4-6 hours

From contributor G:
To contributor F:
MagnaMax - 25% Solids by Volume
CV200 - 32% Solids by Volume
Krystal - 34% Solids by Volume

From contributor F:
To contributor G: Correct as usual. I was going by memory. I had the PI sheet for the CV 200 in front of me. I mixed up the weight versus volume %'s. Thanks for the correction.

From the original questioner:
That still doesn't top ChemCraft's PlasticClear CV at 70% solids - it's like honey. But it takes two hours to dry even when thinned 50% so I can spray it out of an hvlp. So back to Campbell I go.

From contributor F:
A correction in the PI sheet for CV 200 - 1 mil coverage >5 gal - should read per 1 gallon, not for 5 gallons.