# Pre-Cat to Conversion Varnish



## Tony B (Jul 30, 2008)

Has anyone here recently switched over from pre-cat lacquer to Conversion Varnish?
What are the major differences regarding application i.e. temp and humidity requirements and spray equipment etc.?


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## firehawkmph (Apr 26, 2008)

Tony,
I've only used conversion varnish once. I built a set of cabinets for my son's kitchen, shaker style. He wanted a white finish, and after checking around, I ended up at a local SW commercial division. It's not a retail store. The sales rep set me up with the CV, the reducer, and acidic catalyst. I also bought a new 3M cartridge mask with the proper filters. Toluene is the base for their CV, so you don't want to breathe it at all. Temp should be in the 70's minimum. I set up a temporary spray booth in the gravel drive outside my shop. I left one side open that was out of the wind. The CV was mixed with the reducer at 50/50. The catalyst was added in at 6%. I used an HVLP spray gun and it worked fine. To me, it sprays like lacquer, sets up in a few minutes to the point where you can carefully handle the cabinets, doors, etc., to move them. It called for 3 coats, with a light scuffing in between with 320. I had all the cabinets staged in my shop, clean and ready to be sprayed. Same with doors and drawer fronts. I had a platform in the spray booth to set the cabinets on and also had a piece of gaspipe up above so I could hang the doors. I would spray a couple cabinets or a half dozen doors at a time, wait a couple minutes then switch them out with the next bunch. I had another pipe setup in the shop so I could just hang the doors I just sprayed on there. Took less than 45 minutes to spray a coat on everything, including the insides of the boxes. Once it cures, it's a nice hard shell finish. Cleaned the spray gun with lacquer thinner each time. If you decide to use it, just take the proper safety precautions and read all the directions from the manufacturer. Personally, I wouldn't spray this stuff indoors without having a proper spray booth, which I don't have. 
Mike Hawkins


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## Tony B (Jul 30, 2008)

Thanks Mike. I understand that CV is superior to Pre- Cat. I was wondering about a comparison.
I dont have any climate control in my shop and I believe that CV is more temp sensitive.
Do the two look the same when cured?
Does the CV lay flatter?

BTW, Congrats on the new Moderator thing.


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## firehawkmph (Apr 26, 2008)

Tony,
The CV does lay nice and flat, I think more so than lacquer. I was pleasantly surprised at how easy it was to spray and how nice it turned out. The scuffing in between was also very easy and didn't take much time. I was using Abranet for that so it wouldn't get clogged at all. Then I'd just blow it off with an air nozzle and wipe it lightly with a tack rag. I adjusted the gun and checked the spray pattern by spraying some cardboard I had. I'm brand new as a moderator so I have some things to learn to get comfortable with it. Glad to help here.
Mike Hawkins


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## Tony B (Jul 30, 2008)

Now that we are starting to experience some warmer weather here on the Texas Coast, I might just try it out. I also believe it is 'clearer' than pre-cat. Anyhoo, as soon as I need to finish something , like in the next two weeks, I will give it a try. Thanks for the input.


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## JCCLARK (Jan 30, 2007)

I can't think of one single advantage lacquer has over conversion varnish, I'll
never use lacquers again.
Conversion Varnish sprays better, cures harder quicker, takes a lot less product to complete a finish.
less odor once set up, and is at least 10 times more durable than lacquer.
You don't have to worry about sitting a glass of water on a top that has CV on it.
I've wiped cured CV off with lacquer thinner without hurting it.
CV is the only choice for wet conditions like bathrooms or kitchens,
it's so chemical tough.


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## JCCLARK (Jan 30, 2007)

xxxxx


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## WillemJM (Aug 18, 2011)

I use both Pre-Cat Lacquer and Conversion varnish. They both have their advantages and disadvantages.

Pre-Cat is easier to spray, less precise, can be cured at lower temperatures and don't have to bother with measuring catalyst. Also, the type of spray equipment I use, I leave pre-cat in the gun, or the gun container for days, without bothering about cleaning.

Conversion varnish needs to be more precise in it's application, a coat too thick would leave trapped evaporation bubbles, a coat too thin would leave a sandy finish. I have 8 hours pot life, before I have to clean everything. It needs to cure for three days at minimum 68F and it gasses off pretty much during that time, needing a protective mask even while not spraying. The good points are it dries much faster than Pre-Cat, can be touched within 15 minutes can be sanded within 30 minutes. It sands much easier with much less paper clogging. It basically means one can do a wash coat, sand it 30 minutes later, spray a second coat, wait another 30 minutes, do the final coat and you are done in less than two hours. Sometimes a wash coat and a final coat is enough.

Not a good idea to thin any of these products beyond 10%, it affects the sheen and the durability. Best is to spray it without thinning and learning how to set up being able to do that.

Conversion varnish is a bit more durable than Pre-Cat, but not 10 times as some mentioned. And, CV may resist better to water marks and food marks, but it is not bullet proof as the manufacturers would like you to believe.

In the cabinet industry, after and installer does his thing and the Electricians and other skills go in, there is normally damage. We allow a follow up visit to install final trim and a maximum of 1 hour touch up. With lacquer, we order an aerosol to touch up for each job and it works for Pre-Cat. With conversion varnish, not so much. Sometimes a scratch on a door with CV means it has to go back to the shop, sanded and the whole door re-sprayed.


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## JCCLARK (Jan 30, 2007)

Sherwin Williams conversion varnish recommends thinning 45 to 50%.
(it's thick)


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## firehawkmph (Apr 26, 2008)

JC,
I remember thinning it 50%, it did seem about as thick as a paint base. But once thinned it was fine.


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## Rebelwork (Jan 15, 2012)

I was told by S&W commecial shop guys to stick with pre-cat unless I set up a both. Conversion is their #1 and pre-cat is their #2.

Everyone wants the best but #2 is just fine...

Poly I thin to whatever it takes to flow correctly. Not all poly has the same consistency. If the product is thinner it will get less, if it's thicker it will get more.


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## WillemJM (Aug 18, 2011)

JCCLARK said:


> Sherwin Williams conversion varnish recommends thinning 45 to 50%.
> (it's thick)


Not sure if we are talking about the same product and who told you that.

Sherwin Williams, Sherwood Conversion Varnish product V84V80-83 sprays perfectly fine out of the can once catalyzed, airless, air, HVLP and conventional. It works well as a seal coat and a final coat without thinning. If you thin that 50% a gloss finish will change to a satin finish and the durability of the coat will be drastically reduced.

Their only product which may need thinning is the highly pigmented Conversion varnish primer and that is only if you have cheap spray equipment.


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## Rebelwork (Jan 15, 2012)

Do you guys get their fisnishing books?

Everything's in there.


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## WillemJM (Aug 18, 2011)

Rebelwork said:


> Do you guys get their fisnishing books?
> 
> Everything's in there.
> View attachment 425251





https://www.paintdocs.com/docs/webPDF.jsp?SITEID=STORECAT&lang=E&doctype=PDS&prodno=V84V80



Their solids is around 35%
A proficient painter can spray around 40% without thinning.


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## WillemJM (Aug 18, 2011)

WillemJM said:


> https://www.paintdocs.com/docs/webPDF.jsp?SITEID=STORECAT&lang=E&doctype=PDS&prodno=V84V80
> 
> 
> 
> ...


Zahn viscosity at 17 why would anyone want to thin this?


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## JCCLARK (Jan 30, 2007)

WillemJM said:


> Not sure if we are talking about the same product and who told you that.
> 
> Sherwin Williams, Sherwood Conversion Varnish product V84V80-83 sprays perfectly fine out of the can once catalyzed, airless, air, HVLP and conventional. It works well as a seal coat and a final coat without thinning. If you thin that 50% a gloss finish will change to a satin finish and the durability of the coat will be drastically reduced.
> 
> Their only product which may need thinning is the highly pigmented Conversion varnish primer and that is only if you have cheap spray equipment.



You need to read the tech sheet.
45 to 55% is what the tech sheet says.
The mfg is who you should listen to.
Kemvar surfacer, which you should be using first for a sealer coat and durability
reduces only 25 to 50% (it's a great sanding sealer)
I have been reducing both of those more than that and have never seen any
durability or sheen differences, for about 10 yrs now.
I used lacquer for about 25 yrs before switching to CV.


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## Rebelwork (Jan 15, 2012)

When I have a problem I look in the book or data sheet. If I'm still having problems I don't come here for advice, I call the commercial stores and talk to a tech.


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## WillemJM (Aug 18, 2011)

JCCLARK said:


> You need to read the tech sheet.
> 45 to 55% is what the tech sheet says.
> The mfg is who you should listen to.
> Kemvar surfacer, which you should be using first for a sealer coat and durability
> ...


V84 versus H66, two totally different products. V84 SW suggests a maximum if needed of 20%, that is clear not a tint base.

And interesting, I can post up a different version of H66 data sheet from SW, needing no reductions. H66 is a tint base and comes if different formats, reference CCF99 which is a newer superior product to yours.

You are just using different older version products to what we do.


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## Rebelwork (Jan 15, 2012)

This reminds me of when a Sherwin &Williams finish tech came on and joined the forum. .He tried to straighten some finishes up, but got argued with on every point. Don't blame him for not joining in anymore...


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## WillemJM (Aug 18, 2011)

Rebelwork said:


> This reminds me of when a Sherwin &Williams finish tech came on and joined the forum. .He tried to straighten some finishes up, but got argued with on every point. Don't blame him for not joining in anymore...


We had a technical rep from SW visit. He was very knowledgeable, to the point where we put a spray-gun into his hands. From there things spiralled downwards fast.

Then we had a rep, who took a color sample from our customer, we sprayed around $3,000 worth of doors we built, shipped them to NJ and the customer let us know the color was totally wrong. They made it right though as everything was in writing and they paid for a contractor in NJ to respray everything.

We order only from their industrial division and we have to specify exactly what we want, otherwise it is a disaster.


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## Rebelwork (Jan 15, 2012)

This wasn't a paint Store guy, .he is one of the techs who developes the paint and finishes. We spray...

Everybody here has to adapt finishes to his/her equipment. Unlike work I don't have booths so I adapt what works. The tech sheets are the basics for there finish in a perfect environment. ..After that you do what you have too..


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## WillemJM (Aug 18, 2011)

Rebelwork said:


> This wasn't a paint Store guy, .he is one of the techs who developes the paint and finishes. We spray...


Just curious, are you purchasing from one of the SW retail outlets?

They don't carry any of the industrial finishes we use. We have to order from 105 miles away, their industrial division and they deliver. It is a real pain when we need to color match.

We rate their finishes #3, there are two manufacturers both with the good stuff, one more expensive 2K urethane, superb, the other is the same products, same prices, but performs better.


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## Rebelwork (Jan 15, 2012)

No the industrial commercial store is separate from retail. It's were everyone that's not residential goes... if I order something special it comes from St Louis. To the residential store or I can drive to the commercial store..

When I worked at Jakobe, it was delivered, but we were doing 10 mil a year...

But I'm glad I'm out of it now, I get to be on the outside looking in now...


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## JCCLARK (Jan 30, 2007)

WillemJM said:


> Not a good idea to thin any of these products beyond 10%, it affects the sheen and the durability. Best is to spray it without thinning and learning how to set up being able to do that.


I use Lenmar conversion varnish for a clear finish, I was only referring to the Sherwin Williams to dis miss that broad general statement of 10% max. for any of CV finishes.


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## WillemJM (Aug 18, 2011)

JCCLARK said:


> I use Lenmar conversion varnish for a clear finish, I was only referring to the Sherwin Williams to dis miss that broad general statement of 10% max. for any of CV finishes.


Lenmar Megavar is our favorite clear finish.
There is Megavar and Megavar Plus, the latter needing only two coats.

The Zahn #2 viscosity is below 30, meaning any professional gun sprays that pretty good without thinning.

They use to state maximum thinning at 15% but later removed that from their TDS.

We once were over capacity and had a contractor do an island top out of Maple. We supplied Lenmar. The top had water marks and food stains in less than a year. The contractor thinned 40%. We had to strip the whole thing down an re-coat, same finish. It looks fine four years later.


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## WillemJM (Aug 18, 2011)

WillemJM said:


> Lenmar Megavar is our favorite clear finish.
> There is Megavar and Megavar Plus, the latter needing only two coats.
> 
> The Zahn #2 viscosity is below 30, meaning any professional gun sprays that pretty good without thinning.
> ...


For those who are interested, in the article below there is a viscosity table highlighted. It shows a Ford#4 cup viscosity range with the recommended tip size for the different type of spray systems/guns and paint viscosities.

For comparison, Zahn #2 at a viscosity of 30 is equivalent to a Ford #4 measuring a 23 viscosity.

All the paint docs in this post shows a viscosity of Zahn#2 st 30 or below, meaning any professional painter will be able to spray those perfectly without thinning.

Why do folks thin these finishes?

The thinner the finish, the easier it gets to apply, and that is the least path of resistance for the amateur painter. For the professional painter, that means less solids are put down with each coat, meaning an extra or sometimes two extra coats. That takes a lot more time. For example if a job needs three coats to attain optimum mill thickness, the guy who thins his stuff 50% either has to spray six coats or supply a job below mill spec thickness.

If a paint room is not available, and the application is in temperatures substantially above or below 70F the finish may have to be thinned. For high temperatures, a retarder may be needed to slow drying. For low temperatures one may have to add a flow enhancer.

In short, all manufacturers supply their finish ready to spray under ideal conditions. Modification is only needed when conditions are not ideal.






How to Measure and Adjust the Viscosity of Spray Finishes – Wood Finishing Guide







finishing.tips


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## Tony B (Jul 30, 2008)

I really do like Pre-cat lacquer for many reasons. 
I use mostly exotic wood and dont ever stain. However, I do use some aniline dye in my finish.
Why I am thinking of an alternative is mainly due to yellowing over time.


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## Rebelwork (Jan 15, 2012)

Tony B said:


> I really do like Pre-cat lacquer for many reasons.
> I use mostly exotic wood and dont ever stain. However, I do use some aniline dye in my finish.
> Why I am thinking of an alternative is mainly due to yellowing over time.


I'm a pre-cat guy too tony. I still do mix pre-cats and polyurethane on my tables though.. easier repairs..


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## Tony B (Jul 30, 2008)

Rebelwork said:


> I'm a pre-cat guy too tony. I still do mix pre-cats and polyurethane on my tables though.. easier repairs..


What part of the table do you poly and what part do you Pre-cat?
Are talking 2 component urethane or the normal poly stuff straight out of the can?


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## Rebelwork (Jan 15, 2012)

I pre-cat everything low and poly just the top where your hands touch...

I do my thing for maintenance...


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## Tony B (Jul 30, 2008)

Maintenance?
Is Poly more durable than Pre-Cat or is just easier to repair?


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## Rebelwork (Jan 15, 2012)

Maintenance would be on the poly.

Reason I tiled my bar top. Very little maintenance...

Somethings are just better off not being wood..


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## Tony B (Jul 30, 2008)

Thanks, definitely woth considering. 
Any particular brand?


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## Rebelwork (Jan 15, 2012)

The poly? I usee to use Red Devil , but it's not on the market anymore. I ran into a guy onetime on a job spraying a 3-4 inch line of poly on casing in a house. #1 hint.... He suggested the thickest poly you could find. Red Devil it was. Now I buy Sherwin&Williams After years of usage I buy everything S&W....


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## Tony B (Jul 30, 2008)

Thanks fot the input. Read somewhere on the internet that if poly is applied in thin layers and sanded between layers, it wont yellow . Dont know how much I believe that.
My only problem with Poly is drying time. My shop is a small 10 x 30 and machinery is slowly eating up the floor space. I have plenty of room to work but nowhere to put my projects for drying. I seem to keep getting back to pre-cat. 

Do water base finishes also yellow? 
If not do they have the drying time of lacquer?


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## Rebelwork (Jan 15, 2012)

I have a niece who wanted a gloss finish chest of drawers. I made the dresser from oak stained, and put high gloss pre cat on it. I sprayed it but it never looked like it dried. After about an hour I was frustrated and check in a inconspicuous place and it was completely dried. It had a wet look dried, I was amazed...

Now I can go to S&W home store in Blue springs and put a lil color in the pre-cat and I got red, blue, black, etc. I like it alot..

This is black mixed in with T77.. You can buy a gallon, mix into 4 quarts and mix say , red, blue, green and black.


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## Tony B (Jul 30, 2008)

All things considered, I think I will stick to pre-cat.


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## GCTony (Apr 5, 2018)

Tony, have you considered switching to water borne finishes? I was forced to switch from Pre-cat and CV by our insurance company because we didn't have a compliant booth, (Explosion proof everything including the toilet) There is a learning curve but I don't think I would go back to CV. I'll never go back to Pre-cat. I like SW KemAqua Plus and ML Campbell Aqualente. ML Campbell makes a WB conversion urathane but haven't tried it. The Target clear stuff is OK but we've had major issues with their pigmented stuff. (severe yellowing from moderate heat)


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## Tony B (Jul 30, 2008)

Did you have problems with their pigmented stuff only or did you have problems if you pigmented it yourself?


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## Tony B (Jul 30, 2008)

I know a guy that owns a body shop and does high end painting like really wild stuff. Anyway, several years ago he had to go over to water bases also. He says he never had a problem with it also. 
With water base, how long between recoats? With pre-cat it is literally just minutes In summer time like 10 minutes.


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