# Epic Failure with Pre Cat - Please advise



## Knot-a-pro (Nov 10, 2012)

My husband hand crafted a beautiful set of cabinets for our kitchen. He chose to use a Pre Cat lacquer from Sherwin Williams. Unfortunately, there was no hardener added to the product upon purchase. My husband sprayed everything with the lacquer. As it dried, he realized there was a major problem! Sherwin Williams' rep told him to wipe it all off with lacquer thinner and start the process over. He used lacquer thinner on one door and it stripped portions of the stain as well. The problem only seems to be getting worse. What should he do?


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## firemedic (Dec 26, 2010)

*** I have not tried this so this is just thinking out loud ***

As you apply Lacquer it bonds to the previous coat - the solvent dissolves the dry layer a bit and the layers blend. I'm wondering if a batch of the same lacquer sprayed pretty hot (thinned heavily) with extra catalyst would activate the goop you have on it now...? 

Just a thought, you could test it on something small like a door and see what happens. It would likely need to be sanded and top coated again afterwards.

I'm sure there will also be other suggestions as well. 

Good luck!


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## troyd1976 (Jul 26, 2011)

yikes colossal failure by the SW employee, thought it was common knowledge to those in the industry they activate the stuff on purchase.
what was the behavior of the lacquer, did it run, dry but is soft or?. if it doesn't have gnarly runs and dried im with fire medic and would grab a door as a sample piece and try spraying another coat or two and see what happens. as he also stated, lacquer "burns" into itself. as for the door that's already had the finish taken off it with the thinner, you can try touching up the stain, even shading it (mixing lacquer based stain with lacquer) but your best results at this point would probably come from getting back to bare wood and restarting that one.
One of the mind blowing traits of pre cat lacquer is if you get a very small run in it, i will disappear with time.


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## cabinetman (Jul 5, 2007)

Knot-a-pro said:


> My husband hand crafted a beautiful set of cabinets for our kitchen. He chose to use a Pre Cat lacquer from Sherwin Williams. Unfortunately, there was no hardener added to the product upon purchase. My husband sprayed everything with the lacquer. As it dried, he realized there was a major problem!


What was the exact name and item number (off the can) for the lacquer. Can you describe what was the exact major problem?









 







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## Steve Neul (Sep 2, 2011)

I believe at this point I would wait and see if lacquer cures on it's own. It should dry but you would not get the benefits of having a pre-cat lacquer. This can be obtained by topcoating it again with pre-cat lacquer that has the hardener in it. The drying time on the first coat is an unknown though. I would probably let it sit a week after it's dry to touch. There's nothing you can do with the door you washed down with lacquer thinner but to take it down to bare wood and re-stain it. 

Not mentioned, when you use a pre-cat it would work easier to seal and level the wood with a vinyl sealer. It's used like lacquer sanding sealer with nitrocellous lacquer.


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## Knot-a-pro (Nov 10, 2012)

*The Whole Story*

After cycling between anger and depression I am hoping to survive this. My wife was smart and kind to write you all. I have never sprayed lacquer and know very little about it. Sherwin W. local store knows even less. 

Thank you so much for your replies it is nice to know there are people so willing to help. I will tell you what I did.

The cabinets are Northern Hard Maple:
1.) Applied Sherwood Wiping stain to the the face frames doors and sides
2.) Shot two coats of (CC-F20 SHER-WOOD® Vinyl Sealer 24% Solids) I catalyzed this with V66V26 in the gun, I did not measure real accurately (a gravity fed HVLP with 1.3mm tip).
3.) Shot two coats of CC-F43 SHER-WOOD® Catalyzed Lacquer (Precat) Medium Rub. They said it was ready to shoot but they did not add the catalyst.

I sanded beween all coats

I never thinned any of it. The first coats of sealer and Lacquer actually looked good. Then I started to get some orange peel, inconsistent sheen, chipping and scratching, chalking in areas, and doors sticking to the table and the finish coming off. The finish is hard to the touch and the shelves and backs that I sprayed first seem to look and feel ok. I sprayed them about a week ago but I am not sure how hard it is. I think is maybe softer than it should be and am not sure how it will hold up.

I did test the back of a drawer front wiping it with Lacquer thinner and it immediately turns back to liquid and wipes off but it removed some of the stain also. I have not tried but I am pretty sure it will not retake the stain consistently.


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## Steve Neul (Sep 2, 2011)

Knot-a-pro said:


> After cycling between anger and depression I am hoping to survive this. My wife was smart and kind to write you all. I have never sprayed lacquer and know very little about it. Sherwin W. local store knows even less.
> 
> Thank you so much for your replies it is nice to know there are people so willing to help. I will tell you what I did.
> 
> ...


What your experiencing with the lack of hardener is uncharted territory. I've experienced all kinds of problems with lacquers normally from some foreign substance getting into it and normally you can just wait it out. What you are describing now is different problems for different reasons. The orange peal is caused by the product drying before it can flow out. This is usually corrected by thinning the lacquer. In some cases especially inside of a cabinet a retarder thinner is good to use to slow the drying time down so it sprays smoother and all the overspray floating around inside of the cabinet won't just land on the surface making sandpaper out of the finish. What you are describing as the inconsistent sheen sounds like lap marks where there was space between rows of lacquer sprayed. When you spray any finish you layer it on like a roofer puts roofing shingles. Half of the new row of lacquer is layered over the previous row. The chipping sounds like since you didn't thin it, it didn't melt into the vinyl sealer. Lacquer works by melting into the coat you are spraying over. If it's too thick it doesn't have sufficient solvents to do this so a lot of it is just laying on the top. I think the chalking is probably the flatting agent in the medium rub. It's the stuff they add to lacquer that makes the difference between gloss lacquer and satin lacquer. The more of it they add the flatter the sheen. The flatter lacquer you use the more stirring it takes. I normally stir a can a lacquer the day before I plan to use it so it has a better chance to get the solids completely dissolved. Stirring is the correct procedure for lacquer. It shouldn't be put on a shaker at the store. A shaker will not do much to break up the solids in the bottom of a can. At this point you can sand the chalky spots and spray it with lacquer thinner. 

Bottom line is since the finish hardened, sand the orange peal smooth, work the flatten agent out and topcoat with another coat of pre-cat with hardener and thinner and you should be ok. Another note, lacquers don't do well in humid weather. The moisture in the air gets into the finish and turns it cloudy. It's because it dries so fast the water can't come to the surface. If you add retarder thinner at these times it will slow the drying time down so the water can get out. It has it's limits though. At about 68% humidity lacquer starts to blush and you can add retarders so you can work up to about 73% humidity but any higher humidity I would wait till dryer weather.


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## cabinetman (Jul 5, 2007)

Your ambient conditions have an effect on the finish. It may be too cold, or very humid. Adding a retarder will help for the blushing issues. Or if you thin with lacquer thinner, you can use a "slow" thinner, which is in general terms a retarded thinner. 

For the moisture problem, you may be getting it from your airline. If your compressor is on the small capacity and output size, it may be running more to keep up the pressure. When it does this, it creates a hot air discharge to the airline. From that you get condensation that can get carried out the gun mixed with the finish material. If you haven't drained out the tank completely, there can form in the bottom an oily gunky slime that can contaminate the finish.

Ideally, having an air filter/water separator as far from the tank as possible (preferably right on the handle of the gun). You can do this easily with a disposable bulb filter that screws to the air intake thread on the handle. Another suggestion is to arrange your airline out to allow setting up drain petcocks. For small areas you can configure a compact layout similar to this...
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## Knot-a-pro (Nov 10, 2012)

*Thoughts and Questions*

It appears that not only did I spray Lacquer with no Catalyst but I do not have very good technique. The Humidity has been pretty low it has be around 60% and the temp has ranged from 60 to 75 degrees. 

I have a 6.5hp 60 gal compressor and multiple water traps and a filter on the gun. I drain the compressor regularly so I think I am good there. However I am interested in the thinning. 

My pattern will only open to spray wet 2 in. It seems very tight. I seem to get a halo of overspray that I think is causing the chalking and getting to thick in some spots causing the orange peel. I am seeing some of the stripping talked about. I am not sure how big the pattern should be and how much overspray I should get. 

I also realize you have to stir constantly I have not been stirring. I think this also explains the sheen inconsistently.

Questions:
How much should I thin the Lacquer?
Should I add extra catalyst?
What do I do about areas that are scratched or popped off?
What size pattern should I see?
It is getting cooler and my spray booth sucks the filtered air through pretty good so outside temp is important what is my temp range?


Thank you everyone it is good to talk to someone who has done this.


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## Steve Neul (Sep 2, 2011)

Different brands take different amounts of thinner. According to Sherwin Williams website the lacquer is packaged ready to spray so I wouldn't put more than a couple of ounces of thinner per quart to begin with. It sounds like most of your problem is with the sprayer you have. Something is wrong where you can't adjust the spray pattern wider than 2". What make and model gun is it? If we knew perhaps one of us has one and can tell you how to fix it. Most of these guns have internal parts where you have to set the range of the spray pattern. If the gun has come out of adjustment this may be most of your problem. The gun should spray a pattern 6" to 8" wide. In my opinion a gravity feed gun is fine for open work where you can get to it but for finishing cabinets where your going inside of a cabinet to spray is awkward. A siphon gun I think is better for this. 
I would not add extra catalyst. It won't help the lacquer that is already on there and the lacquer will likely become brittle so it doesn't expand and contract with the weather and eventually crack. I would stay within the recommended range. 

If the areas that are scratched and popped off are small I would brush some lacquer on these spots with a small brush until there was enough I could sand it level with the surrounding finish. 

Ideally you shouldn't see any spray pattern. The finish should spray completely uniform all the way across to where you just let it dry and your done. You shouldn't have to come back to do any rubbing to blend everything in.

Lacquer is pretty tolerant to temperature but I would try not to spray below 40 degrees. The colder it is the longer you need to let it dry. What might dry in an hour in summer may take overnight when cold.


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## cabinetman (Jul 5, 2007)

The size and shape of the pattern should be adjustable. It may depend on the type of gun you are using. You should have an adjustment knob for pattern size. Turning the nose tip of the gun should change the pattern from a vertical one to an horizontal one. What else can make a difference is how far from the subject you are spraying and how fast you move the gun.

It may take some experimenting on what air pressure you are using, and again, that may depend on the type of gun.









 







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## Knot-a-pro (Nov 10, 2012)

*The Gun*

I have a Porter Cable PSH1. I have a 1.3 needle in it. It comes with a 1.5. It has a pattern adjustment on the side but it is all the way open. I do not seem to be getting any air out of the pattern ports. The ports are not clogged and the adjustment is working. Not real sure what to do??? I have access to a Kobalt. I might try it.

I looked the doors over good today and some look real good others have striping and rough spots and scratches. The Cabinets are just rough (like sand paper) but look pretty good. 

This is my current thinking. I am going to try this on one door and see what happens. Sand down smooth with a orbital sander and 220 grit. This should take a lot of the lacquer off because it is pretty soft. Then shoot with the catalyzed lacquer. 

I really would appreciate your thoughts on this plan. Thanks again for everyones help.


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## Steve Neul (Sep 2, 2011)

Here is a diagram of your sprayer. The valve that adjusts the spray pattern is just an air valve which adjust the air pressure at the outer wings of the nozzle. You probably need to completely dismantle the gun and soak it in lacquer thinner overnight and then thoroughly clean it. Of course any rubber parts should be removed first. There is nothing in there that can become out of adjustment so cleaning would be the only fix. 

At this point we've been using a lot of imagination trying to guess what your up against. The striping on the doors we could use a picture. More than likely it's just lap marks due to your sprayer problem but I would like to see it. The strainer #34 I would get rid of it and strain any finish you put in the gun through a cone strainer. The filter gets plugged up easily and will give you a lot of grief. 

As far as sprayers Harbor Freight sells a siphon gun for less than 30 bucks that works good for wood finishes. If you have access to one of their stores I would recommend you get one. It would be cheaper than the finish you are wasting fighting with the gun you have.

The roughness of the finish is due to not thinning the lacquer. It may take a couple of coats sanding between coats to smooth that out. Just be careful not to sand so much you take the finish off. It's better to sand and spray than sand through. Sherwin Williams (I know you don't want to go back there but) sells Glit sanding pads that would be helpful to you to sand between coats. I would use the fine pad. They are foam rubber pads with sandpaper on them. 

I think you are asking for more troubles using a orbital sander to sand finish. The sander is so aggressive it's real easy to sand through to the wood. I use one mostly in the inside of a cabinet which I don't normally stain and just let it barely glide around. For me it's just a labor saving device where the finish isn't so critical. I sand the exterior by hand.


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## Knot-a-pro (Nov 10, 2012)

I have gotten rid of the filter I can not get part 10 to separate it may be pressed on but I think the clog is at 13. Anyway I am getting a siphon gun. I think it is the gun also causing the sand paper because it is fogging inside the cabinets.

I attached a picture of a door. It is the worst door and at a angle that highlights the damage. 

As far as the sanding goes. I am worried about spraying over the uncatalyzed lacquer. I am not sure my concerns are that valid???

Thank you again for everyones help.


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## thebossman (Oct 19, 2012)

Seen this problem before on a boardroom table, wrong thinners used, second coat caused the first to orange peel, colassal f_uck-up, not my job thank god, but non the least sad to see. Spray guy should have known better.


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## Steve Neul (Sep 2, 2011)

As far as the sprayer. I have a hunch if you would plug the sprayer into compressed air and aimed it into a cardboard box to catch it, part 10 would come out if you would pull the trigger. It looks like O-rings just hold it in. I wish I could be more help with the gun but I have only recently purchased a gravity feed gun and have never had it apart that far.

I think the siphon gun will help you however it won't eliminate the overspray from settling in your finish inside the cabinet. A control solvent or retarder thinner would help with this however you will really will have to watch for runs in the finish. It slows down the drying time so the mist that is floating around inside the cabinet will melt into the finish. 

The picture looks like good news to me. It looks like it is just lap marks from your sprayer problems. Additional coats of finish will take care of it.

I would stop worrying about the lacquer not having a catalyst. The catalyst is a hardener. The lack of it probably makes the finish you put on equivalent to another coat of vinyl sealer. If it wasn't for the sheen problem you could probably just live with it. It just wouldn't be as durable. Putting another coat of finish over the top will give you the hardness you are looking for. The only thing that I'm concerned about is where it is chipping. It sounds like the finish being applied too thick didn't get a good bond in places. It's the unknown of how much of it is like that. Just keep in mind lacquer is easy to touch up and if you have a chip spot from time to time it's a easy fix. The alternative would be to stop now and chemically strip all of it down to bare wood and start over. I sure wouldn't recommend that.


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## troyd1976 (Jul 26, 2011)

Very intresting thread, im learning lots here as a painter for a living whom has only ever run pre-cat through an airless sprayer. seems after following this thread maybe i will stick to that method, a 210 tip and you've got a 4" fan thats atomized twice. lol.

Steve you mention there recommendation of using vinyl sealer under pre-cat, do you know why that is? is it mainly just to give enough tooth for the pre-cat to not run and sag? i hate the vinyl sealer, just does not powder up as nicely as the traditional sealer.


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## cabinetman (Jul 5, 2007)

After seeing the door, it appears you have an air pressure/fluid combination setting problem, along with some technique. I would not at the moment go spend money on a siphon gun. You can get good results from one, but having an HVLP gun to use in your area would produce quite a bit less overspray. I'm suggesting to work out getting it right with the gun you have. Just a note about spraying, try to keep a lot of light on your working path so you get a glare on how wet it's getting. With HVLP, it's a bit difficult to see sometimes.

The results you have in the picture look like you had too much air pressure and not enough fluid output. Your narrow paths are from needing to be that close to the work to get it wet enough. With too much air, it's causing the spray to flash dry.

First I would try out the 1.5 mm needle. Set the airline pressure to about 45 PSI, and the gun pressure about 10-12PSI. Now these settings are from other HVLP gravity guns, and not yours specifically. I couldn't get anything info other than 45 PSI. The gun may run off the 45 PSI straight...which I doubt seriously, but you'll have to fiddle with using either a split pressure (airline/gun), or a straight (airline/gun) pressure. 

I would try thinning the lacquer with lacquer thinner at first 50%. Test the output by adjusting the fluid control to get enough output to get a wet path from about 12" away and about 8-10" wide. Adjust the air up and down about 5 PSI both ways, and keep adjusting the fluid to get more output. 








 





 
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## Steve Neul (Sep 2, 2011)

troyd1976 said:


> Very intresting thread, im learning lots here as a painter for a living whom has only ever run pre-cat through an airless sprayer. seems after following this thread maybe i will stick to that method, a 210 tip and you've got a 4" fan thats atomized twice. lol.
> 
> Steve you mention there recommendation of using vinyl sealer under pre-cat, do you know why that is? is it mainly just to give enough tooth for the pre-cat to not run and sag? i hate the vinyl sealer, just does not powder up as nicely as the traditional sealer.


One of the benefits of using a pre-cat lacquer is it's more water resistant than nitrocellous lacquer. One reason for the vinyl sealer is if you put a nitro sealer on first you loose much of the water resistance because the nitro sealer isn't water resistant like the vinyl sealer. Another reason is the catalyst used in pre-cat and catalyzed lacquers are too harsh for nitro sealers. I have though used pre-cat over nitro sealer in applications where water wasn't an issue before without any adverse reaction. It's probably a situation where you just run the risk of problems going against the directions. I'm liable to use anything for my own use but I stick to the directions for a customer's project and I've never seen a pre-cat that didn't recommend a vinyl sealer.


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## del schisler (Nov 5, 2009)

Knot-a-pro said:


> It appears that not only did I spray Lacquer with no Catalyst but I do not have very good technique. The Humidity has been pretty low it has be around 60% and the temp has ranged from 60 to 75 degrees.
> 
> I have a 6.5hp 60 gal compressor and multiple water traps and a filter on the gun. I drain the compressor regularly so I think I am good there. However I am interested in the thinning.
> 
> ...


I spray lacquer all the time , i live in florida in the middle east 10 miles from the ocean, This is my set up a 2mm nozel and 30lbs of air if any more you will get bad over spray , and thin sometime's 10 or 15 percent and most of all spray away from you because if you spray the other way you are goint to get over spray and dull the surface and that will not work out at all. If you are spraying a door i would spray starting at depend's which way you lay the door, we will say long ways, than spray from eather right or left and start at the closet to you and move away from you, I use M.L.CAMPBELL pre Catalyalize , also a sanding sealer sand and than with what ever finish gloss you want, this is a cabnet grade which is hard when dryed, M.L.CAMPBELL is owen by sherman williams but M.L.CAMPBELL make's their own lacquer also i only use their lacquer thinner. Sound like the saleman person didn't give you what you what you needed?? Sound's like if it were me i would take a door to the store and say look now what are you going to do about the botch job this finish you gave me ?? sound's like a lot of un-nessary work here good luck


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## Knot-a-pro (Nov 10, 2012)

*Game Plan*

The needling discussed with the over spray flashing is exactly what I am seeing. thank you. I am feeling better about sanding what I have smooth and shooting it with a gun setup right. 

I have been running about 30psi and adjusting the fluid so is doesn't come out to fast. I need to try some lower pressures the guns says to run 10-45 psi. 

I am not going to stress to much about the non-catalyzed lacquer My concern now is fixing the little issues and not getting too thick. I agree I need to hand sand the doors and face frames. 

The non-catalized lacquer seem to slowly be hardening I think it is good I waited a while for it to cure out it seems to not completely dry very quickly without the catalyst. 

Sherwin Williams is giving me the new Lacquer since it was there mistake but it has been a lot of extra work. I have however learned a lot

Thank you


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## Juandelnorte (Aug 16, 2014)

*Shooting pre-cat lacquer*

By now I'm sure that your issue is completely resolved, but here are a couple of thoughts to add to the other good advice here . . .

1. If your lacquer is going on too dry or coming out with orange peel or even with a sandy feel, it is because the material is drying mid-air before it hits the surface. This can be caused by a number of things:

(a) Your air pressure is too high. With an HVLP gun, your air pressure at the gun connection should be no more than 29 psi. Ideally it will be quite a bit lower than that, even below 20 psi. You should have a gauge at the connection to the gun, and you should set the gun inlet pressure WITH THE TRIGGER PULLED. With the trigger pulled, I shoot pre-cat lacquer between 15 and 18 psi at the gun inlet. Too much air will dry the material before it hits the surface. Keep your air pressure LOW. (I use a DeVilbliss gravity-feed FLG-670 with a 1.3 tip, and it sprays very nicely.)

(b) Another problem could be that you are holding the gun too far away from the surface when you spray. Depending upon the gun, you should be no more than 4-6 inches from the surface when spraying lacquer. At this range, keep the gun moving quickly, so that you don't get overbuild and sags.

Thinning the lacquer WILL NOT HELP MUCH! Thinning the lacquer (either with lacquer thinner or butyl acetate) will only dilute the solids and require more coats. It will not make up for a gun and air pressure that aren't set right or for improper technique.

2. Once you have your gun set correctly and your spraying distance nailed down, make sure you lay down the material properly. Move the gun quickly across the surface, maintaining a constant distance. Overlap your strokes by about 50%, and ALWAYS KEEP A WET EDGE. You may wish to spray a very light tack coat for your first coat to promote adhesion and help prevent sags, but make sure it still lays down wet.

3. I'm curious what your uncatalyzed finish was like. If the product didn't get catalyzed when you bought it, it should still dry (the solvents will evaporate out) very quickly. The downside of not having the product catalyzed is that it won't cure to the hard, durable finish that you're looking for with a pre-cat lacquer. I'm wondering: did it stay soft and sticky? 

Best wishes,
Juan


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## Balfour Refinishing (Jul 20, 2014)

It doesn't matter how well you adjust the sprayer if the finish is improperly thinned. It takes proper adjustment as well as thinning the finish to the right viscosity for a sprayer to work well.


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## del schisler (Nov 5, 2009)

Knot-a-pro said:


> It appears that not only did I spray Lacquer with no Catalyst but I do not have very good technique. The Humidity has been pretty low it has be around 60% and the temp has ranged from 60 to 75 degrees.
> 
> I have a 6.5hp 60 gal compressor and multiple water traps and a filter on the gun. I drain the compressor regularly so I think I am good there. However I am interested in the thinning.
> 
> ...


a couple things, i thin all my lacquer about 10 % to a 1/2 cup full i use a HVLP with 30 lbs of air my nozzel is 1.5 i drilled it out my self , i did't want to buy one, as far as spray pattern their should be a spray pattern adjustment on the gun, unless it doesn't have one, it should be the top knob ? the bottom one is the amount of lacquer that is going on , the spray should be from the wood, now this is me others my be different, about 10" works for me , also spray from body to the other end , start closest to you and spray away over lapping pattern of spray , now if the mixture is right and look's nice and wet you can spray comming back at you for a thicker coat, their will be no over spray doing that , now doint wait just spray comming back at you, if you can't adjust the spray pattern i would look for a gun that has this adjustment on it , a 2" pattern is to close , i have a pattern that is at least 5 to 6 inch at about 10" , of course the lacquer must be thinned some, i never spray just out of the can, this is just me, all this works for me, i have been useing lacquer for yrs, i live in florida and i spray somewhere aroung 11:00 depends if the grass has due on it i wont spray unless i want, if it turns milky looking , i let it dry, the next coat come out good, i use M.L.CAMPBELL lacquer which makes their own , but is owned by shermm williams , my wood guy carries my lacquer, that is enough for now , check air and mixtuer and spray pattern good luck


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## Michael Luckett (Sep 13, 2017)

I am a paint chemist and what SW and others do is add a catalyst at the time of sale. Precats have shelf life's of about 6 mos. After that they begin to loose cure and they will yellow. By adding at the time of sale it extends the shelf life. The catalyst used is a weak acid, often used is butyl acid phosphate. If you don't mind adding a strong acid catalyst a conversion varnish will give better cure and better resistance properties. It will have police after catalyzing. 4 to 12 hrs. In which to use.


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## allpurpose (Mar 24, 2016)

And here I was all excited this was about kittens..pre cats..


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## Steve Neul (Sep 2, 2011)

allpurpose said:


> And here I was all excited this was about kittens..pre cats..


That's at my house.


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## Bullseyeguy (Apr 28, 2017)

I think those are "post" cats, not pre-cats. You can still see the carryout box that one of them came in!


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## Bullseyeguy (Apr 28, 2017)

I am a bit taken aback at the quality and amount of information that you can find on this site! Some of you guys really know your stuff!


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