I have just finished a project in Ash, and sprayed it with Sherwin-Williams M-60 Black lacquer. The finish is just the sheen I want , but it is a little fragile, (like most lacquer finishes) you have to be careful or you can chip it if you bang into it . I test sprayed a piece with Sherwin-Williams Pre-cat High build lacquer in a medium rubbed finished. This finish has too much shine for what I like (I like a rubbed finished), This comes in a gallon, the finish I think I would like only comes in a 5 gallon size, way too much for what I need, plus the price would be too much. The question I have is this..are all lacquer finishes compatible with each other? Can difference brands be mixed (not mixed together, but sprayed on top of each other without any problems? Please help me on this!!!
Edited 3/15/2008 11:29 pm ET by 70445
Replies
Your S-W supplier can get the S_W technical support to answer your questions; however, in my experience, they stick to the printed orthodoxy.
Since you are happy spraying two-part material, have you thought about using automotive paint? You can get it in small quantities, it is very durable and you can match any color you want. Although its per gallon cost is high, you won't need very much and you can get it in small quantities.
Just sand the wood to 180, and apply one or two coats of primer (two-part with 1 hour pot life). Sand the primer lightly with 400. Then apply two coats of base (this is the color part). Finally, apply the clear coat (another two-part material). This will leave a glassy surface that you can rub out to the desired sheen. You can do all this in one day, though leave the clear to harden overnight before rubbing it out.
Here's a window I made in spanish cedar (windows and casing) and cypress (exterior trim) using the above process. The cedar needed the pores filling first.
Hope this helps,
Hastings
It's NOT a good idea to spray one brand of pre-cat lacquer over another. There's a good chance the finish will wrinkle if you do. If the lacquer is NOT pre or post catalyzed and is just nitrocellulose lacquer, then it's not a problem.
http://www.finishwiz.com
Thank you very much for that info..that what I thought...I did visit you web site and it is very very good..lots of info and techniques.. I do have a question about spraying..I am having sprayed lacquer and the finish looks like little dots not a even coat at all I've tied about everything, including changing tip size and air pressure..what am I doing wrong? I am using a TurbinAire HVLP..sure could use some help or advice. Where are you located?
I'm in Fredericksburg, Virginia. Are you using a turbine or air from a compressor? What size needle/nozzle? Have you thinned the finish?The most common problem learning to spray is the finish is too thick. It's easier to learn if you thin the finish a lot and use the fluid adjustment knob to control how fast it sprays. Try thinning the lacquer 50% (2 parts finish to 1 part thinner) and see how that works for you.
Paul
http://www.finishwiz.com
I'm using a turbine. I have used the following tips/needles and air tips and turbine air settings. needle tip.50 fluid tip.75mm,1.0 needle and .75 fluid, and 1.5 needle and 2.0mm fluid tip, and a air flow swtting of 2 on a scale of 10 on the turbine. I have been using Sherwin_Williams pre-cat hi-build lacquer, and I have not thinned it much. According to the recommendations on the can it says not to reduce more than 10%, I don't know if one can reduce it more or not. The finish looks a little like the orange peal you have in your web link, but mine looks more like speckles or bumps. I am really appreciating your help on this matter. I live in Pittsburg Kansas, just a little ways from you!!
Paul is right on the money. Your product is too thick for the equipment you are using. I use S-W precat and thin it a little but I am using a Sata RP gun with a 1.6 tip. If your 2.0 tip still gives you orange peel and won't flow out you might need more thinner and add some retarder to get more flow out. Not too much of either but start small and go bigger until you get your desired results. Turbine guns will not give as good of a finish as a HVLP and an HVLP is not as good as RP. AirMix is the best but that is a $3,000 system. You have a top end turbine system so you should get very good results on cabinet lacquer. Hi-build might have too many solids for a turbine gun, don't know, never used one. Do not put a catalyzed finish over and uncatalyzed substrate it will wrinkle or lift. It might lift anyway after this length of time. You might try S-W Kem Aqua dull-rubbed effect. Water-based won't lift your substrate or a spray on poly.
Yeah, that's a long hike! Been a long time since I was out that way. These days I'm hoping for get-a-ways in a southerly direction that feature warm sand, salt water spray, and palm trees.
A fluid needle in the range 1.3mm - 1.5mm would be my preference. I always leave the air setting at the highest point on a turbine and make adjustments with the fluid needle and fan width.
It sounds like you're getting coarse atomization due to low air flow and thick finish. In the picture below, on the left, the droplets that came out of the spray were larger than they should be for best spraying results. The finish was not atomized very well because it was too thick for the amount of air pressure and flow through the spray gun. By thinning the finish, (and/or increasing the air pressure), the finish broke into finer droplets as seen in the picture on the right. The finer droplets flow together more easily to form a smooth flat film.
View Image
Coarse atomization = larger droplets
View Image
Fine atomization = tiny droplets
You can thin the finish as much as you want without causing any harm. The manufacturer wants people to be impressed with how thick a coat you get when you spray their product so thinning it would take away from that and require you to spray an extra coat or two. It's a very big deal in a production environment, but not for the average person or small shop. There's also a need for larger shops/manufacturers to avoid using too much thinner because of air emission restrictions.
The 'best' approach is to turn your air flow all the way open, lossen the fluid knob most of the way, use a 1.5mm needle/nozzle, and then thin the finish in 5% increments until it sprays well. Start with 20 ounces of lacquer and add one ounce of lacquer thinner at a time (5%), stirring it in, and do a test spray. Around 15% thinned, you should see improvement and will probably be getting great results by of before you thin it 30%. If not, go all the way to 100% (1:1) if you have to.
Once fluid is coming out at a good rate, you'll have to control the spray pattern by adjusting the fluid flow and fan width.
Paul
http://www.finishwiz.com
Edited 3/16/2008 11:16 pm ET by Paul_Snyder
Thank You so very much for the information!!! Your last reply was exactly what is happening, your photos and explanation were excellent, they really helped me in seeing what the problem is. I'll try your suggestion today sometime and let you know the results.. Do you work as a professional woodworker, or have your own business? Anyway, Thank You for sharing your knowledge, it's not many people that would offer that kind of assistance and all the trouble you went through..
Larry Hill
Pittsburg, Kansas
Glad to help Larry. I'm strictly a finisher... barely capable of the most rudimentary woodworking skills. But I do like to help others with their finishing projects and the internet provides lots of opportunities for sharing. Good luck to you.Paul
http://www.finishwiz.com
Since I've started this project and seems like I used the wrong finish to start with and made it quite complicated, using the precat lacquer an so on. What is the best method to use for making a black finish on Ash/ How would you do it, or what would you recommend for a hobbyist?
You may chosen the best finish for the project... Spraying is a good way to get a really smooth finish without a lot of added work so let's start by limiting the choices to black spray paints. There's black lacquer (including pre- and post-catalyzed), waterborne, and some other catalyzed finishes (e.g., conversion varnish, polyurethane, polyester).Since you chose to paint ash, I'll guess that seeing the details of the pores was important (since ash has such large pores). That means you want a paint that can be applied really thin. Lacquer is a good choice here. And pre-cat lacquer is a little more durable than regular lacquer.There's always aerosol enamel paint.Paul
http://www.finishwiz.com
I really didn't paint the piece I built I sprayed Sherwin-Williams M-60 lacquer (black) and was not happy with the durability of the finish, so I decided it need a tougher top coat. There is where I sprayed Sherman-Williams high-build lacquer, which is a precat lacquer. That is where I was having problems spraying, because as you stated I need to reduce it further and other recommendations. What better options do I have receive a black finish? Should invalueable apply a dye to the wood and then spray a clear coat of some type of lacquer? What would you do? I want to use ash because I want the grain of the wood to show. Again Thank You for all your help, it is invaluable, and appreciated.
Actually, you did use paint. All pigmented, opaque finishes are technically paints. What sets the black lacquer apart from the paint you get at the paint store is that is dries so fast it's best to apply it with a spray gun rather than a roller or brush. They used to paint cars with lacquer, but now they use catalyzed polurethane because it's more durable and lasts longer.
All the spray finishes are available as clear finishes and paints. Finishing suppliers will match any brand of paint color there is, using the type of spray finish you choose. The key difference between the types of spray finishes is durability. For example, I can get Benjamin Moore "OC-17" mixed in lacquer, conversion varnish, or catalyzed poly. For built-in shelving, a pre-cat lacquer is fine. For kitchens and baths, conversion varnish is better because it's more durable. For even more durability and/or a higher gloss, catalyzed poly would be the best choice.
When a customer says they want a "black finish," the first question I always ask is if they want to see the grain of the wood or do they want it painted. If it's paint, I just choose the finish that has the right durability for the situation. If they want to see the grain of the wood, I'll do a sample for them to approve.
For a black finish that shows the grain, I'll start by dying the wood black and then use a black stain over the dye. (there's another discussion on black finishes that has an example - Black Finish. Then I'll apply clearcoats that are durable enough for the job.
For someone that isn't using spray finishes, there are other choices. In film forming finishes the choices include shellac, brushing lacquer, and oil-base varnish (including polyurethane). Varnishes offer the most durability.
Paul
http://www.finishwiz.com
Thanks for clarifying that for me..You have been a great help, Thanks
My pleasure!Paul
http://www.finishwiz.com
Paul,
Does catalysed lacquer not "melt" into the previous layer as nitrocelluse lacquer does?
Does anyone else mix up liquor, liqueur and lacquer? I talk about the lacquer store more often than the liquor store.Chris @ flairwoodworks
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Each brand is a little different so you have to get the tech data sheet for the one you're using. But... they all have a recoat "window" of time where you can spray another coat without sanding and get a good bond. If you spray another coat before the previous coat has cross-linked sufficiently, the two coats will get a good chemical bond. Beyond that window, you have to scuff sand the surface to promote a mechanical bond. The same is true for all catalyzed finishes.Watch out for those lacquer stores, overdo it too much and the next thing you know you'll be totally shellacked.Paul
http://www.finishwiz.com
The April issue of Workshop News has an article by Greg Williams on aerosol lacquer finishes.
Cheers,
Peter
Better life through Zoodles and poutine...
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