Repairing lacquer sand-through

[Eric Gourieux]

I am SLOWLY climbing the steep learning curve (for me) for spraying lacquer with my cheap-o HVLP. I'm getting some orange peel that I have to sand out. In doing so, I sanded through the lacquer and into the wood in a few small places approximately 1/4-1/2 " in diameter. To repair this in the past, I have re-sprayed the inside or outside, whichever was affected. I'd like to try a smaller repair, if possible. Does anybody have a solution? I used a pre-cat lacquer, if that matters. Can I try touching up the area with a brushing lacquer? What about cutting a hole in some cardboard just larger than the defect and hitting it with some Deft? (I just bought 3 cans at ACE, by the way, for anybody following the Deft thread). Either way, I would have a smaller area to sand and buff. Any recommendations would be appreciated. And, of course, C and C welcomed and appreciated

Cherry natural edge
11" x 7" at the tallest edge

270825270826

[Faust M. Ruggiero]

Eric,
I spray a lot of lacquer so rest assured I have sanded through my share of finish, usually on corners of flat work. The good news is you do not use any stain so you are merely fixing the top coat. All lacquer leaves some degree of orange peel. You will get less of it by sanding previous layers with 320 grit and taking the peel away slowly. The greatest amount of orange peel happens in the first few layers unless you continue to spray over it. If you sanded through lacquer, you probably had not yet built up enough finish on the surface. Don't sand the first time until you spray 2 or 3 coats. Then sand lightly between each layer. You can spray up to 10 coats if you are thinning the precat. Even your "cheap-o" HVLP will spray well if you have the fluid the proper consistency and the air pressure correct. I spray at almost 50 lbs. When you final sand to remove the orange peel from the final coat, start with 400 and work up to 1000 or so then buff lightly.
Now for the answer to your original question, unless you spray a wet coat over the entire bowl you will have to deal with overspray along side of the area you fix. I know, you probably hate to take a chance or a sag or re-sand the entire bowl. But the truth is, that's the right way. Now that you have sanded away the orange peel, the next coat will be really smooth and need less sanding.
faust

[Richard Coers]

Eric,
I spray a lot of lacquer so rest assured I have sanded through my share of finish, usually on corners of flat work. The good news is you do not use any stain so you are merely fixing the top coat. All lacquer leaves some degree of orange peel. You will get less of it by sanding previous layers with 320 grit and taking the peel away slowly. The greatest amount of orange peel happens in the first few layers unless you continue to spray over it. If you sanded through lacquer, you probably had not yet built up enough finish on the surface. Don't sand the first time until you spray 2 or 3 coats. Then sand lightly between each layer. You can spray up to 10 coats if you are thinning the precat. Even your "cheap-o" HVLP will spray well if you have the fluid the proper consistency and the air pressure correct. I spray at almost 50 lbs. When you final sand to remove the orange peel from the final coat, start with 400 and work up to 1000 or so then buff lightly.
Now for the answer to your original question, unless you spray a wet coat over the entire bowl you will have to deal with overspray along side of the area you fix. I know, you probably hate to take a chance or a sag or re-sand the entire bowl. But the truth is, that's the right way. Now that you have sanded away the orange peel, the next coat will be really smooth and need less sanding.
faust

Careful with recommending all those coats of precat. The manufacturer will tell you the recommended film thickness. Exceed that and you will have a finish filled with cold cracking.
Eric, If you think you have a tough surface to level off of that cheap gun, wait till you use a rattle can or brush. Then you will talking about some real leveling issues. If you insist on just spot repairing, get an air brush and that will keep the overspray to a minimum.

[Faust M. Ruggiero]

Richard,
You are correct that precat manufacturers make a high build formula so kitchen producers can spray two coats and call it quits. I cut my lacquer far thinner than a kitchen guy might. I also remove a lot of finish in the process of leveling. I always think in terms of not how much you spray but how much you leave.
faust

[Eric Gourieux]

Thanks for the suggestions. It looks like I'll be spraying more this weekend.

[robert baccus]

All good recommendations above. I spray a lot of laq. and find 2 products make life far easier. Use a good heavy bodied sanding sealer on bare wood --seals the pores and saves on laq. coats. Think of it as a filler as well as a sealer. Use retarder in your laq. to help flowout and reduce blushing and also a good rattle can for flowing out patches. It won't eliminate sanding but will greatly reduce it. I find finishes at big outlet stores to be so-so quality at best.

[Bill Wyko]

I gave up on lacquer for wood & went to automotive clear coats. I use Advantage catalyzed clear, 3 coats are like 10 coats of lacquer. No shrink problem over time either.

[Eric Gourieux]

Robert,
I use shellac sanding sealer (Sealcoat). It's getting harder to find lacquer retarder locally. If I understand correctly, the Indiana Sherwin Williams stores have stopped carrying it. It's not "green", you know!

Bill,
Can you tell me more about the clear coats? Is it a lacquer-like material? What is the advantage?

[Tai Fu]

320 grit on lacquer is very rough... no wonder you are sanding through. I recommend starting on around 1000 or 1500, go to 2000, and then start buffing if necessary. I never get sand through when using that fine of a grit and it doesn't take that long to level out orange peels at that grit. I never used pre-cats so I don't know how it's different but I usually shot the finish out of the gun very thin, and not level between coats (with lacquer this is meaningless because coats always blend into itself. All you will do is reduce film thickness. Do not sand between coats unless there's a bug in the finish or something). I shoot 3 coats after sealing/color coats, let it dry for however long it takes, and then sand with 1500 grit. I've never had a sandthrough to this date.

I don't get how catalyzed urethane is more "green", when the stuff requires full body suit and fresh air system, and one breath of the stuff kills you.

[robert baccus]

When working down laq. try the 3M sponges in 220-400. They are too mild for wood but great for laq. with no stiff corners. Also add soapy water and wet sand.