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NC lacquer disappearing into soft redwood :(

1K views 7 replies 4 participants last post by  SirIrb 
#1 · (Edited by Moderator)
Hey guys this is my first post and I've got a situation.
I am attempting to start a woodworking business including building ornamental redwood planters in geometric shapes and have streamlined my processes but the finishing has got me scratching my head.

I have gotten set up to spray and am running a small 8 gallon compressor with a cheap gravity fed gun that works pretty good in my opinion -will work better with practice of course. It should be noted these items are for interior, not exterior gardening and won't see seasonal elements/ excess moisture. After researching the fastest way to apply a good finish without sanding between coats, I decided to start with spraying Deft brushing lacquer since spraying lacquer is either really hard to find in the Bay Area or really expensive. I found 1 source -Kelly Moore, and wasn't willing to pay ~60$ a gallon to experiment. Even Deft is only available at some big box stores and not others although that is due to it's parent company being a competitor or something..

ANYway I tried spraying redwood sanded to 150 grit with Deft thinned with acetone around 50/50. I've read the fast drying active solvent will kind of offset the slower ones added to make it brushable and it would dry faster. Plus I've also read multiple thinner coats give a better end finish. Later I read (lota research) thinned lacquer can be it's own sealer. So this seemed a good idea to me.

The lacquer built up on the denser rings and totally soaked into the spongy soft wood between. It looks like shiny tiger stripes. Which is kinda cool looking, but not what I am after. I want to build a uniform gloss base and then do my topcoat in satin or semi-gloss. I applied many coats, probably 5 or 6, and the big contrast in sheen was still there.

Then today I realized I may have just applied a sealcoat and that subsequent coats would build more evenly. So I lightly scuff sanded and sprayed straight unthinned Deft on thicker than the thinned coats. Only got one coat on before it started raining.. The stripes were still there when it dried, although the softwood areas were a little bit more shiny.

SO my questions are: Is this just going to take a bunch of thick coats and having to sand down the areas that have built up more? Is there a thicker finish I have overlooked that drys fast and can be applied in fewer coats and more evenly soak into different densities of grain? Since I plan to switch to water based acrylic lacquer (fumes/ being able to spray inside/ almost same working qualities) does this problem occur with most or all finish types?

It's pretty frustrating cause I can't make what I make look like what I want. Any help would be appreciated. I am going for quality and speed of finish.
 
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#2 ·
I think you thinned it way too much. Try 25% thinner maybe less. Soft woods will absorb the finish more than hard woods and exotics. There is also how much air you are pushing and how much liquid the gun is shooting. This comes with practice. I finally got my gravity fed hvlp tweaked in and am able to shoot just right (I learned how to shoot lacquer on a quart cup to there was a little learning curve). But when you drop the amount of thinner and up the liquid going out the gun with the right amount of air you should see the correct build on the wood.

Let us know how it goes.
 
#4 ·
On a side note… NC lacquer is not a great finish for anything that will get wet or live outside. I only mention this because when I read "planter", I read wet or damp, possibly outdoor use.

My favorite WB finish is General Finishes EnduroVar, but like NC lacquer, it is also not exterior rated. I spray it right from the can with a 4 stage HVLP, but it also goes on superbly with nylon brushes, or even disposable foam brushes! It's got a slight amber tint, but I like to add 1 drop / 8 oz. TransTint Honey Amber when I'm using it on medium or darker woods.

GF makes a similar product clear called Exterior 450. I haven't used it, but I've been thrilled with all 10-12 GF products I've tried, and I've been 95% water based since 2005. All the wooden boat guys I know use a spar varnish by the brand of Epifanes. It's very well respected, but oil based so I don't know how it goes with CA VOC rules. Bring money if you want to try Epifanes…
 
#5 ·
agreed. I skipped over that when I read it. Keep it in the family and use lacquer thinner. I am spraying a lot of enamels now and use acetone to thin them and maybe that is why I skipped seeing that you were using it but you want to thin lacquer with lacquer thinner.

Chemically speaking I have no idea of the difference it would make using one over the other.

Also, get rid of the acetone and use lacquer thinner.
Pre-catylized lacquers are self sealing, not NC lacquer. It will still work, probably not as well though.

- jbay
 
#6 · (Edited by Moderator)
You can use acetone, especially in colder areas, (although I think it's too hot to use by itself) but you don't want the evaporation rate to be so fast that the lacquer doesn't level out properly. It's all about the evaporation rate and the temperature your using it at.
Lacquer thinners are made from 4 or 5 different chemicals that have different characteristics. This is why it's usually best to use the products recommended thinners because they are mixed at the best ratios for their product. Doesn't mean you have to, but knowing what to use if it's humid out or 110, or 60 degrees is when it helps to know.
 
#7 ·
Thanks for the tips. I am going to try spraying straight unthinned Deft again today. It has been overcast and a little drizzley but the retarders in brushing lacquer prevent blushing I believe. I think my problem is just a matter of not laying on enough solids.

These are decorative indoor pieces that hold plants that don't require soils so the moisture/ UV protection shouldn't be a big deal.

I am going to tweak the gun settings and see if that will help.

Will application of a sanding sealer help seal the softwood better than a few thinned coats of lacquer? I just want to get the process streamlined with as little steps and sanding as possible to have a better turnaround time. Plus the shapes I make have many, many faces so sanding is annoying..
 
#8 ·
This is based on my experience: A sealer coat does help. Some just shoot more lacquer but I believe sealer works well as a base [hit with 220 grit here] shoot some lacquer [Beer here] shoot some lacquer [beer].

[beer]

[take payment for product you sprayed]

[buy beer]
 
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