Hello woodturners! This is my first post here, although I've been reading posts for over a year. I signed up as I've been having a heck of a time with O.B.'s Shine Juice. I "think" I really love the stuff, at least initially, as when I first coat my turned items, especially Walnut, the shiny look is AMAZING. Looks exactly as "advertised" by those who advocate it, that glass-like reflection, although it still shows the wood and the wood grain just fine, which I like.
The challenge I seem to have is that that beautiful shine fades within an hour or two, and I end up with a diffuse, dull, and rather boring finish. I have tried a few things to resolve this. I've tried putting on a bunch of coats, letting it fully dry, then tried polishing it up with Acks. I also picked up a micro fine polishing grit off Etsy. Those do their thing, but in the end, despite all my efforts, I just don't get a glass-like shine that lasts forever. Its shinier, but not glass. I have also started buffing the pieces, on the advice of others in various threads, including on these forums. That works better...and with a classic trip/white diamond/carnauba buff sequence, I can get side grain or spindle items to shine up pretty well...but, its still not that glass-like reflection that the finish initially has when I first put it on. Shiny, but not detailed reflections.
I also have had significant troubles with finishing bowls, along the end grain parts, where the grain seems to perpetually soak up any amount of finish I put on it, and I can never get a shine along the end grains. I suspect this may be a technique problem...perhaps I am not sanding to a high enough grit. I have also not used sanding sealer on bowls yet, although I have on some other pieces. The sanding sealer on spindles seems to prevent this issue in end-grain parts of spindles, however it also affects the finish...that deep penetration of the oil into the grain of the wood, which gives shine juice some of its most appealing properties, doesn't occur, and something is just missing in the end. Maybe there is a trick to dealing with end grain when using shine juice?
I finally came across someone's recommendation to put on a couple of coats of shine juice, then use just shellac flakes dissolved in DNA, at a 1:4 to as much as a 1:8 ratio. I haven't gotten up to a 1:8 ratio yet, but I have had a lot of problems with shellac finish this way, gumming up on me. When I thinned the solution more, it helped a bit, but it seems inevitable that within two-three coats, the pure shellac gums up and ruins the finish. Now, this does seem to help preserve more of that glass-like shine...but, still not entirely, it still seems to fade a bit, and there is something about just the pure shine juice shine that is just...brilliant, incredible, deeply penetrates the wood and gives you that incredible sparkle in the grains.
So, I'm wondering, hoping, that some of you have some tips...or maybe at the very least, just an explanation, as to why the shine juice fades? I'm not sure if I am doing everything right with it, for one. I've tried polishing it hard with lots of friction, to the point where the heat almost burns my fingers. I've tried polishing it medium with just a slight bit of heat, and I've tried polishing it lighter, with just enough to pull out the shine initially, eliminate streaks, then I leave it. So far, something between medium and light seems to preserve the shine the longest...but in the end, ALL approaches have faded. I do use just the normal 1:1:1 ratio of BLO, DNA and Zinsser Shellac. Is there perhaps a different blend that works better? I have also been working with it during the summer here, and the temps in my garage where my workshop is, are usually over 80F, sometimes over 90F, and I've wondered if the heat may be causing problems with the finish drying/polymerizing/curing properly? I also live in Colorado, and we don't have much humidity most of the time...some times it can drop as low as 10%, a lot of the time it is around 20%. Rarely, it will get up to 50% or so, and when it is actually raining, I can measure 80% or more outside (and if I open up my garage to let all that moist air flow through.) Is a low humidity preventing the finish from drying properly?
In my experience, with a lightish-medium pressure when polishing the finish in, I can get that brilliant glass-like finish, which will remain glassy for about an hour, and then over the next hour will slowly fade and dull, until there is just a diffuse, soft specular highlight left. I use a simple LED lamp that hangs over my lathe when I'm turning and finishing, and its glass reflection shows a bunch of points where the LEDs are, around a circular diffuser in the center of the light, and a bit of a ring of light around the edges. I can see this clearly when I first put the finish on. After 2 hours, I just see a very soft, dull, fainter distributed specular highlight spread along the curve of the piece (currently, turning a very simple walnut and mulliput box, spindle, so its mostly side grain). I can probably get a couple of photos to clearly demonstrate the issue visually here in a little while.
Anyway, I greatly appreciate anyone's insights into preserving that glass-like shine that shine juice is famous for! Thank you.
The challenge I seem to have is that that beautiful shine fades within an hour or two, and I end up with a diffuse, dull, and rather boring finish. I have tried a few things to resolve this. I've tried putting on a bunch of coats, letting it fully dry, then tried polishing it up with Acks. I also picked up a micro fine polishing grit off Etsy. Those do their thing, but in the end, despite all my efforts, I just don't get a glass-like shine that lasts forever. Its shinier, but not glass. I have also started buffing the pieces, on the advice of others in various threads, including on these forums. That works better...and with a classic trip/white diamond/carnauba buff sequence, I can get side grain or spindle items to shine up pretty well...but, its still not that glass-like reflection that the finish initially has when I first put it on. Shiny, but not detailed reflections.
I also have had significant troubles with finishing bowls, along the end grain parts, where the grain seems to perpetually soak up any amount of finish I put on it, and I can never get a shine along the end grains. I suspect this may be a technique problem...perhaps I am not sanding to a high enough grit. I have also not used sanding sealer on bowls yet, although I have on some other pieces. The sanding sealer on spindles seems to prevent this issue in end-grain parts of spindles, however it also affects the finish...that deep penetration of the oil into the grain of the wood, which gives shine juice some of its most appealing properties, doesn't occur, and something is just missing in the end. Maybe there is a trick to dealing with end grain when using shine juice?
I finally came across someone's recommendation to put on a couple of coats of shine juice, then use just shellac flakes dissolved in DNA, at a 1:4 to as much as a 1:8 ratio. I haven't gotten up to a 1:8 ratio yet, but I have had a lot of problems with shellac finish this way, gumming up on me. When I thinned the solution more, it helped a bit, but it seems inevitable that within two-three coats, the pure shellac gums up and ruins the finish. Now, this does seem to help preserve more of that glass-like shine...but, still not entirely, it still seems to fade a bit, and there is something about just the pure shine juice shine that is just...brilliant, incredible, deeply penetrates the wood and gives you that incredible sparkle in the grains.
So, I'm wondering, hoping, that some of you have some tips...or maybe at the very least, just an explanation, as to why the shine juice fades? I'm not sure if I am doing everything right with it, for one. I've tried polishing it hard with lots of friction, to the point where the heat almost burns my fingers. I've tried polishing it medium with just a slight bit of heat, and I've tried polishing it lighter, with just enough to pull out the shine initially, eliminate streaks, then I leave it. So far, something between medium and light seems to preserve the shine the longest...but in the end, ALL approaches have faded. I do use just the normal 1:1:1 ratio of BLO, DNA and Zinsser Shellac. Is there perhaps a different blend that works better? I have also been working with it during the summer here, and the temps in my garage where my workshop is, are usually over 80F, sometimes over 90F, and I've wondered if the heat may be causing problems with the finish drying/polymerizing/curing properly? I also live in Colorado, and we don't have much humidity most of the time...some times it can drop as low as 10%, a lot of the time it is around 20%. Rarely, it will get up to 50% or so, and when it is actually raining, I can measure 80% or more outside (and if I open up my garage to let all that moist air flow through.) Is a low humidity preventing the finish from drying properly?
In my experience, with a lightish-medium pressure when polishing the finish in, I can get that brilliant glass-like finish, which will remain glassy for about an hour, and then over the next hour will slowly fade and dull, until there is just a diffuse, soft specular highlight left. I use a simple LED lamp that hangs over my lathe when I'm turning and finishing, and its glass reflection shows a bunch of points where the LEDs are, around a circular diffuser in the center of the light, and a bit of a ring of light around the edges. I can see this clearly when I first put the finish on. After 2 hours, I just see a very soft, dull, fainter distributed specular highlight spread along the curve of the piece (currently, turning a very simple walnut and mulliput box, spindle, so its mostly side grain). I can probably get a couple of photos to clearly demonstrate the issue visually here in a little while.
Anyway, I greatly appreciate anyone's insights into preserving that glass-like shine that shine juice is famous for! Thank you.
