I need some education on sanding and finishing

[Darryl Fective]

I'm hoping to generate some useful discussion here. After 20+ years, I've improved somewhat at the turning part, but I'll admit, I'm still learning. There's lots of info on turning, but the sanding and finishing of pieces doesn't seem to get as much attention. I feel like I'm still experimenting a lot more than I should be. You'd think I would've nailed down more of it by now.

I can usually do well with dry pieces. The sanding and finishing is a bit more straightforward. My biggest issues come with pieces from fresh wood. I know trying to sand soggy wet wood doesn't work well. It clogs the paper (Abranet works much better) and smears/blends the colors. I try to at least wait for the surface to "dry" before trying to sand, but I still have issues with heavy contrast wood like walnut that has both sap and heart woods, or bark on sapwood. Spalted woods like maple or beech also give me problems. Even dry, the black spalt lines can smear into the surrounding wood and give a muddy appearance. Is sanding sealer the solution for these situations? I have tried wet sanding under running water, but that's not much fun and feels slow going, but was sort of successful.

I know sanding sealer can make endgrain less dark by limiting the penetration of finish, but are there downsides to using it? From my limited use/experience, it seems like it can make the final finish less rich looking. I'm lost on when to use, or not use sanding sealer.

Is it normal that the time spent on finishing is multiples of the actual turning time?

Are there some useful books, videos, etc. that you could suggest for improving my finishing process?

 

[Steve Tiedman]

Book- Understanding Wood Finishing, by Bob Flexner. It's out as a third edition, available just about everywhere. Flexner passed away not long ago...

Generally, wet wood needs to be dry to accept finishes, and even for successful sanding. The book above probably won't address wet wood, not that I recall. (Drying wet wood is a subject all to itself, with plenty of past discussions on the topic.) Putting finishes on wet wood will stunt the drying process of the wood, and prevent proper finish curing. For turners, this is the main rationale with rough turning wet wood, and then finish turning some period of time later- weeks, months, even years depending on thickness.

I hope this helps shed some light. Buy that book, it really is the science and how-to of finishing.

(Edit, Flexner also wrote articles for Popular Woodworking magazine. You can see his articles if you register at their website. But still buy the book.)

 

[John K Jordan]

Book- Understanding Wood Finishing, by Bob Flexner. It's out as a third edition, available just about everywhere. Flexner passed away not long ago...

Generally, wet wood needs to be dry to accept finishes, and even for successful sanding.

I second that recommendation. I see I bought that book 10 years ago, 2015.
I can't imagine me sanding or applying finish to wet wood.

JKJ

 

[Wyatt Holm]

I spent an afternoon with Mike Mahoney a few years ago. He was turning his natural edge nested bowl sets. They were finished green. He was power sanding them with velcro sanding pads. The wet wood kept clogging his sandpaper, so he had a piece of rubber looking stuff hot glued to the headstock of his lathe. He said it was a cleaning stick that is sold for cleaning belt and disc sander paper. I asked him how well it works. He said it works alright, but a brass brush works even better.

 

[Lyle Jamieson]

Darryl, the key is sharp sandpaper. This video might help. Merry Christmas to you and your family.

View: https://youtu.be/anum277hn_s

 

[Darryl Fective]

For some pieces, the end result is better if the sanding is done while the wood is still somewhat wet. As it shrinks and dries, the structure of the wood becomes a wonderful natural texture. Crotch wood gets an almost ripped muscular look and feel, while burl figure gets a sort of antique leather appearance.

 

[Odie]

Book- Understanding Wood Finishing, by Bob Flexner. It's out as a third edition, available just about everywhere. Flexner passed away not long ago...

Generally, wet wood needs to be dry to accept finishes, and even for successful sanding. The book above probably won't address wet wood, not that I recall. (Drying wet wood is a subject all to itself, with plenty of past discussions on the topic.) Putting finishes on wet wood will stunt the drying process, and prevent proper finish curing. For turners, this is the main rationale with rough turning wet wood, and then finish turning some period of time later- weeks, months, even years depending on thickness.

I hope this helps shed some light. Buy that book, it really is the science and how-to of finishing.

(Edit, Flexner also wrote articles for Popular Woodworking magazine. You can see his articles if you register at their website. But still buy the book.)

I don't know about the book, but some of Steve's commentary here is some of the best information to be found in this thread....

=o=

 

[Dave Hulett]

I second that recommendation. I see I bought that book 10 years ago, 2015.
I can't imagine me sanding or applying finish to wet wood.

JKJ

I third that recommendation. But also to answer your question of "Is it normal that the time spent on finishing is multiples of the actual turning time?" not necessarily "normal" but certainly not uncommon. Some woods finish beautifully and easily (mesquite), others (walnut) are difficult.

 

[hughie]

I spent an afternoon with Mike Mahoney a few years ago. He was turning his natural edge nested bowl sets. They were finished green. He was power sanding them with velcro sanding pads. The wet wood kept clogging his sandpaper, so he had a piece of rubber looking stuff hot glued to the headstock of his lathe. He said it was a cleaning stick that is sold for cleaning belt and disc sander paper. I asked him how well it works. He said it works alright, but a brass brush works even better.

yes I have a brass wire brush

 

[Steve Tiedman]

I don't know about the book, but some of Steve's commentary here is some of the best information to be found in this thread....

=o=

Thank you, Odie.

 

[Lyle Jamieson]

For some pieces, the end result is better if the sanding is done while the wood is still somewhat wet. As it shrinks and dries, the structure of the wood becomes a wonderful natural texture. Crotch wood gets an almost ripped muscular look and feel, while burl figure gets a sort of antique leather appearance.

Yes, I do that often because I only turn green wood. The trick is timing. You have to sand it when the outer surface has dried enough to sand without sandpaper clogging up. The center of the wood wall thickness is still pretty wet. At this stage the vessel is not too much out of shape, running pretty true. Wait any longer and the vessel will have considerable movement, distortion and not run true round on the lathe. Sanding after it dries will have a nice smooth surface. Sanding when partly wet will result in the surface you describe with ripples in the surface from the shrinkage of drying. Crotches or burl woods can have a fantastic surface texture from drying. The magic of mother nature showing off her beauty. The timing from finish turning to sandability is short and variable depending on the wood variety and wall thickness. Thin walls will get there in a matter an hour or to thicker vessels can take overnight. This is another reason to have uniform wall thicknesses. The entire vessel dries out at the same pace that way.

 

[Ron Solfest]

Make that a fourth recommendation for Flexner’s book.

I bought the first edition decades ago and read it cover to cover twice as I recall. After giving this away to someone I bought the third edition and read it cover to cover again. BEST finishing book of several I’ve owned, and the only one I’ve read several times. Easy to read, well organized, and very informative.