Wet sanding

[David Walser]

How many of you regularly wet sand your turnings? I saw an interesting video on YouTube last night on the turning of a natural edge bowl. The turner wet sanded using naphtha -- something I've never even heard of before. So, if you do wet sand, could you share some thoughts as to why and how?

[Jim Becker]

I have never wet-sanded turnings. But I DO clean off the pieces between grits with mineral spirits to reduce the chance of scratching from "old grit" as you move to finer abrasives.

[David Fried]

I wet sand when using fine grits but I just use water. A small jar of water and I just dip the sandpaper.

[Bob Opsitos]

I wet sand fine grits, 320+, with mineral spirits. No dust and reduces clogging of the paper.

Bob

[Jim King]

I use a floor grade high gloss polyurethane three part finish and wet sand everything with water and whatever soap to 1000 and then car buffing compound and finally car wax. Very good shine .

[Dennis Peacock]

I've found that when a piece won't sand very well that I get better results with wet sanding with mineral spirits starting around 220 grit and up. If I apply an oil finish, I will put on a fairly heavy first coat of oil and sand with 600 grit to help fill the pores some and let that sit over night. Works good and people love the feel a a nice smooth oil finish turning. :D

[George Tokarev]

Not on the lathe. Too messy. I use a thinned bit of what'll do the final to fill pores occasionally, but it tends to obscure the overall figure of the wood. Free advice - never use SiC (black) paper to wet sand until you're well sealed. Especially on light woods.

Use light lube like mineral spirits to cut fast, heavier, like oil to polish. Keep a margarine tub of the appropriate solvent handy to clean the paper.

[John Hart]

So....I have a question. Never tried wet sanding. I have a piece on the lathe right now. Cherry...burly stuff...with some cool inclusions. At the end grain points, I have some minor fuzzies happening there. Will wet sanding with mineral spirits take that out? The rest of the piece is like glass.

[Gilbert Vega]

I use lacquor for most of my turnings and on the high gloss ones I wet sand with 2000 grit followed by extra fine polishing compound, followed by swirl remover and finally with Carnuba wax.

http://www.woodworkersweb.com/modules/gallery/albums/albus43/Dscn00650002a.jpg

[Jeff Myers]

I always have to wet sand acrylic turnings(pens and bottle stoppers etc.) because if i don't i find that regular dry sanding if not EXTREMELY carefull will cause the dust buildup on the sandpaper to melt back onto the turning. Just keep a glass of water by the lathe and dip the paper into
and sand,,,re-dip to clear off the buildup and go again...really brings out a high gloss shine on acrylic. When i get up to the micro mesh, i keep a towel handy to wipe off the sludge and the mm lasts a lot longer.

[Doug Collins]

Probably a silly question, but when you speak of wet sanding and sanding with the ultra-fine grits, are you just using the black automotive type wet-or-dry sandpaper?

[Jim King]

Yes, I use the normal black automotive type. It is all we have available but works good.

[Jeff Myers]

Probably a silly question, but when you speak of wet sanding and sanding with the ultra-fine grits, are you just using the black automotive type wet-or-dry sandpaper?

I use whatever's on hand but I'm lucky in that there's a Klingspor shop
in town and they have big boxes of cut-offs you can dig through and
get all different grits(depending on the day) and it's weighed at the register....$15 will get me a year's supply of sandpaper in long strips,,,
i just cajole the yungins into cutting those long strips into 3" x 4" pieces
for a pizza night for them :D and i'm set with stacks of usable sandpaper.
It's sanding belt roll scraps i use but whatever you have on hand.
Micro Mesh i have to purchase at retail but buy the larger sheets and cut
them into small pieces and use them sparingly as possible since they do
cost a lot.

[Dennis Peacock]

Probably a silly question, but when you speak of wet sanding and sanding with the ultra-fine grits, are you just using the black automotive type wet-or-dry sandpaper?

Yes...regular old Silicon Carbide sandpaper. Like what's used by many automotive shops.

[David Walser]

Thank you for your comments. It's nice to know that there's not just one right way to sand a turning!

If I can summarize, wet sanding provides the following benefits:

It removes the grit from prior sandings, reducing the chance the grit will scratch the surface.
It cools the sandpaper and wood, allowing the sandpaper to cut better.
It makes the sandpaper last longer (because of the reduced heat and by keeping the paper cleaner).
At higher grits, wet sanding helps polish the wood surface.The turner who wet sands using naphtha (from the Youtube video) said he liked using naphtha because it does not raise the grain. In a prior life I worked in a furniture mill. There, we wet sanded with water because it raised the grain. (Otherwise, our water based stain would raise the grain.) What's your feeling of the importance of raising the grain?

[George Tokarev]

The turner who wet sands using naphtha (from the Youtube video) said he liked using naphtha because it does not raise the grain. In a prior life I worked in a furniture mill. There, we wet sanded with water because it raised the grain. (Otherwise, our water based stain would raise the grain.) What's your feeling of the importance of raising the grain?

Polar compounds like water, to a lesser extent semi-polar alcohols and ketones, will raise the grain because they bond to the sugars and "bulk" them out. Non-polar compounds like the organic solvents we call collectively "thinners" or oils/waxes just occupy the spaces between the fiber. You can see that they're different by putting some water on a piece that's simply oiled or waxed. Up they swell, and the oil gets milky looking.

Which is what leads to my philosophy of water-setting. Mandatory for salad and popcorn bowls which are just getting oil, probably not for those getting resin/solvent finishes, because there'll be enough to reject most water. Water setting has another advantage, in that it breaks heat-hardened surfaces. They're the ones you've pressed too hard on, or the ones you get when you're trying to stretch the sandpaper. The heat superdries the surface, which makes it shiny, but the contrast between the shine and the unremoved scratch is glaring. Setting with water will reexpand the fiber so you can get at it better. This is a good thing, regardless the final finish.

Flat work, where we can sand "with the grain" benefits as well, because sanding into climbing grain roughens it by bending it back, and sanding into descending grain can press uncut fiber into the spaces to surprise us when we use a finish with a polar solvent. We set with water and press while sanding the opposite direction to equalize.

[Joash Boyton]

Often, I will sand a hollow form, to around 1500g, and then soak it with water, for a few minutes, than wait for it to dry, the water will lift the grain, and give it a rough feel, I then sand at around 400, and then finish at 2-3000G. I find I get a much smoother finish.

Not really on the original subject, but......

Joash

[Jonathon Spafford]

For raising the grain I usually just spray my whole piece with DNA and light it on fire to burn off the alcohol... learned it from Jimmy Clewes!

[Dan Gill]

For raising the grain I usually just spray my whole piece with DNA and light it on fire to burn off the alcohol... learned it from Jimmy Clewes!

What could be better? Power tools, beautiful wood . . . and fire!:D

[John Hart]

I like Fire. :)

[Jonathon Spafford]

What could be better? Power tools, beautiful wood . . . and fire!:D

Especially bright blue fire... nice effect!!!