Sanding non flat surfaces has always been a big chore for me. I refinished pianos for 20 years, 15 years ago and all the nooks and crannies of fancy carvings consumes a lot of time if it is to be done right. Now I am sanding bowls from the rough, to a silk smooth finish. Talk about a lot of sanding, there doesn't seem to be a stopping place. Disk grinders and orbital sanders, using finer grits each time seem to be the only way to get it down. Flap sanders do a pretty good job but they are slow. There are a few more things that cut corners but when it comes right down to it, a lot of time and elbow grease seems to be the only way.
If you have some tips and tricks to reduce this endless effort, please feel free to share them. Thanks.
Well, I like to make my finish cut smooth enough that I can start sanding with my 2000 grit and work my way up from there. ;D
I do try to make my final cuts as smooth as I can. Shear scraping can accomplish that on the outside of the bowl. Sometimes I power sand using a 2 inche disk mounted on a rubber pad in my drill. Even with that I sometimes have problems eliminating the tearout in the endgrain portions of the bowl. To do that, I stop the lath and sand the tearout with the grain working my way up through the grits. I find that if I have a stubborn spot, I can get it out faster if I stop the lathe and just work on that spot. Once you get the spot smooth, turn on the lathe and complete sanding.
I really try to cut my bowls without any tearout in the endgrain portion of the bowl, but sometimes no matter how hard I try, I still get a little tearout. Shear scraping helps a lot and also, putting some sanding sealer on the wood and immediately turning while the sealer is wet helps. It somehow supports the fiber and keeps them from tearing out.
Other than that, I don't have any secrets. If your finish cut is smooth, you can start with a higher grit but if rough, don't hesitate to start with 80 grit and work your way up through the grits. And! Don't skip any grits. Be sure to wear a good mask and set a fan at the end of your lathe to blow the dust away from you.
Olen's bowls are like dough bowls Charlie. They are not turned. Everyone will get to see a good look at one this weekend as we will be putting one up for auction. I told him "DONT SEND THAT ONE TO ME, YOU SHIP IT!" :D (Tammy would never let it leave the house again if it came here.) Its amazing.
OK Woodbowl, I'll try again. :) Why not try scraping with a curved scraper? I find scraping removes wood fast and leaves a real smooth finish. Just burnish the edge of the scraper to get that curl of metal on the edge (hook). Pull it with the grain. I've had good success but I've always scraped flat surfaces. However, they do make curved scrapers and there must be a reason.....maybe to scrape inside of bowls. Sheesh! Now you know EVERYTHING I know. ;D
His bowl in his avatar looks like a butter tray and my grandmother used one alot over the years. I think her's was made from basswood, it's not heavy wood and non porous. Market some as butter bowls to the Amish, make'm from basswood as there is no extractives to get into the butter. Make some butter presses/molds and paddles as well. Treat the tray well with flaxseed (linseed) oil. Her's has never cracked. 8)
Olen check out a curved metal moulding scraper, it'll do the trick a lot faster than sandpaper.
Stew
Break some winder glass. Use them as scrapers. You will get LOTS of different shapes. We used them for refinishing gunstocks. ;) ;)
An osborn (osborne?) brush might work. Its kind of like a wire wheel cup brush with abrasive coated nylon bristles.
I've also used a Vonnegut head on odd shaped stuff in furniture plants. Its a large flap wheel with brushes backing up the strands of paper.
A pneumatic rolling pin sander lets you adjust the air pressure to conform to different shapes, it would only work on the outsides, if at all.
Sandbasting turnings with ground up corn cobs is an interesting finish.
Like semi-gloss poly it give it .........Mellow Patina........ ;D ;D ;D ;D Did ya like that ??? ???
I've tried some scraping in the past. I don't know what winder glass is though. All I had were some light weight, curved paint scrapers that would leave chatter marks and I wound up having to sand anyway. I've thought about a heavy scraper with a depth gage on the back. Then it would be a curved planer I suppose. Better still ..... an electric curved planer. Can't find no such thing on the net. BK, do those sandblasted corn cobs eat out the soft wood and leave the hard rings as if it is weathered?
Here are a few bowls in the rough. There're sort of smooth, but a good hour of sanding is what it takes to make a furniture smooth finish. It's a real pain. When I get through my hands are tingling from the sander and
I've had enough. You may remember a topic I posted a while back about a tumbling drum.
https://forestryforum.com/board/index.php?topic=17959.msg258411#msg258411
(https://forestryforum.com/gallery/albums/userpics/12431/DSC02204ff53%25.JPG)
Ya got to keep in mind that the man is from florida and now in the jungle ;) I don't know what winder glass is though
Read window glass ;D
Geesch Olen, Took a Quebecker to translate redneck fer ya, EH ??? ::) ::) :D :D :D
Well why didn't you say you wanted a curved base planer ;D
http://www.timberwolftools.com/tools/makita/M-1002BA.html
Alot of times you can play with the pitch angle youre holding the scraper at and kind of cross the grain at an angle to keep the jitters down. Some wood takes scraping better than others.
Winder glass .......... :P it says, a round piece of glass, got to do with watches or sumpthin'. Wender glass ....... :P it says http://www.gagirl.com/southern/south.html I know what a wender pane is but I was thinking hard to figure out how you sposed' to wind a piece of broke glass and scrape a piece of wood with it. Harold, what duz folks sound like that live south of CR? ::)
You can make some really good scrapers from broken bandsaw blades.
South of Costa Rica, is where them little Dudes wear them tuxeders. ::) 8) :D
Quote from: Don P on April 12, 2006, 10:05:12 PM
Well why didn't you say you wanted a curved base planer ;D
http://www.timberwolftools.com/tools/makita/M-1002BA.html
That's a great link Don. Do you have this tool?
Tom, are you talking about sharpening the back edge of the band, making a small hoop and clamping it with vice grips for a handle?
Now Deadheader, .... whuts a tuxeder? ;D
Many, many years ago woodworkers used glass as a scraper. Me, I'd rather use a metal scraper because the last thing I would want is the glass breaking in my hand.
Woodbowl, we are not talking about a paint scraper. A furniture grade scraper is a flat piece of steel about 3 inches by 6 inches for the rectangular ones that you would use on a flat surface. To make them so they'll work, you have to "burnish" the edge. First, put the scraper in a vise, then file the edge of the scraper so it is true and 90°to the sides. Then you take very hard steel rod (called a burnisher) and run it down the edge of the scraper to produce a "hook" along the edge. It is that "hook that does the cutting. You can feel the "hook" with your thumbnail. It takes a little practice to get the right angle on the "hook". Burnish too much and you roll the cutting edge of the "hook" up and it won't cut. Don't burnish enough and the edge isn't there to cut.
Now, with that said, they sell curved furniture scrapers, which once burnished you could use to scrap the inside of the bowls. You would burnish them the same way as the rectangular furniture scraper.
There are also burnishing tools you can buy where you set the degree of the hook you want. That takes all the guess work out of it but they are quite a bit more expensive at about $35 or so.
A scraper with the right angle hook will literally cut the wood as smooth as glass. You'll usually get fine ribbons of wood as it cuts. A scraped piece of wood is smoother and cleaner looking than a sanded piece of wood because the fibers are cut and not frayed.
Scrapers are really handy when smoothing burl and endgrain too. It might take you a little practice but I assure you that once you have it down you'll be well rewarded.
Olen, I got one of them Vonnegut type sanders you can have if you want to try it. It came on a little machine that B&D made, called the Work Wheel. The little machine has crapped out, but I still have the sander. Pick it up and try it next time you're over here. ;)
ps: Somebody left a big pile of spalted sweet gum in my yard while I was gone. Ya need to come over and pick through it, too. ;D
A while back, I hand sanded my 57 chevy down to bare metal. It took me 6 weeks, working 8 hours a day to do it. After that, someone told me bout a product that is basically a sponge ball with a bit of abrasive material on it. When sent through a sand blaster, it compresses the sponge balls, and they are hurled out at what ever you point it at. You can literally take off layers of paint on a car with it, or take off the paint and leave the original primer on the car. It is THAT sensitive.
try THIS LINK (http://www.nortonsandblasting.com/nsbsponge.html) for more info on the product. I'm sure there are other manufacturers that make this stuff, and several grades of abrasive are available. Because it is on a foam ball, it will also work on irregular surfaces. It can be reused also, so there is just a one time investment if you contain the balls that have been blown out of the sandblasting rig.
this is called "sponge blasting" of you want to google it. It would be my first choice for sanding large objects smooth, especially objects with irregularities.
For those who have tried sandblasting wood, have likely found that the annual ring structure will stand out more, like weathered wood. SYP will hae the latewood portion of the ring which is harder (more dense) resist more of the erosion than the earlywood portion of the ring. Makes for an interesting pattern accentuating the grain. Might be difficult to obtain an even surface with the 'blasting' techniques.
I'm intrigued by the sponge balls. Will look into it, as I prepare to get an old JD 110 '65 lawn tractor ready for some new paint.
Sure wish I had my '57 Chevy back.....4dr hardtop, two-tone blue. Sweet car. They are going for $100,000 and up when fixed up real good.
Lee Valley has carbide scrapers and also a 3" or 4" bowl buff
It sure helps to start with the right species of wood. Like this..........
(https://forestryforum.com/gallery/albums/userpics/10317/paperclip%20holder.jpg)
That's red beech from NZ. No matter what angle that you are sanding to the grain, it shines right up. ;D Somebody put a magnet in the center. makes a clever paperclip holder.
Two things spring to mind
Glass is a good way to go
you need a really good new cutter and a supply of new 6mm glass (scraps from a glass company will do)
cut you glass in about the curved shape you want, you use the back side to scrape
scraping down into the middle of your bowl will leave a very fine finish
and Ive yet to break a bit of 6mm doing this
second you could try a 4" random orbit sander with a foam backing
pad
you can buy the pads from auto finishing suppliers or make you own from a variety of foams from neopren to upholsters foam use spray on contact to stick the Velcro but always peel you sanding discs with care
I've made a lot of these over the years and they are superb for what i use them on (sanding and blending hollows and edges) and i think they would be the same for your application
i use 6" air and a 6" dewalt sander but i think you would be better of with the smaller size
you will find that a foam pad will also make a superb sander for the outside
i would also make a vacuum hold down to hold your work I'll see if i can find the gubbings for you in the land of the yankee ;) and post it for you
Iain
Here you go
http://www.m-powertools.com/products/vacuum-holddown.htm
http://eagleamerica.com/product.asp?pn=500-0100&bhcd2=1145175984
read the top (Brittish site first the second is the American supplier)
the thing you really need it the conical looking bit
its a cone shaped bit of rubber with deep grooves all around it running long ways, these allow for by pass air to reach your hoover motor
the hoover i use ia one of the split in the middle to empty the cloth bag types and has lasted more than 5 years and the amount of suck you get when its set up right is amazing
i make up vac tables of any size and shape to hold stuff, they dont have to be flat just air tight so sael any porus surface with varnish
i use self adhesive neopren or stiff closed cell foam to form the seal between the hold down and the work piece, whack a hole in for the tap (on the cone shaped rubber thing) slip on the normal hoover hose and go with both hands at the flick of a switch
if you mount the hold down on a pedestal type of stand you can work from all sides without remounting
iain
I got as neighbour that makes his own sanding jigs, rubber balls cemented to a stem (to put in the drill) and covered with glue an then rolled in Silica sand.
Different sized balls give you different curves. Renew as required by recementing and adding more sand.
He keeps a veriety of them going at any one time. ::)
What kind of glue does he use, what type of rubber balls, what grit sand, how long do they last, what speed can he sand at, how good a job does it do, what neighbor, is he on the forum, wha........... ? Tellmetellmetellme ......... this is a good idea if it can hold up. I'm suprised I haven't seen something like that on the market.
Olen, I guess I better put my good visit'n cap and go fer a stroll with Deputy Dog .... he likes da pooch. ;D
They looked like regular kids rubber balls, I think he mentioned they came from the dollar store.
The glue smells like some sorta two-part epoxy, does dat stuff come in 'stay flexy' formulas? ::)
Quote from: Murf on April 19, 2006, 02:35:34 PM
The glue smells like some sorta two-part epoxy, does dat stuff come in 'stay flexy' formulas?
Yea, there's 90 sec, and 5 min set up times. There 15 min, an hour and what ever you want set up times. I wonder how well the silica sand sticks? It's got to be coated to make it flow smooth through the blaster hose.
Looks like I need to make a trip to Walmart. Thinking about getting me a beach ball. 8)
I was thinking that a nerf ball was what he was talking about...
Ok, I'll bite, wazza nerf ball? ::) Inquiring minds wanna know?
I know what a Murf........ oh never mind. :D
If this works good, I was just thinking about making a big sanding ball.
If gluing silica sand onto 'rubber' works, then maybe a trailer-size inner tube blown up on a small trailer rim without the tire would work. Thinking of your wood bowls and needing a large diameter spinning in the bowl.
Mount the rim with inflated tube on a lathe (maybe the outboard end of the head block) and hold the shallow wood dough bowls up to it.
Then too, maybe a sanding belt (like 2-3" wide) running over a narrow tire like a wheelbarrow tire and over a driving tire would make for some internal bowl sanding possibilities too. On the order of a band on a band mill that runs on tires.
Or contact someone at 3M to see what technology they have that could be adapted to a flexible, spinning sanding material. They have some interesting pads that can be used for sanding and possibly could be adapted to a flexible wheel-like sanding head.
Murf, them nerf balls have been out for 25 years or more now, I remember when they first came out, all the kids needed one. ;D It's just spongy rubber as near as I can tell, I don't think it takes on water though.
Ya gotta google it. ;D
Pieces of old flip flops make good hand-sanding pads for bowls.
I could see Tom out in his flip flops sanding bowls. ;D
With them on his hands too..... ;D
Stew
Quote from: SwampDonkey on April 21, 2006, 04:23:26 PM
I could see Tom out in his flip flops sanding bowls. ;D
I sure hope you see him more than just flip-flops! :o
This may be a tad bit off topic, but since we are talking about sanding irregular surfaces....
how does one go about sanding in the shape of someone's backside into the seats of rocking chairs? Is this done by hand or???
I saw a machine that did this at the IWF show in Atlanta several years ago. BTW, .... IWF will be comming up again this Aug.
There is also a curved draw-knive that is used to make these indentations. I've also heard it called a bowl knife.
Getoverit,
Over here, the true Windsor chair craftsmen use an adze type tool with a curved blade. They stand on the seat blank, and hang and swing the 'adze' between their legs ( please..no implications ) rough cutting the profile. Definately an aquired skill... I wonder how many boots (or flip flops) have been adzed whilst learning :o
Keep your toes up ;D
The curved drawknife gets called a scorp around here too.
I use a angle grinder with a chainsaw wheel on it to do roughing of those kinds of shapes.
Now a chain saw wheel could be a good tool to have around :) Where did you get it and what does it look like? got any pics?
Ken, its just a little wheel with a saw chain on it. It fits on a 4½" side grinder. I think you can get one from northern tool
Note:Please read the Forestry Forum's postion on this company. The thing was invented and produced in Tallahassee, but I think they outsourced it to China.
Better known as the suicide wheel. One day I'll tell you the story about the day I got mine in the mail and had on a new "t" shirt. ;D ;D :(
Quote from: woodbowl on April 23, 2006, 10:23:11 AM One day I'll tell you the story about the day I got mine in the mail and had on a new "t" shirt. ;D ;D :(
O.K. I'm ready for the story. Tell away ;D
I like a good story and I'm sitting down too :)
This sounds like it will be a real "rip" snorter. :D :D
A real 'hum dinger' ;D :)
Actually, it was a 4" tungsten carbide burr wheel. It is a wicked tool as well, but does a fine job on bowls and chainsaw carvings. I've got a chainsaw wheel too, and scared of it like a rattle snake. I've heard some awfull stories about it.
When I recieved the 4" burr in the mail, I did the normal procedures for mounting the tool and starting the work. You know, ..... rip the box open, toss the directions, slap it on your 4" grinder and stick it in the wood as fast as possible to see what it will do. As I bent down to do all this, my flopping "T" shirt got a little too close to the burr wheel. Did you know that a tungsten burr is like velcro? ....... In a fraction of a second, the grinder was twisted up to my neck, my new "T" shirt looked like a teenie bra, the grinder was humming, locked up and I could not find the cut off switch. The switch was positive lock and not spring loaded. I took off running and screaming like a girl untill I unplugged myself.
I've always thought of myself as being extra carefull. I don't think there is really any such thing anymore. I've still got all my fingers and toes, but I hope I can keep a fear and respect for all tools.
I've got teenage drivers now. I guess I better head off to the Prayer topic.
I was using one of them impact wrenches to remove old harrow teeth. I stuck my finger up against the head of the bolt and began spinning the wrench to remove the old nut. Well, once that got loose enough the head of the bolt started spinning and sliced a little meat on the finger yielding a little stream of blood. Hmm, guess we won't do that again. Using that harrow on our gravelly soil had ground down the head of the bolt to a razor sharp edge. YIKES!! ::)
Olin,
I'm laughing with ya, I promise ! Just glad you didnt get seriously hurt over it.Maybe the story will do me some good to and remind me to be more careful. Thanks for Posting it !