AWGB Woodturning Forum
General Category => Tool tips & reviews => Topic started by: edbanger on February 09, 2014, 07:35:34 AM
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Hi All
I've been trying different sandpapers I started with the Faithful and Flexovit paper backed sandpaper in the course grits and with silicon carbide from 240, I had to get a clothed back sandpaper from Axminster for the 600 grit, I found that the cloth back seem a bit better to use, I seemed to get a good finish with this arrangement of papers.
But as the 600 grit seemed a bit better, I invested in a full set from 80 up to 600 grit Klingspur cloth back sandpapers (that should be sanding cloth) and what a difference.
Then someone told me that I should reverse the lathe alternately between grits and this seems to have made the sanding process quicker.
Does anyone have any other sanding tips or opinions on sanding?
If anyone wants some Klingspur sandpaper/cloth PM me I purchased a 50m roll of each so I could cut it off in meters and sell it on.
Ed
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Hi Ed,
I find that the "J" weight cloth backed abrasives work best for me. Kilngspur is a good make. If you do reverse your lathe between grits make sure your chuck or faceplate is fixed so that it cannot unwind with the opposite rotation. Not sure why you would want 80 grit. If you are using this you may want to readdress your sharpening and tooling techniques, try to get as good a finish off the chisels and other tools before applying your abrasives.
I normally use 180,240,320 and 400 in this type of abrasive. I also use 600 and 1200 for really fine work but you have to be careful sanding too finely as sometimes it is so shiny you cant get a finish to stick.
John BHT
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Hi John
I'm new to this only been turning for about 6 weeks, sometimes I find a rub mark from turning and then I use the 80 grit but I'm happy to say that I'm using it less and less, the cloth I have if J rated it's very flexible. I normally sand to 600, I'll try stopping at 400 and applying the finish and see how that works.
The reversing came from Mark Baker at a demo day I went to a couple of weeks ago.
Ed
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Hi Ed,
Sanding in opposite directions is only really relevant on cross grain (bowl) turnings, where the fibres have been pushed back by the tool and/or previous abrasive. For spindle turning, it is not so effective. Instead, stop the lathe after each grit and sand along the spindle (with the grain) as you would in ordinary carpentry.
I do accept there will be some end grain exposed on spindle turnings, on the sides of beads and coves, but the amount of true end grain fibres in these areas is minimal. As John pointed out sharp tools should sort those out.
Another tip is don't always start your sanding at a particular grit, just because you've got it. A sharp tool, on a 'friendly' piece of wood may result in a 320grit finish, so you would be spoiling the surface if you started with a coarser grit than that, and wasting your abrasives. With experience you will be able to guess with which grit to start sanding. The decider is if the marks you are sanding are still there after using the first sheet of abrasive, you need to use a coarser one. An unfriendly piece of wood, with grain problems, may well benefit from 80grit but that is pretty rare.
Finally, if you've got a real problem area, consider putting on some of the finish (oil, sanding sealer, etc.) let it dry completely (ideally 24hours) then try sanding again. The finish should stop the fibres flexing and lets the abrasive cut them, but you need to let the finish dry or it will clog your abrasive almost immediately :(.
There are a lot of other tips and techniques to sanding, almost as many as to do with the turning, but I hope these help.
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Hi edbanger , Power sanding ( using a drill with a soft foam pad ) is great for sanding either the whole object or just at the problem areas ( end grain ) and then finish by hand in the finer grades . I use a special slow sander with 6" sanding discs , from car body repair shops , whenever I can as it is quick ( and the discs are cheap yet good ) and I can get a great finish from it , especially on the exterior of hollow forms with voids, bark inclusions , large cracks etc ... where hand sanding with the lathe running is not possible . Also as you are new to this I hope you are taking all necessary measures to protect your lungs from dust , as it is not easy to get out once in there !!!! A small compressor is also invaluable for dusting of a piece before applying a finish and for dusting of yourself and the workshop !!! 50 metres of each grit was a sizeable investment, in a year or so in time it will be worth having a stock take to see which grade you are using most of 120 and 180 at a guess .... happy turning !!! ( and sanding!!! ) .... Terry...
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Hi All
Darenth I'm sanding this way as I am turning bowls and large at that,
Terry I'm well protected, I have a Jet air filter and a Trend Airshield Pro
Thanks all for the tips, I seem to be getting a good finish, but I'll try the sanding sealer when I next get a bit of rough grain that's proving difficult.
Ed
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I'm prepared to get my hand bitten off for this but I find sanding a strange subject.
To start with, I don't consider that it is necessary to finish everything to a super-fine mirror finish, certainly no visible scratches but on something ring porous, like oak, 180 or 240 is plenty good enough, if you finish sanding with the grain, as you should.
I also agree that you need a full range of the good grits, but I also use plain ordinary 'Decorators Roll' - the yellow stuff.
It's cheap and that is important when it comes to sanding, You need ti be able to use and throw away, not try to keep using it 'because it's expensive.'
I use the cheap stuff up to 320 grit, but my golden rule is I use the best stuff for the highest 2 grits.
So if I'm sanding to 240, I'll use the cheap stuff up to 120 and then 180 & 240 to finish. Likewise if I do want a high polish finish then I'll use the cheap stuff up to 320 and then 400 & 600, and possibly even higher to finish.
Power sanding or the use of an Inertia sander I find gives a finish at least one grit higher than it claims. So a hand finished 240 can be made better by a 240 power sanding.
But I can't prove that, it's just how I see the result - comments.
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Hi Bryan, consider both hands intact, as with the other comments, there is always a sandable finish off any tool, resharpen at best, shear cut for fine finishing cuts, like wise should you sand to a ultra smooth surface, will it be of benefit as you've said, not if it's pine to be painted, then most would say to stain or paint a piece, any marks will show.
A question I ask at a demo once on finishing, what grade are some of the buffing compounds, would some be coarser than the already sanded finish, there was not a real reply or moving along .. as embarrassment it was not known, but some polishes can be found to be abrasive.
Then hand, Power or to include rotary sanding, it's a case of time, this is the benefit to both the last options, as are using fresh adbrasive, worn out never works, 240 never makes 120 ..
Pens .. if it comes to a finish are the exception, when you find many using grades going into the thousandths.
I've "J" cloth, first real breakthrough, an since micromesh and velcro discs' and somewhere besides, I do have what is classed as medium and fine in green sandpaper 1/2 sheet rolls .. have I taken to use it .. :-\ ..
Cheers David
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I agree with the points stated already, something no-one has mentioned though is the finest that you can abrade to. Have a look at this:- the final grit was tooth paste!
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Mmmm, minty fresh bowl!!
I would argue that everyone should have 80g in their tool box. True, you won't need it on every/many jobs (almost never on bowls once you have sorted your tool sharpening and presentation) but some jobs it is a must!
Buy the best quality abrasive you can, it really makes a difference. Cheap abrasive is not worth it! I know a good supplier if you're interested ;-)
After good tool technique, power sanding is usually the best way to a good finish on bowls, but be warned, if you get it wrong, it will quickly screw up all your hard work!!
Cheers
Richard
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Hi All,
Health and safety (as on an earlier thread Last week)
Don't use compressed air for removing dust and shavings, you are just making more airborne dust. Use a filtered vacuum cleaner.
John
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Have a look at this:- the final grit was tooth paste!
Of course toothpaste is mostly Bicarbonate of Soda, an abrasive in it's own right. Used in compressed Air Line abrasive systems, and works very well.
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I hoped to start sanding with 240 but some woods have to resort to 180 0r 120. I also use those to cut back brass or other metal fillings in splits. For general sanding I user a battery drill and sanding discs.
Pete
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The problem I found with the cheaper paper type is it's flexibility the J cloth molds with the shape that your sanding.
I don't understand the use of a power sander, I thought that it would damage the work, do you use the sponge backing pads? A lot of you seem to use them I'll have to give it a try.
Ed
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I saw the great Bert Marsh demo and he started with 80 grit so no shame in having it at hand, the trick is to let the abrasive do the work not the pressure of the hand and dont let heat build up in your wood when using abrasive. With abrasive you have to treat it as if someone else is paying for it, us tight fisted woodturners tend to think its good enough for a couple more uses instead of chicking it away.
Cheers Martin
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The thing about power sanding is that you need the right balance between too firm and too soft. The Hope arbors that I do are just right, with the option to add a softer pad to help with tight curves etc.
The key to using power sanding is to keep the arbor square to the surface of the wood, and so using the full face of the pad. When you start using the edges of the pad it can very quickly produce shapes that weren't intended. It is important to continually check your progress to ensure you are not spoiling your tool work.
My other top tip, which applies whether power or hand sanding, is to clear the dust and detritus from inside the bowl between each grit to give the best possible finish.
Cheers
Richard
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Power sanding or the use of an Inertia sander I find gives a finish at least one grit higher than it claims. So a hand finished 240 can be made better by a 240 power sanding.
But I can't prove that, it's just how I see the result - comments.
I would agree with that statement as I use inertia sanders a great deal, so mush so I own more the half a dozen of them. I would suggest one grit higher is a conservative estimate on the finish.
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i use a tack cloth inbertween grits to remove any left over abrasive (that the eye cant see )
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Well I've taken my sanding to a whole new level, use both Inertia sanders and power sanding the power sanding while the turned item is spinning on the lathe seems to give me the best results which is ok for the outsides and on something shallow the inside, other wise it the Inertia sander.
If it's a natural edge bowl then I use the airline between grits, otherwise I too am using tack cloth.
Thanks for your advice and help, I'll take a couple of pictures and post my latest finished pieces in the next day or so.
Ed
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i use a tack cloth in bertween grits to remove any left over abrasive (that the eye cant see )
At a demonstration at our club, we were recommended to keep one's tack cloth in a glass jar to retain the tackiness. As I'd rather minimise the amount of glass in my workshop, I use a small unbreakable card tub with airtight lid (it contained Marigold Bouillon powder originally) with entirely satisfactory results.
MC
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i use a tack cloth in bertween grits to remove any left over abrasive (that the eye cant see )
At a demonstration at our club, we were recommended to keep one's tack cloth in a glass jar to retain the tackiness. As I'd rather minimise the amount of glass in my workshop, I use a small unbreakable card tub with airtight lid (it contained Marigold Bouillon powder originally) with entirely satisfactory results.
MC
yes forgot to mention that part i use a plastic jar