Sanding question

[Chris152]

Can someone advise me on the relative merits and otherwise of sanding with:
handheld abrasive;
using a rotating disc with a handle (like this - http://www.ockenden-timber.co.uk/index. ... ts_id=1688);
using a powered disc (attached to a cordless drill) as the piece rotates?

According to the link the second one helps do away with sanding lines that follow the direction of the wood on the lathe. Does this work, and what would having a powered sanding disc add to that (I've watched videos of people using the latter).

Thanks
Chris

 

[Phil Pascoe]

The beauty of a drill or flexible drive system is that it can be used to sand certain spots - a Sandmaster or the like depends upon the wood moving, so can only sand the whole item. Look at something like this -
https://hopewoodturning.co.uk/tools-han ... x-set?c=27

 

[stewart]

HI Chris

Powered sanding is often quickest - but throws dust around much more than hand-sanding with abrasive, especially if you have a dust extractor nozzle close to the sanding paper. However, the hand held approach can sometimes leave marks so you have to move the paper all the time. I find better success with handheld if I use a large piece of abrasive and use very little pressure on the wood. If a piece is big enough I'll use my random orbital sander hooked up to a vacuum cleaner to help reduce airborne dust.

 

[CHJ]

1. Nothing wrong with hand sanding, it's really a case of experience that teaches you when, where, and how to get best results.
Has safety limitations for access inside rotating pieces and broken continuity of surface, very useful for stationary treatment of rogue spots.

2. Friction driven sanding discs can be much quicker to remove material and small circular scratch marks that result are less visible to the naked eye.
Very easy to spin up far too fast, reducing the effective cutting of the abrasive, plain bearing versions rapidly fail due to grit getting in bearing, sealed ball bearings are essential for good working life. Only works whilst piece is rotating so useless for spot treatments.

3. Slow speed Drill or Flex drive driven discs can alter the approach angle to get in areas that a friction driven device can't access or won't work.
Does not rely on rotational speed of piece therefore allows better control of material removal, works with piece stationary on rogue areas, allows use with interrupted surface and natural edge pieces. If using small hand held Drill/Driver speed of cutting disc is infinitely variable to give better control of material removal, (not all flex drive systems have speed control).

 

[Dalboy]

Hand sanding at a slow speed and keep the paper moving is good in some applications as you can feel if you are overheating the piece which can lead to checks in the wood, it is also used for irregularly shaped pieces where you do not want the pice rotating and getting your hands in the way like natural edged work.
I think CHJ sums it up better than I can
A lot of how to sand comes through experience and obviously the safest way to sand.

 

[Chris152]

Thanks all - those are really helpful replies. I guess my only concern about using the powered set is controlling the dust as you say, Stewart - but that looks a really useful kit Phil, and maybe by using the lower left quarter if the discs I can direct most of the dust down toward the dust extraction which is below and to the right of the bowl. It's got to be worth a try, though with my turning I may also need to invest in grits for the 40-120 range that don't come with the set.
Cheers
C

 

[CHJ]

Big plus for the expenditure on the Hope Kit of multiple heads is that you can mark each head up for different grit levels and leave the discs attached until used up, quicker and easier to use once you get into a routine.
Constantly applying and pealing off discs on a single head reduces the life of the abrasive loops and often results in failure to adhere before the grit is finished useful life.

One thing to note is that replacement abrasives are cheaper to buy in sheet form and just cut it into suitable sized squares.
If you try to use coarser 100 or 80 grit papers on a 50mm head they may not adhere well enough (depends on brand) to overcome the resultant cutting forces of the rough grit, usually fine on a 75mm head if a more robust use of the multi faceted cutting gouge is needed.

 

[Phil Pascoe]

multi faceted cutting gouge?

Mod Edit:- sorry, that better? auto correct kicked in (was faced)

 

[Chris152]

Thank you Chas. Whether multi-faced or multi-faceted (I had to search on-line), both are beyond me and it's simply a lack of finesse with regular gouges that I'm trying to sand away. That said, I often find I can start with finer grits now, so long as I've avoided tearout. I'm definitely going to try the set and making my own discs sounds like the way forward.
C

 

[Robbo3]

When hand sanding, if you can feel the heat, then you are pressing too hard. I often hold both ends of the abrasive, so that it molds to the shape of the piece, whilst moving from side to side.
Chris, you obviously have a talent for turning. A days tuition with a professional turner will answer all your questions & refine your techniques.

 

[Phil Pascoe]

As Chas said the sets are good as you don't ruin the velcro by changing discs perpetually. Use intermediateb sponge pads - they help with the wear and tear and also prevent too much pressure being used which stop overheating. Especially with the lighter grades of abrasive you don't need to cut it round, just leave it square, it acts like a flapwheel.

 

[Chris152]

A days tuition with a professional turner will answer all your questions & refine your techniques.

Thanks Robbo - I'm getting to the point where I might well do this - I'm still trying to get the basics right through lots of practice but I know there's a point where concentrated tuition will help lots.
C

 

[John15]

I use the Abranet system for hand sanding. It's effective, there's zero dust, and no clogging.

John

 

[Steliz]

1. Nothing wrong with hand sanding, it's really a case of experience that teaches you when, where, and how to get best results.
Has safety limitations for access inside rotating pieces and broken continuity of surface, very useful for stationary treatment of rogue spots.

2. Friction driven sanding discs can be much quicker to remove material and small circular scratch marks that result are less visible to the naked eye.
Very easy to spin up far too fast, reducing the effective cutting of the abrasive, plain bearing versions rapidly fail due to grit getting in bearing, sealed ball bearings are essential for good working life. Only works whilst piece is rotating so useless for spot treatments.

3. Slow speed Drill or Flex drive driven discs can alter the approach angle to get in areas that a friction driven device can't access or won't work.
Does not rely on rotational speed of piece therefore allows better control of material removal, works with piece stationary on rogue areas, allows use with interrupted surface and natural edge pieces. If using small hand held Drill/Driver speed of cutting disc is infinitely variable to give better control of material removal, (not all flex drive systems have speed control).

CHJ - You mention in the second point about the problem of sanding grit getting into non-sealed bearings but does the grit cause a problem for the power drill?

 

[CHJ]

CHJ - You mention in the second point about the problem of sanding grit getting into non-sealed bearings but does the grit cause a problem for the power drill?

Never had a problem, powered drills invariably have air intake at rear to give maximum cooling to comutator and expell it out the front to aid armature cooling and blow dust away from chuck and workpiece.

I do not have dust problems myself from 'spin-off ' from either friction drive (rarely used these days) or from hand drill, there is a reason for this though, I have a very high air flow extraction rate at the chuck area, such that I have to be careful not to loose anything that will fit in a 100mm dia. hose and need to fit a mesh grill when parting small pieces or working with hand abrasives.

Enough grit does however get into the brass/bronze bush bearings of something like the older Sorby design to wreck them in short order.*

Downside is the noise generation of the extraction air, drowns out any lathe or tool noise.

* Don't ever be tempted to oil such bearings as is advocated occasionally, that way lies a widespread splatter of black oily residue over machine, you, and more disastrously the work piece.