Bowl sanding

[TFrench]

Does anyone have any advice on bowl sanding? I've been using abranet sheet but I'm getting light scratches - are the sanding pad ones with the angled head any good - everyone seems to make a version of the same thing. Does one stand out as being very good or are they all similar?

 

[woodpig]

I use a 2" pad on a portable drill. It works well but I still work down through the grades to get a good finish.
Not sure there's much difference between makes and some folks even make their own.

https://youtu.be/G44HICpHgqg

https://youtu.be/PgwkIEFYjo4

 

[Dominik Pierog]

Inflatable drum sanders?

I dont know how its perform but i wish someday buy this set and try.

And also cheaper version...
Fiber ball on stick for drill.

 

[Phil Pascoe]

http://www.hopewoodturning.co.uk/sandin ... rs_17.html

For most purposes you can use the Abranet in squares, in fact unless you are going right up to something that could be damaged they act a bit like a flapwheel.

 

[CHJ]

For maximum control that works both on rotating work and stationary when working on the odd rogue grain, using sanding pads in a slow speed hand drill (battery operated) works best for me.

The friction driven devices used to be my original method but I found that they often rotated far to fast and just generated excessive heat rather than let the abrasive cut efficiently, and of course they don't work on stationary pieces.

Of the pads I've found the Hope ones to be the most robust and convenient. To reduce the cost of abrasives I use sheet stock cut into suitable squares to match the head size most of the time, the resultant corner flaps being particularly good inside boxes and small bowls as they act as mentioned above as small flap-wheels.

On the abrasives front I find there is a balance between quality and cost that is best decided by how you use them, clean cutting being the essential factor, price usually means better bonding and grit retention, but the latter is not always the best option as it can lead to trying to keep using the abrasive after it has passed its best performance and just generates heat. Cheaper brands that cut well but loose the bonding early on can encourage the use of fresh abrasive more often and cost wise still be competitive.

Edit:-
Going back to the original comment about getting scratches, regardless of abrasive type, work down through the grades and be prepared to finish off by hand with the piece stationary, sand with the grain direction where possible, any residual scratches will then blend in with the natural grain rather than across it. You will probably find that for most wood species there is no need to sand below 240 grit by doing this, it's very rare that I sand below 320 on bowls and boxes.

Rotary sanding often produces an acceptable finish because any scratches are in random small circles that form a broken image for the eye/brain to resolve, sanding by hand can produce tramlines that the eye/brain computes as continuous lines even if they are interrupted dotes passing across side grain.

 

[Keithie]

Crikey ... I'm very comfy with accepting I may not be doing things the 'right' way or the most efficient way..but sometimes I'm really surprised.

All I do for sanding is use hermes cloth backed sanding media through the grades by hand on the piece (bowl or spindle) while its still on the lathe. 100 & 150 for cutting & removing glitches then 240,400,600,1500,2500 (the latter two rarely and not hermes cloth backed, just fine paper). I guess it takes a while to get the 100 & 150 right (optically) but I'm not typically in a hurry.

I'm def not saying I'm right ...it just never occured to me to do it another way..is there something wrong with using your hand to hold sanding paper against a piece (you def know if you're applyng friction heat!) ?

 

[Phil Pascoe]

There's nothing wrong with anything that works. The problem comes when you find a timber that is inclined to show scratches, and then doing it the simple way tends to show them as rings - which is when a rotary device or hand held drill (better, as it can be used stationary) comes into its own. I've never needed to go below 320 or 0000 steel wool. If your fingers burn, the paper's blunt or you're holding it too tight.

 

[graduate_owner]

Hi all, regarding making bobbin sanders as per the links, can anyone tell me what thickness of neoprene is generally used?

K

 

[CHJ]

.... 100 & 150 for cutting & removing glitches then 240,400,600,1500,2500 (the latter two rarely and not hermes cloth backed, just fine paper). I guess it takes a while to get the 100 & 150 right (optically) but I'm not typically in a hurry...

Just a personal observation but I think you need to concentrate a bit more on tool control and the finish straight off the tool.
Although sanding grit can be considered as a multi faceted cutting tool, the use of anything coarser than 180 grit on most species of wood is likely to just remove turned features rather than removing the last remnants of tooling blemishes. *

Very few woods show any benefit from going beyond 320 grit, in fact for a lot of sealing and coating finishes polishing the wood down below this is likely to reduce the adhesion of lacquer etc. resulting in it being prone to damage and showing adhesion loss.

Just ask a professional cabinet maker what level he finishes his pieces to before applying his sealing finish.

For me I find it's the sealing finish that benefits from being polished with the finer grits, not the wood.

* That's not to say that there are never times when all turners will resort to the 80 grit tool to shape something, but its shaping not finishing.

 

[Phil Pascoe]

Osmo recommend when using PolyX not to go below 180 (iirc).

 

[selectortone]

When I was having lessons my teacher introduced me to one of these, an Axminster deluxe bowl sander. I was never able to get a better finish at home so I invested in one and I'm very happy with it - well worth the investment. Still going strong 18 months later. despite heavy use. Axminster sell a less expensive one without bearings and from all I've heard they wear out quite quickly.

I sand through 120 (probably not necessary now I'm better with my tools), 180, 240, 320, 400 and 600 grits then finish with an assortment of buffing wheels and finishing compounds - triple-E, then diamond white, then wax (carnauba and beeswax) and then a soft buffer to finish. I used to apply paste wax directly to the piece on the lathe but I find the buffing wheel method gives a much better looking finish, unless I'm after semi-matte (for tool handles etc).

 

[Phil Pascoe]

The downside to them as opposed to a battery drill is that you can spot sand with a battery drill, with them you're dependent on the item moving. Quite often there are only two places on a bowl that need the work, going into the end grain on both sides.

 

[graduate_owner]

Sorry, not bobbin sanders, I meant bowl sanders.

K

 

[TFrench]

Thanks guys, some brilliant advice here. The hope one looks to be a great deal - small, medium and large pads in hard and soft with the handle - plus you can put them in a drill if you need to as well. Christmas money spent!

Keith - I was struggling a lot with tear out, the most recent bowl I did I kept the tools a lot sharper and made sure to take very fine finishing cuts - much less sanding required.

 

[Phil Pascoe]

Hi all, regarding making bobbin sanders as per the links, can anyone tell me what thickness of neoprene is generally used?

K

About 8mm, I'd have thought.

 

[Keithie]

thanks again everyone for the feedback, all much appreciated...sharpertools, finish better with tools, experiment&reflect more on finishing process (just doing sanding, tung oil & wax currently), consider buying drill/other pads to improve finishing, no real need for finishing wood beyond 320ish grit etc ... many many things to learn, many many years to do so!

 

[Paul Hannaby]

If you sand properly through the grits, you shouldn't need any mechanical sanding aids for simple bowls. Get to grips with manual sanding first. Start with around 120 grit and get rid of all the tool marks, torn grain etc. If you can't get all the marks out with that grit, go coarser to 80 grit. Once you have a consistent surface, go down through the grits. The next grit should be no finer than the one you last used + 50% of the number so from 120 grit don't go beyond 180 grit, then from 180 not beyond 270 etc. So 120, 180, 240, 320, 400, 600 etc.

You probably won't notice much difference beyond 320 or 400 depending on which wood you're using.

When sanding, keep it moving and you will avoid sanding rings. Reduce lathe rpm's to reduce friction and heat.

By the way, with abranet, watch the edges. They can leave fine scratches on the surface so try to use it in a way that minimises edge contact.

 

[TFrench]

This is the bowl in question:
20161227_204426
20161227_204435

My third one, its really started to click with this one. Tool movement feels a lot more natural, and I've got a much better feel for what the edge is doing in relation to the bevel, and what I need to do to affect it, if that makes sense?
Thanks for all your help and comments guys, as a beginner I really appreciate it.
Tom

 

[Blister]

You need to be careful with these sponge / velcro type sanding pads , You can overheat them and the velcro will start to come off the pad , also care is needed when removing the sanding docs from the velcro or you will pull the velcro off the sponge

 

[Robbo3]

You can make your own rotary sander :
Cap'n Eddie Castelin - https://www.youtube.com/watch?v=G1DR3Ptv1QQ
Marius Hornberger - https://www.youtube.com/watch?v=myBwALrpYeM

Doesn't look to be anything wrong with the bowl but to view the larger original needs a Yahoo account.
I would be proud to have produced that.