Sanding - what grades?

[julianf]

Working with english oak, and trying to get a good finish -

Parts come off the drum sander, which im abusing a little as a thicknesser, to take out any final movement in the parts. So i have 100 grit loaded up in that.


Im having trouble going from that to the medium grades.

It seems that if i go to, say, 180, i never get rid of the lines from the drum sander. So i evidently need lower, but what would be a good grade to go with?

The reason im asking and not doing, is that i dont have anything lower for the ROS so need to buy a box, but, at £25 a hit or something, i dont just want to buy randomly.

This will, i guess, be some sort of mirka paper for use on one of their air ROS units.

Thank you.

 

[MARK.B.]

You need to work through the grades with each one removing the scratches from the previous one, next one at 120 should remove the 100. looks like you are going to need to beg -steal or borrow some different grades if you want a good finish

 

[Jameshow]

You could get a cheap pack off eBay about 50 for £8.

Gets you out if a hole?

Cheers James

 

[Phil Pascoe]

You can buy mixed boxes of abrasives - you pay a bit of a premium but if you're uncertain what sort to use it's a way of finding out.

 

[julianf]

You can buy mixed boxes of abrasives - you pay a bit of a premium but if you're uncertain what sort to use it's a way of finding out.

I've bought them in the past for metal paint work, but that's all fine grade stuff.

I had a brief look about and didn't immediately see any at the starting grades, but I'll have another look in a bit. Thank you.

 

[julianf]

You need to work through the grades with each one removing the scratches from the previous one, next one at 120 should remove the 100. looks like you are going to need to beg -steal or borrow some different grades if you want a good finish

So is it really a case of buying each and every number?

If so, that makes it simple, if expensive...

I mean even to get to 200, there's, what, 120,150,180,200?

Is it really a case of using each and every one? I mean in the real world?

Thank you.

 

[Phil Pascoe]

I make pens - I use sixteen grits, 120 - 12,000

 

[MARK.B.]

If you want a good finish then yes going up through the grades is the way to go, sure you could skip grades to try and save time and money, but imho time spent in finishing is well spent and costs you nothing but time itself. It can be a pain in the bum but is a neccessary evil.

 

[MARK.B.]

If you get a mixed box from Ebrasives they let you choose the mixed grades, so you can do away with grades you dont want and get only what you need.Around 25 quid for a box of 50.

 

[Adam W.]

Plane it by hand.

 

[TheTiddles]

I drum sand oak to 120 with abranet (from 80 usually), then random orbital with 120, 180 then 240, no gain going further than that

 

[Hornbeam]

Totally agree with Tiddles. No point going beyond 240 on english oak.Finer if using a tighter grained denser hardwood

 

[Phil Pascoe]

Iirc Osmo actually specify going only to 180. For some finishes that's adequate.

 

[HOJ]

Iirc Osmo actually specify going only to 180. For some finishes that's adequate.

Interestingly my tin of Osmo UV oil says no finer than 120, but that's for exterior joinery, I only go down to 180 on Oak.

 

[Ollie78]

Cabinet scraper.
Superior to sandpaper for removing planing ar machining marks. Leaves a very nice finish on Oak.
Get a few all sharpened up and it is very quick.
You could try a number 80 or a 112 but I just use the cards freehand mostly.
Of course this is mostly suitable for flat surfaces. For sanding I go 120, 180, 240, 320
Depending on the finish. 180 will be good for oiling oak.


Ollie

 

[MARK.B.]

Agreed 240 is about right for oak but it is important not to skip grades as there is more chance that you will be left with scratches visible that will in all likely hood only become visible once you start finishing

 

[Cabinetman]

Plane it by hand.

Dead right, The glassy smooth finish from a sharp plane is all you need, what you get with sandpaper is scratches.
I have made bespoke furniture for years and I hardly use any abrasives at all. Ian

 

[DougR]

If you're sanding to a finish then there is no need to work through every available grit number - as a guide line - just double the number each time, that way each step halves the depth of the scratches.

Lighting is critical to judging progress.

 

[martin.pearson]

I drum sand oak to 120 with abranet (from 80 usually), then random orbital with 120, 180 then 240, no gain going further than that

Can I ask how well mesh type sanding rolls work on a drum sander, thought about giving it a try but haven't got round to it yet lol
I've got abranet pads for orbital samder & they seem to work well but wasn't sure if they would work as well when fitted to a solid drum on a drum sander.

 

[Droogs]

As they have a fair bit of give in them(relatively speaking) compared to paper belts, they work best at finishing on a belt sander rather than as a thicknesser on a belt sander. I use mesh on all my hand held stuff but paper belts on the big drum sander, especially if using it to get the last couple of x/y mm off a large panel etc.