Sanding prior to staining

[GarciaJ]

I've just been reading a tin of commercial stain. The recommendation is to sand with 120 grit sand paper and then to sand again thoroughly with 400 grit paper before applyng the stain. Really? I have never even seen 400 grit paper, but judging from P240 it must feel like photocopy paper (smooth)... What o others here think? Does anyone know what dressed timber of the sort that you get in the hardware stores is finished to? Sanding must be the least rewarding part of any job... but if you don't do it right, well....

[Wrongwayfirst]

I'll give you an example. I used to sand to 80 then 120. Definitely made SWMBO happy. Then I started sanding to 400 and now I sand to 1200. Many many oohs and ahhs later I pretty much sand to 1200 I am looking to get some even finer sandpaper to see if I can increase brownie points.
oh and no skipping steps I run through the lot. In the finer paper it sometimes is as quick as thirty seconds work and move up.
if the finish is important the sanding is too. If not then not.
Extra Info (http://www.ubeaut.com.au/swinfo.html)

[Superbunny]

If you want the finish you have to do the work. The reward will be long admiration of your work that will last longer than the memory of the effort applied.:D:D

SB

[LGS]

I'll give you an example. I used to sand to 80 then 120. Definitely made SWMBO happy. Then I started sanding to 400 and now I sand to 1200. Many many oohs and ahhs later I pretty much sand to 1200 I am looking to get some even finer sandpaper to see if I can increase brownie points.
oh and no skipping steps I run through the lot. In the finer paper it sometimes is as quick as thirty seconds work and move up.
if the finish is important the sanding is too. If not then not.
Extra Info (http://www.ubeaut.com.au/swinfo.html)

What finish do you use. Oil or Shellac or Poly or somethin else?

[GarciaJ]

Thanks everyone.
Seems to me that the comment made by LGS is very pertinent, even though he pretended it was a question :U. I can understand sanding to microgrit levels if the timber is going to be oiled... The oil does not sit on the surface - it penetrates - so you will always be feeling the surface of the timber when you touch it. But I would have thought that going much beyond 240 is a waste of time when the piece is destined for stain and polyurethane... The polyurethane forms film on the surface... Uhm, I seem to be answering my own question :doh:

[Skew ChiDAMN!!]

Even with PolyU how fine you go depends a lot on the timber itself.

I work down through the grits until I can not see a difference when I rub the next finest grit along the direction of the grain. I'll finish with that last grit, using a sanding block, along the grain just to be sure.

[Wrongwayfirst]

What finish do you use. Oil or Shellac or Poly or somethin else?
Brushed shellac is my latest finish of choice, prior to that I used tung oil. I have now realised why my painted furniture doesn't have that gloss I want. I only sanded roughly with 80 and 120 :U

[Trav]

I've got 2000 grit random orbit sander paper. If I ever run out (which I seriously doubt I ever will) I could replace it with a piece of wet lettuce, which is just as abrasive. Once you get past 600 it is hard to tell the difference. For a box or a table top, I would almost always sand to at least 800. I always use shellac or oil though, not poly.

Trav

[LGS]

Brushed shellac is my latest finish of choice, prior to that I used tung oil. I have now realised why my painted furniture doesn't have that gloss I want. I only sanded roughly with 80 and 120 :U

These are some photos of Tung Oil hard burnished up to 4000 grit. This method of using Tung Oil gives strong resistance to heat and liquid and maintains it's shine even after wipe down with Spray and Wipe. (which I use regularly to clean the pieces.)

Regards,

Rob

[AngelaPetruzzi]

The fine sanding prior to staining is dependent on thefinish one uses.

For example. If one was to use the Livos oils in a stain and would sand to e.g. 1000 grit, the pores would be glazed over and will not allow any of the pigments to penetrate....giving little if any effect of a stain. If however one would sand to anywhere from 120 # to 240#...again, depending on the timber and the project, the pigments would be trapped in the pores, giving more depth to the stain.
You may feel this is “rough”, well with a natural coating one can manipulate the surface to win some of those brownie points. When the surface is dry, one can go over the surface with something like a scotch brite, fine steel wool, old worn sandpaper, anything to flatten the wax crystals in the oil.
This then give more shine as the light reflects off the surface, it is not to cut back any fibres that may stick up which often happenswith water based coatings.....builds on the “fine furniture feel”.

Either way with stains, always do a test sample prior as the result may not be what you anticipate.

[GarciaJ]

These are some photos of Tung Oil hard burnished up to 4000 grit. This method of using Tung Oil gives strong resistance to heat and liquid and maintains it's shine even after wipe down with Spray and Wipe. (which I use regularly to clean the pieces.)

Regards,

Rob
Those pieces look amazing. Howver they would have looked just as good if they were sanded to a coarser grit, I think...

[Chesand]

Those pieces look amazing. Howver they would have looked just as good if they were sanded to a coarser grit, I think...

I doubt it. :(

[LGS]

Those pieces look amazing. Howver they would have looked just as good if they were sanded to a coarser grit, I think...

Well, it took me 2 years to get that kind of finish reproducibly and I can assure you that anything under 2000g just doesn't give the finish and durability. Like Chesand, I think "good enough is low aim"

Regards,

Rob

[Skew ChiDAMN!!]

Just to throw another cog into the works, I find that the grits I use between & after coats - esp. the first - are where the finer grits really make the difference. They make a diff before applying the first coat, but I think it's negligible and feel it's often wasted work and effort.

Mind you, I'll often almost remove the first coat completely, making it more a pore/grain filler than an actual coat and use progressively finer grits from then on. That way these finer grits have a progressively smoother & flatter surface to actually have an effect on. Otherwise it's a bit like trying to sand out the holes in Swiss Cheese! :D

It works for me, anyway. :shrug:


Well, it took me 2 years to get that kind of finish reproducibly and I can assure you that anything under 2000g just doesn't give the finish and durability. Like Chesand, I think "good enough is low aim"

2 years, a lot of hard work and more than one or two disappointments to get there, I'm thinking. They look good. :2tsup:

[GarciaJ]

So I started out with P240, and then changed to P360. The P360 defintely feels rougher on pine... so I figure that one of the previous commenters is correct. How fine to go must depend on the timber, even when using oils.

Also I looked this up on Wikipedia, and some of the grit sizes being quoted here are just off the charts. The finest I could get at the local hardware was P240 on normal sandpaper. The finer grades can only be found on emery paper, and described as being for metal finishing. Yet some of you are describing 4000 grit and even higher... surely we are talking about different roughness scales.

The wikipedia chart stops at P2500... which is american grit 1000. The average particle size is only a few microns. At these grit numbers. Yet some of the responses here talk about serval thousand grit.

[Chesand]

You will need to get the finer grits from one of the sandpaper specialists such as "The Sandpaper Man" or "Pilatus" who are sponsors of this forum. Do a search on here for sandpaper suppliers and I am sure a couple of other names will come up.
There will probably be sandpaper on sale at the Wood Show in Canberra this weekend.
The "emery papers" can be used on timber if necessary.

[LGS]

Chesand is right. Call the Sandpaper Man and ask his advice. Tell him what you want to achieve and he will direct you to the right products.

Regards,

Rob

[GarciaJ]

Sorry, I mis-read the previous posts... the highest grit number mentioned is 2000 which IS on the charts... :B only just...

Thank you for all the posts everyone...

Jorge

[GarciaJ]

Well, it took me 2 years to get that kind of finish reproducibly and I can assure you that anything under 2000g just doesn't give the finish and durability. Like Chesand, I think "good enough is low aim"

Regards,

Rob

Hi Rob - As I said, your pieces look amazing, but what I meant is that it's not possible from just looking at the photographs that you posted to see what effect sanding with finer grit sandpapers might have had... I get that you think it's very important to make the effort and that sanding all the way down to 2000 grit makes a big difference.

As for my pine shelves... I started with fine quality DAR pine (already fairly smooth) thinking that I would sand with progressively finer sandpapers. I sanded the DAR with P240 and that made a BIG difference - the pine was noticeably smoother. I then sanded with P360 and the wood felt noticeably rougher!!! - I don't understand why - I asked a couple of people to feel the wood to confirm. So I've decided to stop at P240... Sanding is my least favorite part of any job, and I'm not going to spend time making the timber seem rougher. May be pine reacts differently to sanding compared to the hard Australian timbers from which your pieces seem to be made???

I will keep experimenting, in the meantime, thank you for your reply!

[LGS]

Hi again,
I'm sorry that the 320 came up rougher than the 240 and I am surprised. But it's good that you can see the benefit even just going up from 180 to 240 grit. You will definitely notice a difference in the final finish as well. The stain should go on nice and even and resanding between coats at 240 will definitely give you a result that you want.

Try using 400 rather than 320 at some time in the future and see what that does for your result. I think you'll see the benefit to taking the time to finish the work piece with a little extra TL.

Regards,

Rob

[Xanthorrhoeas]

So I started out with P240, and then changed to P360. The P360 defintely feels rougher on pine... so I figure that one of the previous commenters is correct. How fine to go must depend on the timber, even when using oils.

Also I looked this up on Wikipedia, and some of the grit sizes being quoted here are just off the charts. The finest I could get at the local hardware was P240 on normal sandpaper. The finer grades can only be found on emery paper, and described as being for metal finishing. Yet some of you are describing 4000 grit and even higher... surely we are talking about different roughness scales.

The wikipedia chart stops at P2500... which is american grit 1000. The average particle size is only a few microns. At these grit numbers. Yet some of the responses here talk about serval thousand grit.

Many of the people that I know do not sand below 320 grit, and are happy with that. Fine, if you are happy with that, but it is not a fine quality IMO. However, what you need to consider is that a finish from a sharp hand plane or scraper is more akin to a 10,000 grit because it is sooooo fine.

If you need/want to sand then a really fine finish requires a really fine grit. Before I French polish I sand to 1000 or 1200 grit wet and dry, even on a soft timber like Australian cedar (Toona ciliata) and it makes a real difference in the finish. Harder timbers like Blackwood can cope with 320 to 400 grit, but do not deliver a fine finish, IMHO.

Hard work and fine sanding produce better finishes. I leaned to polish from an Austrian cabinet maker. He was taught to polish timber for two days (20 hours) with metho and pumice powder before any shellac was added. THAT is fine quality polish. What we do is pretty rough by comparison.

However, as i have said elsewhere, if you are matching an Australian antique finish then much lower polish levels are appropriate, so it is horses for courses.