Hi Folks,
I’m sure you’ve heard the phrase rubbing out a finish but what is really going on here? Does this process melt the finish to some degree from the friction? The use of rottenstone or pumice implies sanding it but with very fine particulate.
I’m curious about rubbing out a finish with just cloth. Could one use different types of cloth in the same manner as going through the grits as with sandpaper?
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edit: I missed the p in particulate. Not trying to be particular though. 🙂
Edited 6/9/2009 8:11 pm ET by KiddervilleAcres
Replies
Well, not "sanding", exactly, but abrasion by very fine particles. Rubbing is like sharpening -- you just make smaller and smaller scratches until the surface appears smooth. As for cloth, yes, cloth does have some abrasive qualities -- just try to clean the plastic lenses of your glasses too vigorously with some denim, or burlap, for example! (DAMHIKT)
Festool used to have a video of using their sander to polish the surface of a board by just going through successive grits up through, IIRC, a buffing cloth. Made a mirror surface w/o the use of any additional finish. You may still be able to find it on their site or on the Web somewhere.
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
When you rub with cloth or burlap or kraft paper, you're basically just removing dust nibs that are trapped on the surface. You'd rub for a long, long time to get rid of an air bubble or a run that way.
-Steve
Rubbing out a finish is a phrase that's thrown around to describe a process that can be accomplished in a number of ways. Someone looking to rub out a finish is trying to accomplish one of two different things: Either drop the appearance of a finish from a gloss to a semi-gloss or satin; or more often, they are trying to improve the tactile experience of the piece - How it feels.
Rubbing a finish can be done with many different supplies and tools. Using wax and 0000 steel wood is a real common way, it's easy, and gives great results. Another is using pumice or rotten stone along with mineral oil. There are also commercial rubbing compounds available, and mechanized buffers and such to speed the process.
Hope this helps a bit,
Gregory Paolini
http://www.GregoryPaolini.com
Thanks Gregory,
I understand about the use of materials such as 0000 steel wool, pumice and rotten stone but what is one actually doing to the finish when using just cloth with no abbrasives?
Are there abbrasive qualities to cloth? I can relate to burlap or perhaps even canvas as a tool but cotton cloth like from old tee shirts, often stated as being worn?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Hi Bob ,
Depending on the fabric or cloth there can some abrasive qualities however this may not be efficient in all cases .
A painter showed me a trick to remove overspray , take the back side of a piece of sand paper as though you are sanding off the overspray .So , a slight amount of abrasive is sometimes all that is needed .
In general the way I learned it the main reasons for rubbing out a finish is to make it smoother or knock the gloss down .
Also the good part is the rubbing makes it smoother but at the same time makes the finish weaker not more durable , depending on the rubout you are actually removing some finish from the very surface that needs it .
I learned to prep the wood for finish properly and apply the finish so that rubbing out is no longer needed , I control the sheen or gloss with the product I use , not with rubbing out and therefore do not weaken my finishes .
regards dusty
I've heard of lots of people doing lots of different things, some of which sound plausible, others I'm not sure I would bother trying. With that said, every material in existence, including used t-shirts, have a certain coefficient of friction, so in theory, every thing has some sort of abrasive quality. in reality, I think a worn t-shirt would make a poor choice for an abrasive on its own.
But, here's another possibility: I occasionally talk with woodworkers across the pond. Some times our languages don't mesh 100%, even though we're both speaking English. For example, If I get a rebate on a plane, I expect to get some money back, however they expect to create a joint that would hold a cabinet back - A joint which we call a rabbit. I've had conversations where I've heard "rub the shellac", and upon further questions, I've come to realize we're talking about French Polishing. And it turns out that the applicator for the french polish, called a "rubber", is often made from wadded cotton, wrapped in a used t-shirt.
Just a thought
Gregory Paolini
http://www.GregoryPaolini.com
Good point!
I was in Scotland twice. They DO NOT speak English! At least any words I understand. Great folks to be around..
As in I recall, I had to buy a round of Ale for all inside the Pub when I thought some guy was offering this Yank a free drink! LOL... Money well spent anyway!
Some people use the term "hand-rubbed" to mean literally using their bare hands to apply (rub) the finish into the surface. I guess in the belief that the physical force and slight increase in temperature from friction will increase penetration.
Kinda funny the first time I heard about rubbing out a finish. Asked my grandfather what he was doing and he told me he was rubbing out the finish. When I asked why he replied, cuz you're spose to. Ye grab a rag and just start rubbing.
Well hells bells, that explains everything! Gramps may have been long of tooth but surely short of tongue, especially when it came to all things woodworking. Kinda like those guys who hold making a cabriole leg as guarded as the Holy Grail.
To me a satin finish calls for oil, maybe oil/varnish? Satin finish also means to me an in the wood finish, maybe because that's where they seem to make more sense to me. Not really sure why I feel that way about it. I hand rub all oil finishes cuz, well I'm spose to.
I heard about what I call slathering on a finish with your hands when I tried refinishing a rifle stock. One person told me he warms up the finish on his stove and then just slathers it on with his hands. Said warming it up helped it to penetrate the wood deeper. Have no clue if this is true or not, but I doubt it.
Just recently I was applying Cabot Spar Varnish over BLO, and after the varnish had just started to dry I noticed several runs on the other side of the slats. It had just started to skim over so I made a pad out of old tee shirt material and began wiping the runs. They broke almost on contact so I tried to just blend it with the rest of the finish.
The piece then sat in the sun for over 4 hours and when I looked I could see no imperfections. Whew. I waited another day and then padded on two more coats over the course of the next 3 days. I sanded between these two coats veeerrrryyyy lightly with 320.
Gregory mentioned something about a tactile feel/look. I'm not sure what a tactile feel/look is. To me that means the maker left behind, intentionally or otherwise, traces indicating that the piece was handmade. Could tactile also mean that the finish highlights the contours of the piece?
I mean no disrespect to Mr. Paolini in any way but could tactile also be another one of those, well, rubbing out a finish kind of things? I've heard the term used to describe rooms as in, "We added textured cushions to balance out the leather couch and give the room a more tactile feel". It's another one of those I think I know what they mean, but.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Me again,
I feel like a dunce, but not a Scottish one.
Did some more research and think the process is very similar to preparation of the wood surface(s) but at a much finer level - is that safe to say? In other words the goal is to remove surface imperfections in the applied finish as one might do to remove machine marks and imperfections in the wood itself.
The choice of materials used for the rubbing out process determines the resulting sheen of the finish? Along these lines would one use different tools depending on the finish material used?
A concern is about weakening the finish as dusty talked about. How does rubbing out a finish weaken it? Not meaning to be argumentative but I should think a goal of this process would be to strengthen not weaken the finish.
Regards, Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Simply put
Rubbing = friction = heat = crazed/cracked finish
Too much rubbing can be a bad thing - It happens all the time in Body shops, where the rookie buffs through the new paint job.
Cheers,Gregory Paolini
http://www.GregoryPaolini.com
Uncle Bob ,
When I said rubbing out a finish can weaken it , it is a general statement .
I think we need to speak specifically about which finish or what products do you need to rub out .
How does rubbing weaken a finish ?
Well, Bob if you rub with enough friction to smooth and remove any imperfections from a surface chances are you are removing some of the top coat, therefore leaving less coverage and perhaps uneven in areas .
My application experience is largely with lacquers of various types . There are so many types of finishes to use some have the hardening agents in the top coat not the base or sealer coats so removing the strongest part of the finish in my opinion can lead to a weaker not stronger finish , think about it .
When we rub out a finish we are putting very fine scratches in the surface that create a new surface sheen while removing any imperfections , now if you recoat over without rubbing out you have something .
So , back to my original post here imho the way you prep the wood for finish and the finish schedule and products used will determine if you need to rub out a finish .
A good quality finish does not have to be laid on thick , just good adhesion and prep between coats .
Bob , did you lose your hammer ? ask too many questions or what ?
regards dusty
Nephew dusty,
Wait a minute, I'm only 13 years your senior. Hmmmmmmmmmmmmmmm. :-)
OK, I see what you mean about the weakening thing. Over the years I've made an effort to apply finish layers/coats as thin as I could, never really thought about rubbing them out as the final result looked good to me.
What kind of got me started into this is the finish I put on the new stairs. I used a water based gloss Polycrylic. This was the first time I had used a water based finish.
Followed the directions on the can but am not happy with the results. To be honest I'd have to say I don't like how it came out, with regard to the color or complete lack thereof. But that's another story.
Early in the morning the sun shines on the stairs and I noticed that the finish looked kind of wavey? in the sunlight, especially the risers. I had a few boards left over so I applied the Poly (3 coats) to them for test boards to experiment with.
If you have any recommendations as to a process for this type of finish I'm all ears. I'm thinking of starting with 400 and work my way up to 800 or 1,000. Prolly won't go to pumice or rotten stone.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob, cloth alone cannot due much but slightly effect the luster. There is no removal of defects or evening of the surface.
I worked as a supervisor of "Rubbing and Crating" at Lane Furniture Co in VA. many years ago. What we meant when we said we had a "hand rubbed" finish was this. We started the process by picking up an air powered finishing machine, with hands, :). This machine had 2 pads of felt with wet or dry sandpaper attached that moved back and forth in a straight line fashion to cut the finish. A light water application was used for lubrication. We started with 400 and went to 1200 with a series of machines and operators. This was assembly line work and the furniture was moving on a platform on a conveyor system. When the formula called for it rotten stone could be used also. This process leveled the surface and imparted a gloss to the surface that could be altered to produce different degrees of gloss by which products were used. After the "hand rubbing" the top was cleaned and waxed and proceeded down the line to have pulls attached, was inspected and sent to crating to be boxed and skidded for shipment to the warehouse.
Only the top was rubbed and all other surfaces were as they came off of the spray gun.
Hopefully this helps to understand what a furniture company means when they refer to hand rubbed.
Bruce
Edited 6/9/2009 9:39 am ET by Wingdoctor
Bob
And then if you can find Linen Cloth for the in between rubbings!
I love it when you bring up interesting topics, Bob.
My guess is that "rubbing out" has different meanings for both different individuals and for different types of finishes. Similarly, the phrase "look and feel" has different meanings depending on the context of the discussion. Interior designers and software developers use definitions of the latter phrase that are similar, but quite different that ones usually associated with woodworking, for example.
To me, the "look" of a finish is a combination of surface reflections and translucency, along with color. A "glossy" finish will have hard-edged reflections of light sources within the room, or perhaps even mirror-like reflections of other brightly-lit objects within the room. In contrast, a "satin" finish will have soft-edged reflections of the same light sources - more like an area of glow, as opposed to an actual reflection. Similarly, both finishes will have a different tactile "feel" when one actually touches it with one's hands. A glossy finish will have a smooth, but often somewhat "grabby" feel as you run your finger tips across the surface, while a satin finish will still be smooth, but will often allow the finger tips to glide more easily. The actual differences are microscopic, but easily discernible with both the eye and the touch.
What happens physically when "rubbing out" a finish depends on what is being used to do the rubbing, the nature of the finish, and the amount of pressure (i.e. heat and friction-generating qualities of the effort). At first, we're probably removing microscopic fibers that may protrude from the finish, such as dust, or fibers from tools used in the application of the finish. After that, we're probably abrading the surface in some manner. How much depends on what we're using to do the rubbing. At the microscopic level, even cloth has some abrasive qualities, and that varies with the nature of the cloth fibers and the weave. Cotton, for example, is pretty soft, and the weave of T-shirt material makes it useful for polishing and rubbing.
When I "rub out" a finish, I'm usually talking about altering the top surface with (a spare amount of) Rottenstone and paraffin oil. Since canned "satin" finishes produce the "satin" by including particulates which reduce the transparency of the finish, I personally prefer to use clear varnishes on wood, and then reduce the surface reflections in this way. To me, this approach improves both the "look" and the "feel" of the resulting piece. But, tastes and techniques vary.
I also see some parallels between this subject and sharpening. Consider the different grits we work through when sharpening, and to what extreme different people go when sharpening. In this sense, "rubbing out" a finish might be akin to final stropping of a tool using a pinch of super-fine abrasive rubbed into the surface texture of a piece of leather.
Ralph,
Just before I came into Knots I read Rubbing out a Finish by Jeff Jewitt in FWW #119, specifically the sidebar about Sheen. Seems like I just read it again in your post.
Huzzzah, as Mr. Froe might say.
I've read the article several times and Jeff says to use lots of pressure with 4F pumice when polishing for a glossy sheen. That almost sounds counter intuitive but perhaps depends on the finish schedule? Kind of finish applied and maybe even how it was applied, i.e brushed vs sprayed?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
"I've read the article several times and Jeff says to use lots of pressure with 4F pumice when polishing for a glossy sheen. That almost sounds counter intuitive but perhaps depends on the finish schedule? Kind of finish applied and maybe even how it was applied, i.e brushed vs sprayed?"That does sound counter-intuitive to me, but I'm certainly not a finish expert. Jewitt is, I believe, one of those experts, as are a few others here on Knots. At the microscopic level, even "fine" pumice is scary abrasive. The extra pressure may also break down the pumice particles into smaller, finer bits, allowing it to function more like Rottenstone for such polishing. I would think, however, that using pumice in that manner would remove a lot of finish - at least a layer or two. But I might easily be wrong in that respect. I'll try to find the article and give it a read. Thanks for the reference.
Ralph,
At the microscopic level, even "fine" pumice is scary abrasive.
Don't yet know enough about this rubbing out thang but the pressure kinda well, go to me. :-)
On a slightly more serious note I wonder what the effect(s) might be were one to use jewelers rouge, tripoli, etc. I envision a wood sanding block lined with cork for padding and a cloth material charged with the rouge. I'm using rouge in an inclusive way here - there are several grits. Also, as opposed to sprinkling the abrasive on the finish one would charge the cloth on the sanding block instead.
I'm sort of equating the rubbing out process with polishing cutting iron edges or perhaps suggesting the use of the same materials. Then again maybe pumice and rotten stone grit sizes are way smaller/finer than the rouges? I don't know.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
"On a slightly more serious note I wonder what the effect(s) might be were one to use jewelers rouge, tripoli, etc."
One thing to always keep in mind is that no matter what you dream up, it's almost certain that someone has already tried it before. So if you do your homework but still can't find examples of anyone using a particular technique, there's probably a good reason.
That doesn't mean you shouldn't experiment, but rather that you should use the established technique(s) as a starting point, and go from there. If you don't have any experience with the standard technique, you don't have a baseline to which you can compare your experimental results.
-Steve
Steve,
Oh yes I agree with you on the baseline thing. I also think I should concentrate on one finish material too and right now I'm leaning towards varnish.
Edit: Plan on following the same steps as Jeff Jewitt did in the FWW article.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 6/12/2009 9:32 pm ET by KiddervilleAcres
Bob..
Dang.. Folks have been using Pumice Stone and Rotten Stone abrasives for years on wood! For new AND old finishes!
http://www.empireblended.com/engineered/specialtysundry-pumicestone.html
http://www.empireblended.com/engineered/specialtysundry-rottenstone.html
I think I get mine at Rockler but not sure where...
Maybe hire a teenager for the arm work required!
Edited 6/12/2009 10:37 pm by WillGeorge
Bob,Do me a favor please. Take your project out in front of your house, possibly the drive way. Then take your jacket off and rub the top for about 20 minutes. Next take your shirt off and rub for 20 minutes. Lastly take your undershirt, or long johns, off and rub for 20 minutes. Then study the surface carefully. With any luck, and there being a God in heaven, a neighbor will take notice and get you the help you so desperately need :)Seriously though, you should play around with a french polish. I think you'll see it's not about the finish, per se, but about how much better the wood looks...which, by the way makes the whole process relative to the wood. The shellac in a french polish gets flatter and smoother through remelting and rubbing. Other finishes require something with a grit. Either way you should have a clear goal and playing with a french polish is cheap, fast and gives you some control over the process.
BG,
About a year after I joined Knots I started copying/pasting little snippets from posts here and saving them to a Wordpad file. Your first paragraph just got copied/pasted. I wouldn't start counting on any royalties just yet however. (=)
I've ordered some rotten stone and pumice and have all the grits for sandpaper, along with a project that's almost to the sanding step. And yes I do like to sand outdoors so I can see better and don't have to worry much about the dust.
Now after three days of pretty much steady rain.........
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bjob,Thanks for having a good sense of humor, hope your project works out well.
I would think that the actual abrasive compounds in metal polishes would be finer than even Rottenstone. But, they also have a substantial amount of binder, to get the compound to adhere to the polishing wheels. The binder might be difficult to remove from the wood surface.
Too young to be my uncle Bob ,
I have always associated the rouge and tripoli with Brasses and metals and such , I'm not sure if I have ever heard of pumice and rottenstone to be used on metals , maybe it is ? so as Steve said the established is what it is for a reason .
If you put multi coats of finish with good prep between coats and rub the top coat out you still have the many coats under it .
I learned that unless you sand between coats it really is not another coat just a thicker one . So the folks that say they put 6 coats on then rubbed it out may not have sanded between , once I do this and really lay my last coat out nice , it is already smooth before the last coat and needs no rubbing .
btw only 4 years difference in youngness
regards dusty,have done the rotten stone and pumice rubouts
Bob,
I routinely rub out varnish. First to get it smooth and also to remove dust nibs, etc. I wet sand with 1500 wet and dry under a cork faced block using water for the lubricant. I used to start with 400 and work up but always had a scratch or two show up.
After the finish is flat I use one of two options. Straight-line rub with 0000 steel wool and wax for a satin finish or Meguiar's 1, 3 and swirl remover for high gloss. I only rub out the horizontal surfaces, never the vertical.
If you're going to rub a film finish, you need to sand well between coats so the final coat is level enough that yyou won't cut through! DAMHIKT!
Hope this helps.
Dick
Edited 6/14/2009 11:13 pm ET by rwdare
This forum post is now archived. Commenting has been disabled