How long do you let your poly (final coat) cure before smoothing out with
0000 steel wool or pumice?I don't have very much patience with finishes. I want it finished yesterday. I like the look of poly after it's finished with pumice. Is 48 hours enough? Flexner says wait at least a month in Understanding Wood Finishes. How long do you wait??
I usually try to wait at least 2 weeks, but I've done it as fast as 2-3 days. It does make a difference. The best approach is to actually put the piece in it's actual location to be used and wait several weeks for it to acclimate. Some things are simply too big to move around a lot, and I find once something is in the house it get's used, so I have backed off from that and just play it by ear. I don't tend to want the shiniest of finishes anyway, so rubbing it out a bit premature doesn't bother me as much as it might others.
Mike
I guess it all depends on your environment. If you live in cold climate, I'd wait at least 48 hrs. It took me 1 week to put on 3 coats of poly for my project.
I'll assume you're refering to the final coat of 3 or more layers. A month is about what I wait, sometimes longer. However, since you're also refering to poly, it's more subjective. Once it "fully" cures, its a bear to rub out. Not really any more difficult, just more work. More time. A little more muscle. I wait the full month in the summer, unless we're going through a long dry spell. In the winter, since I'll rub it out in the "play room" which is well heated and dry as the Saraha, I only wait about two weeks. ( I dont do much finish work in the winter.)
Good luck,
Myx
A day, two days, a week tops. Usually can't afford to have something sitting around longer then that.
If you are math oriented, the finish cures with a logarithmic curve. This means that in a month, it is 98+% cured, however, within a week, it is probably 80% to 90% cured. It is best to wait a month, but realistically, you can rub it out in a couple of weeks. You must remember however, that poly is not as hard as lacquer or shellac and cannot be rubbed out to as glossy a finish.
Preston
I'd have to agree with that last on several points.
Varnish is quite a bit harder then shellac or lacquer. Poly even more so, something that makes varnish more prone to cracking from wood movement then shellac or lacquer. It's the reason spar varnish (a long oil varnish) is marketed. The additional oil makes the varnish not quite as hard so it can accommodate the movement of wood that is exposed to the greater extremes found out of doors.
Further, while it is far more labor intensive rubbing out the harder finish the harder the surface it can be rubbed out to as good a finish as lacquer or shellac. If you want glossy don't rub out the finish. Glossy is not the aim of rubbing out the finish. Rubbing out is a process who's aim is to remove the reflective gloss of a newly applied finish then refine it so the light passes through the surface and reflects off the wood giving the finish a sense of depth and the wood grain a 3D effect..
Mike,
You are WAY off on this one.
Rubbing out a finish puts finer and finer scratches on the surface creating more of a sheen (glossy). Glossy is the aim of rubbing out a finish.
Reflect light off the wood?? 3D effect on wood grain???
I think you might have been breathing in to much lacquer thinner this morning. :)
realistically,
No, I've just been rubbing out finishes for years.
If you have rubbed out a finish on a nicely figured wood and have to question the statement of having depth and 3D effect you have been doing something wrong.
As for gloss. Next time you apply a finish and the final coat has cured hold it up to a glancing light, or even just plain looking at it. 90% of what you will see is light being reflected off of the surface of the surface of the finish. That is gloss. Now, really rub out that finish. Yes, you are putting scratches in the surface and when they disappear to the eye see where the light gets reflected from.
Now, if you want a more easily seen example of what rubbing out is all about go to a car show and take a look at a cobalt blue metal flake hand rubbed 12 coat layer of automotive lacquer looks like. You won't see any light reflected off the surface of that finish, what you will see is a finish that practically glows from the interior with a real sense of depth.
This is incorrect from what I have read:
Read here:
"You'll be able to control the degree of luster (flat, satin or GLOSS) by the materials and techniques that you use. "
This is incorrect from what I have read:
Read here:
"You'll be able to control the degree of luster (flat, satin or GLOSS) by the materials and techniques that you use. "
I put a "mirror finish" on poly by rubbing out with 000 steel wool followed by pumice. (lots of elbow grease). :)
I put a "mirror finish" on poly by rubbing out with 000 steel wool followed by pumice. (lots of elbow grease). :)
You have been rubbing out finishes for years and you can't make a finish glossy?
Do you think maybe YOU are doing something wrong?
Tell you what, when you figure out what depth in a finish is and can get your grain to appear to actually be 3D come back and talk to me.
There may be some difference in the definition of gloss but you obviously don't have any idea what you are talking about and are parroting something you read.
Of course you can stay blissfully ignorant if you wish, that is your business.
Mike,
I'm not parroting, I'm backing up my experiences with literature. Can you? Show me where you have read that rubbing out a finish doesn't produce a gloss. Maybe your not doing it right. Have you thought about that?
I put a glossy finish on poly by first rubbing with 0000 steel wool followed by pumice.
One of the purposes of rubbing out a finish are to put a "gloss" on the finish.
You said you can't put a gloss on a finish by rubbing out. I simply disagree.
did you mean 0000?
dave
stoutman wrote:
yes, Thanks. :)
Patience shows in fine finishing. In a few days, it'll be done and you will have a piece to enjoy.
Depending on humidity and temperature, drying times vary. I usually apply one day and then "adjust" the next.
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