Finishing mistake

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I have built a Library Table out of quarter sawn white oak and made a bad finishing mistake.
I did not use filler and have finished with three coats of Rockhard Table Top Varnish and the grain pores are visible.

Do I have to sand off to bare wood and start over or is there something I can do now to correct. When I finish sanding they were not visible.
 

LeftyTom

Tom
Corporate Member
Larry, Bill wanted a clarification, since you did not mention if you sanded between coats. One may not mention a step because "everyone know to do that," or a step not mentioned was forgotten.
 

BThompson

New User
Bill
I think Wyatt was saying like he (Wyatt) was going to ask the "stupid question" not that you, Larry, had asked a stupid question.
 

Wyatt Co.

New User
Bill
I certainly didn't mean to insult. My question was based on the fact that I don't always sand between coats. It depends on what I'm doing and sometimes there is no need for it.

I have used varnish/poly top coats as grain and pore filler. There is a method to the madness of sanding between coats when doing this.

Sorry to offend.
 

JeffH

Jeff
Senior User
A major problem with varnishes like poly is that they take a long time to fully cure -- literally months -- and they shrink during that curing process. So what may have looked glass smooth to you when you applied it can look very textured a few months later.

I have never been able to find a good clear grain filler than can adhere well over a finish coat ... and the pores in your wood now have finish in them. My suggestion would be to sand the whole thing down (past the existing pores), apply filler, and re-do the finish.

You might think about doing a base coat or two with a high-solids varnish, which means less shrinkage, then sand level and topcoat with the finish varnish of your choice. Test for compatibility, of course.
 

Brogan

New User
.
Stupid question time for me ...

My office desk is oak and the grain pores are visible through the finish.
Why is that a bad thing?
I happen to like the look and feel and believe it works better as a utilitarian piece of furniture than something with a smooth finish and much more likely to show scratches and scuffs.
 

pcooper

Phillip Cooper
Corporate Member
I had that problem on some Red Oak one time, it got the same results. I sanded some of it back off and tried to start over, got the same result again. My only conclusion was I didn't fill the grain, as Red Oak has an open grain. I always thought that White Oak was not the same, but wonder if using a grain filler would have helped on Bill's project. I'm interested in knowing what the 'fix' is for this one.
 

pcooper

Phillip Cooper
Corporate Member
Stupid question time for me ...

My office desk is oak and the grain pores are visible through the finish.
Why is that a bad thing?
I happen to like the look and feel and believe it works better as a utilitarian piece of furniture than something with a smooth finish and much more likely to show scratches and scuffs.

If it were a kitchen table, I would want the top sealed for bacterial reasons, but a general use table such as a desk, maybe not so much. I'm like you in that I figure there's a place where it won't matter. My project was one that mattered, but I've also had some that I didn't care. It does have its advantages though...
 

Jeff

New User
Jeff
Misunderstandings of statements are commonplace. For example, check out this quote from Alan Greenspan, ex chairman of the Federal Reserve...

[h=1]“ I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant”[/h]
 

Jeff

New User
Jeff
A "Library Table" can have several meanings but usually it's a desk of some sort.

I did not use filler and have finished with three coats of Rockhard Table Top Varnish and the grain pores are visible.

Did you expect the pores to disappear or be hidden?

So that's okay without grain filling if that's the look and texture that's acceptable to the builder. "Ooops, I didn't realize how it'd look or I simply forgot to grain fill before finishing". :icon_scra



Is it worth stripping the finish, filling the pores, and redoing it?
 

JohnW

New User
John
Larry,

I'm making some assumptions here but, if you are talking about filling pores on just the flat top and not any curves etc, here's something to try before sanding Rock Hard all the way off. The pores on QSWO should not be too large. Try sanding the flat top with 220 using a very flat backer pad. Give it a good sanding, not all the way through, just try to get most of the high spots flat. Next, mix Rock Hard with mineral spirits to get a very thin mixture. Probably 80% finish and 20% spirits will work. Put on a couple coats of this thinned finished, light sanding with flat backer between coats. The thinner mix should get down into the pores better and dry/level out better. If/when you see the pore marks going away, go back to full strength Rock Hard. You will need to put on enough coats to fill all the pores and have enough buildup to sand down to a flat surface. To get that glass like smooth finish, I'd guess 5-8 coast.

I've used Rock Hard many times and always start out with a couple coats of thinned finish first, then go to full strength as the surface gets flatter. If the above doesn't work, you may have to sand off and start over, but I think thinning the mix should work.

If you do start over, once the surface is prepared, I'd get a real thin mix of Rock Hard and spirits, like 65% RH and 35% spirits, and wet sand the entire flat surface using 400 grit wet/dry paper and the mixture as a lubricant. This creates a slurry that can be pushed down into the pores which will fill them. Once done sanding and while the surface is still wet, I use a plastic spatula or credit card and pull the slurry at a 45 degree angle to the grain to help encourage it into the pores. Use one of your wife's cards, she will not mind...Let it dry, sand and repeat. A couple of slurry coats should fill the pores and you can move on to full strength or slightly thinned RH varnish.
 

Wyatt Co.

New User
Bill
The above is somewhat what I was eluding to.

I've made the same mistake and it was on a commissioned piece so just accepting it for what it was, just wasn't going to happen.

I wound up sanding with 400 grit with an ROS. Thinning the varnish by 30% and applying a thick coat of this thinned mix. Sanding again with 400 grit (wet) with an ROS and applying a second thick coat of the same thinned mix. After that, I wet sanded with 600, buffed, and the customer and I both were happy.
 
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