LumberJocks

I need some help with finishing Please

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by HuntleyBill posted 10-04-2010 05:41 PM 1316 views 2 times favorited 14 replies Add to Favorites Watch
View HuntleyBill's profile

HuntleyBill

86 posts in 2550 days


10-04-2010 05:41 PM

I am building a small project out of walnut. I am using poly gloss as the finish ( not a wipe on ). What I am looking for is a glass smooth…high gloss finish. I have attached some pictures of what problems I’m having. Hopefully you can see them in the pictures.

First, I have used the poly to fill the pores sanding down with 220. I then put a couple more coats on and let it cure for about 8 days. I then BLOCK sanded with 400, 600, 1000, 1500, FF pumace, and finished with rottenstone. According to Stevin Marin’s video on his chess board finish, at this point I should have a nice gloss finish. I don’t! The finish is a dull satin. I even tried waxing and buffing and it helped a little…not much.

First question: How do I get that high gloss finish? I have a smooth as glass finish but not high gloss.

Second Picture: In the picture shown, there are “layer of poly” that seem to be showing through. I keep sanding and more show up, obviously from the layer below. You can see them in the picture as shiney spots. I figured I just keep sanding untill I get one even layer but as you can also see just to the right of the shiney spots I now have a big area the LOOKS as if it is sanded through. I’m guessing as that area has a different look to it. Even when I sand with finer and finer media, it doesn’t go away and can be seen even after the rottenstone.

Another thought…when I finally get that “gloss finish” do those areas dissapear and I sanded my @#$ off for nothing????? I must have 15 coats of poly all together applied to this. Of course a lot of that sanded off.

How do I fix this? Did I sand through? What am I doing wrong?

Thank you All for your help

-- If you think you can, or think you can't...your right!


14 replies so far

View shipwright's profile

shipwright

7163 posts in 2258 days


#1 posted 10-04-2010 06:37 PM

1) I get my best gloss by applying the last coats in wipe on poly or by spraying. Both are done in dust free conditions and not polished with any grit of any kind.

2) You have what are known as “witness lines”. they are the edges of sanded through high spots in previous coats. To avoid them, check your product spec to see how long you can wait between coats and still have burn in. That’s when the new coat dissolves itself into the previous coat. I suspect you have allowed your initial coats too long to cure.

3) When starting out, (check material spec as I said) apply several coats within the burn in time window to build film thickness. Sand only as much between these coats as the manufacturer requires, often not at all. Let this film fully harden and sand it flat. Stop before you sand through the film. If you still have shiny spots, apply another five coats or so and repeat the process being careful not to sand through the “current” coats. Keep repeating until there are no shiny spots when you have flat sanded and then apply your finish gloss coats with wipe on or spray.

I don’t know your product so I don’t know if you can lose the witness lines that you have already got, sorry.

Paul

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees. http://thecanadianschooloffrenchmarquetry.com/

View HuntleyBill's profile

HuntleyBill

86 posts in 2550 days


#2 posted 10-04-2010 06:45 PM

Hi Paul. Unfortunately, I don’t have spray equipment. Even with wipe on, I still get some dirt and/or imperfections that need to be removed. Thank you very much for your advice. A big help.

-- If you think you can, or think you can't...your right!

View Builder_Bob's profile

Builder_Bob

161 posts in 2519 days


#3 posted 10-04-2010 07:00 PM

I think rotten stone is used to bring a high gloss finish down to satin. Even wax will bring down a gloss finish.

You have to have a gloss finish immediately after application. Can you find a spray can version of your product?

You might want to try Zinsser Clear Spray Shellac. Shellac can work wonders in situations where modern finishes fail. You’ve got to get that wax off before spraying anything. I know, that makes for more sanding!

-- "The unexpected, when it happens, generally happens when you least expect it."

View Gofor's profile

Gofor

470 posts in 3247 days


#4 posted 10-05-2010 02:35 AM

First, you need one thick coat of the poly as a final coat. Poly and varnish oxidize with air as they dry, and do not “burn in” or meld with the previous coat. Lacquer and shellac just dry by evaporation, and the solvents in the new coat dissolves the surface of the older coat, leaving no “witness lines. Poly will not do that.

After you apply the last full thick coat (do not thin), let it dry at least 3 days to let it fully oxidize on top (full cure takes up to a month throughout the full layer of all coats, but even then you will see witness lines between coats).). Sand lightly with fine grit just enough to level any dust nibs. I hand sand (fingers, not sanding pad) with 600 grit or finer as I have yet to see a wood perfectly flat. You already have built up enough coating to fill any voids. If it gums up the sandpaper at all, it is not yet cured enough, so let it dry more).

Polish with automobile polishing compound (not rubbing compound). Goes faster with a random orbit sander with a hook and loop pad. Put a piece of old sweat pants or terry cloth under the pad for the polishing. IF you want it super shiny, then use micro polishing compound (also found at an auto supply store). Don’t spend too long in any spot so as not to burn through the top coat.

JMTCW

Go

Pumice, rottenstone, etc are meant to flatten gloss, not make it shiny.

-- Go http://ncwoodworker.net/pp/showgallery.php?cat=500&ppuser=730

View Dark_Lightning's profile

Dark_Lightning

2631 posts in 2569 days


#5 posted 10-05-2010 02:45 AM

Gofor does what I do. I can get a finish on satin most people think is gloss. It does take work, though. If you have a large flat area, you can wet sand (you have to have the finish film over all the wood, of course) up to 2000 grit. Then, as soon as you start to use the car polish, it’ll shine right up, and be flat, to boot. I use carnauba wax after that, just like on a car. I wish I could get some better pictures to show what I mean.

-- Random Orbital Nailer

View HuntleyBill's profile

HuntleyBill

86 posts in 2550 days


#6 posted 10-05-2010 03:01 AM

Thank you all for your advice. I will get started in the morning.

-- If you think you can, or think you can't...your right!

View CharlieM1958's profile

CharlieM1958

16241 posts in 3678 days


#7 posted 10-05-2010 03:34 AM

I agree that Gofor’s advice should work beautifully for you.

However, I’d have to disagree with the statement that rottenstone is meant to flatten gloss. Pumice is a coarser abrasive that will leave a somewhat satin finish, but rottenstone is a finer powder, and will produce a high gloss. You can see the reflection of the flowers in the lid of this box I finished with rottenstone:

-- Charlie M. "Woodworking - patience = firewood"

View shipwright's profile

shipwright

7163 posts in 2258 days


#8 posted 10-05-2010 06:33 AM

Sometimes we have to just agree to disagree.

Paul

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees. http://thecanadianschooloffrenchmarquetry.com/

View HuntleyBill's profile

HuntleyBill

86 posts in 2550 days


#9 posted 10-05-2010 04:39 PM

The first picture I have above was rubbed out to rottenstone. Clearly it is not a gloss finish. Are you saying Charlie that I didn’t rub long enough? As a new guy to this art, I’m trying to learn.

-- If you think you can, or think you can't...your right!

View CharlieM1958's profile

CharlieM1958

16241 posts in 3678 days


#10 posted 10-05-2010 08:01 PM

When you rubbed it out, were you using a lubricant? The way I do it is to make a paste of rottenstone and paraffin oil, and rub small areas at a time in a circular motion with a soft cotton cloth. It takes a lot of rubbing and a lot of elbow grease to get a good gloss. Like with sandpaper, depending on the smoothness of the finish you are starting with you may need to gradually work up to finer grits, using pumice first, then rottenstone. The automotive polishing compound Gofor suggested is even finer than rottenstone. I was just illustrating that it is possible to get a pretty glossy finish with rottenstone.

-- Charlie M. "Woodworking - patience = firewood"

View Gofor's profile

Gofor

470 posts in 3247 days


#11 posted 10-06-2010 12:50 AM

Thank you for the info/correction CharlieM. I was under a false impression of rottenstone’s purpose, and admit i have never used it. ( I should have stated that in my post. My bad and I apologize). The plus side is that I again learned something new here.

By the way: Beautiful job on that box. The grain fit on the top is really striking with the lighter banding.

Go

-- Go http://ncwoodworker.net/pp/showgallery.php?cat=500&ppuser=730

View Steven H's profile

Steven H

1117 posts in 2520 days


#12 posted 10-06-2010 03:18 AM

1) What product are you using?
2) How are you applying it?
3) Did you also apply other finishes before or only poly?

View HuntleyBill's profile

HuntleyBill

86 posts in 2550 days


#13 posted 10-06-2010 03:51 AM

Steven:
1) Minwax Gloss Poly
2) Wiped on with soft cloth.
3) Only poly, no other finish

Charlie: I used water with a little soap in it. I didn’t have oil and the directions said I could use water.

-- If you think you can, or think you can't...your right!

View Natedawg4081's profile

Natedawg4081

39 posts in 2266 days


#14 posted 10-06-2010 04:32 AM

I use a technique called French polishing using a lacquer based product. It should give you the gloss look you are looking for.

-- Nathan Corson

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com