Yet another mess-up

ChuckBarnett said:

Can you use enough applications of other pore-fillers like the aqua coat for example and accomplish the same goal?

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Technically yes, but you would need a lot more and then as Mikeyb2 points out there is the significant and dreaded shrinkage factor (shudder)... Another thing to keep in mind when sanding off your pore filler is to not go to bare wood and then deeper because you may just expose more pores! This is known as diminishing returns.

If I've started with Aqua Coat can I use CA glue over that? Do I have to sand back, and how far back?

Hi - I'm at a similar stage to you in my learning (eg early!) and have had variable results with Acquacoat. I also might try epoxy. My reason in posting is to suggest you have a look at the first few episodes of Pablo Requena's French polishing guide where he talks about surface preparation (https://www.youtube.com/watch?v=Uf4z14Vjkxk). What he seems to be aiming for is a process where the pores are filled to become level with the surrounding timber - but there is no filler remaining on the surface timber. He forensically examines the surface after pore filling and removes any remaining epoxy while trying not to pull the epoxy out of the pores. Once you have a nicely filled surface, you can proceed with whatever finish takes your fancy.

I have found this really hard to do with Acquacoat - I have either left some on the surface, resulting in a sort of blush under the true oil finish, or pulled it out of the pores leaving obvious pores and an uneven finish. As I said, maybe I will give epoxy a go - perhaps the epoxy sets harder and holds in the pores better?

ChuckBarnett said:

If I've started with Aqua Coat can I use CA glue over that? Do I have to sand back, and how far back?

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Yes, sand back to bare wood and sand out to at least 220 (I sand to 320). You are basically going back to square one.

I thought I would do an update. Here are some shots of the Tru-Oil thus far. I've got four coats on each surface. I see a run on a shoulder in a photo. There is still a bit of a dip on the bottom edge of the top from when I overzealously tried to fix some imperfection. The reason I didn't stand further as I was concerned that I was actually seeing the Walnut end block and thought that I had sanded right through the top. I am not sure but I suspect that co-op comes with built-in imperfections? I don't know how else that could have gotten there, but I will certainly be more educated next time! I think that my putting it on with a blue shop towel and making sure that I didn't put it on too thick has helped with those. I'm not satisfied with the workmanship that I see in this but I'm fighting a deadline of a granddaughter's birthday and I'm done with this. I will tell her it is not perfect before she sees that. I know her well enough to know that she will accept it as a treasure from her grampa nonetheless.

I don't know what I am seeing when I look at this finish, or any finish for that matter. I did send the top back to bear wood. I saw that there were some shiny spots in what I now understand to be the pores of the wood. I think that must be the Aqua Coat that got in there. I put about five coats of Aqua coat on after sanding back. Sure how you know when to quit.

Regarding doing Tru-Oil, as far as I can understand, you wipe on a bunch of coats and then scuff sand, level sand, somehow sand with probably 600 grit or thereabouts, clean it off and keep going with more coats till you're happy? I see little dimples, particularly on the sides. I have no idea how they got there. But I surely am tired of trying to sand back and fix that stuff.

I talked to Brian at Aqua Coat and he discouraged me from rubbing the true oil in like I saw on a video someone suggested. He said that the heat generated in that process can break down the pore filling done by the Aqua Coat. Better to wipe it on. He also said that it's good to leave it a couple of days to minimize shrinkage. I was considering doing the CA glue method but I'm looking for more information on that before I start in. I will certainly practice on scrap wood.

So at some point I'm going to attempt sanding and hope that some of those things will magically disappear. I welcome, as always, your wisdom and observations. It's difficult to look at photos and see clearly what is really there, but you guys do a great job with that!

One of the problems with attempting a super shiny finish like that is the gloss highlights the imperfections in the wood. My advice would be to go for a satin finish by hitting it lightly with 0000 steel wool to take off the gloss. This will tend to hide your open grain and pores and other imperfections. I actually like a satin finish sometimes and it is more forgiving over the long haul when the inevitable scratches and dings start to happen.

As for your dimples, it looks like you sanded with your fingers rather than sanding with a block. It is tempting to use your fingers to get at imperfections but you end up with an uneven surface like you are seeing.

Overall it doesn't look that bad and your granddaughter will love it. You have also learned a lot in the process. We learn through error and failure.

Thanks!

If I remember correctly, after the steel wool sanding you finish off with a finala coat of Tru-Oil?

No. Just rub with a cloth and call it good... You done.

If you still aren't sure what you are trying to accomplish with pore filling, then look at the picture you have of the back . Those pores are enormous and don't look to be filled at all. If your goal is to have it perfectly smooth once the finish is applied, then those pores need to be level with the timber before you start applying any sort of finish. Otherwise you'll just be chasing your tail and get dissapointing results.

In class situations where we don't have time to pore fill, the students would do a brush on shellac finish. And the next day we would burnish the instrument with super fine steel wool and a bit of paste wax. Then a good rub with an old cotton (t-shirt) rag. Leaves a nice "Duck Egg" sheen that is quite pleasing.

Thanks, Allen. I've given up on any kind of a nice finish on this. I think I will try what Sequoia suggested.

I certainly got in over my head on this.

Hey, it was your first attempt and it really isn't that bad. My neighbor and accomplished luthier Dave Sigman never did any pore filling at all because he thought that wood should look like wood pores and all and his ukes looked great. I found his approach refreshing. Another luthier I knew hated that shiny candy apple appearance because he thought it intimidated people. "I can't play it because I might scratch it!". He wanted his instruments to be played and did a nice satin shellac finish that looked great and didn't show scratches. I have a suspicion that some of these super high end ukes with the perfect shiny finishes spend most of their time in their cases and are rarely played. Only taken out occasionally and admired. But they look great!

Going forward with a satin or matte look, what is a good target for number of coats of Tru-Oil before the finish-off with steel wool? I'm applying it with a folded blue shop towel, wiping with the grain, and going over it lightly again to avoid runs and globs.

Thank you.

Hello!

See my finish way with Danish Oil on my you Tube chanel.

Tamiya sanding paper.

Each grade twice, with about 20 hours drying time betwen each.

#400-600-800-1000-1200-1500-2000

https://www.youtube.com/channel/UCziSQkCbbAlq4LbYRCucl8g/

gerardg said:

Hello!

See my finish way with Danish Oil on my you Tube chanel.

Tamiya sanding paper.

Each grade twice, with about 20 hours drying time betwen each.

#400-600-800-1000-1200-1500-2000

https://www.youtube.com/channel/UCziSQkCbbAlq4LbYRCucl8g/

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thank you for the video. Notot sure what I was watching there. Somebody had some sort of folded rag or cloth in their hand, wiping in random motion and then set the uke down on a rubber pad. I'm assuming you weren't wiping on oil? Was that the Tamiya sandpaper? It sort of looks like a folded up cloth of some kind and it was being used to rub the surface?

What is there to dry if you are sanding?? I'm sure that these are stupid questions if you know what you're doing, which it's self-evident that I do not. Forgive me.

A follow up question: how long after applying the last coat would you use the steel wool? Fairly quickly? Wait a day? And I assume it's simply guesswork to know how much steel-wooling needs to be done.

Let the last coat thoroughly dry. Read the directions for dry times. A couple days maybe. You don't want to steel wool a tacky surface. Patience... Don't go at it too aggressively with the steel wool. The idea is to just take off the sheen and dull the surface.

As Sequoia say, not use steel wool !
No no no !
On pineapple with mapple top, it's just polishing cloth.
Several days after the last Tamiya #2000 grit step.
You just have to use Tamiya in wet sanding with Danish oil, and wip excess just after.
There is only one Tamiya sand paper.
Look at my blog, many pics on the D.O. finishing.
Ok for you ?

https://pandahobby.store/products/tamiya-sandpaper-p180-3pcs-87092

After 14 coats of Tru-Oil, I feel imperfections on the surface of the ukulele -specs, that if you hold the surface to the light correctly you can actually see period or at least see the shadow created by them. Am I feeling dust particles that somehow got trapped in the oil? How do I avoid that? I thought I had been careful. More importantly, how do I get rid of them at this point? Will using steel wool take care of that? And what about bronze wool? Somebody suggested elsewhere that I should use bronze wool? I have no clue.

ChuckBarnett said:

Will using steel wool take care of that?

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No it will not. You have sawdust trapped in the finish probably because you didn't properly clean the surface prior to applying the finish. The only remedy will be to take off the finish and start over. My advice would be to ignore the problem and move on.