Wet sanding help... are these low spots >?

[OscarG]

I'm trying my hand at wetsanding some ash that's had 5 coats of waterborne lacquer sprayed on, I used 800 grit, but not really a lot of white stuff/slurry was generated, maybe the grit is too fine and I should use 600.

It's real smooth but there's some marks, I've tried to highlight in the red circles. They're only visible when viewed from certain angles. Are these low-spots? It feels level and smooth so I'm a little puzzled.

What do you think, shall I keep sanding down until they've gone or is normal to expect marks like that?

Sorry if this is a really dumb question, but this is my first go at finishing some wood.

Cheers!

 

[bugbear]

You're too late - the fault is (minor) tearout, and it's in the wood, not the finish.

You might be able to add enough finish to fill in the tear out, and then re-sand it down flush.

I LIKE the colour contrast you're getting in the grain, BTW.

BugBear

 

[OscarG]

Thanks for reply. The colour's nice even if nothing else is!

Oh so I'd need to sand back to bare wood to fix this? Sh*t!

There's little marks like that all over the wood, minor but can only be seen in certain angles of light.

It's had 3 coats of sanding sealer and I think 5 coats of lacquer sprayed on. I had wondered if I hadn't left enough time to dry between coats and that's why I had these marks.


Do you think if I ignore them and buff it up with polishing compound they'll be less or more obvious?

 

[ED65]

Yes those look like low spots. If the tearout is minor enough that you missed it until now I think you'll get away with filling with finish and cutting back to a level surface if you don't mind that you have to apply additional coats.

600 might be a bit fine for the initial flattening, but it's preferable to using 400 and finding it cuts just that little bit too aggressively!

 

[bugbear]

(oh, and note for the future; your grain filler clearly didn't )

BugBear

 

[OscarG]

Thanks guys.

I did originally grain fill the body, it was real smooth but later on I had a complete mare with the dye (ruined by painting on sealer) causing me to sand back to bare wood to reapply dye. If I smart I'd have reapplied grain filler too but I was anxious to restore the colour I didn't think of that

If I sand down, apply more clear lacquer and keep doing that. You think I'll eventually get rid of these marks?

Is Ash generally a sod to finish? I'm wondering if for my first project I'd made it hard for myself.

 

[bugbear]

Thanks guys.

I did originally grain fill the body, it was real smooth but later on I had a complete mare with the dye (ruined by painting on sealer) causing me to sand back to bare wood to reapply dye. If I smart I'd have reapplied grain filler too but I was anxious to restore the colour I didn't think of that

If I sand down, apply more clear lacquer and keep doing that. You think I'll eventually get rid of these marks?

Is Ash generally a sod to finish? I'm wondering if for my first project I'd made it hard for myself.

If this is your first project, I'd say it's looking pretty good.

Ash can be a little tricky, because the soft parts of the grain are very soft indeed.

But it's far from the worst.

Since you'll soon be building another guitar (*), I'd keep going on this one, and get your techniques "down pat"

BugBear

(*) nobody builds one guitar. "zero" or "several" are the normal number

 

[profchris]

What Bugbear said!

After wet sanding I wipe off the residue and then, when it's dry, buff quickly with a yellow duster. Look at it in a raking light, and any shiny spots are low.

If you have enough finish on to sand some more now, without going through, then I'd do that to reduce the work with later coats. But err on the cautious side, you definitely don't want to sand through the lacquer!

 

[custard]

Is Ash generally a sod to finish?

Yes it is, the grain pores are so deep it's a pig to fill, especially if you want to preserve the pale look of the timber, I've has some success with Aqua Coat on Ash, it's good but it's not perfect. It's a little too soft, a little too glossy, and a lot too expensive!

Plus, as BB pointed out, Ash is no fun to plane either. The problem timbers for planing aren't the super hard timbers, or oftentimes not even the wildly figured timbers. The real problems are the timbers that seem to have a blend of both hard and soft fibres, like Yew and Ash or indeed anything that's spalted or even partially spalted like Brown Oak or Olive Ash. What's more, those are exactly the same timbers that are also the most difficult to scrape, so there's just no get out off jail free card.