Micromesh question + update + update?

[Steve_Karl]

Hi there,

I've got 8 coats of Minwax satin poly on my mahogany body and it's pretty shiney right now.
I think I finally figured out how to use the micromesh set that I got a few years ago but I wanted to get some input on the whole process.

What I've been doing is targeting areas that are showing scratches or look slightly foggy.

Where the light bulb really turned on for me was with an area that had some scratches.
I kept going down to lower grits until I saw that I was cutting away the scratches.
Turned out I had to go down to 1,500 to see results.
Then up, up, up all the way to 12,000 and it looks great.

I was worried about 1,500 taking off too much finish and kind'a still am, but after I saw the results
I'm wondering ....

should I just take the whole body down to 1,500 and then up to 12,000 grit by grit,
or should I just continue to target areas where I see a problem?

How do you do it?

Thanks!

UPDATE:

Yea .... I think I've got it fugured out now. I took a fairly large section down to 1,500 and then back up to 12,000 and it's a whole lot like glass now but the finish is looking thin compared to areas that I haven't rubbed.
Gonna spread out from there and try more area and see how it goes ...

... but might want to scuff the whole body with a grey scotchbrite real good and then put one or 2 more thicker coats of finish on.

Might take a day or 2 but I'll report back.

UPDATE 2
Gray scotchbrite > taking it all down to where is *seems* like I'm getting below the imperfections that were bothing me, and I'm getting a consistent dull frosty look. Very similar to the micromesh 1,500 grit but a bit quicker to get there.

(Getting rid of little sparkely bits that seem to be lodged in the pores ... any thought on this ? would be welcome )

I say *seems* because I'm not sure if the frosty look is now just hiding what I didn't like or it's really getting rid of it.
I know I'm taking a lot of the finish back off, but not sure how much, and not sure if I'm going to have to put an other coat on, and if I do
(here's the real question in this update)
will I be right back where I started today with the micromesh, or will I be closer to a glassy smooth finish?

 

[Cagey]

It's pretty straightforward. The coarser the grit, the duller the finish, and vice-versa. 1500 grit is not going to give you a gloss finish; it's going to look somewhat "satin-y". Also, the finer the grit, the longer it takes to see a difference in finish quality. Finer grits cut less per pass, so finer finishes will eat your life if you're trying to do it with paper. Most folks will use a rubbing compound, which is like a polishing paper (finer grits), but is more suited to mechanical assistance from something like a buffing tool. Lets you apply a more abrasion in less time.

Usually when trying to get a gloss finish out of traditional materials you wet sand up to maybe 2000 grit, then start with the compounds. You say you're using a satin finish material, so it isn't going to gloss up. There are particles in the finish itself that will refract the light so it won't shine, and you can't really polish that out completely. By the same token, it's tough to match that appearance with abrasives.

 

[Steve_Karl]

Thanks. I don't want to get into compounds this time around. Maybe next time.

So, back to the drama ...
After the 8 coats of finish, unrubbed or polished, I'm seeing and feeling with the pad of my finger, grain lines and pores that aren't filled.

From the beginning: I sealed, sanded, grainfilled, sanded <> sealed, sanded, grainfilled, sanded <> sealed ... sanded.
Then 8 coats of finish, scuffing with grey scotchbrite (lightly) inbetween.

I'm thinking now, that I was way to gentle with the scuffing inbetween coats,
because now,
what I see is that now, after those 8 coats, if I hit it hard with the scotchbrite,
most all of those unfilled looking areas are gone.
BUT ... not all ... to a perfectly level surface.

If I then do the full micromesh routine, 1500 thru 12000, the surface is a lot more level, (not as shiny, light reflecting, as just the untouched 8 coats) but more level.

My grainfilling wasn't totally perfect and I knew that, but I was hoping that an other coat of sealer and 8 coats of finish would level everything out.
---
So, what I'm thinking now, is rub it all really good with the grey scotchbrite and then an other coat of sealer.
But would the sealer be a bad idea if there's still some finish on there?

Then an other coat of finish and a good scuffing with the grey scotchbrite. ... more finish ... more scuffing etc.

Am I delusional to think I can get it totally level, taking care of those minor areas, with sealer and finish?

 

[Cagey]

Not delusional, but it depending on how uneven the surface is, it may take you a long time and turn a lotta (relatively) expensive finish into dust. Grain filler is the fast, inexpensive way to get a level surface. Moral of the story: Prep is everything in finish work.

 

[Steve_Karl]

Yea. I hear ya.

Will there be a problem putting sealer on if there's still some finish on there?

 

[Cagey]

Can't say for certain. I wouldn't expect anything to stick to an "oil" finish. But, sometimes sealer is just a thinned-out version of the finish it's designed to go under, so there'd be no issue there. Unfortunately, because it's thinned out, it has little filling capability. With more traditional hard finishes, there's often a "sanding sealer" that's just the opposite - it has more solids in it, so it will fill imperfections.

You may have to just dig down deep into your patience reserves and continue putting coats of finish on, letting them cure, and leveling them out. Lather, rinse and repeat until you get where you need to be. 

I don't do "oil" finishes, though. Too fragile. I'm a lacquer/poly guy. So, someone who has more experience with that material may have better suggestions.

 

[Steve_Karl]

Thanks for the talk.

So this is a minwax poly (oil based) finish so it seems minwax sanding sealer would probably be my best bet for the next step after I get it
down close to bare wood.

http://www.minwax.com/wood-products/hardwood-floors/minwax-professional-formula-sanding-sealer

 

[Steve_Karl]

Tried the Minwax sanding sealer on a very small part of the back.

Not good for this application.
It left a blue/purplish hue in the wood.
Had to sand it out with 220.

 

[Cagey]

You may be stuck with using grain filler to get to a good, level surface. Mahogany will do that to you. So will Ash. Even Tonar has joked that he'll never do a Mahogany body again. It's a real bear to get a good surface on. I had that trouble with the L5S in my sig, and a Strat that nobody's seen yet. Fill, sand, fill, sand, fill, sand... it's enough to try the patience of a saint.

 

[Steve_Karl]

yea ... I guess I've got to bite the bullet and either grain fill again or 2 ... or settle for a tiny bit of texture in places.
It's good the hear that it's not just me doing something wrong.

I'm working on building a few sets of drawer/shelves also out of 3/4" melamine,
so I go back and forth between projects.

Hey ... thanks for all the help over the yrs. I really appreciate it.

 

[Cagey]

If you are having any trouble with the grain filler you're using, you might want to consider some of this stuff. Works well, is nice and clear, and can be stained if you want.

 

[Steve_Karl]

Thanks. The filler seems fine. It's the dark brown (chocolately) LMI
http://www.lmii.com/products/finishing/filler/lmi-micro-bead-acrylic-paste-filler

I only filled twice ... should have been more observant and not assumed finish would fix the minor missed spots.

 

[Cagey]

I think many look at grain filler like it's wood filler or putty, and expect more out of it in one or two passes. But, it's for filling wood grain instead of cracks or nail/screw holes and such, so it's relatively thin. Something with a very coarse grain like Mahogany or Ash fills slowly as a result.

I'd be curious to know how Warmoth fills grain on those woods before finishing. I can't believe they use grain filler - they'd have to charge a premium for finishing some woods due to the labor involved.

 

[Steve_Karl]

I'd be curious to know how Warmoth fills grain on those woods before finishing. I can't believe they use grain filler - they'd have to charge a premium for finishing some woods due to the labor involved.

Yea. Maybe someone will spill the beans and tell us ... would be nice if there's something more effecient.

 

[bagman67]

TonyFlyingSquirrel used to be on the inside - maybe he knows?


Tony...?  Bueller...?

 

[Steve_Karl]

TonyFlyingSquirrel used to be on the inside - maybe he knows?


Tony...?  Bueller...?

Bump!