Filling Pores on Mahogany and Rosewood

[JimLowther]

Just curious--what do you all usually do about filling the pores of
timbers like Mahogany and Rosewood when prepping for finish?

Best wishes,

Dr. Jim Lowther

[Benoit Meulle-Stef]

I'm a mad man I usually don't... But If I HAVE TOO I use the water base pore feeler from stewmac:
Shellac on bare wood, then stewmac pore feeler, then 3 coats of cellulosic sealer, then too many coats of nitro...

Cheers

Benoit

[JimLowther]

I am getting ready to put together an octave "Walkabout" dulcimer and
I am thinking to use some Mohagany I bought for another project that I
never got around to. I've noticed that Stewmac water base filler and
might give it a try. In the past I've used nothing more than sanding
sealer (actually I've used a lot of stuff in the past that did not
work for me, but that is another story).

I have three Mohagany Larrivees that all look a good bit different. I
do not know what Jean does in finishing, but looking at the pores I
wonder if there isn't a different shaded filler in each.

[Guy On The Internet@internet.com Some Guy On The Internet]

Zpoxy

Egg whites, if you dare.

[Kevin Hall]

"JimLowther" <JimLo...@aol.com> wrote in message
news:19d6be94-5cd6-4bb0...@q9g2000yqd.googlegroups.com...

I use a slightly modified version of Martins' old spray schedule. A
silex-based filler is mixed to the consistency of thick cream then applied
with the grain, packing it in with a stiff bristled brush. I just shorten
the bristles on an old paintbrush for that. The filler is tinted one shade
darker than you really want it, since it lightens as it dries. A good
layer is left on the instrument until it 'flashes' or dries to the point
where it has a slightly dull appearance and goes leathery. At that point
you wipe it off, pushing hard across the grain to pack it in.

I generally do this twice just to be sure, then leave it 24 hours to make
sure it's cured before going any further. If you continue too soon you'll
have sunken pores in the finished job.

On mahog. a further wiping of stain is generally used if you want to get it
similar to the dark Martin mahog. look.

Martins' old schedule called for a sprayed coat of sanding sealer at this
point, followed by a coat of vinyl sealer to eliminat any compatibility
issues between sealer and top coats. I prefer not to use that many
products on one project since the manufacturers are forever buggering about
with their formulae without informing the end user and that can cause all
sorts of grief.

The only reason for using sanding sealer, which is just slightly cheaper
lac. with higher solids content for a quicker build, is to save a buck on
each unit. Makes a big difference if you're building a couple of hundred
guitars a day, but for tiny hand building operations the extra hassle of
having 3 different jugs of finishing materials is not worth the tiny saving.

Once the pore filler has cured properly I buff the instrument with towelling
or something similar then spray 3 coats of lac. approx. 15 to 30 min. apart
and leave overnight. The following day that set of coats is knocked back
with 240 grit, just enough to take the shine off and eliminate any bumps
and lumps. Another 3 coats are sprayed as per day 1, and left overnight
again. After this second set I sand back to flat with the 240 again, and a
third set of 3 coats is applied. I let that last set cure for a week or
so then wet sand with 400 then 600 grit using varsol ( mineral spirits) as
my lubricant. Some folks use water with a bit of dish soap in it but the
vasol cuts faster.

After that it's on to the 12" rag mop and 2 types of Menzerna polishing
compound. If all goes well you'll end up with an even coat of lac approx.
.006" thick and well filled pores.

I've tried all sorts of miracle fillers over the years including a couple of
water-based ones, but always come back to the old fashioned silex based
stuff thinned with varsol.

KH

[dhaji...@gmail.com]

I use LMI's System 3 Clearcoat epoxy made for this purpose. Squeegee on, pass a heat gun over it to blow air out of the pores, let sit a minute to return to room temp and squeegee off the excess. Do a second coat if necessary. 3M scotch bright between coats and before finishing to knock off any fuzz.

One could do a wash coat of shellac or thinned lacquer first as otherwise Rosewood tends to bleed a little color into the first fill of epoxy, making it darker. This could otherwise cause some bleeding issues, depending. (washcoat perfling too, for example).

This has no shrinkage and pores don't telegraph through later. It brings out the grain very well and toughens the wood a bit without adding film thickness.

Dave

[JimLowther]

I appreciate everyone's response. The LMI epoxy sounds like a good
solution for many reasons (like adding stiffness to the wood), but I
just don't really like working with epoxy anything. I have a can of
the Stewmac water based stuff, which I might try. It is the "medium
brown Rosewood" although I am needing to use it on Mahogany. In
general, what do you all think of these water based finish products?
I am sure they are more friendly to the environment, and for my small
projects they sure make clean-up simpler.

I still say that one of the things that separates a professional from
an amateur (like me) is the quality of the final finish. I get way
too impatient at times, and it shows.

[Guy On The Internet@internet.com Some Guy On The Internet]

On Mon, 13 May 2013 13:18:18 -0700 (PDT), JimLowther
<JimLo...@aol.com> wrote:

>I appreciate everyone's response. The LMI epoxy sounds like a good
>solution for many reasons (like adding stiffness to the wood), but I
>just don't really like working with epoxy anything. I have a can of
>the Stewmac water based stuff, which I might try. It is the "medium
>brown Rosewood" although I am needing to use it on Mahogany. In
>general, what do you all think of these water based finish products?
>I am sure they are more friendly to the environment, and for my small
>projects they sure make clean-up simpler.
>
>I still say that one of the things that separates a professional from
>an amateur (like me) is the quality of the final finish. I get way
>too impatient at times, and it shows.
>
>Best wishes,
>
>Dr. Jim Lowther

Have you contacted the manufacturer of the finishing products you
intend to use? They can tell you which filler mates well with their
products. The finishing process is an unsuitable candidate for the
"mix 'n match" approach.

[JimLowther]

On May 13, 7:37 pm, Some Guy On The Internet <Some Guy On The

Of course.

[dhaji...@gmail.com]

Some waterborne products work well. The clear waterborne filler I tried (LMI?) left a cloudy fill, in my opinion. But I'm fussy. A shellac washcoat before filling is a good idea. I haven't done much with waterborne stain/fillers. The little bit I tried seems to work pretty well.

Crystalac finish works. You need to spray coats as soon as the previous coat has set up (1 to 2 hrs) or you will get witness marks. Do about 5 coats in a set. Build is less than .0005" per coat (dry). Kind of a pain. The next day, scuff the surface before spraying to minimize witness lines. I add a little alcohol to help the coat to burn in and to set faster so it doesn't run. Gets very hard eventually. It takes quite a while to lose the blue (trapped moisture) tinge. It gets pretty resistant to chemicals after a while.

Target Coatings, EM6000 and EM7000 can burn into the previous layer somewhat. This helps avoid witness lines. Less haze (I think) than with Crystalac. Much more forgiving too. Buffs more like lacquer. If I was going to brush coat, I'd use this. (They also have a brushing product which is very similar.) It stays a bit soft at first and eventually gets pretty hard and resistant to mild chemicals.

This can be used for pore fill (after a shellac wash coat). But the pores will continue to shrink for quite a while. Better to use epoxy so shrinkage is not an issue.

Dave

[Alan D.]

Jim, I keep oscillating/vasillating on fillers. Currently I'm back to useing a
water based gell that I got years ago. It is OK but requires at least two fills
and sometimes three to get it flat. I also have an oil based silex filler that
works well but is a bear to sand back level to the wood, even after a good
level scraping. Some general rules for filler that will help:
- Always do a seal coat to the wood first. Plain Ol' shellac is good. This will
help keep the filler from pulling out as you scrape level and seal it so
waterbased fillers don't dry out too soon and detach and come out when level
sanding.
- Fill as many times as is necessary to _really_ get it level. It is a real
PITA when you get to the lacquer stage to discover all the drop-outs.
- when filling, don't forget to look really close at the top wood too. The
rosette area and binding can have voids. I shellac fill these to avoid any
discoloration. Shoot a shellac coat to the top as you are shooting to the
back/sides for seal coat, then follow with shellac drop fills as needed. Just
level sand back the drop fills till true but not back to the wood.
- Always _ALWAYS_ do a seal coat after filling and sanding back to wood. Again
shellac is good, or a vinyl sealer as it doesn't add much in the way of
thickness.

All this just happens to be fresh in my mind as I just did finish to Serenade
model. Waiting for the lacquer to cure out now.

FWIW,
Alan D.

[MikeC]

Somewhere I read about using 5 min epoxy (generic home depot stuff)... I tested it and seemed to work well. I am now finding it is a sanding nightmare unless squeegied very thin.


Mike

[dhaji...@gmail.com]

On Friday, June 28, 2013 3:48:49 PM UTC-5, MikeC wrote:
> Somewhere I read about using 5 min epoxy (generic home depot stuff)... I tested it and seemed to work well. I am now finding it is a sanding nightmare unless squeegied very thin.
>
>
>
>
>
> Mike

The 5 minute epoxy stuff is crap, pardon the expression. It is too thick to fill the pores well (sits on surface) and traps bubbles (can look milky). It may not harden fully either. The 2 hour stuff would probably work as it gives you some time. The stuff I use starts to set in an hour or two, but cures over night. It wets the wood very well and is intended to work with finishes.

Use a scraper to level the epoxy if you have to (don't have to with the longer cure stuff) and a Scotch Bright pad to scuff the finish if you didn't have to level it.

Mineral spirits will lubricate sanding if that is needed.

Dave

[Frank]

Couple of spit coats of dewaxed shellac, followed by rubbing with 4F pumice
and alcohol, same as when you're filling before French polishing.

[robbie....@gmail.com]

Any powder that has very small grains - dental plaster, linseed and pumice or rottenstone, drywall compound, etc. See thread at

http://fretsnet.ning.com/forum/topics/drywall-mud-pore-filler