TB

Tom B

30/08/2009 12:46 PM

Stain Problem/Question

Building a bookshelf (80LX32HX11W) for one of our local seniors as
part of my volunteer activities (Plain-O-Helpers, we work for free and
supply materials from contributions if the requestor can't afford it,
as many can't).

Because the lady doesn't have much $, I used HD handy panels which are
junk, but look OK on the surface wood. She wanted a "dark stain" but
when I met with her and showed her some samples of the panel with
various stains and poly overcoat on them, selected MinWax Red Mahogany
as her preferred shade. She has a bunch of really nice old furniture -
walnut, mahagoney, teak and a burled maple cabinet that I'll try to
get a pic of - it's glorious, so the mahogany wasn't out of place.

I've done all the cuts, dadoes, and rabbets, etc. Masked glue surfaces
and began the staining yesterday. Applied MW stain conditioner to
minimise blotching 'cause the Handy Panel surface wood is really soft.
Waited 2 hours per instructions and applied MW Red Mahogany oil stain
(from a brand new quart), waited ~10 minutes, wiped off with blue shop
paper towels. I didn't try to rub off the stain, just wiped until the
surfaces didn't look wet. If I'd wipeed more or harder, ther would
have been additional stain on the towels. Instructions say to dry for
8 hours, so, in an excess of caution I thought, I let all the pieces
sit from 1300 hours yesterday to 0900 hours this AM. I then applied a
coat of MW poly (semi-gloss) that I had thinned about 5% with MS (1/2
cup in 3/4 qt). Not a heavy coat, but not wiped off either, just
enough to leave the surface looking wet. It went on fine and the foam
brush didn't turn paint thinner colored when I dunked the foam brush
into it to clean up after finishing.

I went out about 30 minutes ago (after ~2 hours of drying time) and,
oh my gosh (or other similar words), I've got little pimples of dark
stain rising in the poly. Like measles, pin head sized, but dark ones,
darker than the surrounding stained wood. Now these are the inside
sides of the shelf carcass and I figure after I hit it with 220 grit
and apply another coat of poly, the problem won't be noticeable on the
finished piece. I would, however, like to avoid it on the outside
"show" parts.

I can only assume:

a) I did not wipe off enough of the stain so it didn't dry adequately

b) I didn't give it enough drying time

or both.

The drying environment was about 80 degrees F and RH has been around
30% for the last 24 hours (Thank you Lord for a N Texas cold front in
August!).

I know there're a bunch of finishing gurus out there 'cause I read
your posts. Any bright ideas to avoid a repitition? I mean it's just a
volunteer project, but I like to do it right (or as right as my
limited abilities allow).

Tom


This topic has 4 replies

Nn

Nova

in reply to Tom B on 30/08/2009 12:46 PM

30/08/2009 7:21 PM

Tom B wrote:
> Building a bookshelf (80LX32HX11W) for one of our local seniors as
> part of my volunteer activities (Plain-O-Helpers, we work for free and
> supply materials from contributions if the requestor can't afford it,
> as many can't).
>
> Because the lady doesn't have much $, I used HD handy panels which are
> junk, but look OK on the surface wood. She wanted a "dark stain" but
> when I met with her and showed her some samples of the panel with
> various stains and poly overcoat on them, selected MinWax Red Mahogany
> as her preferred shade. She has a bunch of really nice old furniture -
> walnut, mahagoney, teak and a burled maple cabinet that I'll try to
> get a pic of - it's glorious, so the mahogany wasn't out of place.
>
> I've done all the cuts, dadoes, and rabbets, etc. Masked glue surfaces
> and began the staining yesterday. Applied MW stain conditioner to
> minimise blotching 'cause the Handy Panel surface wood is really soft.
> Waited 2 hours per instructions and applied MW Red Mahogany oil stain
> (from a brand new quart), waited ~10 minutes, wiped off with blue shop
> paper towels. I didn't try to rub off the stain, just wiped until the
> surfaces didn't look wet. If I'd wipeed more or harder, ther would
> have been additional stain on the towels. Instructions say to dry for
> 8 hours, so, in an excess of caution I thought, I let all the pieces
> sit from 1300 hours yesterday to 0900 hours this AM. I then applied a
> coat of MW poly (semi-gloss) that I had thinned about 5% with MS (1/2
> cup in 3/4 qt). Not a heavy coat, but not wiped off either, just
> enough to leave the surface looking wet. It went on fine and the foam
> brush didn't turn paint thinner colored when I dunked the foam brush
> into it to clean up after finishing.
>
> I went out about 30 minutes ago (after ~2 hours of drying time) and,
> oh my gosh (or other similar words), I've got little pimples of dark
> stain rising in the poly. Like measles, pin head sized, but dark ones,
> darker than the surrounding stained wood. Now these are the inside
> sides of the shelf carcass and I figure after I hit it with 220 grit
> and apply another coat of poly, the problem won't be noticeable on the
> finished piece. I would, however, like to avoid it on the outside
> "show" parts.
>
> I can only assume:
>
> a) I did not wipe off enough of the stain so it didn't dry adequately
>
> b) I didn't give it enough drying time
>
> or both.
>
> The drying environment was about 80 degrees F and RH has been around
> 30% for the last 24 hours (Thank you Lord for a N Texas cold front in
> August!).
>
> I know there're a bunch of finishing gurus out there 'cause I read
> your posts. Any bright ideas to avoid a repitition? I mean it's just a
> volunteer project, but I like to do it right (or as right as my
> limited abilities allow).
>
> Tom

1/2 cup of mineral spirits added to 3/4 quart of poly would be 4 oz/24
oz, closer to 17%. I'd suspect the added mineral spirits lifted the stain.

--
Jack Novak
Buffalo, NY - USA
[email protected]

TB

Tom B

in reply to Tom B on 30/08/2009 12:46 PM

30/08/2009 7:20 PM

On Sun, 30 Aug 2009 19:21:35 GMT, Nova <[email protected]> wrote:

>1/2 cup of mineral spirits added to 3/4 quart of poly would be 4 oz/24
>oz, closer to 17%. I'd suspect the added mineral spirits lifted the stain.

Guess I had a brain seizure when I did the mental math.

As I often thin poly by 20% (when I wipe it), I didn't think it would
be a problem. You may well be right. I rarely use stains in my
finishing because most of my work has been in woods where I want the
natural wood color to show. This one was an "on request" type thing
using inexpensive materials.

I think a wash coat of de-waxed shellac after the stain has dried may
be in order on the rest of the surfaces.

Thanks.

Tom

dn

dpb

in reply to Tom B on 30/08/2009 12:46 PM

30/08/2009 2:12 PM

Tom B wrote:
...
> Because the lady doesn't have much $, I used HD handy panels ...
> and began the staining yesterday. Applied MW stain conditioner to
> minimise blotching 'cause the Handy Panel surface wood is really soft.
> Waited 2 hours per instructions and applied MW Red Mahogany oil stain
> (from a brand new quart), waited ~10 minutes, wiped off with blue shop
> paper towels. I didn't try to rub off the stain, just wiped until the
> surfaces didn't look wet. If I'd wipeed more or harder, ther would
> have been additional stain on the towels. Instructions say to dry for
> 8 hours, so, in an excess of caution I thought, I let all the pieces
> sit from 1300 hours yesterday to 0900 hours this AM. I then applied a
> coat of MW poly (semi-gloss) that I had thinned about 5% with MS (1/2
> cup in 3/4 qt). Not a heavy coat, but not wiped off either, just
> enough to leave the surface looking wet. It went on fine and the foam
> brush didn't turn paint thinner colored when I dunked the foam brush
> into it to clean up after finishing.
>
> I went out about 30 minutes ago (after ~2 hours of drying time) and,
> oh my gosh (or other similar words), I've got little pimples of dark
> stain rising in the poly. Like measles, pin head sized, but dark ones,
> darker than the surrounding stained wood. Now these are the inside
> sides of the shelf carcass and I figure after I hit it with 220 grit
> and apply another coat of poly, the problem won't be noticeable on the
> finished piece. I would, however, like to avoid it on the outside
> "show" parts.
>
> I can only assume:
>
> a) I did not wipe off enough of the stain so it didn't dry adequately
>
> b) I didn't give it enough drying time
>
> or both.
...

Don't know what the actual wood is and not familiar w/ what you're
calling "HD handy panels" (no HD's within 200 miles) so guessing a little.

My conjecture is this is a porous wood like oak/luaun/similar and there
was stain captured in them that wasn't entirely dry even though the
surface appeared so.

I would expect a rubout a little more and additional drying time will
solve the problem. Alternatively, a cut shellac coat before applying
the varnish would stop the telegraphing.

--

ST

Steve Turner

in reply to Tom B on 30/08/2009 12:46 PM

30/08/2009 2:59 PM

dpb wrote:
> Tom B wrote:
> ...
>> Because the lady doesn't have much $, I used HD handy panels ...
>> and began the staining yesterday. Applied MW stain conditioner to
>> minimise blotching 'cause the Handy Panel surface wood is really soft.
>> Waited 2 hours per instructions and applied MW Red Mahogany oil stain
>> (from a brand new quart), waited ~10 minutes, wiped off with blue shop
>> paper towels. I didn't try to rub off the stain, just wiped until the
>> surfaces didn't look wet. If I'd wipeed more or harder, ther would
>> have been additional stain on the towels. Instructions say to dry for
>> 8 hours, so, in an excess of caution I thought, I let all the pieces
>> sit from 1300 hours yesterday to 0900 hours this AM. I then applied a
>> coat of MW poly (semi-gloss) that I had thinned about 5% with MS (1/2
>> cup in 3/4 qt). Not a heavy coat, but not wiped off either, just
>> enough to leave the surface looking wet. It went on fine and the foam
>> brush didn't turn paint thinner colored when I dunked the foam brush
>> into it to clean up after finishing.
>>
>> I went out about 30 minutes ago (after ~2 hours of drying time) and,
>> oh my gosh (or other similar words), I've got little pimples of dark
>> stain rising in the poly. Like measles, pin head sized, but dark ones,
>> darker than the surrounding stained wood. Now these are the inside
>> sides of the shelf carcass and I figure after I hit it with 220 grit
>> and apply another coat of poly, the problem won't be noticeable on the
>> finished piece. I would, however, like to avoid it on the outside
>> "show" parts.
>>
>> I can only assume:
>>
>> a) I did not wipe off enough of the stain so it didn't dry adequately
>>
>> b) I didn't give it enough drying time
>>
>> or both.
> ...
>
> Don't know what the actual wood is and not familiar w/ what you're
> calling "HD handy panels" (no HD's within 200 miles) so guessing a little.
>
> My conjecture is this is a porous wood like oak/luaun/similar and there
> was stain captured in them that wasn't entirely dry even though the
> surface appeared so.
>
> I would expect a rubout a little more and additional drying time will
> solve the problem. Alternatively, a cut shellac coat before applying
> the varnish would stop the telegraphing.

I have to nod my head "yes" when reading this response. Before
proceeding further I would suggest testing your original method (of
following the instructions) modified by the proposed solutions on a
scrap piece of the same wood. You want to eliminate the surprises
before forging ahead on the final product.

As far as my proposed solution: If this is indeed porous wood, I
*always* follow up the wipe-down by blowing the stained surface with
compressed air, then wiping away any additional stain that weeps out of
the pores. You'd be surprised how much stain something like red oak can
collect in the pores, and you'd have to wait far longer than the
suggested drying time for that to cure fully and not come seeping back
out when you try to apply the top coat.

--
Free bad advice available here.
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/


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