Finishing mistake?


Ok, I just finished putting the LAST coat of 3 of a water-based poly (General) on my "show piece".
According to Bob Flexnet (sp?) he said to achieve a rubbed finish - use mineral oil with water-based poly and a Scotchbrite pad. The piece is two parts - legs and a top (it's) a small table. While I did the legs first - they had no problems. I applied the oil with a foam brush, use the pad and the legs were very smooth at the end. The wood is mahogany.
However... on the TOP, which is curly maple, I applied the oil and almost immediately - it darkened, part of the wood. Ok, I thought - it acted like the soapy water I used between coats and it will "dry out" in a day or so. Well, it didn't. While it doesn't look like "crap", it's not the look I was after. I didn't think the mineral oil would darken the maple.
So my question, 1) what happened? 2) while I put the piece into the show - when I get back is there any opp. for correction?
I'm living with it as it is for now.
Any help would be appreciated.
Thanks,
MJ Wallace
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snipped-for-privacy@onebox.com wrote in

Flexner
Oil & mahoghany are good friends.

This is consistent with my experience with oil & maple. Didn't have any scrap to test with?

Would this show be the one in Santa Rosa at the museum? Run by the Sonoma County Woodworkers? I'll have to go take a look. A friend of mine told me he got a piece accepted in that show as well, in the pro division. His stuff is generally worth looking at.
The 'not doing this for a living' woodwork last year was pretty amazing as well.

Patriarch
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On Thu, 14 Jul 2005 23:29:38 -0500, the opaque Patriarch

Methinks MJ could use a lesson in finesse. Waterborne finishes are super thin, like shellac. Look at them wrong with sandpaper or steel/plastic wool and they go away. I've found that to denib or wetsand (which I don't like) a finish takes only the weight of my hand, -no- extra pressure, to achieve. With oil/film finishes, I use a no-burr scraper and a light touch to great effect.

Isn't "curly maple scrap" an oxymoron? <vbg>
Sounds like he used the sandpaper and soapy water to cut clean through all three coats of super-thin waterborne finish. The oil darkened the wood through the holes in the finish just as an oil-based finish would. C'est la vie.
If if were mine, I'd have taken naphtha or lacquer thinner to the top to remove the oil, let it dry thoroughly (perhaps aided by a hair dryer and/or sunlight) and then recoated with the finish -before- submitting it to the show. I learned a lot of those finishing mistakes and fixes early on, while refinishing junk for Mother Dearest and my closest sister. ;)

Hey, Glenn. If you're going Sunday the 24th, maybe I'll see you there. I'll be at Mom's in Vallejo over the weekend to celebrate my sisters' and my birthdays and will be heading home on Sunday. A chance to meet you (OK, and to see some of David Marks' work, too) and any other Bay Area Wooddorkers would be great. They open early (the crack of noon) so I'll be there early. (What's this 11am - 5pm crap? <sigh>)
- - - Brain cells come and brain cells go, but fat cells live forever. --- http://diversify.com Website Application Programming for YOU!
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Hi MJ, Maybe I am not awake yet. So you applied 3 coats of WB poly. And after it dried ( 2 or 3 weeks?) you rubbed it out with mineral oil and a Scotchbrite pad. OR did you mix the mineral oil and poly and apply it with a pad? JG
snipped-for-privacy@onebox.com wrote:

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JGS:
JGS wrote:

Here's the steps:
3 coats of WB poly - dried over several days (the first and second coats were at least a week old, the last, days old).
Took pad (white) and flowed on mineral oil.
That's when I saw the darkening effect on the maple. The legs didn't show any problem and were treated the same.
Thanks for any assistance.
MJ Wallace
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Rule of thumb: if the top coat is oil based use an oil based solvent to rub out , water based use water. If any penetrates the surface easily repaired. Pumice and rottenstone work with either. Generally I use a water based or alcho. stain under oil and oil based under water, less chance of migration. Or seal the stain with shellac and then use any top coat you want.

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