Printable View
I am staining some spruce with Minwax Oilbased Dark Walnut Stain. I initially use wood conditioner, then I apply the stain. After 10 minutes I wipe of the excess stain. I was just wondering, if I don't want to apply a second coat of stain, do I really need to wait 8 hours to apply polyurethene over top of the stain? Can I put oil based polyurethane right after I wipe of the excess stain?
No...it will likely cause drying problems.
IIRC Minwax stains also have some type of sealants in them, so they need to dry fully first. Otherwise when you start brushing poly you might brush the stain around as well.
good luck,
JeffD
Although I've gone right from stain to applying poly finish - with no drying time in between, and, never had a problem - - both with oil based poly and water based poly (yes - WB poly over wet oil stain)....
Listen to the other two posters above.
I only did it - well - -because I was rushed & willing to risk disaster. I was also ready to take all the blame for it had something bad happened.
I never had a problem doing it - but - - that means exactly nothing.
Guys also stop and bend their elbow a bit too much on their way home on Friday night, then get behind the wheel and weave their way home - - and nothing bad ever happens to them either....
Doesn't make either right ....
If your stain is not fully dry, you run the risk of your first coat of finish not drying for days. Wait at least the amount of time recommended or more if the temp is low or the humidity is high.
The first coat of finish does not bond to stained wood well if it's applied to soon after the wood is stained. If the finish does not bond well in the beginning, it will never bond well. I see this happen too often on floors. I put rosin paper down to protect floors (done more than couple weeks, months or even years ago) where I work and secure it with blue painter's tape. Pull the tape up at end of day (just one day) and I peel off the finish floor the stained floor. Sure, everything looks great until.....the damn tape!!!
I did do a test quite a whiles ago on a sample. Applying finish too soon after staining and the tape test tells the tales.
On an "open grain" wood like oaks, walnut, etc., the poly will want to "pull" the stain out of any reservoirs of stain (the open pores). You will see it bleed out and float in the poly or lacquer. You may be able to seal with light dust coats, or with shellac. But otherwise I can almost guarantee the effect will not be that you desire.
Sometimes on the web a whole chorus of people keep repeating the same information and it turns out to be false. This isn't one of those times. Don't rush the dry times on the stain, it will not benefit you in any way. Exercise patience and follow the schedule. And the "suggestion" on the can is under ideal conditions of temperature, humidity and air movement. The real test....if you can smell solvent it ain't ready. With minwax that might be 8 hours, it might be 2 days. Minimax stains are formulated to work well under certain conditions, large scale flooring projects, slow moving DIY'rs. Its got a lot of binder in it so it doesn't blotch as easily or dry out too fast and leave streaks, witness lines etc, the color is more even, but also more muddy IMO than some others. You can flood the surface, take your time, wipe it off, repeat as desired. Down side is it dries real slow.
If you cover uncured stain with a top coat, and that top coat skins over and flashes off to form a coating, it will trap the stains unflashed slow drying solvents beneath its skin. These will keep trying to get out, possibly breaking the bond between wood and finish. Minwax has enough binder in it to nearly be called a sealer, you need to let that dry. There are stains that dry much faster, NGR's both alcohol and lacquer based, water based stains and dyes, metal acid dyes in a solved formula, but you will find these much more difficult to apply if you are accustomed to minwax products. The finisher where I work detests minwax, he's got far too much time pressure to wait for that, and not enough space to to let things cure for days with stain, so we don't use it much. But I've used it plenty in the past. The other problem is the solved in the poly can interact with and lift the color from the stain, reactivate the uncured stain. You stand less chance of this if the top coat has a different solved than the stain, but in many cases you still need to respect the dry times required. Water based coatings don't adhere well to uncured oil based stain.
I'd encourage to to structure your production to work within the finishing schedules requirements, its no place cut corners.
I don't have any Minwax stain but, the Varathane stain I use says to add poly after 1 hour. I haven't been that quick but,just sayin'.:confused:
You can shorten the necessary drying of the stain by aiming a fan at the piece to circulate more air. But that's usually going to go from 8 to 4 hours, and even then it may not be cured adequately to allow proper bonding of the topcoat.
Biggest mistake in finishing? Rushing the process.
There. I said it.
Bill
Quote:
Originally Posted by Roger Pozzi
Last job job we used to use some stains from hood, basically oil based NGR's, but they were water thin, very little binder, very very fast drying solvents. Those could be recoated much quicker, but man did you have to move when applying them. I worked with an older gentleman, semi retired , who grew up on minwax and was not happy with the pace required for application. He used to cuss something awful when he got streaks or witness lines. A few times on open grained woods they pushed him to recoat too soon, still stain in the deepest pores, top coats got some nasty bubbles and fish eyes. First time you sand a piece all the way back to restain is the last time you rush a finishing schedule.
Patience is a virtue that also applies to woodworking and finishing..Read manufacturer's use guidelines and remember they are guidelines and variables occur from wood type and environment.. In the end one can always goof up by coating over not dry enough oil stain and never suffer that mistake by waiting longer than recommendations...
That's my 2 cents worth on oil stains.....Have fun have no regrets.
When "time is of the essence", then using a water or alcohol soluble dye to color the wood followed by a quick seal with de-waxed shellac in an hour or so can permit you to move on to applying top coats same-day. But as folks have already stated, when you use an oil-based stain like Minwax products, you have to allow the binder (dilute varnish in effect) to cure before you begin top-coating. Nature of the beast...
What is wrong with following the manufacturer's instructions? Cheating will often lead to disaster.