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Forum topic by Eastwestdesigns posted 444 days ago 643 views 0 times favorited 14 replies Add to Favorites Watch
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Eastwestdesigns

8 posts in 444 days


444 days ago

Hello everyone Iam New to the forum and look forward to interacting with you on my favorite hobby of wood working and design . Since I retired I have got back into the above I am having a problem when I applying stain.the stain is from a new can(minwax) and it is getting white streaks when i appl

ly a coat of polyurethane . The stain was dry when I applied the poly .I would appreciate any input . Thanks

-- Steve


14 replies so far

View Bill White's profile

Bill White

3353 posts in 2565 days


#1 posted 443 days ago

What poly are ya using?
Bill

-- bill@magraphics.us

View Eastwestdesigns's profile

Eastwestdesigns

8 posts in 444 days


#2 posted 443 days ago

I used a semi gloss by mi Inwax

-- Steve

View Finisherman's profile

Finisherman

190 posts in 454 days


#3 posted 443 days ago

Is the poly oil based or waterborne? If it’s waterborne, then you need to let the oil based stain cure for a much longer time than the label suggests, otherwise, the uncured oil in the stain can cause the kind of problems that you’re currently experiencing. Better yet, let the oil stain cure, then apply a thin coat of dewaxed shellac to seal the wood and to act as a barrier coat before you apply any waterborne coating. Since you already seem to have a compatibility problem here, I would suggest stripping off the failed coating, then following the procedure outlined above. In the future, try to only use waterborne stains with waterborne coatings. You’re a lot less likely to experience difficulties like this.

View pintodeluxe's profile

pintodeluxe

3281 posts in 1418 days


#4 posted 443 days ago

I have resolved 90% of finishing problems by using oil based finishes sprayed over oil based stain. For example, oil based stain (Varathane, Cabot, or Rodda), allowed to dry a minimum of 24 hours. If the weather is colder, sometimes I wait longer. Then spray lacquer (Valspar, or Magnalac) with any gravity-feed HVLP gun.
Two coats with a light scuff sanding between coats yields a beautiful finish.

White streaking is usually due to moisture in the finish. Was it a humid day, or were you finishing outside / in direct sunlight? Always finish inside, away from direct sunlight.

Good luck!

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

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Eastwestdesigns

8 posts in 444 days


#5 posted 442 days ago

I was outside and the temp was in the high low 70s and dry. I used an oiled stain ( minwax) which had been drying for about a week, then I applied a minwax oil based semi-gloss polyurathane.

-- Steve

View Finisherman's profile

Finisherman

190 posts in 454 days


#6 posted 442 days ago

I think that your problem can be traced to the fact that the oil in the stain hadn’t completely cured when you applied your polyurethane. Cured is quite different than dry to the touch. If the stain was applied thickly, or if you applied more than one coat, then the oil can take quite a long time, (weeks in some cases, especially if the weather is humid), to cure completely. In any case, you can try spraying a coat of lacquer thinner over the dried finish and see if this helps. If it doesn’t you’ll have to strip the finish and start over.

View a1Jim's profile

a1Jim

112002 posts in 2182 days


#7 posted 442 days ago

I agree with many of the points Finisherman has brought up in addition I’m not thrilled with many of the Minwax products. My first thought was that you did not stir the top coat well enough or that the poly was beyond it’s shelf life.
If you have some sort of pollution problem I would lightly sand the surface with 600 grit sand paper, if you see the sandpaper gum up then your finish is not dry,If your surface is not dry you may have to strip off the old finish. If you feel it is dry wipe the surface down with naphtha possibly a couple time,then use a barrier coat of de- wazed shellac as previously suggested and reapply some more poly.
A critical point: when your going to finish a project it’s always best to sand a separate board of the same type of wood and sanded the same way your project is sanded,then try some of your finish on it. If you have problems you will find out on your sample board.
Another idea is to get some training regarding your finishing. It’s easy to spend $50 plus trying to buy finish for your project and still not have it come out right. Charles Neil is a finishing expert with 40 years of experience, authored a book on the subject and now is offering a on line class on finishing for only $10 a month.
http://www.cn-woodworking.com/finishing-class/

-- http://artisticwoodstudio.com Custom furniture

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Eastwestdesigns

8 posts in 444 days


#8 posted 441 days ago

I would like to thank all of you for your input. Finisherman and a1Jim I think you both hit it on the head. It has been humid and also very cool here and possibly the stain was not totally cured. I will in the future do the sample deal a1Jim and maybe that will save me some time.

-- Steve

View RobertStix's profile

RobertStix

19 posts in 440 days


#9 posted 438 days ago

Glad you got that resolved. I used to believe everything on the cans and thought I knew what I was doing until I read Bob Flexner’s book “Understanding Wood Finishing” – Rondale Press 1994. Since reading, re-reading and even taking notes I doubt if I’ll use Poly for a final topcoat on anything unless I absolutely have to. There are still phenol/alkd varnishes available out there usually labeled as “spar varnish”. They’re not plastic and can be built-up with light sanding in the end be polished.
I’m also now a huge fan of de-waxed shellac. It dries almost as fast as you can apply it and is very sandable and user-friendly, as well as completely natural and the fumes, while a bit heady when sprayed, are non-toxic as the solvent is denatured alcohol. It can grain-fill, prime between dissimilar finishes as mentioned above and I’m using it now as a final topcoat over latex paint for trim-work in my remodel. In town here I can only get it in a Zinnser spray can, but I’ll be ordering flakes and making my own mixes.
I’ve also said goodbye to pigment-stains for good and will be making my own dye-stains in both oil and water base.
I HIGHLY recommend that book. I got mine as a gift, but even if it costs $100.00 now, it’s worth every penny.

-- "I wear eye protection when using power tools because my blood stings my eyes and because I can't read braille."

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a1Jim

112002 posts in 2182 days


#10 posted 438 days ago

Robert
I felt the same way when I first got Bob flexner’s” Understanding Wood Finishing” and a later edition. I now follow the advice of Charles Neil who has has brought finishing up a couple more notches with more current finishing advise on finishing using more modern finishes than those available when Bob wrote either version of his books. Charles has raised the mark even more by offering finishing advice in a very extensive 10 disc video set”Finishing A to Z beyond the books” Also”Finishing Nightmares” video and now a new finishing book and on line finishing class due out in June.
Besides being a master at finishing Charles is a master furniture maker with 40 years experience. It’s good to get information from folks who just write books on the subject but far far better from someone who uses his finishing expertise to make a living on a daily basis . The proofs in the pudding when you look at Charles work on his web site.
http://www.cn-woodworking.com/

Edit I just noticed I had already given information on Charles Neil a few days ago ,please excuse my duplication of information.

-- http://artisticwoodstudio.com Custom furniture

View Eastwestdesigns's profile

Eastwestdesigns

8 posts in 444 days


#11 posted 438 days ago

Thank you very much for the information on the new finishing techniques available. I will have to say that now that I am completing projects for coating I hold my breath with Minwax which I will attempt to move on to something that works better. I just got through using the Spar Varnish on some cabinets I built and did not have one problem what so ever.

-- Steve

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a1Jim

112002 posts in 2182 days


#12 posted 438 days ago

Hey Steve
Don’t hold your breathe use a sample board ha ha :))

-- http://artisticwoodstudio.com Custom furniture

View Eastwestdesigns's profile

Eastwestdesigns

8 posts in 444 days


#13 posted 438 days ago

Sounds like a good idea a1Jim, I will certainly remember that!

-- Steve

View RobertStix's profile

RobertStix

19 posts in 440 days


#14 posted 437 days ago

Thanks a1Jim, I’ll check out Charles Neil. I’m about to order my first dye-stain for the handle of a grafting knife I’m making for my wife.
I really like, and also use, the sample board technique. I sometimes follow the same process on three or four different sections and mark them at what stage they are, then experiment with what my next move might be and document the results. It has saved me more than a few screw-ups and given me some amazing surprises!

-- "I wear eye protection when using power tools because my blood stings my eyes and because I can't read braille."

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