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View Vindex's profile

Varnish Application problem

by Vindex
posted 07-25-2017 02:14 AM


11 replies so far

View TungOil's profile

TungOil

1163 posts in 821 days


#1 posted 07-25-2017 02:34 AM

In my experience, fisheye usually manifests itself as small (~1/16”-1/8” diameter) circles around a contaminated area. I’ve never seen them the size you are showing above so I would not think it’s fisheye. Hard to say from just images, but it looks like the finish applied unevenly.

When I wipe on finish I use a finish specifically formulated for wiping so I don’t have to bother with thinning it and I apply it with a pad of folded cheesecloth. The trick with wiping finish is to apply may thin layers and build the finish slowly. The first coats usually look uneven.

Perhaps you applied it to heavily, need to thin it a bit more, or both? keep experimenting before you go back to your finished piece.

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View Vindex's profile

Vindex

93 posts in 1148 days


#2 posted 07-25-2017 02:51 AM

Thanks for the quick response, TungOil. That makes me feel a bit better. I forgot to mention that I initially brushed the varnish on (I also tipped off the varnish until all the bubbles were gone). When I saw an hour later that the brushed on varnish had nickel sized “craters” forming (see my test piece above), I decided to used the mineral oil soaked rag to thin the varnish and level it out before it cured.

View TungOil's profile

TungOil

1163 posts in 821 days


#3 posted 07-25-2017 03:07 AM

If the first coat went on as uneven as it looks in that first photo, I think you will need to let it dry good then sand it flat before you proceed. Best bet is to be sure you are getting the finish you want on a test piece before committing to the real thing.

Edit: are you sure the shellac was de waxed? Any chance there was some kind of contamination like silicone, wax, WD-40….?

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View Loren's profile

Loren

10477 posts in 3974 days


#4 posted 07-25-2017 03:10 AM

I haven’t used that varnish but when I
do use varnish I have seldom thinned
it. Instead, I dip the bristles in spirits prior
to beginning. This seems to help prevent
the bristles from loading excessively near
the brush ferule.

I am hardly an expert on varnishing but
from what I do know your problems may
come from over-thinning and over-brushing.
It can be hard to trust a varnish to level-out
on its own but that is exactly what they
are formulated to do.

View Vindex's profile

Vindex

93 posts in 1148 days


#5 posted 07-25-2017 03:11 AM

Luckily, the first coat went on much better than the first photo. The first photo is a test piece that I did not try to save. The first coat on the real thing looks decent. It’s just the area in the bottom two photos (those are pictures of the same area from different angles) that looks off.

I had planned to brush on the varnish, but given my problems with brushing, I am contemplating wiping on thinner coats. Is that a bad idea if it is not formulated for wiping?

View Loren's profile

Loren

10477 posts in 3974 days


#6 posted 07-25-2017 03:14 AM

If wiping, varnish can be thinned. I’ve found
wiping thinned varnishes easier than brushing
but it requires more coats.

View Lazyman's profile

Lazyman

3221 posts in 1714 days


#7 posted 07-25-2017 12:16 PM

Are you sure that mineral spirits was the correct solvent to use to thin the Behlen’s Rockhard Tabletop Varnish? Behlens sells a a special thinner (rockhard reducer) for this finish so perhaps the mineral spirits caused finish to break down or something?

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Fred Hargis's profile

Fred Hargis

5454 posts in 2820 days


#8 posted 07-25-2017 03:51 PM

Well, having never used the Behlen’s product I looked it up. It’s a urethane varnish with a very high resin content, so I have to think thinning it a little makes it go on easier. In looking at the MSDS for the reducer I can’t tell if it’s different than standard MS, but can’t imagine it’s new invention. My conclusion is that you should be able to thin the Behlens to a wiping consistency and use it if you want to. I would also think normal MS would be just fine, just be sure to skip any of the “green” stuff. But back to what shows in your pic, that looks like a missed area and it’s possible you sanded through the shellac at the spot. If you did sand through, you may have removed the color enhancement from the Watco, and that’s causing the appearance. But now you’ve sealed it with the Behlen’s so I’m not sure if you can get back to where you can blend it in. I think I would try to recreate the problem on your scrap, then sand it down and see if adding a little BLO will get the color back, then recoat with the varnish. I don’t think just more coats of Behlen will solve the problem, though it may get less noticeable as the finish builds.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Vindex's profile

Vindex

93 posts in 1148 days


#9 posted 07-25-2017 11:43 PM

Thanks so much to everybody for the help. I managed to solve the problem today. It turns out that I needed to stir the varnish more thoroughly. Once I did that, I managed to get an even application when the varnish was brushed on a test piece. Nevertheless, the brushed on varnish took so long to dry, that it accumulated far too much dust for my taste. I have applied two wiped coats of the varnish using the method described here:

http://www.askhlm.com/Articles/ArticleViewPage/tabid/75/ArticleId/5/Wipe-on-Varnish.aspx

so far, it has gone on very well, and the uneven spots have blended almost completely.

Regarding the solvent, the Q&A section on the Rockler website says that Behlens reformulated the Rockhard varnish so that it can now be thinned with MS.

I guess, “Did you stir the finish thoroughly?” must be the finishing advice equivalent of, “Is the device plugged in?” I feel like a bit of a fool now.

Thanks again!

View TungOil's profile

TungOil

1163 posts in 821 days


#10 posted 07-26-2017 01:16 AM

glad you figured it out.

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View Fred Hargis's profile

Fred Hargis

5454 posts in 2820 days


#11 posted 07-26-2017 12:22 PM

Ditto, good to see it resolved.

-- Our village hasn't lost it's idiot, he was elected to congress.

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