Fisheye in varnish

Heard a lot about fisheye somewhere.  Now I know what it is.    My search only came up with one post which did not have a cure.  I have sanded down once and still have it.  I heard there are additives to varnish to eliminate them.  Anyone have experience with this?


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RE: Fisheye in varnish

Made some trips around town and learned of a product called Smoothie.  But he did not carry it.  The key words to search for on the net are 'fisheye eliminator.'  On searching for Smoothie I found it is sold at woodworking sites and at auto body sites.  I went to a paint store known for auto supplies and picked up a can of their fisheye eliminator.  First coat with the additive showed a lot of improvement.  I may not have to use it for the next coat.  I'll see after sanding.

Didn't have any idea how much to use so I added a cap full to 3 oz. of varnish. I will stick with that amt.


RE: Fisheye in varnish

The problem with "fisheye eliminator" is that once you start using it you have to keep on using it on the project. The usual cause of fisheye is silicon contamination. FE essentially adds silicon to your finish so you no longer have localized contamination. You now have generalized contamination so all subsequent coat need the FE. For the sake of future projects see if you can find the source of the contamination. Silicon was banished from my shop long ago. Also, don't ever put FE in a spray gun. You'll never get it out and risk contaminating anything you spray.


RE: Fisheye in varnish

Sanding, wipe down with denatured alcohol or whatever thinner is recommended for you varnish (Brushing Liquid 333 for Interlux Schooner varnish). Keep all silicon sprays far away. Don't use rags that have been in a dryer with fabric softener sheets.


Ogata (eric)

RE: Fisheye in varnish

I think y'all meant "silicone", not silicon.  Them are two different things.

Some info I found on fisheyes...

"I have coated wood or an epoxy surface with solvent free epoxy and it has “fish eyed” (often described in other ways such as ‘small holes’, ‘pulling away’, etc)"

There are several possible reasons:

a) Fish eyes are commonly reported when applying the second coat of a solvent-free epoxy on to a sanded surface. Remaining by-product and insufficient sanding of the first coat are very common causes. Sanding wet achieves by-product removal and gives a good key. When sanding dry it is especially important to remove by-product as it will only clog the sand paper. Use 80-120 grit.

b) If the work has been cleaned down with solvent immediately before recoating epoxy or after sanding bare wood then some solvent may have remained on the surface. Acetone or cellulose thinners are not as good as cleaning materials because they may be contaminated and their use sometimes leads to problems.

c) Check whether cleaning rag was contaminated with other types of solvent. It is likely that if other solvents were used previously, the customer may have inadvertently used one such as this to clean the surface.

d) If the work was wiped down with White Spirit - this is really bad news as it means that epoxy then cannot be used unless all traces are removed, which is almost impossible.

e) Wrong resin-hardener mix ratio can also give the same symptoms in some cases.

f) Traces of contaminant in the atmosphere - e.g. mould release agent aerosols, wax polishes, etc.

g) Some types of pigment dispersed in epoxy resin, may make the problem worse especially when coating is applied in a thin film.

h) Direct heat from the sun may also make problem worse.

i) Syringes can cause this problem if not cleaned out first. This is quite a common cause. Mixing cups or pumps do not have any surface contaminants.

j) If “fish-eyeing” is persistent when coating bare wood see next question.

"I am coating bare wood, I followed all your instructions regarding preparation and I get “fish-eye” effects."

If everything listed above has been done correctly then it may be one of those rare cases where the resin in the wood is causing the problem, even after the surface has been solvent-wiped. With some woods, such as oak, it is always difficult to wet out the surface and fish-eyes form readily. Note that oak is recognized as being a ‘difficult’ timber to glue. Resorcinol won’t work at all so epoxy is always the best alternative.

RE: Fisheye in varnish

Thanks for all the responses.  I need to be slapped again for what I have done.  Started out by grabbing an old chamois to wipe down the yak.  Later I used HD40 in the area to clean the table on the band saw.  AND...Just thought up a new may laugh...used an old tuna can to hold my varnish.

I think I had to use the FE.  I resanded as much as I dared and put on at least 5 coats. 

It looks a lot better since I used the FE.  Hopefully one or two more coats and it will be done.

Thanks a bunch


RE: Fisheye in varnish

You didn't say what varnish your using but surface prep is all the same.

Soap and water will clean off blush better than sanding.

I have been getting good results with Interlux Perfection Varnish adding the 2333 thinner brushing it on the boat.

I clean the surfaces just before the next coat of varnish with a wipe of the 2333 thinner on a paper towel. I agree with using the towels not exposed to fabric softeners. I like the microfiber cloths for cleaning up after wetsanding between coats.

RE: Fisheye in varnish

Interlux Schooner varnish

RE: Fisheye in varnish

Have the last coats gone on without that?

One of the problems 1 part varnish has is the smell can last weeks instead of days on the 2 part LPU.

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