Replies

1. 
   Recyclewood | Aug 28, 2010 10:46pm | #1

   Fisheye problem

   Is it new wood or a refinish job,  you may have to add what use is called ( Smoothy ) can't buy it a home building supply,

   Only a finish supply , like sherman williams, bengermin mores might handle it. It might be called another name ,it's just a additiveto prevent fisheye,  Or wipe your wood with aceatone or naptha before any finish product.

   I've had this problem mostly with stuff I refinish, because someone used Pledge on the furniture,  I found a good artical

    in fine woodworking a long time ago ,what to use and what not to use.  I use that artical for reference to me customers yet  today.

   I would have to look it up to find what isue it is in, I save that magizine.

2. 
   zgmc | Aug 29, 2010 10:37am | #2

   Are you spraying waterlox? You can also wipe or brush it on. Maybe try wiping on a coat on a test piece, and try spraying a coat on another test piece, and see what happens.

3. 
   MikeIke | Aug 29, 2010 10:49am | #3

   Fisheye continued

   I am spraying Waterlox tung oil based topcoat, actually. I thought some more about what I could have done to cause it. Between coats, I rinsed the cup out with mineral spirits, as well as the orifice and needle. Then I poured min spirits through the top part. Then I put some soapy water through, rinsed, and let it dry. Could that cause the problem?

   I think I'll blast out the gun with compressed air, run some solvent through (Naptha?) and then give the table a wiping with it.

   As for the fisheye that is already there, shouldn't I sand the top to level it, or should I try to fill the 'eyes' with subsequent coating?

1. 
   DonStephan | Aug 29, 2010 01:33pm | #4

   The next steps may depend on whether the cause is silicone contamination of something else.  Certainly try cleaning the gun well with thinner recommended for your finish, then spray some test coats on another piece.  Perhaps some renegade water in the gun could cause the spots?  If silicone was the cause, think I read recently to spray a couple light coats of dewaxed shellac, then a wet coat of same, to seal?  Check your files, books, other resources for silicone fisheye.  It's my understanding that fish eye eliminator additive is simply silicone, which means it would be contaminating your spray equipment and anything else it touches.

   Not familiar with that product to know how easily the spots could be filled.  Perhaps the manufacturer can offer suggestion.

2. 
   SteveSchoene | Aug 29, 2010 06:12pm | #6

   Waterlox is an oil based varnish.  It has phenolic resin modified with tung oil to create the varnish.  You do need to level the existing surface.  You also need to clean it with copious naphtha or mineral spirits, turning your rag frequently to avoid just smearling the contaminant around.  Then I would spray dewaxed shellac to create a barrier between the contaminated surface and the rest of the finish.  (The aerosol cans of shellac sold by Zinsser work just fine for this.)  Make the first coat dry to avoid lifting any contaminent left.

   I DO NOT recommend a fish eye killer additive except as a last resort after you have cleaned everying numerous times without success.  The most typical c ause of fisheye issilicone, and the fish eye killer adds silicone to your finish. It will prevent the fisheye, but force you to use it consistently--a PITA. 

   Oil based varnishes aren't ideal finishes to spray because they dry so slowly that yoy can end up with a lot of mess, and unless to have sufficient airflow over the surface pulling the atomized finish away, you are liable to get overspray settling on the surface.

1. 
   MikeIke | Aug 29, 2010 08:22pm | #7

   Reply to Waterlox is an oil

   I like your plan, Steve, thank you! Dumb question- please clarify dry vs wet coat of shellac. Thanks again!

   M

1. 
   SteveSchoene | Aug 30, 2010 09:09am | #8

   When spraying, you can just mist the coat on, just giving coverage, not wet enough to really flow. It dries almost instantly giving no time to lift surface contaminants into the shellac.  A full wet coat flows together, just not so wet that it creates runs and sags.

4. 
   hammer1 | Aug 29, 2010 03:42pm | #5

   There are a couple different conditions that may happen with a finish, one is called 'fish eye' and the other is 'orange peel'. Fish eye is caused by contamination or incompatibility, one of the most common examples is in refinishing older furniture that was polished over the years with products containing silicone. The remnants of silicone may not bother some finishes very much but its a real problem with lacquer. Fish eyes are usually larger crater like spots where the finish has refused to adhere, sort of like the reverse of water on a waxed car. It may happen in just certain spots, areas or evenly over the entire surface. If you thouroughly washed your gun, its probably not contaminated enough to cause an all over fish eye.

   You may have orange peel. This can be caused by a number of spraying errors as well as excess solvents. Essentially, solvent based finishes cure by the solvent evaporating. As it does, it forms small craters. Its almost always there but it may be invisible to the eye or very visible. Too much air pressure, too much material, gun too close and too much solvent are common causes.

   Someone else will have to talk about the product you are using. How suitable it is for spraying and any peculiarities it may have in that application method. I've never used it. Some products can be a little quirky, which could add to the above mentioned.