I have just sprayed a white urethane paint over a shelac based primer which is supposed to be great under all paints. The shelac based primer sprays great and dries in less than one hour, ready for the top coat. This process caused fish eyes everywhere. With a test of my top coat on another surface, there were no fish eyes. Finally I sanded off the fist primer and reprimed with a regular oil based primer and had great success with the top coat. Has anyone else had this experience or know what all the fish eyes. Obviously incompatible finishes but why?????
Discussion Forum
Get It All!
UNLIMITED Membership is like taking a master class in woodworking for less than $10 a month.
Start Your Free TrialCategories
Discussion Forum
Digital Plans Library
Member exclusive! – Plans for everyone – from beginners to experts – right at your fingertips.
Highlights
-
Shape Your Skills
when you sign up for our emails
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. -
Shop Talk Live Podcast
-
Our favorite articles and videos
-
E-Learning Courses from Fine Woodworking
-
-
Replies
Any chance the wood was contaminated with silicones. Was it new wood or salvaged or a refinishing job??
John W.
The wood was new, soft maple sanded to 150 grit, sprayed with the "Zinzer" brand shellac based primer. The primer was fine...no fish eyes. Dries fast, sands smooth like glass.
What was the primer you used?
Were the fish eyes in the primer or did they develop when you sprayed on the top coat?
What was the paint you used?
What had you been spraying with your equipment before spraying this job? In other words, was the equipment clean?
The fish eyes developed when I sprayed the top coat. My gun was clean and dry from previous work.
Hi Barrie,
I would say it is silicon contamination, it could come from any where, do you use silicon spray on tools/machines when yes that's the where it comes from.
Use anti silicon drops in your spray ( cant remember the name of it) any good paint shop should have those.
I have the same problem and use the drops, stops it in there tracks.
The contamination can come from many other things as well, these days it is in everything.
Hope this helps.
Bernhard.
I don't use silicone sprays. The odd thing is that when I changed the primer , the problem disappeared. I did not change the material I was spraying. My sanding technique, the sandpaper and tack cloths are all what I have been using for years.
Fish-eye preventer additives are generally just a "hair-of-the-dog" and put silicone into the top coat so that the surface tension disparity that causes the finish eyes to form is eliminated. Using these is, in my opinion, a last resort, since once you do you will have likely contaminated your finishing space and equipment so you have to continue to use it. Better to find other solutions to an isolated silicone problem if possible, before capitulating to it and resorting to the fish eye killer.
What's the brand and product name of the paint you used?
website
I used Benjamin Moore, INDUSTRIAL, Moore Soec, urethane alkyd, gloss enamel paint. I have used it many tmes before with great success.
Barrie,
Maybe Benjamin Moore changed the ingredients for it?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I believe it to be an incompatability between the shellac based primer and the urethane based paint. This doesn't make much sence but because the fisheyes disappeared when I changed the primer it is all I can deduct.
Barrie,
You've used this exact combination of primer and paint with success in the past If so then I can only think there was some kind of contamination. Something is obviously different, primer, paint or foreign contamination.
Stumped,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,Maybe they've developed a new, silicone based finish?Chris @ http://www.flairwoodworks.com and http://www.flairwoodwork.spaces.live.com)
- Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Chris,
I'd be curious to know what, if any top coats are recommended/not recommended to be used over the primer, but the OP has used this recipe before so I huess I'm stumped.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Do you have an oil trap in your air line from the compressor? It may be that your air supply has some oil in it. I would expect that oil droplets would remain isolated on the surface of shellac because oil is not miscible in alcohol.
When you shot your oil based primer, the solvents might have harmlessly dissolved any oil droplets dispersing them into the film, but droplets on the surface of the shellac primer might have caused the topcoat to crawl away.
I'll give my experience from the high end auto refinishing. Fish eyes are a contamination on the surface that pushes away the applied material. NEVER use red wipes, cloths. We purchased new, washed polo jersey trimmings by the bail. 125-160 lbs. Only the reds were problematic. We changed over to a shop wipe (for refinishing)when they solved their contamination problems.
I was one who tested many shop products, wipes were produced by a number of companies. Eventually they all got their act together.Tac rags (store bought) can be overly sticky and smear the surface = contamination.Incompatible products. ingredients within a product may be unable to cross link with another product.Just a comment on "fish eye eliminator", if used, it makes your surface one large fish eye.
Later on with the advent of acrylic, polyurethane and poly oxathane products, the paint manufactures created a "Flow Agent".In the end cleanliness was imperative, booth, shop, equipment, compress and air supply lines, separators, painter, paint bench, vehicle or in your case wood. just my experience of 35 years.Ron in Peabody
If I wasn't as busy as a woodpecker on a hollow tree, I would do some testing to try and redo those fish eyes and maybe come up with the answer. I may still put the time aside. I have been spraying since 1987 without this problem. I even sprayed a 1958 MGA which I restored and many vintage snowmobiles.
Sir..
Sorry.. Just me...
Why not call Benjamin Moore and ask them? I have in the past and they will try to help you.. Maybe just a dead end but they know their product!
EDIT: I am not blaming Benjamin Moore in any way...
Edited 7/6/2009 4:39 am by WillGeorge
more fish eyes than in the sea!!!!!
The best discription of anything I have ever seen in here!
This forum post is now archived. Commenting has been disabled