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Discussion Starter #1
So I have some veneer, very nice stuff, blah blah, for my dash. I stained it, let that dry longer than recommended. Using a oil & urethane topcoat. Used matching brands recommending eachother. First coat applied as directed, looked very nice going on, but after it had dried, I noticed these marks that I can only describe as pin pricks. So, sand/buffed with 0000 steel wool as recommended, another coat. After it dried, pin pricks still there and more noticable as the topcoat is getting thicker and more clear and glossy. Just put on 5th coat, still there. What the heck did I do wrong? Using drop tent to keep out dust (not dust issue) and have electric heater (temp not an issue). Oh yeah, this is also on a test piece, saythankya. Starting over on the backside of the test piece to see if I get same results. If any of ya wood guys out there know what this could be...? Also did test using resin clear coat, didn't turn out good. The urethane looks extremely good, except for the pin prick marks. Took a pic, but you can't see it, might try another pic later.
 

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Try going to a wood workers supply (not home depot or lowes) and get some pore filler goes on before you stain will fill the pin holes might try highlandhardware.com they should plus a bunch of guys that know there buss.

good luck!

ErnieIII
 

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are you describing the pin pricks as small craters or small raised fibers. The sanding sealer would help the small fibers. but the fraters sound like fisheyes or oil/water contamination.
 

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The "pin pricks" if they are depressions are probably just the pores in the wood sucking in the finish. The sealer should help. Do you have any superfine sandpaper (like 1000 grit)? It might be better to block sand the finsh flat, tack cloth it off, then recoat. The veneers are pretty opened grained so I can see how this could happen. Going to a woodworker's store or even a woodworker is good advice. They can help you.
 

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Discussion Starter #6
Thanks for the advice guys!! Yes, the pinpricks are depressions or "holes" and not raised fibers. On my test piece, I did not sand or seal prior to using the topcoat. If I get a sealer, that would go on after the stain or before? Oh, as stated above, goes on before. Also, the topcoat stated to not sand the wood w/ anything greater that 250 grit, I believe. Other than the pricks, the topcoat looks very good, gives the veneer a nice clear coat while still having some wood texture that I like.
 

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Brian,
Try sanding with 400 between coats. The first two coats go very lightly just to knock the fuzz down. After you have some thickness, sand to flatten the surface. Before your last coat, wetsand with 600. Use a block when sanding. Wipe with thinner then tack rag before each coat.

C
 

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Even if you seal the surface, if it is an open grained wood and you did not use any filler (many people do not like the filler as it tends to obscure the grain), you will get that effect until you fill all the depressions up, so it is a question of coating, sanding, coating, sanding until you get enough of a build to have the finish material flat. If you sand too hard too soon you may damage your work. This requires patience and persistence. The veneers these days are so thin that even a tiny touch with sandpaper will go thru them to the base wood.
 

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Another possibility is that these holes could actually be air bubbles if you have mixed the urethane by shaking it. Bubbles might not be visible until they dry. Dunno, but could be your problem.
 

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Foam brushes can also cause air bubbles, I normally will spray the urethane top coat on in thin coats sanding between each coat with 12-1400 super fine paper wet slightly with water. Good Luck-Larry
 

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Brian, sounds like silicon contamination to me. Have you ever used spray silicon in your shop? Most finishers/painters won't let silicone spray anywhere near their shop.

Go to a professional paint store and get a bottle of fish-eye remover. Lightly sand the surface of your dash with 320 or so and add the stuff to your topcoat.

All the best,
Tag
 

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From the description, it sounds like bubbles to me. I think the first coats would have sealed the pores of the wood. Without knowing the urethane brand, type of oil, or mix ratio; two things come to mind.

First, IMHO, most urethanes are to thick out of the can to be applied without bubbles. Try thinning it a little for your top coat.

The other is that you are using an "electric heater (temp not an issue)." I'm concerned that the heater may be your issue. If the finish is too warm, it can skin over before the solvents escape causing bubbles that then pop. I've had this happen to me on a clear lacquer finish. You might want to try naptha as the thinner as it evaporates faster.

HTH
 

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Start over.

Use top quality marine varnish. The first coat should be thinned at least 20%.

You will not find urethane on fine yachts and woody wagons.

The stuff is for furniture.
 
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