chopnhack Posted December 15, 2013 Report Share Posted December 15, 2013 Ok, I have used Shellac a few times and I really don't know what went wrong today..... I sprayed on a thin coat, three passes, I usually do no more than two thin passes, but I wanted a heavier coat as I was breaking for lunch and knew I had extra time for this to dry. As I was looking at the eveness of the finish I could see an outline forming on the surface of the panel I was spraying! I was like, what the ... and then as I watched more I just said F'it Spraying zinnser shellac out of the can with about 5 drops transtint in 1 cup of shellac. I have used way more transtint with shellac with no problems. This was straight shellac not cut with more alcohol as it is cooler today than usual, only 73 :-P mostly overcast with little wind. Perfect spraying weather if you ask me. Pressure at the gun ~10-12 psi, using a wagner hvlp with a #3 aircap and needle set - same setup I have used numerous times. The gun was cleaned out well the night before and left to soak with DNA inside over night for anything I might have missed with the scrub brushes. Sprayed out the DNA to test pattern before filling and spraying the shellac mix. The shellac is less than 3 years old, 2012 stamp on can. I am thinking of sanding down to even out the surface and to recoat as soon as this stuff has had time to dry and harden up. What say you all? What caused it? How would you go about fixing it? Here are the mug shots: Quote Link to comment Share on other sites More sharing options...
Bob Rozaieski Posted December 15, 2013 Report Share Posted December 15, 2013 Looks like classic fish eye. I'm guessing either contamination in the gun or your shellac is bad. If the can says 2012 I'm betting it's the shellac. Put some on a piece of glass and see how it dries. If it doesn't dry hard and brittle but instead stays gummy, the shellac is bad. Also, you don't mention anything about what you are finishing/refinishing and your surface prep regimen. How'd you prep the surface before spraying? 1 Quote Link to comment Share on other sites More sharing options...
Trip Posted December 15, 2013 Report Share Posted December 15, 2013 ==>^^^ Spot-on, but I'm going with contamination... If the fish-eye was in patches rather than lines, I'd go with bad shellac... A line pattern smacks of contamination to me... Of course, aged shellac is more prone to interference from contaminants... So it could be both... Quote Link to comment Share on other sites More sharing options...
wintersedge Posted December 15, 2013 Report Share Posted December 15, 2013 What is the shelf life on canned shellac? Quote Link to comment Share on other sites More sharing options...
dwacker Posted December 15, 2013 Report Share Posted December 15, 2013 What is the shelf life on canned shellac? 12 months officially 10 to be safe. Glass check it all. Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 Looks like classic fish eye. I'm guessing either contamination in the gun or your shellac is bad. If the can says 2012 I'm betting it's the shellac. Put some on a piece of glass and see how it dries. If it doesn't dry hard and brittle but instead stays gummy, the shellac is bad. Also, you don't mention anything about what you are finishing/refinishing and your surface prep regimen. How'd you prep the surface before spraying? Bob, I hit my quota for likes today, so thank you!! To answer your question, the wood is pine, freshly planed and sanded by hand, starting at 100,150,180,220 - I needed the 100 to blend in some plane trails... (I know, round over the corners of your blade, its a new to me #5 stanley and I haven't broken it down yet other than to sharpen it.) I am using Zinsser shellac and what I read on their website is that it has a 5 year shelf life. I don't use silicone in my shop so I didn't think contamination from silicone was an issue. It did look like fish eye cratering to me too, but I thought only silicone caused that? That is what stumped me. As for the spray gun, the day before I had mineral spirits in it to loosen and dissolve some old paint, followed by a rinse with acetone and then another rinse of DNA. I then left the pot and gun together with a little DNA to fume the passageways in case I missed anything else. I sprayed that out to check my pattern on a different piece of wood and then filled up with shellac/TT mix and off to the races. I am going to run to the garage and put some of that on a snapple bottle to test it! Quote Link to comment Share on other sites More sharing options...
dwacker Posted December 16, 2013 Report Share Posted December 16, 2013 I am using Zinsser shellac and what I read on their website is that it has a 5 year shelf life. it! Don't believe it. Its shellac. 1 Quote Link to comment Share on other sites More sharing options...
Tkf530 Posted December 16, 2013 Report Share Posted December 16, 2013 Shellac isn't known to fisheye or crater as much as modern day finishes but is often the solution as a barrier coat with a 2 lbs cut. Nonetheless, you've for a contamination problem on your hands. Have you perhaps lubed any of your machines recently? Sprayed some WD 40 in your garage, wax you plane with the wrong wax? Retrace your steps. 1 Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 Don't believe it. Its shellac. True, be wary of marketing! Quote Link to comment Share on other sites More sharing options...
TRBaker Posted December 16, 2013 Report Share Posted December 16, 2013 +1 on what Tkf said. My first thought was machine lube of some kind. WD 40 works great to displace water, but it displaces finishes too. Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 Shellac isn't known to fisheye or crater as much as modern day finishes but is often the solution as a barrier coat with a 2 lbs cut. Nonetheless, you've for a contamination problem on your hands. Have you perhaps lubed any of your machines recently? Sprayed some WD 40 in your garage, wax you plane with the wrong wax? Retrace your steps. Definitely contamination of some sort.... Just glassed two different batches, the older batch of amber fisheyed all over the glass.... so its not the wood or a contaminant on the wood itself. That rules out the johnson's paste wax that I have been using for the last 6+ years (same can mind you) because that is the last thing that was on the sole of the handplanes I used. I did spray some liquid wrench onto my plane at the end of the day yesterday and today, but I don't spray it so its aerosolized, I just gently squeeze the top so that a small dribble comes out and then I wiped it down with the same towel that I use to wrap it. I sprayed 5 pieces today. 4 were with the new can of shellac the 5th piece was with the old can - it was amber shellac and the other was clear, I was looking for that amber/red tint for that particular piece To prevent this in the future, should I rub down the pieces with a clean rag soaked in the finishes solvent? Getting back to the fixing of the issue, should I sand this down to level or back to bare wood? Clean it with some DNA or other thinner? I don't think I will get more than one pass before it starts to pickup the old finish... Quote Link to comment Share on other sites More sharing options...
Trip Posted December 16, 2013 Report Share Posted December 16, 2013 ==> 5 year shelf life Yea, maybe if you happen to have a Liquid Nitrogen(LN) bath handy... I bet is goes within 12 months after opening... Quote Link to comment Share on other sites More sharing options...
TRBaker Posted December 16, 2013 Report Share Posted December 16, 2013 Chop, if I had to guess, I'd say the liquid wrench is the prime suspect. Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 Chop, if I had to guess, I'd say the liquid wrench is the prime suspect. I don't know, the one board that failed had the old amber shellac in a can that only had about 1/4 left. The other four boards all got finished with the clear shellac from the new can. The board that failed was sprayed last. The only difference that I can think of was that the final board, the one that failed was a mixture of about 1/2 amber shellac (old) and 1/2 clear shellac (new) - but they were the same brand, zinsser. The results certainly look like fisheye/cratering, but very limited. The odd thing was the first and second pass took beautifully. After the third pass when I bent to catch the board in the light to see if the coat was even everywhere did I see it start. At first there was some uneveness on either side of the centerline of the board. It looked like the wood was soaking up the finish, basically two small ovals on either side of the midline that were more dull that the surroinding areas, no big deal... Then the dull area start to extend up and down making the oval longer and then other areas erupted as well... I was pissed!!! Anyways, how about the fix? What do you all say? <<To prevent this in the future, should I rub down the pieces with a clean rag soaked in the finish's solvent? Getting back to the fixing of the issue, should I sand this down to level or back to bare wood? Clean it with some DNA or other thinner? I don't think I will get more than one pass before it starts to pickup the old finish...>> Quote Link to comment Share on other sites More sharing options...
Tkf530 Posted December 16, 2013 Report Share Posted December 16, 2013 I don't know, the one board that failed had the old amber shellac in a can that only had about 1/4 left. The other four boards all got finished with the clear shellac from the new can. The board that failed was sprayed last. The only difference that I can think of was that the final board, the one that failed was a mixture of about 1/2 amber shellac (old) and 1/2 clear shellac (new) - but they were the same brand, zinsser. The results certainly look like fisheye/cratering, but very limited. The odd thing was the first and second pass took beautifully. After the third pass when I bent to catch the board in the light to see if the coat was even everywhere did I see it start. At first there was some uneveness on either side of the centerline of the board. It looked like the wood was soaking up the finish, basically two small ovals on either side of the midline that were more dull that the surroinding areas, no big deal... Then the dull area start to extend up and down making the oval longer and then other areas erupted as well... I was pissed!!! Anyways, how about the fix? What do you all say? <<To prevent this in the future, should I rub down the pieces with a clean rag soaked in the finish's solvent? Getting back to the fixing of the issue, should I sand this down to level or back to bare wood? Clean it with some DNA or other thinner? I don't think I will get more than one pass before it starts to pickup the old finish...>> Once the contamination is in the wood, it's in the wood. Soaking it in the strongest solvent you can find won't help your troubles. You can either try mixng another batch of shellac to seal the fisheye as that's what some finishers like Bob Flexner recommends or testing to see if the anti-fisheye additive will work with shellac. 1 Quote Link to comment Share on other sites More sharing options...
dwacker Posted December 16, 2013 Report Share Posted December 16, 2013 It probably not contamination just old shellac drying at different rates this is what happens. You can use shellac on a greased up pile of dog shi$ with no issues that's the beauty of shellac. 1 Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 It probably not contamination just old shellac drying at different rates this is what happens. You can use shellac on a greased up pile of dog shi$ with no issues that's the beauty of shellac. LOL I agree. Being that all the woods were processed in the same way with the only variable being the one board getting a different color shellac (older). I think I will give it a light sanding tomorrow. This will at least let me know if the finish hardened up. I will let you guys know tomorrow what I find. And yes, I will topcoat with the new shellac, just a spit coat to start and then come back with another spit coat about an hour later and just build it up slowly. Quote Link to comment Share on other sites More sharing options...
Trip Posted December 16, 2013 Report Share Posted December 16, 2013 ==> greased up pile of dog shi$ Well... For one, silicone's an issue... I hear you, but I've always seen aged shellac fish eye in a patch pattern... It's the lines that confuse me... Could be age, just never seen it like that... Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 ==> greased up pile of dog shi$ Well... For one, silicone's an issue... I hear you, but I've always seen aged shellac fish eye in a patch pattern... It's the lines that confuse me... Could be age, just never seen it like that... Now that you mention that, it follows my last pass spray pattern to a degree... First pass was with the grain as was second pass, third pass was going across the grain and then the final pass again with the grain. These were all thin coats with low pressure, but it kind of reminds me of when you spray lacquer, if your pressure is too high you leave rippled pools if its really hot out! Not enough time to level out. But, again, low pressure and it was overcast and cooler today... To be safe, I will flush the gun out tomorrow, test the batch that goes in on glass before spraying it on the project. Thanks to all for the advice and insight into this weird problem. I will definitely post some pics tomorrow. Quote Link to comment Share on other sites More sharing options...
Trip Posted December 16, 2013 Report Share Posted December 16, 2013 ==>>^^^ First things first, eliminate the shellac itself. Do the glass-plate test... Or just get yourself a new can... If it's not the shellac, you're only choice is to sand-back and start-over... PB is right, shellac is just about the best barrier coating out there --- but not universally... It takes quite a bit to contaminate shellac... Usually, it's a wayward squirt of WD40... Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 I did the glass test - the old shellac fish eyed on a bottle of snapple. The new can did not. I guess the shellac got old. I will sand it to level the surface and then spit coat it slowly. Quote Link to comment Share on other sites More sharing options...
..Kev Posted December 16, 2013 Report Share Posted December 16, 2013 Nice! Not that you have a lot of work to do but that you have the answer you were looking for! Good luck Chop! Quote Link to comment Share on other sites More sharing options...
Trip Posted December 16, 2013 Report Share Posted December 16, 2013 ==> bottle of snapple Outstanding... Quote Link to comment Share on other sites More sharing options...
chopnhack Posted December 16, 2013 Author Report Share Posted December 16, 2013 Nice! Not that you have a lot of work to do but that you have the answer you were looking for! Good luck Chop! LOL thanks bud! No I am thankful for all the advice and insight. Great forum and great people :-) I was confused. I had read about cratering in a book, but I am careful about what I use where and silicone is almost never used in the shop. Liquid wrench is rarely used, I just could not find my can of 3 in 1 oil which is what I usually wipe down my handplane for the day. I think that the shellac was not adhering or drying at different rates like someone else mentioned because of its age. The can was mostly empty, so maybe that allowed it to age faster? Kind of like when you have a full can of paint, it stays good longer versus a half can that will skin over and start to dry underneath. ==> bottle of snapple Outstanding... LOL, hey! I didn't have any plate glass laying around ;-P I keep all my snapple bottles because I have found them to be indispensable in the shop for storing remnants of finishes. Great for touchups and "oops" missed a spot. Trick I learned is to put a bit of plastic wrap under the cap before you cap it. Keeps the finish from gumming up the threads and also helps to seal better. And since they are thicker glass, they withstand being knocked over. Quote Link to comment Share on other sites More sharing options...
dwacker Posted December 16, 2013 Report Share Posted December 16, 2013 ==> greased up pile of dog shi$ Well... For one, silicone's an issue... I hear you, but I've always seen aged shellac fish eye in a patch pattern... It's the lines that confuse me... Could be age, just never seen it like that... You get alligatoring with old shellac when applied in thin coats and allowed to dry between coats, applied properly if you will. You will get fisheye if put on thick. Silicone is no issue for shellac. Quote Link to comment Share on other sites More sharing options...
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