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I have been trying to finish my table top with some Enduro-Var semi gloss. My shop is in the low 60s but I warm my spray booth to about 70. When I tested the viscosity of the product I came up with 26-27 sec with a #4 ford cup. This is much lower than the manufacturer's claim of 50-60 sec. Any one know why this might be so thin? Several years ago I found an email address on General Finishes web site but is seems to be missing now. I wanted to ask them why my can might be so thin. The horizontal surface is fine but any vertical surface like the sides and the 2" apron either run or are rough due to not enough material to flow out properly.
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That's pretty strange compared to the readings I've taken on EnduroVar; always in the 45 - 55 second range. And those readings were at temps. of around 65 - 70 F. Lower temp. should make the viscosity go up. I've never had a bad can of EnduroVar. Are you sure yours didn't get frozen at some point?
John
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Unless it got frozen getting shipped to Woodcraft. It has not been frozen since I got my hands on it. When I opened the can nothing looked separated. There were some flatteners on the bottom but that is all. The emulsion looked intact.
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Can't explain it then unless you got bad product or your #4 Ford cup isn't accurate. What N/N size are you using? For 45 seconds I used a 1.8 mm with my gravity feed HVLP conversion gun. At 25 seconds I would use a 1.4 mm N/N.
John
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My Ford #4 is a plastic cup with a brass insert. I originally had an all plastic cup that had a mold burr on the whole. I though this might affect testing so I bought the better cup. My plan was to use a 1.8mm but when I measured the viscosity I used the 1.4mm.
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Are you sure the cup is accurate? Your comment about the dry spray sounds like low flow, which would be consistent with trying to use a 1.4 mm N/N with something at 45 - 55 seconds. Olive oil should be around 34 seconds through a #4 Ford cup. You might want to check it to see.
John
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Let me confirm I am measuring this correctly. I dip the cup in the can until the top of the cup is just below the surface of the finish. I pull the cup out of the can and start the timer. When the stream coming out of the bottom breaks, no longer a steady stream, I stop the timer. Am I doing anything wrong? I will see if I can find something to "calibrate" it tonight.
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Your method is the way I was told to do it; when the steady stream stops, you stop the time.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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Well I tested my ford cup last night. I used cotton seed oil which is 84 cP or 23-26 sec. I got 23 sec. An oil standard of 115 cP should be 32-36 sec. I got 30 sec. The glycerin on the other hand was way off. The chart says 112 sec. I got 197 sec. I need to track down the CPE52 cone for the Brookfield to test the viscosity to see how temperature affects the viscosity of the glycerin. I am also going to bring home a something to sample the Enduro-Var to test on the Brookfield to see if my cup matches the viscosity in the lab. I was using
this and
this table to convert from cP to seconds. I might also try diluting the glycerin to get something that should be around 60 sec.
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So it seems your cup is OK. That must mean the EnduroVar is bad, or at least way off the norm. I always get 45 - 55 seconds when I test it at about 67F. Only way to find out is to get some more product and test it. If you get 50 - 60 seconds then you can ask for a refund where you bought the first can.
John
