Replies

1. 
   HowardAcheson | Jan 18, 2005 05:41am | #1

   The first question is whether you used a dewaxed shellac? If you want to overcoat with an oil based poly varnish or any waterborne finish, you must use dewaxed shellac. Anything can be used as an overcoat over dewaxed shellac.

   If you used a non-dewaxed shellac, you will have to use a non-poly oil based varnish.

   Howie.........
1. 
   Curtis | Jan 18, 2005 12:21pm | #2

   Yes the Shallac is de-waxed, I didnt know that ! Thank you.

   Ive been useing Shallac as a sealer for years, but I never have used anything but oil based stuff before.

   Its cold out side, 11 deg F. and keeping my shops heat up for 24hrs isnt going to be cheap. so I am starting to look at water based stuff that will dry in les time.

   If you have any more insites on water based finishes,Please let me know.

   Thank you again.

   and have a good day.  ;-)C.A.G.

1. 
   HowardAcheson | Jan 19, 2005 12:35am | #3

   While the waterbased varnish will become tack-free in less time than oil based, it still needs the same length of time to fully cure. And, the temperature needs to be maintained for that curing to occur. Both oil based and waterborne will attain about 30-40% of their final cure within about 24 hours in 70 degrees and 50% humidity. At the end of one week, it is about 80% cured and can take from 3-4 weeks for full cure.Finishing is not a cold weather sport.Howie.........

1. 
   Curtis | Jan 19, 2005 03:34am | #4

   Thanks Howie

   I agree, and with the temp. in the single digits, finishing is down right costly this time of year.

   "O"Well You cant take it with you! And just think I read this morning how Europe is sewing the US for pulling out of the Global worming issue.

   I CAN FEEL IT, is it warmer there than Here?

   Lets bring on the heat! ;-)

   sincerely.C.A.G.

2. 
   douglas2cats | Jan 19, 2005 06:22am | #5

   For what it's worth, I built some matching end tables but not at the same time. I used dewaxed shellac on both, then poly. On the first one I used waterbased poly. It was set up about 2 feet from a heat register. Before I got to building the 2nd one, I happened to discover that on the side of the table near the register, the poly was flaking off like an old sunburn. The shellac underneath still appears intact. So I ended up using oil-based poly on the second one. It's about the same distance from another register and has never had any problems. Don't know if it was the WB poly brand, slight environmental differences, fate, bad kharma, or what. But I've been afraid to use WB poly ever since.

   I love the smell of sawdust in the morning.

1. 
   nikkiwood | Jan 20, 2005 10:00am | #6

   I'd say bad kharma ...................Zinsser's SEAL COAT is ideal sealer when you're working with any water based poly. I assume everyone knows Seal Coat is simply a dewaxed shellac. Can't explain why your WB poly failed on the first table. Were all the coats adequately dry before you recoated? Did the table sit for at least a day or so before it was exposed to the direct heat? Maybe it was the brand of WB poly you used, but I have used maybe a dozen different brands in this fashion, and have never had a problem.Can't blame you for being skittish, though.

   Edited 1/20/2005 2:01 am ET by nikkiwood

1. 
   douglas2cats | Jan 20, 2005 03:21pm | #7

   I'll chalk it up to bad kharma too.

   I used Behlens superblond shellac flakes and Behkol and make my own shellac. The tables were done before I'd heard about Seal Coat. As soon as I use up the rest of my flake shellac, I think SC is what I'll be using in the future though.

   I don't remember for sure which I used, but so far I've only bought 2 cans of WB poly. One was General Finishes and the other was Minwax. Just can't remember which I used on the problem table. Cant swear to adequate dryness before recoats, but I really doubt that was an issue. By the time I did the table I'd already learned my lesson about trying to rush finishing. If anything I tend to wait a day between coats of anything. Even if the can says I can do it in a matter of hours. The table was done and finished around late July and the furnace probably didn't start running until September, so a good 5-6 weeks before exposure to direct heat.

   On the 3 sides not facing the heat register, there's absolutely no problem. Finish looks great and there's no sign of it trying to peel.

   Kharma.

    

    I love the smell of sawdust in the morning.

3. 
   Sancho | Jan 30, 2005 02:41am | #8

   Yea. Using de waxed shellac under a w/b finish is a normal method of applying a barrier coat between a O/B stain and a W/B finish. So olet them dry good and sand lightly between coats.

    

    

1. 
   Curtis | Jan 30, 2005 03:13am | #9

   Thank you very much. Ive used it as a sealer over many types of finishes. but not the other way around.

   Thamks again.C.A.G.