Replies

1. 
   SteveSchoene | Oct 04, 2010 12:28pm | #1

   Padauk is one of the "oily"

   Padauk is one of the "oily" hardwoods that can give oil based finishing problems in curing properly and waterborne finishes adhesion problems.  I suspect this is what has happened to you in some form. 

   I'm afraid that the solution is to strip off the Minwax poly and refinish beginning with a coat or two of shellac.  Shellac will adhere to the padauk.  You can then cover with varnish if you like.  If you still want to use a varnish that includes polyurethane it must be a dewaxed shellac. 

1. 
   johnlill | Oct 04, 2010 03:15pm | #2

   Thanks, Steve. I did some research before I applied the finish and nothing I found said that the padauk needed to be sealed before finishing. The wipe-on poly is not a waterborne finish (it's an oil/poly blend) so I did not expect a problem. All the info I found said to just finish as any other hardwood. Stripping will be a bear since the panels are already in the frames. 

   This is not good.... :(

1. 
   SteveSchoene | Oct 04, 2010 04:48pm | #3

   I see plenty of sources talking about it being an oily hardwood.  Of, course, there are several species that enter trade as padauk and experiences may differ.  But, in your case I would be hard pressed to find another cause for the oil based varnish not to cure properly.   Even if it isn't caused by the wood but some defect in the varnish the solution, strip and refinish,  is likely to be the same.  You can of course give it a few more weeks to see if the varnish eventually cures properly. 

   Methylene Chloride is the most potent stripping chemical, but requires caution and PLENTY of ventilation.  Relatively fresh varnish will strip fairly easily at least. 

   By the way, the product sold by Minwax as Wipe On Poly isn't a mix of oil and varnish(poly) it is just thinned varnish. Minwax does sell some oil/varnish mixes, but this product with minor variations is labeled either Teak Oil, Antique Oil or.Tung Oil Finish.   

1. 
   johnlill | Oct 05, 2010 04:07pm | #4

   Thanks again, Steve. The finish did seem to cure - it just has a chalky dust that appears in a few spots and wipes right off. I'm beginning to think that it may not be a finishing problem after all but may be some kind of mildew. My shop is in the basement and can be rather humid. I wiped it with mineral spirits yesterday. So far so good. But time will tell....