Have you ever painted a knotty pine or red cedar chest that you so lovingly built
for toys for the kids or those linens passed down from Grandma to you
that you'll probably never use? And then, after only a few months the knots are
glaring right back at you and ruining your paint job? Or, you painstakingly
applied a beatiful hand-rubbed varnish or lacquer finish only to have sap leach
out of the knots? This is what is known as "extractive bleeding."
Welcome to the world of tree sap! Yes, even kiln dried wood will weep unless it is properly sealed
before the finish is applied.
When I first experienced extractive bleeding I thought
there was something wrong with the paint, (me? never). Maybe the paint was too thin so I
had to apply another coat... but that didn't work either. I took the can back to the store to get a fresh one. The salesperson, who I knew very well, smiled and said, "it's not the paint
that's the problem, it's you!" In order to keep the sap in the wood you have to use
a shellac based sealer to keep the sap from weeping out and ruining the finish.
Water, lacquer or oil based sealers will not stop the extractive bleeding. Only pigmented
shellac based sealers will do the trick. Pigmented shellac based sealers are also good for
sealing in household dirt, grease, wax etc.. Another great product is SealCoat Shellac.
SealCoat Shellac is the product to use when applying clear finishes and does a great job
of sealing in sap or whatever other contaminants, like silicone, are present. Also,
SealCoat Shellac can be used as a sealer under any clear finish and also to isolate one finish
CLICK HERE to visit the Highland Woodworking Finishing Department
Alan can be reached directly via email c/o Alan Noel Furniture Refinishing at email@example.com. You can also visit Alan's website by CLICKING HERE.
Visiting Atlanta? Attend one of Alan's upcoming highly informative Highland Woodworking wood
May 16, 2018 French Polish Workshop
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May 19, 2018 Finishing 101
June 6, 2018 Finishing the Finish
June 9-10, 2018 Antique Restoration