The method to use PVA as sealcoat
#4
I have found some videos online mentioning that PVA glue can be an effective sealcoat before staining wood. But I found very few information about what the exact method is. How to use it as a sealcoat? What I managed to find: dissolve 1 part of glue in 10 part of water. But how do you need to apply? Soak the surface heavily or lightly? Do you need to sand the surface lightly after the glue dries, or will that remove the sealant surface?
Reply
#5
(04-06-2022, 04:41 PM)Bencuri Wrote: I have found some videos online mentioning that PVA glue can be an effective sealcoat before staining wood. But I found very few information about what the exact method is. How to use it as a sealcoat? What I managed to find: dissolve 1 part of glue in 10 part of water. But how do you need to apply? Soak the surface heavily or lightly? Do you need to sand the surface lightly after the glue dries, or will that remove the sealant surface?
The problem as some see it.  Portions of the wood surface could be more porous than others.  When stain is applied these parts will soak up more stain than others and stain darker.  Some disparage the result by calling it "blotching".  Others celebrate the enhancing of the wood figure.  The technique is called applying a "wash coat".  

Let us begin by considering what needs to be accomplished. To prevent portions of the wood from "over staining" we want to partially fill up these wood pores with something that won't take stain.  Shellac is commonly used.  But white glue could be used.  Shellac is applied, but not so much as to fill all the wood pores and leave no pores for the stain to penetrate.    The more porous areas take up more shellac than the less porous areas.  The result is that the porous parts take up more wash coat and the other parts less.  Next the surface is sanded with fine paper.  This step removes most of the wash coat from the less porous areas and leaves wash coat in the porous areas to resist stain penetration.  

The wash coat needs to be something that is clear and can be diluted so as to partially fill the wood pores, and be able to cleanly sand after cure and not load up the paper.  

White glue is little different from latex paint, minus the pigment.  A dilute solution will accomplish the requirements of a wash coat.  Being a water based product it will raise the grain, but the light sanding will level it again.  I don't know how it will sand.  Not as well as shellac I suspect.  

Bottom line as with all finishing adventures.  Try it and see if it meets your needs.  Dilute, apply a wet coat, perhaps wipe away any excess,  let dry, sand, stain and see how it worked compared to a control piece not wash coated.  

I wash coated these doors with shellac to keep the porous end grain from staining too dark.


Attached Files Image(s)
   
Bill Tindall
Reply
#6
That is truly an amazing piece, Bill.  Really well done.  

John
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.