What is best way to prep for a waterbased finish?

[vanstry]

Okay, ran into a problem with the wood having something on it, that sanding didn't remove and it seriously messed up the water based stain and water based clear coat I was using.

Which I didn't discover until I was in the polishing phase.

So, is there something I can use on the wood, that will keep whatever oils or chemicals that have soaked into it from becoming a problem? Preferably something that would still allow me to stain it.

 

[bagman67]

Well, judging from your other thread, it looks like the water-based finish failed after staining, assuming the finish flake was not the result of trauma. 


Ordinarily I would recommend a liberal dose of naphtha to clean the surface before applying a finish, but one doesn't want to risk wiping off the color coat on has applied and is happy with.  So: 


I would


a) sand your color-coated part very lightly,
b) blow off with an air compressor if you have one handy,
c) wipe with a minimal amount of naphtha after first testing on an area that will be covered by a pickguard on the finished item, and then
d) apply a wash coat of shellac and scuff-sand with 320, and possibly repeat if you're nervous about whether you have sufficiently protected the color coat; and finally
e) proceed to the real topcoat. 


Shellac is a near-universal interface coating that keeps coatings from interacting in ways that might otherwise lead to failure.

 

[vanstry]

Thanks. would you apply the shellac with a sprayer or by hand? I spray the finish because I want it to come out nice and smooth.

 

[bagman67]

I have had perfectly acceptable results using Zinsser Bullseye rattle-can shellac, available at all hardware and home improvement stores.