Sealers--are they effective?

[Maury S]

There is an article in the latest issue of Popular Woodworking Magazine (June, 2016 #225) on wood (sanding) sealers.  While it probably does not broadly apply to us modelers, there are comments on the advisability of thinning, water based, poly, etc.  Some comments excerpted...Water-based sanding sealer-- no need for it.  Sealers for lacquer and alkyd varnish weaken the finish.  No sealer needed for polyurethane varnish.  No reason to thin the first coat (this does not apply to thinning paints to get better color at scale!).  They do admit that thinning  provides better bonding, but lack of bonding probably applies to boats in wet environments and that problem arises from moisture getting under the finish.  I have no opinion on any of these conclusions...above my pay grade.

Maury

[grsjax]

My personal experience is that using a sanding sealer prevents the grain from lifting during sanding resulting in a better surface.  I haven't any problems with the finish as a result but I generally use a water based sealer with water based finishes.

[Jaager]

The products that are labeled as "Sand and Sealer" strike me as being too thick  for model use.   It may save having to fill pores with dilute Plaster of Paris for a smooth surface in Oak, Walnut, Ash, Hickory, etc. but those species are out of scale for model use anyway.

 

The soak in products bare a look:  50% pure Tung oil in Mineral Spirits or  5% Super Blonde/ 10% Orange shellac.

Edited April 24, 2016 by Jaager

[Keith Simmons]

  I generally skip any sealer by just applying a thin first coat of finish and sanding lightly to knock off the hairs, then build up the finish from there. I find this method maintains the original color of the wood and creates a deeper looking finish.