Replies

1. 
   bill_1010 | Mar 30, 2002 05:34pm | #1

   sanding sealer is basically a thinned down version of water borne or oil based finish used to "condition" splotchy woods (cherry, pines, birch and other soft wood), seal end grain to prevent uneven stain penetration. IN the water borne finish it helps to keep (prevent)the grain from raising from finishes applied after the sealer. Since on a sealer (water borne) you give a light sanding to knock the raised grain back down.

   grain filler is a paste or gel like substance used to fill gain. Its dyed and contains solids that help smooth out the surface of oak, mahoganies, walnuts and other open grain woods.  Original filler was plaster of paris i think.  Grain filler helps with a smooth final finish. If youre familar with drywalling it might be considered very similar to the action of skim coating.

2. 
   StanleyNiemiec | Mar 30, 2002 06:59pm | #2

   I disagree with part of what Bill wrote!

   Grain fillers (best understood if you use the complete name "paste grain fillers") are heavy thick substances that fill the pores.  This compound is rubbed into the wood prior to finishing more or less as Bill stated.  It is primarily used for ring porous woods or woods with large pores.  About the only woods I paste fill are red oak and mahogany.  For diffuse porous woods like cherry or maple, paste filling is generally unnecessary unless you desire a super high-gloss finish.

   He description of sealers is more appropriate to something called sizing which is often a thinned adhesive in an aqueous solution.

   True sanding sealers are whatever the finish (eg lacquer or varnish) with added zinc stearate.  Zinc stearate has a soapy feel to it and it facilitates sanding so that the sandpapers do not clog.  As this is generally the first coat of finish, it seals the wood.  You don't have to use sanding sealer per se; often times I seal with lacquer (the finish I use) and sand it.  I often choose this methodology  because sanding sealers are slightly softer and as such the overall finish is slightly more susceptible to damage.

1. 
   HowardAcheson | Mar 30, 2002 08:42pm | #3

   You got it. There is a difference between sanding sealers and stain pre-conditioners. Sanding sealers are used as undercoats primarily for lacquer coatings. In fact, they should never be used under an oil based polyurethane varnish or adhesion problems will result.

   Pre-conditioners or just plain sealers are sometimes used to even out the penetration of stain. Sealers are also used to separate two incompatable finishes.

   Fillers are used to fill the pores of open pore woods like oak if you want a perfectly flat, piano finish.

1. 
   bill_1010 | Mar 31, 2002 02:21am | #4

   l'll be damned, i was always under the impression that conditioners and sealers were the same thing.  Learn something new each day

3. 
   DaveinPa | Apr 19, 2002 04:58am | #5

   Thank you for the insight on this question. I am sorry it took so long but I lost my cpu for a few days (my duaghter borrowed it) and now I am back in business. You folks truly cleared up the problem for me. Thank you

   Dave in Pa.